Q. Why won’t Elastic Audio recognise the tempo of my loop?

I’m trying to build a session from loops using Elastic Audio in Pro Tools. I’ve been referring to the technique article in SOS January 2010, but it’s not quite working for me. I understand that when I import the first file into the session, Pro Tools should ask me if I want to import the tempo from the file as well. However, this doesn’t happen for me and, when I click on Import, I have my first loop in place but the session tempo doesn’t match the loop’s tempo. Where am I going wrong?

A tick next to the file name in the Pro Tools Workspace window tells you that Pro Tools has completed its Elastic Audio Analysis, which should include tempo detection.

If the file remains sample based even though it has been analysed, this is because no tempo was detected, perhaps because the file’s tempo is not regular enough to identify, or the file only contains a single transient.

Carla Scott, via email

SOS contributor Mike Thornton replies: 

My first theory is that I suspect the loop hasn’t been analysed in the Digibase Workspace window. One reason for this could be that the loop isn’t an approved file format. For Digibase to be able to undertake an Elastic Audio Analysis it must be an AIFF or WAV file. MP3s and SD2 files aren’t supported.

If your loops are WAVs or AIFFs, make sure that Pro Tools has completed the Elastic Audio Analysis. Check that there is a tick in the column to the left of the Name column in the Workspace window. If not, highlight the loop in the Workspace window and select ‘Calculate Elastic Analysis’ from the toolbox. Pro Tools should then analyse the file and put a tick in the left-hand column. Now try dragging it into the Edit window and see if Pro Tools asks you if you want to import the tempo from the file.

If that doesn’t work, check that Pro Tools has identified the loop as having tempo information in it. You can do this by looking in the Kind column of the Workspace browser and seeing which type of icon Pro Tools has assigned to that loop once it has analysed it. If Pro Tools identifies the loop as a sample-based file, it will display a circular clock-type icon. If Pro Tools identifies the loop as a tick-based file, it will display a miniature metronome icon.

Analysed files in which Pro Tools detects a regular tempo are updated as tick based, display their duration in Bars/Beats and display their native tempo in the Tempo column. Analysed files in which no tempo was detected remain sample based. These files typically contain only a single transient (such as a snare hit) or they are longer files without a readily identifiable regular tempo (such as entire songs).

One final thought: if you do not see the Elastic Audio Analysis icon or the duration does not become tick based during the preview process, check the permissions for the folder. You need to have write access to the directory for this feature to work.  

Published in SOS May 2010