How to use subwoofer test tone?

gmorris

How do you use the subwoofer test tone?

I was playing around last night, trying to set up my homemade subwoofer, using my old receiver to drive it. (still don't have the plate amp) The old receiver is getting an 80 Hz lowpass signal from the line level sub-out of the Onkyo.

When I use the Onkyo's test tones, it seems the tone is above the 80 Hz crossover point. I turned up every possible adjustment (bass level, subwoofer output level, and volume on the old rec.) to MAX, and the test tone was still very much lower than the 6 other speakers.

After giving up on the test tone, I put in my own bass test tone generator, Metallica!! With actual musical bass playing, I was able to blend the sub rather nicely. I set the bass adjustment back to 0 (which is where I wanted it in the first place), the subwoofer level to +4, and the volume of the old rec. to just below max. With these settings the bass is great. Very well blended to the other speakers, and completely non-localized. I think it is just right for not having a proper sub amp.

So, what is the point of the subwoofer test tone?

walk

I noticed the same thing on my Onkyo. The sub test tone definitely goes above 80hz (or whatever xover is set at), or it has harmonics that go above it, because if I play with the sub's own xover dial, it still has a very noticible effect even has high as 140-160hz. With the Onk xover set to 80hz I wouldn't think there would be much left at 120+ but there is.

I'm not sure why, maybe the sub test tone just ignores the xover and pushes out a full-range signal. But that's not going to give you a good calibration if you disable the sub's xover (or set it to max), it's going to be a lot higher.

What I do is set the sub's xover to about 110hz and calibrate with the test tone to about 6-7db higher than the other speakers, it seems to work out OK. Careful calibration using the Eardrum Mk.I is also advised.