Does your system have a subwoofer? Shouldn't your main monitors be able to handle the bass?

If your monitors are too small to handle deep bass, then there's stuff going on your recordings that you don't know about. Would a subwoofer help?

By David Mellor, Course Director of Audio Masterclass

It is a law of nature that loudspeaker design is a three-way trade off. You can have any one of these features, or a compromise of any two, but you cannot have all three...

• High-fidelity sound quality - the sound the speaker produces corresponds very closely to the input signal.
• Loud, with deep bass and plenty of it.
• Compact and convenient size.

Very few speakers are as big as they need to be to produce the lowest frequencies our ears can hear at anything approaching an adequate level. And the vast majority are far too small.
Nearfield monitors struggle to get down to 70 Hz and below, and since our ears are sensitive down to 20 Hz, and various bodily organs even below that, plainly we are not hearing everything we really ought to be entitled to hear.

The best answer is simply to make speakers bigger. It really is that simple. But current preferences dictate that manufactures concentrate on compact loudspeakers, particularly for domestic use, so we need an alternative.

An alternative is to dedicate one speaker to low frequencies, so the two (or more in a surround system) conventional speakers can handle their own preferred frequency range.
Only one low frequency speaker is necessary because the ear isn't particularly sensitive to the directionality of low frequencies, nor to their stereo content. So the low frequencies of the two channels (or more for surround) can be mixed together and fed to this special speaker, known as the subwoofer, sometimes simply as the 'sub'.

For domestic purposes, this really isn't a bad compromise. And since the subwoofer can go anywhere in the room, it doesn't have to be all that small (behind the TV in the corner is common).
However, the problem is that the output from the subwoofer has to be closely matched to the conventional speakers, so where the conventional speakers are starting to roll off in the bass, the subwoofer is smoothly taking over. This doesn't happen all by itself, but by careful alignment of amplifier power.

For domestic purposes, it's not that much of an issue - people are not that bothered. However, if you were to use a subwoofer for monitoring in the studio, then it is vital that the output is well matched, and the overall frequency response is flat.

Otherwise your mixes will end up with too little or too much bass to compensate for the errors of your monitoring system.

To rely solely on a subwoofer system for monitoring would be a risky practice, but as one of a selection of monitoring systems, it could provide an additional perspective on the way an increasing number of people listen at home.

When to use delay on vocals

Delay is a useful technique for enhancing all sorts of signals. But when should you use it on vocals, and when should you not?

By David Mellor, Course Director of Audio Masterclass

When we talk about delay as an effect, it isn't just a matter of delaying a signal. The delayed signal is added to the original, normally at a lower level. So you get the original signal followed by a quieter echo, a fraction of a second later.
But you don't have to use it. Why not just keep the vocal nice and clean, as it was recorded?
There are three reasons to use a delay...

• You want to imitate a sound you have heard already - the 1950s 'Elvis' sound for instance.
• The vocal needs to be richer
• The vocal needs to be more interesting.

Using delay to imitate the 'slapback' sound of the 1950s is probably a little too straightforward to require explanation. Wanting a vocal to sound richer is commonplace. The best solution for a richer vocal is a richer-sounding singer, but too often we don't have that option. A subtle delay will warm and enhance the vocal, hopefully without sounding too obvious.
A richer vocal sound might also be useful in helping the vocal blend with the track. If you find that the vocal seems to sit on top of the track, then a delay at a low level might work wonders. Worth a try.
If the vocal needs to be more interesting, then a delay might just do that. But you don't always need the delay to go the whole way through the track. You might just switch it in every now and then. In the 1980s it was quite common to switch in the delay only at the ends of certain lines. (Hint - switch the send, not the return.)
There's a lot more to delay than this, but knowing when to use it is a start.

Publication date: Saturday April 16, 2011
Author: David Mellor, Course Director of Audio Masterclass

Beethoven: Symphony No. 8 / Abbado · Berliner Philharmoniker

Does your studio look like a studio, or just another room?

What is it about your studio that makes it look and feel like a recording studio, and a nice place to work? Or is it just another room in your house?

By David Mellor, Course Director of Audio Masterclass

I think we all aspire to have a studio that really looks and feels like a 'proper' recording studio.

Except me... I've had one. It was very nice and I've moved on. But I still remember exactly how I felt when I wanted it, and how I felt when I eventually got it - FANTASTIC!
Most of us start out using any room that happens to be handy as a studio. So it's just any old room in the house or apartment that doesn't happen to have any other use. Or maybe it does have other uses and you only sometimes use it as a studio.

In the 'olden days' of recording, it was easy to make a room look like a studio. Just put the gear in there.
Believe me, when a room has got a huge great mixing console in the middle of it, it's a studio!
The rack of outboard effects helps too, and an old-fashioned analog 24-track tape recorder adds the final touch.

But those were the old days. We generally don't have that kind of equipment now. We have a computer and audio interface, a microphone, a keyboard and a couple of instruments...
And lots and lots of plug-ins!

But plug-ins don't make a room look like a studio. And if you want to record the best talent around, you really do need to make them feel that they are working in a pro environment.
So what is it these days that has replaced the old bulky equipment in making an ordinary room 'studio-y'?
Well I reckon it's acoustic treatment.

Going back to those 'old days' again... (Notice I didn't say 'good old days' because there was a lot that wasn't so good about them, mainly the cost of everything.)
In the old days of soundproofing and acoustic treatment, we would go down to the local builders' merchant and buy sheets of plasterboard (gypsum board), bales of mineral wool, and roam the roofing supplies section for suitable flexible materials to make low-frequency absorbers with.
Now, although plasterboard (gypsum board) is still very cost-effective for soundproofing, all manner of acoustic treatments are available off-the-shelf, and don't take any building expertise to set up.
And they look good, and studio-y, too!

So if your recording room doesn't look like a professional studio, it probably doesn't sound like one either.
And when you install your acoustic treatment you will kill two birds with one stone. Properly installed, your room will sound much better.

And it will look much more like a pro studio. You're bound to make better recordings right away!
If you would like to share photos of your studio with the world, please send them to newsletter@recordproducer.com
Don't forget to tell us who you are and what your studio is called. Any other information on what you do would be great too. We will publish as many responses as we can.

By David Mellor, Course Director of Audio Masterclass, Thursday January 28, 2010

Beethoven: Symphony No. 7 / Abbado · Berliner Philharmoniker

From The Vault - Getting To Know the Korg PA80

Straight from the Korg USA archives, join Korg's Steve McNally in this comprehensive overview of the PA80!

What if there were no copyright in music?

Copyright in music has allowed songwriters and musicians to make a living for decades. But would they now be better off without it?

By David Mellor, Course Director of Audio Masterclass

As we saw from this recent article and YouTube video, the fashion industry seems to prosper without the protection of copyright. At the same time, the music industry, with all its copyright protections, continues to founder.

So can the music industry take a few hints from fashion? Or are the two industries so very different that the same rules simply don't apply? Here are some points, not necessarily in any order of importance...

Firstly, there is a fundamental difference between an original garment and a knock-off copy. Since the original is made in the designer's own workshop (or by a licensed manufacturer), the buyer can be confident of the quality of the materials and workmanship. The copy might look the same, but it won't necessarily feel the same, have the same level of detail or be as robust.

Contrast that with a CD. A knock-off copy of a CD can be exactly the same as the original. The only slight defect might be an almost invisible degradation in the quality of the artwork. And a copy of a digital download can be identical in every respect to the original.

So if an original CD from an artist's label costs $10, and a (legal) knock-off $3, who would pay the extra $7 for something that is hardly any better. And why pay the Apple Store's price for a download when you can have a legal alternative for pennies?

I think we can see therefore that both physical and downloaded music products need protection, otherwise their creators won't get paid for their work.

But that isn't the only issue...

Forget knock-off copies, now let's think of a superstar fashion designer and someone newly out of fashion school.

The superstar designer spends six months creating a new range and shows it on the runway. The newbie designer sees the show and likes the combination of cut and color, but isn't so struck with the detailing.

So they go back to their workroom and make near-identical copies, but with different details. They have stock manufactured to a high level of quality and put it on sale.

In the fashion industry in the USA, this is entirely legal.

Imagine if this applied to music...

You could hear a new song and if you liked the hook you could immediately incorporate into a song of your own, you could make CDs or make your song available for download.

If the rules of the fashion industry applied, this would be perfectly legal.

I'll leave it to the comments section to explain why this would a bad thing.

I'm more interested in speculating whether it would be a good thing...

Suppose you are a songwriter and you have just reached the level of ability to write a hit song. So you write a song and it becomes a hit. Legal safeguards protect your income from physical sales and downloads.

But then someone else comes along and makes a new recording of your song and say that they wrote it - equivalent to a knock-off fashion designer putting their own label in a garment they have merely copied.

You as the original writer of the song get nothing for the copy version.

But you did get paid for your own release. And since you were first you got the lion's share of the money. There will be few 'long tail' returns, but you have been paid. If you want to earn some more money, you'll have to write another song. Hey, you're a songwriter - isn't that what you do?

So genuine songwriters get a bit less, copyists get a few slim pickings. Is that a big deal?

But there could be another advantage in treating music in a similar way to fashion...

The way things stand at the moment, if you write a song and release it, you put yourself at risk.

There area only twelve notes in an octave so how can you be sure that no part of your song infringes someone else's pre-existing copyright?

What you can be sure of is that if your song becomes a hit 'copyright trolls' will be analyzing it in fine detail to see if there is a note sequence, even momentarily or in the background, that they can say they own already.

If they find anything promising, they will threaten legal action. Since in law it is generally the rule that the big guy beats the little guy, you'll have to cave. You might lose ALL of your money. It has happened.

And how fair is that?

Remember that there are only twelve notes in an octave and it is becoming exponentially more difficult not to repeat a sequence that someone else has previously used. In fact it may be impossible already.

Releasing music from copyright could be the best thing that happened to musicians, and music.

OK, there is no guarantee that this is going to be the best solution, but music copyright is in a bad way at the moment. Bad for music and musicians, good for lawyers. It's bad for corporations too, except they have had their heads in the sand for the last ten years so they don't realize.

If we don't talk about the options, things will only get worse. McCartney, Bono and Elton John made their money years ago. How are you going to make yours?

By David Mellor, Course Director of Audio Masterclass, Monday May 31, 2010

Beethoven: Symphony No. 6 "Pastorale" / Abbado · Berliner Philharmoniker

Beethoven: Symphony No. 4 / Abbado · Berliner Philharmoniker

Take a sad butt edit, and make it better

Suppose you wanted to make a compilation of extracts of tracks from an album. You could butt edit them together, if you choose not to crossfade. But there's a good way to do it, and a better way...

By David Mellor, Course Director of Audio Masterclass

Suppose you have made an album, in breaks you have somehow managed to take from continually upgrading your studio. You might want to make a 60-second sampler track that shows off the best of all of your work. Just the thing to take with you to MIDEM.

You could crossfade the segments together. But that can be a little messy, uncomfortable on the ear, and - let's face it - it can be the easy way out.

Butt editing therefore can be a better solution. There are no crossfades and one track can flow seamlessly into the next.

In general, the best way to do this is to edit on the first beat of the bar on each outgoing segment, and also on the first beat of the bar of each incoming segment.

Sometimes however this doesn't work. For instance, the vocal could anticipate the first beat of the bar, and you don't want to cut it off.

Here is an interesting example. The tracks are both from around 1990ish as this was a period where the beat was strong and regular, and it makes the demonstration very clear...

butt-edit.ogg

The edit comes just before 0.22.

The edit here is clean and on the beat. But the bar structure is not maintained. Here is another edit where both the outgoing and incoming segments have been edited at the start of Beat 4 of the bar...

butt-edit-better.ogg

See how much more smoothly the music flows?

In fact you can edit on any two similar points in the bar structure and this will usually work. Of course, butt editing tracks that are at very different tempi is another matter altogether.

Happy butt editing!

P.S. The tracks are Ride On Time by Black Box, and Doin' The Do by Betty Boo.

Publication date: Friday April 20, 2012
Author: David Mellor, Course Director of Audio Masterclass

The famous $5 preamp - everything you need to know

Some time ago we published an article about a preamp that cost less than $5, yet was judged to sound better than other preamps costing MUCH more. Here we present the original articles, with our additional commentary.

By David Mellor, Course Director of Audio Masterclass

A few years ago in our website Record-Producer.com, which is now integrated with Audio Masterclass, we published an interesting test of microphone preamplifiers. And here it is...

Microphone preamplifiers - can *YOU* hear the difference? (with audio)

Three mic preamps, one costing over $1000, another mid-price, another that cost just $5. Can *you* hear the difference?

Three mic preamps, one costing over $1000, another mid-price, another that cost just $5. Can you hear the difference? I'll admit straight away that this isn't a scientific test. It just kind of happened on the spur of the moment, hence the air conditioning noise in the background of these recordings.

However, I think you will find the recordings interesting. Three different microphone preamplifiers were used. One has a list price of well over $1000, another costs around $200, the third costs less than $5. Yes, five dollars.

The obvious question is, can you tell which is which?

I made three recordings using each preamp in turn, then three more similar recordings with a different microphone at a greater distance, allowing more reverberation to be picked up.

Let's label the mics A and B, the preamplifiers 1, 2 and 3. So here are the recordings, all in 16-bit .WAV format...

A1 - A2 - A3 - B1 - B2 - B3

(Notice that the preamps are in the same order for both A and B mics.)

Questions:

1. Which is the most expensive preamplifier? 1, 2 or 3?
2. Which is the least expensive preamplifier? 1, 2 or 3?
3. Optional comments on the sound qualities you perceive.

Please post your answers in the comments section below. (If you're at all worried about getting the answers wrong, then you'd better give your name as 'anonymous'!)

This challenge is now closed. You can see the answers here...

---

That was the first article, and there were quite a number of responses. Here is the second article in the sequence...

Well, could *you* hear the difference? Could you??

A recent Record-Producer.com feature demonstrated three microphone preamplifiers costing from $5 up to $1000. Could RP visitors hear the difference? (Apparently not!)

Take a look here [The link in the original article referred to the previous test, the text of which is presented above] and you will find audio examples of three microphone preamplifiers. One costing over $1000, another around $200, and a third a mere $5.

Record-Producer.com visitors were asked to identify which preamp was the most expensive, and which preamp was the cheapest of the three.

Well the results are in, and here are the votes cast as of Jan 13...

Microphone A, by the way, was the humble Shure SM57. Microphone B was the Neumann U87 Ai. Each set of three tests used the same mic at the same distance.

	Most Expensive	Least Expensive
Preamp A	8	19
Preamp B	28	7
Preamp C	18	24

The clear winner is Preamp B, which I will tell you more about shortly. In second place is Preamp C, which is the Universal Audio SOLO/610 Classic Tube Recording Channel - a single channel preamplifier costing around $1000 [at the time the article was written] and therefore the most expensive. Yet it didn't win.

In third place is Preamp A, which is the infamous Behringer Ultragain Pro MIC2200, complete with LEDs to make the tube appear to glow. Most people identified this as the cheapest sounding preamp, yet it is not the cheapest - it just, apparently, sounds cheapest.

So - shock news headline - by a margin of 28 to 18, it is the five dollar preamp that people feel sounds the most expensive. And here it is...

"What on earth is that?", I hear you say. Let me tell you the story...

In September 2005 I was working with students in Audio Electronics classes. The object of the classes wasn't to turn them into electronic designers, but to give them a feel for the inner workings of the tools of the Sound Engineer's profession.

So we made some audio circuits and tested them, objectively and subjectively. And this is one of the circuits we made. I say 'we', but the students did the making and I did the checking of connections to make sure not too many components got fried.

This preamp has at its heart a Texas Instruments INA217 mic preamp integrated circuit, which is widely regarded as state-of-the-art, even though it is inexpensive. The circuit was constructed according to the data sheet, with a few features left out for simplicity.

You can see two IC's on the circuit board above. The lower one is actually a completely different amplifier that we had constructed on the same board. In the photo above, and in the test, it was totally disconnected.

The power supply consists of the four PP3 batteries you can see to the right of the picture.

Once assembled, the first test was with the Shure SM57 microphone, recorded into Pro Tools using the Digidesign 888/24 interface. The results seemed promising, so at that point I decided to make comparison recordings with the other two preamps, which just happened to be to hand.

I played these recordings to an associate who commented that I should try similar recordings with a U87 mic. To do this, we had to add phantom power to the preamp, which is provided by the five PP3 batteries to the left of the photo.

After the tests were recorded, it seemed like a good idea to upload the files to Record-Producer.com for your enjoyment.

To make the circuit simpler to construct, a fixed gain of 50 dB was set. This proved to be too much for the U87, which has a higher output than the SM57 and clipped the audio interface, so I stood a little further away. This accounts for the increase in room ambience, and for the lower LF content because of the reduced proximity effect. I could have clicked in the pad on the mic, but in the moment I chose not to.

The change in microphone does not affect the preamp test. For each set of preamp recordings, the mic and distance were the same.

So in conclusion, well at least my conclusion because I am sure you will have your own too, it says a lot that a preamp assembled from $5 worth of components and not even mounted in a box can compare favorably against a preamp costing $200, and another costing $1500!

Your comments will be very welcome.

---

We're having a little trouble retrieving the comments from our old database, but when we have done that, we will include them here. In the meantime, here is the third article in the sequence...

Giant-killing $5 mic preamp - its secrets revealed

Fresh from a comparison test against preamps costing $200 and $1000 - which it beat handsomely - the secrets of the $5 preamp are at last revealed.

If you're not up to speed on this topic, you need to read this article, and listen to the audio examples carefully. When you have made your judgment on which is the most expensive preamp, you can see the results here.

In summary however, significantly more people judged the $5 preamp to be sonically the most expensive sounding. To be fair, the test was limited, but even so, surely a $1000 preamp should have proven its mettle in comparison? Surely it should have blown away the $5 home-made one?

Since the tests to place, several requests have been received to see the schematic of the $5 preamp. Well it certainly isn't a secret. The preamp is based around a Texas Instruments INA217 integrated circuit, using the schematic provided on the manufacturer's data sheet. You can see the schematic right below.

But the $5 preamp doesn't even use the full circuit. R3 and its associated capacitor are intended to reduce any click when phantom power is switched on. The $5 preamp doesn't bother with that.

The four diodes you can see are protection for the IC against unexpectedly high input voltages. Omitted.

A2 is a secondary op-amp intended to eliminate any DC offset in the output. Well Rupert Neve didn't always bias the output of his push-pull stages to zero volts, so why should the $5 preamp do that either?

So basically the circuit is what's left. Not much is it? Oh, and the power supplies... the power for the IC was from four PP3 batteries, wired to give +18 and -18 volts, which is the maximum the INA217 is specified for.

Phantom power was supplied from five PP3 batteries wired in series to give 45 volts nominally. One commentator remarked that this "seriously under-powers the Neumann U87 microphone". This is not so. For one thing, new batteries will give higher than their rated voltage. Secondly, a microphone that couldn't operate on 45 volts instead of 48 simply wouldn't be up to the job of meeting real-world conditions. They're not that stupid at Neumann - they rate the U87 for 48 V +/- 4 V, and I suspect there is some margin beyond that.

It might be that it's the battery power supply that gives the $5 preamp the edge over the others. In my earlier tests, I found that I was spending an inordinate amount of effort getting a power supply derived from AC to be quiet enough, so using batteries eliminated that problem and perhaps produced a benefit.

One thing's for sure. The cat's among the pigeons and feathers are flying.

Would anyone care to repeat my test?

---

A while later we reprised the $5 preamp...

Is it time for the $5 preamp to make a comeback?

Is it really possible to get a state-of-the-art mic preamp for just $5. Possibly it is. So why would anyone pay $1000 or more?

Record-Producer.com has been going for quite some time now. And certain articles from the archive keep on raising interest and questions. And none more so than the ones about the famous $5 preamp. A giant-killer in miniature.

You can read about it here, here and here...

One story I didn't tell at the time was about the 'boutique' 8-channel preamp I once owned. The reason I owned it is because I had it for review, it worked fine and I needed an 8-channel preamp, so I made an offer.

That preamp normally sold for somewhere around a thousand UK pounds. That's around 1500 Euros or $2000 US dollars. Not cheap therefore.

Unfortunately it eventually developed a fault. I'm not recommending you do this yourself, but I thought it might be a good idea to take the lid off and see if there was something simple and obvious that was wrong.

I was astonished...

There was hardly anything inside. In fact the 'boutique' preamp was nothing more than a few integrated circuits, resistors and capacitors. And the main integrated circuit for each channel was the SSM2017 chip which you could shortly before that time buy for around $3 in small quantities.

It was in fact this chip that had failed on seven of the eight channels. This happened after several months of only using one channel, and then suddenly having the need to use all eight.

Since this chip had by that time gone out of production, I replaced it with the INA217, which is the successor to the SSM2017 and is the same chip as used in the $5 preamp. It worked fine.

Shortly after that, the unit received a 'drop test' and sustained serious damage, so I scrapped it.

Always ready to learn lessons, I noted two things from this...

Firstly, an expensive preamp might be nothing more than inexpensive components in a fancy box.

Secondly, the SSM2017 and INA217 sound damn good!

Oh and thirdly, don't drop a $2000 preamp.

So, over to you. Everyone is entitled to their opinion on preamps and there are no rights nor wrongs.

What do you think about preamps based on cheap chips? And are expensive 'boutique' preamps really all that much better?

---

Following this, we received some messages by e-mail...

In response to Is it time for the $5 preamp to make a comeback?, H.C.D. Studios writes...

While it may be true that you can find a great sounding chip in most cases pres that are based around a chip sound kinda blah. Over time transistors repalced tubes as gain blocks, then ic's were developed to make things smaller and cheeper. I have used every mic pre from $40 tube pre (with ic) boxes to avalon, real vintage Neve, 610 tube, SCA handmade, amek, crane song and the list goes on.

The thing is that all those pre's have a sound of their own. If you open up a behringer box you see lots of chips. While they are functional they sound like shi* compared to say, any of the ones listed above. If you have ever built a SCA (or other kit) pre you can see what goes into a discrete circut.

There is a reason that you pay so much for classic circuts. They have lots of componants and many are hand wired. This whole discussion could go round in circles till we all drop dead. F the gear if the song aint great even a $4500 mic pre won't help. A C12 won't make a great singer it just captures what you put in front of it.

---

In response to Is it time for the $5 preamp to make a comeback?, Chris writes...

Hello Record-Producer.com,

I love the $5 preamp story. One question, I understand that you had some difficulties powering the unit, hence went with batteries. Do you have any new insight into powering it so I can build one without obtaining an EE degree?

Thank you,

Chris

RP response: We used the batteries to solve an immediate problem and in doing so removed a potential variable. You don't need a degree to understand voltage stabilizers followed by heavy capacitative and inductive filtering. It's outside the range of topics of this site for now, but the topic is normally covered in basic electronics text books.

---

In response to Giant-killing $5 mic preamp - its secrets revealed, Antti writes...

Thanks for the great point-out to these pre-amp schematics. I've got one rather stupid question, though. How are the four 9V batteries supposed to be wired to give both +18V and -18V? Can't you just use two and connect them together to give 18V, and then connect the + and - ends to the suitable connection points provided by the schematics. Or if I use four batteries, where am I connecting the extra + or - ends that I'm left with, when I connect two and two together?

RP response: If you connect them all in series, then the midway point becomes the 0 volts reference and the two ends are +18 and -18 volts respectively.

---

So there you have it, the full story of the amazing $5 preamp!

By David Mellor, Course Director of Audio Masterclass, Thursday April 19, 2012

Shotgun Mics and Video Production

By Shure Notes 4-17-2012

With sites like YouTube serving 800 million unique users per month viewing over four billion videos a day, there’s no doubt that the user-generated content (UGC) revolution has taken root and is here to stay. Today, the digital applications that have put recording within just about anyone’s grasp have done the same with video.

But if you spend any time on YouTube, Hulu and other UGC sites, you’ll notice that the audio (especially when a subject is speaking) can be garbled, muddy and unintelligible. If there’s one thing we’ve learned, it’s that audio quality can make or break any video project. No matter how creative and professional the visual aspects of a production may be, these qualities can be completely negated by lackluster audio. According to one videographer we know, “It’s easy to fool the eye, but it’s a lot harder to fool the ear”.

Creating good audio can be a real challenge when shooting video – especially if you’re using a consumer-grade camcorder. Mics that are built into camcorders aren’t really designed for high-quality audio. They are designed for sound sources that are very close to the camera and they tend to pick up a lot of background noise.

We like how video expert Israel Hyman puts it: “The microphone is in the wrong place. Frankly, the reason the microphone is on the camera is because it’s built for the camera operator to do the talking. If you’re a parent narrating your child’s birthday party, this is perfectly fine. It will get your voice and your child’s voice (even though it will sound distant). If you’re aiming for a more professional sounding video, you don’t want the off-camera, out-of-frame camera operator’s voice. You want the microphone on the subject”.

Adding an external mic – a handheld, lapel (or lavalier) or a shotgun mic – gives you what matters the most – the best signal-to-noise ratio. In this Shure Notes® blog post, we’re going to give you some tips about the third type – the shotgun mic. Its extremely directional pickup pattern (called a line/gradient pattern) makes the shotgun mic popular for TV news and movie sets.

The shotgun microphone is named for the long, slotted tube in front of the microphone cartridge that makes it resemble a shotgun. This “interference tube” helps reject sounds coming from more than about 30 degrees off to the sides, while still picking up sounds from the front. Because a shotgun mic is either mounted to a camera or a boom, it is rarely seen by the viewer. In fact, it’s almost impossible to imagine a situation in which the mic should appear in frame (unless you’re making a video about making a video).

Advantages

Let’s talk about what shotguns mics are not: They are not telephoto lenses for sound. They do not allow you to zoom in on a conversation from 100 feet away.

Here is how Shure’s Chris Lyons explains it: “Imagine looking through a long tube at a person standing 20 feet away. The person’s image does not appear to be any larger or closer, but is somewhat easier to see, because the eye is not distracted by things happening off to either side.”

This is exactly what shotgun mics do best: they screen out sounds coming from the sides. In practice, a shotgun microphone can typically be placed at four to five times the acceptable distance for a standard omnidirectional microphone. But keep in mind that the shotgun mic will also pick up sounds coming from behind the subject.

Tips for Using Shotgun Mics

• Shotgun mics can be positioned slightly above, below, or to the side of the sound source, so that the mic doesn’t appear in the camera frame.
• Try to avoid aiming the mic at a hard surface, such as a tile floor, brick wall, or hard ceiling. These surfaces reflect sound waves, and may reflect background noise into the microphone or cause the sound to be slightly hollow. (A heavy blanket can be placed on a reflective surface to provide some temporary sound absorption.)
• Shotgun mics are more sensitive to wind noise than standard microphones, so try to avoid moving the mic rapidly and use a foam windscreen if possible. (Larger “zeppelin” or “blimp” type windscreens are usually necessary outdoors.)
• It’s a good idea to use a rubber-isolated shock mount to control handling noise that may be transmitted through a stand or boom.
• If you’re using a boom for a scripted video, make sure your boom person has a script. If more than one speaker is going to be miked, the boom person needs to point the shotgun at the right person at the right time, a challenge when the mic needs to remain out of frame, the sound has to be consistent and the boom may be over 20 feet long.

What to look for when buying a shotgun mic

Mics with a balanced XLR outputs signals will give you better noise and interference immunity. Remember, too, that if you have a stereo mini-jack input on your camcorder, you’ll need to get an XLR camcorder adapter that will allow you to use professional quality microphones.

Shure offers two end-address shotgun condenser microphones.

VP89

Offers a choice or interchangeable long, medium and short capsules. Hand-tuned and assembled in the US, offers natural off-axis rejection without coloration.

VP82

This mic is designed for camera-mounted applications. It is extremely lightweight and has an integrated preamp.

Beethoven: Symphony No. 4 / Abbado · Berliner Philharmoniker

Are your recordings too QUIET?

We receive a lot of recordings here at Audio Masterclass. Some are strangely quiet. Why should this be? Can quiet ever be good?

By David Mellor, Course Director of Audio Masterclass

What level should you record to? Well the answer is in the meters of your DAW. For instance, Pro Tools has green lights up to around -13 dBFS or so, canary yellow up to -3 dBFS, golden-yellow over that. And right at the top there is a single red.

Clearly the inference is that you should aim to be in the golden zone, in other words peaking above -3 dBFS. This would accord with the philosophy of digital recording that best performance is achieved when the signal level is as high as possible, without clipping of course.

In reality however, as long as your signal is bobbing up and down in the canary yellow zone in a 24-bit recording, then it is perfectly OK for all practical purposes. It will save you time being over-finicky in level setting, and it will also allow headroom for any unexpected peaks.

However at Audio Masterclass we often get sent material that doesn't even hit -20 dBFS, ever. Plainly, that is far too low. An original recording needs at least touching the yellow.

While recording in the yellow zone is fine and has certain benefits, when you create a piece of finished work for a client, they will expect its level to be of what I could call the 'normally expected level'.

In other words it should be comparable in level to other commonly-found audio produced by professionals.

If you are recording music in a genre that is normally put through the volume-maximizing mastering process, then you need to peak right at the top... 0 dBFS.

For any other kind of audio, if it peaks somewhere around -2 dBFS, then it will be fine. Any lower than -6 dBFS and it's starting to sound a little on the quiet side in comparison with everything else.

As we can see therefore, there can be a difference between the levels that are good for recording, and the levels that are good for finished work. Finished work must fulfill the client's expectations. And a client that doesn't have their expectations fulfilled will go somewhere else to have the work done.

If you are recording for a radio or TV broadcaster, they may have formal standards. Find out what they are and stick to them.

There is another point to bear in mind if you are an audio perfectionist...

It is possible for levels above 0 dBFS to be created in a digital-to-analog converter, at the listener's end of the chain. This is fine, except for those converters that can't handle these so-called intersample peaks.

In this case you would regard around -3 dBFS as your peak level for final output. Or equip yourself with an intersample peak meter.

When should I normalize, and by how much?

by Audio Masterclass on Tuesday, April 17, 2012 at 8:35am ·

In the days of analog recording it was important to set the recording level so that signals peaked close the the maximum allowable level before distortion would occur. In this way, normalization happened almost automatically. No-one would ever think about normalizing a signal after recording, and in any case it would cause further noise and distortion.

It is nowhere near as important in multitrack digital recording to set the level anywhere near peak. The signal-to-noise ratio of a 24-bit digital recording is so vast and the amount of distortion so small that for any practical purpose it wouldn't matter if your signal level was 20 dB below peak.

Except...

You might worry that the meters hardly twitch when you play the track, and the waveform display looks like a straight line. Well you can live with that. The only problem might be if you are mixing and have pushed the fader all the way to the top, and the signal isn't as loud as you want it.

What you can do is add gain, if you have a gain plug-in. Or you can normalize the track.

If you waste spend time on audio forums, then you might be led to believe that all manner of ills are caused by normalization.

However the truth is that if doing it makes things more convenient for you in some way, just do it without a second thought. It is true that any process you carry out on a signal degrades it slightly. But it really is a tiny difference that you probably won't hear and your client or market certainly won't.

Now, the question of 'how much'...

Your normalization plug-in might have options. It might offer 'peak' or 'RMS'. Choose peak... RMS is a different issue that I'm not talking about here.

Also it might offer a level to normalize to, from 0 dBFS down to some arbitrarily low value. Choose 0 dBFS and normalize all the way to the top. If you're going to normalize, it would be hard to find a reason not to.

So in summary, don't bother normalizing unless you feel that you need to. If you feel you need to, do it without a second thought, and go all the way to the top.

P.S. Normalizing your finished mix file is a different issue - http://www.audiomasterclass.com/?a=392

Beethoven: Symphony No. 3 "Eroica" / Abbado · Berliner Philharmoniker

Is your music beautiful? Is it exciting?

If your music is neither beautiful nor exciting, then it is unlikely to find an audience. We hear many recordings at Audio Masterclass that are professional. But mere professionalism isn't enough to get you noticed.

A professional-sounding recording can be useful as an album filler, and even in the age of the download there are album-fillers aplenty being bashed out in pro studios. But to make an impact and achieve true success, your work needs to be beautiful. And if it isn't beautiful, then it needs to be exciting!

By David Mellor, Course Director of Audio Masterclass

Here's an interesting experiment... Go to a website where ordinary musicians and home-studio producers can sell their work to the public. Take a listen to sample tracks and previews. Typically you will easily find work of amazing professionalism. But will you buy? Will the general public buy?

The problem is that achieving professional-sounding work is seen as the objective by many home recording studio owners. True professionalism is hard to achieve, and when you get there, then it seems that some kind of laurel wreath of victory is warranted. Yes, wear it with pride, but you're not done yet. You have only made it to the first rung of the ladder.

I have been thinking long and hard about what it is that the general public really want from their music. Music that they will be willing to pay for. I'll certainly pay good money for a piece of music that is beautiful. Anything by Sade will fit the bill for me, for instance. Adele, also for instance, seems to fit the bill for a younger audience.

But music doesn't have to be beautiful to sell. If a track is exciting, then it can sell well too. It doesn't have to be beautiful, and in fact quite a number of ugly-duckling recordings have sold massively simply because they generate excitement.

Grass roots beauty/excitement

I was playing with a new compression plug-in the other day on a drum track. "Wow, that's an exciting sound!" I thought. I could tweak the settings from hardly any difference at all, through a little bit exciting, to really exciting, to it's-all-too-much-to-handle. It wasn't hard to find a sound that really was over the top.

What I found, which of course I knew already but hadn't thought about recently, is that there is a point where the excitement is just at the right level. But then there's a point just beyond that where the sound is really exciting!

It occurred to me that perhaps I have myself concentrated too much on achieving professional sounds from all of my instruments and vocals, and maybe I should be a little more adventurous and try adding excitement at the recording stage, to each instrument and to each vocal. Of course there are more ways to do this than with compression, but my feeling is that if excitement is added, or at least considered, in every stage of production, the result should be a really exciting song at the end of the recording, mixing and mastering process.

I could of course apply the same logic to a song that I wanted to sound beautiful. If the multitrack recording is packed out with beautiful sounds, how would it be possible to fail?

New punk recording

I was about to summarize that professionalism should be taken as a given, and excitement or beauty added on top of that. But then I thought back to the punk era where many musicians - or should it be 'musicians'? - could hardly play their instruments. But boy they made an exciting sound.

So maybe music production has gotten a little too professionalism these days. Perhaps we need to get back to basics. Exciting sounds or beautiful musicianship, and who cares about a few rough edges?

If anyone would like to send in their new punk recordings, I'll be happy to feature the best in these pages.

david.mellor@audiomasterclass.com

Beethoven: Symphony No. 2 / Abbado · Berliner Philharmoniker

Why are ribbon microphones damaged by phantom power?

In theory, a microphone that doesn't need phantom power should just ignore it. So why are ribbon microphones supposedly so sensitive?

By David Mellor, Course Director of Audio Masterclass

One of the beauties of phantom power is that microphones that need it use it; microphone that don't need it ignore it. But ribbon microphones are different. They can be severely damaged by phantom power. Why is this so?

The first thing to remember is that ribbon microphones are inherently delicate due to the way in which they are constructed. There are exceptions to this but it's best to regard a ribbon mic as needing special care unless reliably informed otherwise.

Any shock could damage the ribbon and its mounting. It is often considered good practice not to let air push against the diaphragm as you walk from the mic cabinet to the studio floor, and certainly don't run with it (although when do you ever see sound engineers run?)

And just as it is sensitive to physical shock, the ribbon mic is sensitive to electrical shock too.

In theory, phantom power should not affect any transformer-output mic that doesn't use it. This is because the coil of the diaphragm in a dynamic mic, and the ribbon in a ribbon mic, is connected across the primary coil of the transformer. In phantom power, +48 DC is connected to both ends of the secondary coil. Transformers to do not pass direct current, and in any case, both ends of the secondary coil are at the same voltage, so no current flows through the secondary coil due to phantom powering.

But that's the theory. How do things work out in practice?

The secondary coil of the microphone's transformer is connected to pins 2 and 3 of the XLR connector, which in turn are both connected to the +48 volts DC of the phantom power supply.

What could conceivably happen is that one pin makes contact a fraction of a second before the other. So for a moment, one pin has +48 volts connected, the other doesn't. Now in theory, until the other pin has connected, there is no circuit for any current to flow through, and when it does connect it will be at the same voltage so still no current will flow. Unless a microphone is unreasonably delicate therefore, connection to a phantom-powered input should pose no problems.

Patchbays are definitely a problem however. If you have a tip-ring-sleeve microphone patchbay (which some would argue against, but they can be very practical) with phantom power applied, then as you plug in the patch cable the microphone is exposed momentarily to the full 48 volts across pins 2 and 3 which, at the moment of connection, will transmit through the transformer to the ribbon. Needless to say, the ribbon will not like this and is likely to be stretched, at the very least. Continued plugging and unplugging on a daily basis will repeat the stress.

The scenario that is least likely to damage your ribbon mic is where phantom power is switched. Since switching occurs simultaneously on pins 2 and 3 of the XLR mic input, there is no possibility for any current to flow, other than a very small amount due to any slight mismatch of the resistors through which the phantom power is fed. This will only transmit through the transformer momentarily.

One final point - if you have a vintage ribbon microphone, then it might have a centre-tapped transformer and current from the phantom power supply will actually flow through the secondary coil. I don't have any personal experience of what damage this could cause, but my alarm bells would certainly be ringing.

Over to you. Have you ever damaged a ribbon mic? How did you do it?

P.S. Some ribbon microphones have internal preamplifiers and require phantom power. Clearly they are not going to be damaged by it.

Beethoven: Symphony No. 1 / Abbado · Berliner Philharmoniker

'Soundproofing' or 'sound isolation' - which is correct?

Some people talk about soundproofing, others about sound isolation. But which is correct? And what about sound insulation - is that correct too?

By David Mellor, Course Director of Audio Masterclass

We received a comment recently saying that where we mention soundproofing at Audio Masterclass we should use the term 'sound isolation' instead, which is supposedly more correct.

Well the short answer to that is that we tested both terms in the marketplace a few years ago, and our results showed that vastly more people were interested in The Audio Masterclass Guide to Soundproofing, than they were in The Audio Masterclass Guide to Sound Isolation.

So we use soundproofing because most people readily understand what it implies. And when we talk about soundproofing, we explain what it really means (and how it is a different concept to acoustic treatment).

Sound isolation is however a useful term in the sense of being a desirable state to achieve.

So if for instance a studio has an isolation booth, then the implication is that sound from outside the booth doesn't get in, and sound from inside of the booth doesn't get out.

Perfect sound isolation is however extremely difficult to achieve in practice, to the point that you could never say that a booth is completely isolated and actually soundproof.

Sound insulation is an expression that is often used to mean the process of achieving sound isolation.

So you could design a booth with a modest amount of sound insulation. When constructed, you would call this your 'isolation booth'. It would be neither completely isolated nor soundproof, but it would provide a certain amount of separation from the main recording area and you would find it useful.

If in future you wanted to upgrade the degree of isolation, you would upgrade the insulation by thickening the walls, improving the seals and blocking any transmission paths.

To be honest, more important than worrying about fine distinctions between soundproofing, sound isolation and sound insulation is to understand the difficulty of achieving an effective degree of soundproofing or sound isolation. For this reason it is important to seek expert advice, otherwise a considerable amount of time, effort and money could be wasted.

Having said that, we did find two examples of places that are completely soundproof to the world...

This...

and this!

The importance of a neat and tidy fade

Do you use fades in your work? If you work in radio or TV sound, you'll use them all the time. They had better be neat!

By David Mellor, Course Director of Audio Masterclass

This isn't about fading out the end of a song. It's about making sure that a piece of audio is neat and tidy, as pro work should be.

Let's suppose for instance that you are given a perfect recording of speech to top and tail. (That means cutting out any preamble and postamble, leaving only the wanted material.) The recording is super-clean and super-quiet. So all you have to do is cut it at the beginning, and cut it after the last syllable has ceased to sound. Easy-peasy, no fading required.

But suppose that there is some background noise. Perhaps the piece was recorded in a public place for instance. There are two possibilities...

The first possibility is that the background is low enough in level that the speech completely masks it. Since normal speech is full of gaps, you'll hear the background then, but not when the person is actually producing sound.

Topping is usually easy in any situation - just cut as close as you can to the opening syllable.

At the end however, what you need is a very quick fade that 'chases down' the last syllable as it ends, in terms of the speed of the decay and the shape of the delay curve. Some experimentation might be necessary but the aim is to completely remove any trace of background at the end, without losing one iota of the speech. This would also apply if the recording venue was quiet, but there was some electronically-generated noise for whatever reason.

It might be the case however that the background is audible throughout. Clearly this isn't ideal, but in the professional world you often have to deal with imperfect source material.

In this case a quick fade is not the best solution. The listener will have gotten used to the background throughout the duration of the piece, and fading too quickly will simply draw attention to it.

The solution here is to hold the level for a short period - probably less than a second - after the last syllable, then fade out gracefully taking around another second to do so. Adjust the timings to taste.

Sometimes perfection is unachievable. But professionalism in audio always is. Keep the pleasure of the listener in mind above all else and you won't go wrong.

Understanding Mic Specifications - Part 4 - Electrical Output

How much power do you need to fill a venue with sound?

By David Mellor, Course Director of Audio Masterclass

Small venues need small amplifiers. Large venues need racks and racks of amps. But how do you know how much power is enough?

Working in live sound can encompass venues of all sizes from a small and intimate bar all the way up to the biggest sports stadium seating 100,000 or more.

So is there a way to calculate how much power you need to fill the venue with sound?

Firstly, we need to be a little more precise about this. "Fill the venue with sound" needs quantifying. One way to do this would be to say that the system should be capable of a level of 100 dB SPL over the whole seating area of the venue. Or a map of levels could be produced that allows some areas to be louder than others.

So now let's consider the variables in the system...

Let's say that you have 1000 watts of power available. This will be supplied to loudspeakers that have a certain efficiency rating. If a loudspeaker can convert 1000 watts of electrical power to 20 watts of sound power, it is doing pretty well at 2% efficiency. The rest of the energy is wasted as heat.

So now we have 20 watts of sound power to play with. All loudspeakers focus their output to a greater or lesser extent. The more focused the output, the higher the level in the direction of 'throw'.

Now for the difficult part - reflections from the room...

Any room (in acoustics, 'room' means an enclosed space of any size) holds and contains sound energy to an extent. A reverberant room will allow sound energy to bounce back and forth. A well-damped room will absorb sound energy. The reverberant room will be louder for the same sound power input because you get the opportunity to hear the same sound several times as it bounces back and forth.

Plainly, we are talking about some difficult calculations here. But there is an alternative... good old-fashioned 'rule of thumb'!

I don't think you will find a better rule of thumb than that provided by the experts at Crown Audio who collectively probably have at least as much and possibly more experience than anyone else in providing amplification for venues of varying sizes, and for different purposes.

So here it is...

• Nearfield monitoring: 25 W for 85 dB SPL average (with 15 dB peaks), 250 W for 95 dB SPL average (with 15 dB peaks)
• Home stereo: 150 W for 85 dB SPL average (with 15 dB peaks), 1,500 W for 95 dB SPL average (with 15 dB peaks)
• Folk music in a coffee shop with 50 seats: 25 to 250 W
• Folk music in a medium-size auditorium, club or house of worship with 150 to 250 seats: 95 to 250 W
• Folk music at a small outdoor festival (50 feet from speaker to audience): 250 W
• Pop or jazz music in a medium-size auditorium. club or house of worship with 150 to 250 seats: 250 to 750 W
• Pop or jazz music in a 2000-seat concert hall: 400 to 1,200 W
• Rock music in a medium-size auditorium, club or house of worship with 150 to 250 seats: At least 1,500 W
• Rock music at a small outdoor festival (50 feet from speaker to audience): At least 1,000 to 3,000 W
• Rock or heavy metal music in a stadium, arena or amphitheater (100 to 300 feet from speaker to audience): At least 4,000 to 15,000 W

Crown also provide a calculator, but this does not account for the directional properties of the loudspeakers, nor for reflections in the room. Still, it makes for a good starting point. (You could bear in mind that they want to sell you more amplifiers!)

Opinions from live sound practitioners would be welcome.

Understanding Mic Specifications - Part 3 - Polar Pattern

Rachmaninov: Symphonic Dances / Rattle · Berliner Philharmoniker

Tchaikovsky: The Tempest / Abbado · Berliner Philharmoniker

Brahms: Hungarian Dance No. 5 / Abbado · Berliner Philharmoniker

Shotgun Microphones

Published Tuesday, May 24, 2011 - 11:50am

What is a shotgun microphone?

A shotgun is a long, cylindrical microphone that excels at picking up sounds in front of it, while rejecting sounds to the sides and rear. Shotguns are designed to have a narrower focus than an average microphone. Shotgun microphones do a great job of picking up the frequencies the human voice produces. Their sound grabbing and voice-capturing abilities make them a great choice for picking up on-camera dialog.

When would I use a shotgun microphone?

Shotgun microphones are most commonly used when you cannot position a microphone directly in front of a sound source. For example, if someone is speaking in front of a video camera and you don’t want them to hold an interview microphone up to their mouth, having an off-screen shotgun mic is a great option. Shotguns are commonly used in film and video production, as well as in live theater, sound reinforcement and in the creation of sound effects. Shotgun mics reject a certain percentage of ambient noise, but retain enough to render a richness that sounds natural.

Do shotgun microphones have any downsides?

A shotgun microphone’s ability to reject ambient sound is frequency dependent; meaning that they do a good job of rejecting high and midrange frequencies, but they don’t reject bass frequencies as well.

Most shotgun microphones have a “rear lobe” in the back: they pick up sound primarily in the front, but they also pick up a little sound from the rear. If you have a shotgun microphone mounted on a video camera, the camera operator needs to be aware that the mic will pick up the sounds they make as well. Another example is when a boom operator is hoisting a shotgun microphone up near a ceiling. They need to be mindful of ducts and other fixtures that may be creating noise behind the mic, as well as to listen for sound reflections that may be creating an unnatural ambience.

As mentioned before, shotgun microphones do a good job of picking up the mid frequencies of the vocal range, but they’re not the best choice for recording musical instruments and other more dynamic sounds.

How is a shotgun different from other kinds of microphones?

The thing that really makes a shotgun different from other kinds of microphones is its long “interference tube.” It’s basically a long, vented tube that‘s positioned in front of the microphone capsule. The length of the interference tube is usually an indicator of how much “reach” a shotgun microphone has; the longer the interference tube, the more focused it will be, but it will not amplify a very distant sound. One downside to longer interference tubes is that they often strip away the natural quality of the sound. However, this is not a rule. Some higher-quality long shotguns capture great-sounding audio.

Does a shotgun microphone “zoom” into a sound?

People often assume that a shotgun microphone is a “zoom microphone.” This is not the case. Shotgun microphones do not actively chase sounds. They are not the audio equivalent of a photographic telephoto lens. Even though shotgun microphones do an above-average job of picking up sounds that originate from a short distance away, they all sound better when they’re physically close to the sound source. That’s why a skilled boompole operator will always strive to get the shotgun microphone as close as possible to the sound source, which often means hovering right at the edge of the frame of a shot.

What is the best way to position a shotgun microphone?

The ideal position for a shotgun microphone is as close to the speaking person’s mouth (or other sound source) as possible. If a shotgun is more than three feet away, the audio will start to sound distant. The farther away the shotgun is, the more distant and reverberant the audio will become. That’s why one of the biggest challenges you face when using a shotgun microphone is getting it as close as possible to the sound source. That’s why boompoles, pistol grips and boompole C-stand mounts are all regularly used.

Can I mount a shotgun microphone to my camera?

Mounting a good shotgun microphone to a video camera is usually a smart idea, simply because the mics that are built into camera usually don’t sound too good. The improvement in sound quality over the built-in mics is great, but it’s important to understand that any sound source which isn’t directly in front of the camera is still going to sound far away, even when you use a high-quality shotgun microphone. The challenge of keeping the audio clear and intelligible for your audience is a constant one, and there is no set-it-and-forget-it solution.

What is “handling noise” and how do I avoid it?

When you mount a shotgun microphone to anything (be it a camera, a boompole or otherwise), you have to be really mindful of vibration and “handling noise.” Shotgun microphones are very sensitive. When you mount one to a camera, it will pick up the sounds of your hands as they support and adjust controls on the camera. Therefore it's necessary to use a piece of equipment called a “shock mount” to attach the microphone. A shock mount suspends the microphone with rubber bands (or utilizes similar kinds of suspension systems), which eliminates most of the vibration and handling noise the mic would otherwise pick up.

We strongly recommend that you use a dedicated shock-mount accessory to fasten a shotgun to a camera, as opposed to using the microphone clamps that are sometimes built in. The microphone clamps built into cameras do not provide enough suspension for higher-quality shotgun microphones, and your audio will be riddled with unwanted noise if you don’t use a proper shock mount.

How does a shotgun microphone connect to a camera?

There are essentially two kinds of shotgun microphones: consumer and professional. Consumer shotgun microphones connect with a 3.5mm mini-plug jack. Professional shotgun microphones connect with a three-pin XLR jack. If you’re connecting a shotgun microphone to a camera, it’s really important to determine what kind of microphone input your camera has, so that you know which microphones will be compatible.

Does a shotgun microphone need power to operate?

Most shotgun microphones have “condenser” elements which are responsible for picking up the sound. This kind of microphone element requires power to operate. Some condenser microphones require a battery, while others need to draw power from the device into which they’re plugged.

Consumer and professional shotgun microphones that don’t operate on battery power require different kinds of external power. Non-battery powered consumer shotgun microphones require the camera or device they’re plugging into to provide them with “Plug-In Power.” Non-battery powered professional shotgun microphones require the camera or device they’re plugging into to provide them with “Phantom Power.”

What is “Plug-In Power” and why would I need it?

Plug-in Power is a small electrical charge that travels through the cable to power the microphone. It’s exclusive to consumer microphones that connect with 3.5mm jacks. Plug-In Power is typically something that you don’t even have to think about. You plug in the microphone, and if the input supplies Plug-In Power, the microphone will operate and that’s it. However, not all 3.5mm mic inputs supply Plug-In Power. If a device has a 3.5mm mic input but lacks Plug-In Power, a non-battery powered consumer microphone will not work in this input.

What is “Phantom Power” and why would I need it?

When the device that a professional shotgun is plugged into is supplying it with electricity, the charge is referred to as “phantom power.” Many professional video cameras that feature XLR mic inputs will also feature phantom power. Because only certain kinds of microphones require phantom power, the camera will also have a switch to turn it on and off. Phantom power is also commonly found on audio mixers and computer audio interfaces. Phantom power tends to intimidate beginners because it just sounds spooky. Fear not. Using phantom power is about as complicated as flipping a light switch to turn on a table lamp. Besides being called phantom power, it is also referred to as “+48V.”

What is “wind protection” and why do I need it?

The term “wind protection” applies to any additional accessories that are designed to keep wind and drafts of air from distorting your audio. Using robust wind protection is absolutely necessary for outdoor shooting. Remember, shotgun microphones are very sensitive. If one is exposed to wind, the shotgun won’t be damaged but the audio it picks up will be terribly distorted.

Every shotgun microphone comes with a basic foam windscreen, but this isn't enough protection for outdoor use. Purchasing additional heavy-duty wind protection is critically important. Even a gentle breeze on a calm day will distort the audio that an under-protected shotgun microphone picks up. There are many names for different kinds of wind protection: wind jammers, softies, dead cats, smoothies, blimps, zeppelins, etc. When you’re estimating the budget of a complete shotgun microphone rig, it’s strongly advised that you factor in the cost of buying proper wind protection.

Are there any controls to adjust on a shotgun microphone?

Some (but not all) shotgun microphones will feature a miniature switch or two. On professional shotgun microphones the switches are almost always recessed into the cylindrical body of the mic. The switches on consumer shotgun microphones aren’t always recessed, and are sometimes found on the rear or base of the microphone.

What is a “Low Cut” switch, and why would I use it?

The most common switch on a shotgun mic is a filter. The filter is sometimes referred to as a “High Pass Filter” or a “Low Cut” switch. These are both the same thing. When this switch is engaged, the activated filter will remove low frequencies from the audio that the mic outputs. Low frequencies are often undesirable, and they’re usually unnecessary for dialog.

A shotgun microphone will pick up more low frequencies than you can hear in any given location. For example, a shotgun will sometimes capture the rumble of distant vehicles, and unnaturally deep sounding footsteps. These sounds can be really distracting to a viewer on normal speakers, and the subwoofers in surround sound systems make it far worse. That’s why it’s usually a good idea to engage the low cut filter if your shotgun mic features one.

What is a “Pad” switch, and why would I use it?

Another common switch is a “pad.” A pad simply makes a microphone less sensitive to loud noises (or in layman’s terms, it turns down the volume of the mic). If you’re using a shotgun microphone in a noisy location such as an active factory or a live band performance, it’s usually a good idea to engage the pad switch. You just need to be mindful to disengage it when the loud noises stop; otherwise the output of the microphone will be unnecessarily low.

Why would I need a switch that allows me to increase the volume?

A few shotgun microphones give you the option to increase the sensitivity of the mic (or in layman’s terms, turn up the volume of the mic). This can be useful if you’re using the shotgun in a really quiet location, where distant sounds are barely audible. You’re more likely to capture quiet sounds if you can boost the sensitivity of the mic.

If the camera or recording device that you’re plugging into allows you to turn down the input level manually, boosting the sensitivity of the shotgun microphone can sometimes help you capture better-sounding audio. The quality of sound that you achieve with any given microphone is partially dependent on how good sounding the “microphone preamp” is on the device that you’re plugged into. A mic preamp is just a small amplifier that raises the soft mic-level signal coming out of the mic up to line level so it can be properly recorded. For example, if the camera you’re plugging into has a noisy, low-quality mic preamp, you may get a better sound if you turn down the input level in the camera manually and engage the sensitivity boost switch on the shotgun mic.

What makes one shotgun microphone better than another?

The trite phrase, “you get what you pay for” applies to shotgun microphones as well. Better-quality shotgun microphones will be put through more rigorous testing during their design phase, made with higher-quality materials and components, and subjected to strict quality-control testing before they are sold. Shotgun microphones are often used in the field, so they have to be durable, especially since the term “in the field” could be anywhere from the Sahara Desert to the Arctic Pole.

While construction and durability are major factors, the attribute that always makes one shotgun microphone more desirable than another is how good it sounds. The better sounding the mic, the more expensive it is likely to be.

The Takeaway

• A shotgun is a long, cylindrical microphone that excels at picking up sounds in front of it, while rejecting sounds to the sides and rear.
• Shotguns are designed to have a narrower focus (sometimes referred to as more “reach”) than an average microphone.
• Shotgun microphones do a great job of picking up the frequencies the human voice produces.
• Shotguns are commonly used when you cannot position a mic directly in front of a sound source.
• Shotgun microphones are used in film and video, live theater, live sound and in the creation of sound effects.
• Shotguns do a good job of rejecting high and mid frequencies, but they don’t reject bass frequencies as well.
• Shotguns have a “rear lobe,” meaning they pick up sound primarily in the front, but also pick up a little sound from the rear.
• Shotguns aren’t the best choice for recording musical instruments and other dynamic sounds.
• An interference tube is a long, vented tube that‘s positioned in front of the microphone capsule.
• A shotgun microphone is not a “zoom” microphone.
• Shotgun microphones always sound better when they’re physically close to the sound source.
• The best place for a shotgun is as close to the speaking person (or other sound source) as possible.
• If a shotgun is more than three feet away from a sound, it will start to sound distant.
• Shotguns are a big improvement in sound quality over the built-in microphones in a video camera.
• It's necessary to use a “shock mount” to attach a shotgun mic to a video camera or boompole.
• Consumer shotgun microphones connect with a 3.5mm mini-plug jack.
• Professional shotgun microphones connect with a three-pin XLR jack.
• Plug-in Power is an electrical charge supplied through a mini-plug input for consumer mics.
• Phantom Power is an electrical charge supplied through an XLR input for professional mics.
• A basic foam windscreen isn't enough protection for using a shotgun outdoors.
• Using additional robust wind protection is absolutely necessary for outdoor shooting.
• When a “High Pass Filter” or a “Low Cut” switch is engaged, the low frequencies are removed.
• When a “Pad” switch is engaged, the shotgun will be less sensitive to loud noises.
• More expensive shotgun microphones typically sound better than low-cost ones.

Published BHphotovideo/ProAudio