# Using pink noise to balance levels



## tkc (Sep 11, 2007)

Hi all,

I've been working the last few days to set up a Rythmik DS12 kit. I'm using an integrated amp instead of an A/V receiver, so the only crossover available to me is in the Rythmik's amp. I've tried high-passing the mains and also running them full-range, and I think I like the latter option better so far -- the Rythmik amp has a fixed high-pass filter at 100Hz.

I'm playing with REW to fine-tune the bass response (no EQ as of yet). One thing I haven't seen mentioned yet so far is using pink noise to balance the overall bass reponse with the mains.

With my current setup, is it "correct" to set the gain on the sub amp by using bandwidth-limited pink noise (say from 20 to 80 Hz, and from 500 to 2000 Hz) to make sure the bass level matches the level produced by the mains?

The reason I ask this is that my mains in-room response is pretty peaky between 100 and 300 Hz, and it's hard to set a level on the sub that "matches" the levels I plot with a sweep measurement.

Any feedback from you knowledgeable folks here?

Thanks!


----------



## tonyvdb (Sep 5, 2007)

The best way to set your levels is to use full bandwidth pink noise. If you have a big peak at the 100-300Hz zone on your mains and your crosover is at 100Hz you can eliminate any issues by simply disconnecting the mains from the amp if they dont have any other way of turning them off. Then by simply leaving the volume on the receiver where the mains were set at to achieve 75db then just set the subwoofer to your desired level and reconnect the mains once done.
Ideally you should have your mains crossover set to 80Hz and the sub at the same but from your description you dont have that option.
Your best off using a tone sweep to do the test for how the crossover sounds not pink noise as pink noise is used for setting the speaker response flat and to get proper levels not for checking crosover settings and how it sounds at the crossover.


----------



## Wayne A. Pflughaupt (Apr 13, 2006)

According to house curve theory, you’d want the sub a bit hotter than the mains, probably at least a few dB.  Here is an informational article on the topic that you might find helpful.

Regards,
Wayne


----------



## thewire (Jun 28, 2007)

Set the subwoofer so that the level sounds best. If your mains are having some SBIR try playing some pink noise and move them while watching the response in the RTA with REW. Keep in mind the area that works and mark this off with some tape on the floor or by some means. Then listen to some material and adjust as needed in your space that gives you a less boomy response. You might try backing off the level some also until they match better. A quick comparrsion of a higher pitched tone with known dB with a lower one with known dB will reveal any abnormalities. What is important is that the Left, Center, Right, are as close as possible to matching. Also be sure that the soundstage will match the size of your image. Is this for movies?


----------



## tkc (Sep 11, 2007)

Thanks to everyone for your replies.

I'm pretty constrained as to placement of main speakers and sub, and the system is used for music, TV and movies.

As I was saying, part of the difficulty is the peakiness of the mains' response just above the crossover area. If I set the sub to match right at the crossover point, I'm not sure that the overall bass response will match the overall response above the crossover. Thus the question about using pink noise over a couple of octaves, rather than just at the crossover, to set the relative level of sub to mains.


----------

