A Subwoofer Torture Test from Don Keele -
Hi everyone on the Bcc list (all forty of you!),
As a gift from the “The Real Don Keele”, here’s a very-handy subwoofer tone burst test signal that I prepared.
Attached is very-handy composite 30 to 80 Hz bandwidth tone-burst test WAVE file (with descriptive PDF) that can be used to test the low-frequency maximum output capability of woofers and subwoofers including both domestic and pro woofers. I actually developed this test back in 2004!
Easy to Use:
It is very easy to use. Just double click on the WAVE file (“LoopedBurst32To80HzV2Mod.wav”) and play it using any program such as Windows Media Player, Quick Time, iTunes, Winamp, etc. The WAVE file will generate 10 bursts repeated once per second for exactly 10 seconds and then stop. I suggest putting your player into “Repeat Mode” to continuously play the bursts.
Use the headphone output jack of your computer as a signal source and then send the signal to the power amplifier, preamp, or the input of your powered sub. Make sure the computer’s volume is set to the highest level.
Make sure your amplifier level control is at minimum when you start playing. Then gradually increase the level until you hear any objectionable sounds coming from the sub and then subjectively note the reproduced volume level, tonal characteristics, and LF extension, etc.
The composite tone burst is excellent for comparing two side-by-side subs! Just set them up and alternately switch between the two.
This is a brutal test for any sub so watch out that you don’t exceed the displacement limits of the driver in the sub!
Crest Factor and Amplifier Requirements:
The crest factor of the looped burst is a high 15.5 dB so the thermal limits of any sub you test will not be exceeded. If you test a passive sub with an external power amplifier, I suggest using an amplifier with a power rating this is at least three to four times higher than the power rating of the sub you are testing so that the amp doesn’t run out of gas and clip before the sub reaches its limits.
Make sure the power amp is set to its highest input sensitivity. Without the woofer connected, you should be able to turn your power amp up the point where it clips! (All pro amps have clipping indicators).
Test May be Freely Distributed:
This test may be freely distributed, just give me credit!
This test was developed and programmed by me using Igor Pro (http://www.Wavemetrics.com