Studio Recording Studios Services Technical Articles

Rick's Control Room frequency Test

Please if you are going to use this test or copy it please give me credit—Thank you Rick

This is a really easy way to check your control room's low frequency response. I know this is not a very accurate test but it will indicate to you exactly what the troubling frequencies are and by repeating this test and moving things around (like subs) you will see if you are actually improving things or not.

You can use any sequencer that shows an accurate waveform display and a timeline showing bars.

We use Nuendo.

Setup a session with the tempo set to 120 bpm

 

This is a single wav file with sine waves starting at 35 hz and going up to 400 hz each lasting for 1 second on and 1 second off. If your tempo is set to 120 bpm this calculates to 2 seconds per measure. That way each frequency will last 1 measure-- So line the wav file up with the leading edge of the first 35hz cycle up with the beginning of bar 35 and the last frequency should end on bar 400.

Adjust your layout so you can see the bar numbers with the playback track BIG.
The bars now represent the frequency. Playback the file at your normal mix volume sitting in your mix position. You will notice the volume sounds different as different frequencies are played back.
Get 2 or 3 of your best microphones and place them near where your ears are pointing towards the speakers--- record these 3 mics as you are playing back the above file. You will be able to see a rough graph of your room response when you zoom out to look at the recorded files.

 

The mics don't look that much different as compared to the problems your control room will show. You will notice different peaks and dips in your room's response with different bandwidth. Try moving your sub if you have one. If not try moving things in a BIG way and see what happens. Try to even the response out as much as you can –

Rick Naiser
Festival Recording Studios
3413 Florida Ave.
Kenner, La. 70065