Wednesday, February 4, 2015
Q. Is flutter echo a problem in a well-treated room?
Sound Advice : Recording
My daughter managed to play a tough piece she's been practising on the keyboard this weekend. She played it so well that we clapped our hands... then we noticed how strange the clapping sounded. It rang on but died very quickly, and for the time it rang on, it sounded very metallic and almost robotic.That was close to the middle of the room. The room is partially treated at the moment, with panels at the side-wall reflection points and ceiling, one on the ceiling, and three corner superchunks. I tried clapping again with some further panels on the side walls directly to the left and right of where I was sitting, and the noise disappeared. I understand enough to realise the sound is the clap bouncing back and forth between the two walls, and I'm guessing that this is what folk refer to as flutter echo. What I'm a little less sure about is whether it is a problem, and what — generally — a hand clap should sound like in a well-treated room.
Via SOS web site
SOS Technical Editor Hugh Robjohns replies: If we're talking about the sound in a control room, the point is what the room sounds like when listening to sound from the monitor speakers. It is conceivable that, by design (or coincidence), the acoustics could well sound spot on for sounds from the speakers, but less accurate or flattering for sources elsewhere. And, unless you're planning on recording sources in the control room at the position you were clapping your hands, those flutter echoes might not represent a problem or require 'fixing'.
However, in general, strong flutter echoes are rarely a good thing to have in a control room and I'd certainly be thinking about putting up some absorption or diffusion on those bare walls to prevent such blatant flutter echoes.Flutter echoes in a studio can be distracting and fatiguing, so it's often worth putting up some absorbent foam on bare walls to reduce them. Don't overdo it, though: you need to maintain a balanced acoustic.Flutter echoes in a studio can be distracting and fatiguing, so it's often worth putting up some absorbent foam on bare walls to reduce them. Don't overdo it, though: you need to maintain a balanced acoustic.
You shouldn't go overboard with the room treatment, though, because while working in a control room that has 'ringy' flutter echoes or an ultra-live acoustic can be very distracting and fatiguing, so too is trying to work in a room that sounds nearly as dead as an anechoic chamber!
Of course, traditional control rooms are pretty dead, acoustically speaking, and that is necessary so that you can hear what you are doing in a mix without the room effects dominating things. But the key is to maintain a balanced acoustic character across the entire frequency spectrum. The temptation in your situation might simply be to stick a load of acoustic absorbers on the walls, and that would almost certainly kill the flutter echoes, but in doing so there is also a risk that you'd end up with too much HF and mid-range absorption in the room (relative to the bass-end absorption).
That situation would tend to make the room sound boxy, coloured and unbalanced, and that's why a better alternative, sometimes, is to use diffusion rather than absorption; to scatter the reflections rather than absorb them. The end result is the same, in that the flutter echoes are removed, but the diffusion approach keeps more mid-range and HF sound energy in the room.
The question of which approach to use — diffusion or absorption (or even a bit of both) — depends on how the rest of the room sounds, but from your description I'd say you still had quite a way to go with absorption before you've gone too far.
To sum up, I'd suggest that you're not worrying unnecessarily, and that it would help to put up some treatment to reduce those flutter echoes.
My daughter managed to play a tough piece she's been practising on the keyboard this weekend. She played it so well that we clapped our hands... then we noticed how strange the clapping sounded. It rang on but died very quickly, and for the time it rang on, it sounded very metallic and almost robotic.That was close to the middle of the room. The room is partially treated at the moment, with panels at the side-wall reflection points and ceiling, one on the ceiling, and three corner superchunks. I tried clapping again with some further panels on the side walls directly to the left and right of where I was sitting, and the noise disappeared. I understand enough to realise the sound is the clap bouncing back and forth between the two walls, and I'm guessing that this is what folk refer to as flutter echo. What I'm a little less sure about is whether it is a problem, and what — generally — a hand clap should sound like in a well-treated room.
Via SOS web site
SOS Technical Editor Hugh Robjohns replies: If we're talking about the sound in a control room, the point is what the room sounds like when listening to sound from the monitor speakers. It is conceivable that, by design (or coincidence), the acoustics could well sound spot on for sounds from the speakers, but less accurate or flattering for sources elsewhere. And, unless you're planning on recording sources in the control room at the position you were clapping your hands, those flutter echoes might not represent a problem or require 'fixing'.
However, in general, strong flutter echoes are rarely a good thing to have in a control room and I'd certainly be thinking about putting up some absorption or diffusion on those bare walls to prevent such blatant flutter echoes.Flutter echoes in a studio can be distracting and fatiguing, so it's often worth putting up some absorbent foam on bare walls to reduce them. Don't overdo it, though: you need to maintain a balanced acoustic.Flutter echoes in a studio can be distracting and fatiguing, so it's often worth putting up some absorbent foam on bare walls to reduce them. Don't overdo it, though: you need to maintain a balanced acoustic.
You shouldn't go overboard with the room treatment, though, because while working in a control room that has 'ringy' flutter echoes or an ultra-live acoustic can be very distracting and fatiguing, so too is trying to work in a room that sounds nearly as dead as an anechoic chamber!
Of course, traditional control rooms are pretty dead, acoustically speaking, and that is necessary so that you can hear what you are doing in a mix without the room effects dominating things. But the key is to maintain a balanced acoustic character across the entire frequency spectrum. The temptation in your situation might simply be to stick a load of acoustic absorbers on the walls, and that would almost certainly kill the flutter echoes, but in doing so there is also a risk that you'd end up with too much HF and mid-range absorption in the room (relative to the bass-end absorption).
That situation would tend to make the room sound boxy, coloured and unbalanced, and that's why a better alternative, sometimes, is to use diffusion rather than absorption; to scatter the reflections rather than absorb them. The end result is the same, in that the flutter echoes are removed, but the diffusion approach keeps more mid-range and HF sound energy in the room.
The question of which approach to use — diffusion or absorption (or even a bit of both) — depends on how the rest of the room sounds, but from your description I'd say you still had quite a way to go with absorption before you've gone too far.
To sum up, I'd suggest that you're not worrying unnecessarily, and that it would help to put up some treatment to reduce those flutter echoes.
Tuesday, February 3, 2015
Q. How can I make using headphones less fatiguing?
Sound Advice : Mixing
I have been making music for years now, and although I have a set of Genelec 8040s that I use during the day (when I'm home), I have been using a set of Audio-Technica M50 headphones for writing at night, when I usually have the ideas and desire to write, but am unable to, due to neighbours and a sleeping wife.However, lately I have been unable to use the cans, as I've been experiencing discomfort and what I believe is the onset or warning signs of tinnitus. It's been a nightmare trying to adapt to not using cans at night, and I find it almost impossible to get anything other than sequencing done at this low volume!I'm wondering whether there are any miracle headphones or bits of kit that would minimise hearing damage or discomfort while still being (relatively) accurate and enjoyable to use.
Via SOS web site
SOS Technical Editor Hugh Robjohns replies: Firstly, regarding the tinnitus: it's very common, often temporary and may be nothing to worry about. It can be brought on by something as simple as drinking too much coffee or suffering a mild ear infection, but don't ignore or neglect it. Go and see a medical professional and get checked out! If there is a problem, early intervention could make all the difference.
I don't think there are any 'miracle' solutions in headphones. Basically, it comes down to self-control in establishing the most appropriate maximum level for those particular headphones and sticking to it. The simplest solution is to put a mark on the headphone volume control and exercise enough self-discipline to never turn it up past that. If you reach a stage in your mixing when you're finding that maximum level is too quiet, take a break. Give the ears a little time to relax and reset, and then start again.
More volume is not the answer, though. It might seem more exciting and involving, but it doesn't really help to make better mixes — in fact, it usually makes them worse! The reason is that greater volume allows you to hear through a bad mix more easily, and poor balances aren't perceived as such. Working at more moderate levels — the kind of volume that most end listeners will use — encourages a far more critical approach to the mix, as poor balances sound obviously awful! Mixing becomes much harder, certainly, but also much more accurate and with far better end results. This is true of both speakers and headphones.
By all means turn the volume up if you need to check low-level background noises and so on, but do so only briefly. Try to mix at a modest level, and keep that level fixed. If you continually change your monitoring level, your mix will change continually too!
However, the fatigue you're experiencing may involve more than just sheer volume. The M50s are pretty good for the money, but I think you might find it easier to work with a pair of good open-backed headphones that are more revealing. You might find it helpful to read the comments and suggestions for different models in a headphone comparison article we ran in the January 2010 issue (/sos/jan10/articles/studioheadphones.htm). If possible, try different models before buying, to make sure the weight, headband pressure and size of the ear cups suit your head and are comfortable. Open-back headphones do 'leak' more sound than closed headphones, though, and that may be an issue for your wife!
The M50, being a closed-back design, tends to be less revealing of mid-range detail than a good open-backed headphone, and a consequence of this is a natural tendency to keep cranking the level to try to hear further into the mix, but more volume still doesn't quite reveal what you want to hear! Headphones that exert a strong pressure on the sides of the head can also add to the sense of physical fatigue, and the sealed nature of the earpieces quickly makes your ears hot and uncomfortable, which also doesn't help.
I'd recommend trying some good open-back headphones, like the AKG 702s, Sennheiser HD650s or the Beyerdynamic DT880 Pros. They are expensive, but I think you'll find it far easier to mix with them and you'll be much less tempted to wind the level up, although it is still very important to take frequent breaks to allow your perception of volume to reset! Headphones of this calibre provide a top-notch monitoring system that will last for decades if well looked after, and you'll probably hear all sorts of details that your Genelecs don't reveal, too.If you find that your closed-back headphones are quite fatiguing, it may be a good idea to try some open-back headphones, such as these AKG 702s. Decent open-back headphones are often more revealing than closed-back models, and may therefore reduce the temptation to increase the volume.If you find that your closed-back headphones are quite fatiguing, it may be a good idea to try some open-back headphones, such as these AKG 702s. Decent open-back headphones are often more revealing than closed-back models, and may therefore reduce the temptation to increase the volume.Q. How can I make using headphones less fatiguing?
Obviously, though, there is no physical sensation from the low frequencies when using headphones, as there is when using speakers and that can also be a factor in the continual desire to turn the level up, especially if you're producing music that demands strong bass content. The only way around that is self-discipline and learning to trust your headphones.
As a last resort, if you don't think you have the self-discipline to leave the volume control alone, it might be wise to consider investing in a suitably calibrated headphone limiter. Again, it's an expensive option, but I'd suggest that it's well worth it to protect your priceless ears! There's some useful background information here: www.tonywoolf.co.uk/hp-limiters.htm. Also, Canford Audio offer various types of headphone level limiter that can be installed inside headphones or wired into the cable. These are based on a clever BBC design, which is now mandatory within the corporation to ensure that BBC staff don't expose themselves to excessive SPLs through their phones, and it works extremely well. You can read more about it here: www.canford.co.uk/technical/PDFs/EarphoneLimiters.pdf.
I have been making music for years now, and although I have a set of Genelec 8040s that I use during the day (when I'm home), I have been using a set of Audio-Technica M50 headphones for writing at night, when I usually have the ideas and desire to write, but am unable to, due to neighbours and a sleeping wife.However, lately I have been unable to use the cans, as I've been experiencing discomfort and what I believe is the onset or warning signs of tinnitus. It's been a nightmare trying to adapt to not using cans at night, and I find it almost impossible to get anything other than sequencing done at this low volume!I'm wondering whether there are any miracle headphones or bits of kit that would minimise hearing damage or discomfort while still being (relatively) accurate and enjoyable to use.
Via SOS web site
SOS Technical Editor Hugh Robjohns replies: Firstly, regarding the tinnitus: it's very common, often temporary and may be nothing to worry about. It can be brought on by something as simple as drinking too much coffee or suffering a mild ear infection, but don't ignore or neglect it. Go and see a medical professional and get checked out! If there is a problem, early intervention could make all the difference.
More volume is not the answer, though. It might seem more exciting and involving, but it doesn't really help to make better mixes — in fact, it usually makes them worse! The reason is that greater volume allows you to hear through a bad mix more easily, and poor balances aren't perceived as such. Working at more moderate levels — the kind of volume that most end listeners will use — encourages a far more critical approach to the mix, as poor balances sound obviously awful! Mixing becomes much harder, certainly, but also much more accurate and with far better end results. This is true of both speakers and headphones.
By all means turn the volume up if you need to check low-level background noises and so on, but do so only briefly. Try to mix at a modest level, and keep that level fixed. If you continually change your monitoring level, your mix will change continually too!
However, the fatigue you're experiencing may involve more than just sheer volume. The M50s are pretty good for the money, but I think you might find it easier to work with a pair of good open-backed headphones that are more revealing. You might find it helpful to read the comments and suggestions for different models in a headphone comparison article we ran in the January 2010 issue (/sos/jan10/articles/studioheadphones.htm). If possible, try different models before buying, to make sure the weight, headband pressure and size of the ear cups suit your head and are comfortable. Open-back headphones do 'leak' more sound than closed headphones, though, and that may be an issue for your wife!
The M50, being a closed-back design, tends to be less revealing of mid-range detail than a good open-backed headphone, and a consequence of this is a natural tendency to keep cranking the level to try to hear further into the mix, but more volume still doesn't quite reveal what you want to hear! Headphones that exert a strong pressure on the sides of the head can also add to the sense of physical fatigue, and the sealed nature of the earpieces quickly makes your ears hot and uncomfortable, which also doesn't help.
I'd recommend trying some good open-back headphones, like the AKG 702s, Sennheiser HD650s or the Beyerdynamic DT880 Pros. They are expensive, but I think you'll find it far easier to mix with them and you'll be much less tempted to wind the level up, although it is still very important to take frequent breaks to allow your perception of volume to reset! Headphones of this calibre provide a top-notch monitoring system that will last for decades if well looked after, and you'll probably hear all sorts of details that your Genelecs don't reveal, too.If you find that your closed-back headphones are quite fatiguing, it may be a good idea to try some open-back headphones, such as these AKG 702s. Decent open-back headphones are often more revealing than closed-back models, and may therefore reduce the temptation to increase the volume.If you find that your closed-back headphones are quite fatiguing, it may be a good idea to try some open-back headphones, such as these AKG 702s. Decent open-back headphones are often more revealing than closed-back models, and may therefore reduce the temptation to increase the volume.Q. How can I make using headphones less fatiguing?
Obviously, though, there is no physical sensation from the low frequencies when using headphones, as there is when using speakers and that can also be a factor in the continual desire to turn the level up, especially if you're producing music that demands strong bass content. The only way around that is self-discipline and learning to trust your headphones.
As a last resort, if you don't think you have the self-discipline to leave the volume control alone, it might be wise to consider investing in a suitably calibrated headphone limiter. Again, it's an expensive option, but I'd suggest that it's well worth it to protect your priceless ears! There's some useful background information here: www.tonywoolf.co.uk/hp-limiters.htm. Also, Canford Audio offer various types of headphone level limiter that can be installed inside headphones or wired into the cable. These are based on a clever BBC design, which is now mandatory within the corporation to ensure that BBC staff don't expose themselves to excessive SPLs through their phones, and it works extremely well. You can read more about it here: www.canford.co.uk/technical/PDFs/EarphoneLimiters.pdf.
Q. Does it make sense for me to mix with a mono 'grot box'?
Sound Advice : Mixing
I realise that there are advantages to monitoring on a single 'middly'-sounding small speaker (such as an Avantone MixCube) from time to time while mixing, to get an idea of what the music might sound like on typical cheap consumer playback systems. However, I mix mainly deep house and lounge, which is quite rich in high and low frequencies, and these are easily conveyed by the full-range playback systems in trendy restaurants, cafes and clubs, but not by these small monitors. Does using one while mixing, therefore, actually make any sense for me? Also, if I did decide to get a single MixCube, I guess the best place to put it would simply be in the middle of the desk, but the problem is that that's where my computer screen is! Should I buy a higher speaker stand to go above my screen and angle the Avantone down towards me?
Nicolas Issid via email
SOS contributor Mike Senior replies: If your music were only ever played on larger full-range systems like those you mention, the usefulness of limited-bandwidth referencing would indeed be reduced. However, I'd personally think twice about targeting the sound too narrowly for one type of playback system, and would be inclined to prepare my music for lower-resolution playback in case it, for any reason, gets transmitted for wider consumption — on the Internet, say, or as part of a TV programme, radio advert or computer game.Rather than buying a mixer with lots of outputs and manually routing sound effects to different speakers for a theatre production, why not use a dedicated computer-based 'playout' system, in conjunction with a multi-output soundcard or audio interface? Some suitable software is even available free.Rather than buying a mixer with lots of outputs and manually routing sound effects to different speakers for a theatre production, why not use a dedicated computer-based 'playout' system, in conjunction with a multi-output soundcard or audio interface? Some suitable software is even available free.Even if you mix music primarily aimed at full-range venue playback systems, there's still something to be gained at mixdown from checking your mix on a single small speaker.Even if you mix music primarily aimed at full-range venue playback systems, there's still something to be gained at mixdown from checking your mix on a single small speaker.
That apart, though, I think you're slightly underestimating the value of something like the Avantones, because they're not just about the 'middly' frequency response. Their small-scale, single-driver, portless design makes them much more revealing as far as simple mix balance issues are concerned (ie. for deciding what level each instrument should be at) than almost any even marginally affordable full-range nearfield/midfield monitoring system. This is even more the case if you use only one such speaker, rather than a stereo pair, as you also avoid inter-speaker phasing issues. Overall, I think you'd still benefit a great deal from this kind of speaker even if you mix primarily for larger speaker systems.
As far as speaker placement is concerned, in my opinion it doesn't really matter much where you put it, as long as it's pointing roughly in your direction and you're not getting acoustic reflection problems from a nearby room boundary or other hard surface. The only disadvantage of mounting a single speaker off centre is that it may temporarily skew your stereo perception to one side after you've been listening for a while. Not that this is actually a significant mixing problem in practice, though, because it's very easy to work around.
I realise that there are advantages to monitoring on a single 'middly'-sounding small speaker (such as an Avantone MixCube) from time to time while mixing, to get an idea of what the music might sound like on typical cheap consumer playback systems. However, I mix mainly deep house and lounge, which is quite rich in high and low frequencies, and these are easily conveyed by the full-range playback systems in trendy restaurants, cafes and clubs, but not by these small monitors. Does using one while mixing, therefore, actually make any sense for me? Also, if I did decide to get a single MixCube, I guess the best place to put it would simply be in the middle of the desk, but the problem is that that's where my computer screen is! Should I buy a higher speaker stand to go above my screen and angle the Avantone down towards me?
Nicolas Issid via email
SOS contributor Mike Senior replies: If your music were only ever played on larger full-range systems like those you mention, the usefulness of limited-bandwidth referencing would indeed be reduced. However, I'd personally think twice about targeting the sound too narrowly for one type of playback system, and would be inclined to prepare my music for lower-resolution playback in case it, for any reason, gets transmitted for wider consumption — on the Internet, say, or as part of a TV programme, radio advert or computer game.Rather than buying a mixer with lots of outputs and manually routing sound effects to different speakers for a theatre production, why not use a dedicated computer-based 'playout' system, in conjunction with a multi-output soundcard or audio interface? Some suitable software is even available free.Rather than buying a mixer with lots of outputs and manually routing sound effects to different speakers for a theatre production, why not use a dedicated computer-based 'playout' system, in conjunction with a multi-output soundcard or audio interface? Some suitable software is even available free.Even if you mix music primarily aimed at full-range venue playback systems, there's still something to be gained at mixdown from checking your mix on a single small speaker.Even if you mix music primarily aimed at full-range venue playback systems, there's still something to be gained at mixdown from checking your mix on a single small speaker.
That apart, though, I think you're slightly underestimating the value of something like the Avantones, because they're not just about the 'middly' frequency response. Their small-scale, single-driver, portless design makes them much more revealing as far as simple mix balance issues are concerned (ie. for deciding what level each instrument should be at) than almost any even marginally affordable full-range nearfield/midfield monitoring system. This is even more the case if you use only one such speaker, rather than a stereo pair, as you also avoid inter-speaker phasing issues. Overall, I think you'd still benefit a great deal from this kind of speaker even if you mix primarily for larger speaker systems.
As far as speaker placement is concerned, in my opinion it doesn't really matter much where you put it, as long as it's pointing roughly in your direction and you're not getting acoustic reflection problems from a nearby room boundary or other hard surface. The only disadvantage of mounting a single speaker off centre is that it may temporarily skew your stereo perception to one side after you've been listening for a while. Not that this is actually a significant mixing problem in practice, though, because it's very easy to work around.
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