Proper way to calibrate a sub in a two channel setup?

[AaronD]

I was wondering what methods, test CDs, etc, people are using to properly calibrate a sub woofer for two channel? I'm using the bass management in my receiver to set the low pass for my sub woofer at 80hz. The high pass for my mains is also at the same frequency.

Is it as simple as playing full range pink noise and calibrating L, R, and sub to the same DB level with all but one disconnected?

In case you're interested:
I've got a HK AVR-310 feeding a Rotel RMB-1075. My mains are B&W 604s3 and the sub is a Velodyne SPL-1000.

Thanks,
Aaron

[David Meek]

Aaron, that's a good start.
:T

One thing you should do is to overlap your cross-over setting a bit. For example, set the sub to pass at 80 Hz and set your speakers to pass at 70 Hz. That way the corresponding slopes won't produce a "suck-out" of frequencies in that range. You'll have to play with the overlap a bit to get it smooth. Check this with the sweep tones until you are happy. This may be as far as you feel you need to go - it's up to your ears to tell you when you are happy.

But, having accomplished that and you decide you want to go further, to really optimize your setup you'll need to look into using something along the lines of a Behringer Feedback Destroyer, aka BFD. Our own Sonnie Parker is a guru of sorts and has written the Comprehensive Setup Guide for you. There are numerous posts on BFD usage by our members - just hit the search engine. . . .

Best of luck to you. Keep us posted on how things turn out.

P.S. I thought I'd posted a reply to you earlier in the week - not sure what happened. Sorry for the delay in getting back to ya!
:smackbutt:

[ThomasW]

David certainly pointed you in the proper direction for integrating a sub into the room... :T

For setting the overall sub output with regard to the mains, I tend to trust my ears more than test tones or measurements.

When the sub level is too high, it tends to make the midrange 'fat' or 'muddy.' Some refer to this as 'chesty'. When the sub level is set to low the overall sound will be 'thin' or lacking 'sufficient weight'.

Well recorded female vocals provide a good test to see if the relative output levels are correctly set. The goal is of course to have the voice sound 'live'.

[Azeke]

Just to provide a point of reference, I have my 7.1 channel setup as follows, calculated at 75db utilizing a Rat Shack SLM and the test tones of my pre-pro:

Fronts: 60Hz
Center: 80Hz
Rears: 80Hz
CB's: 80Hz
Sub: 80Hz

All speakers set to small.

This provides the proper acoustical environment for me, but of course, as mentioned, you need to listen to your own ears. This is dependent on your speakers, room layout, etc.

Your mileage may vary,

Azeke

[Bam!]

Azeke!

I`m curious....why are your surrounds at 80 hz ?

My sub is now at 60hz.....for me that is bass.....higher than that it is just too boomy.....this way everything is just so much more pure and transparent and much tighter....

Just my 2 cents....

[Sonnie Parker]

Welcome to htguide Aaron.

LFE is encoded up to 120hz on DVD's and some receivers and pre/pro's have a crossover for your sub vs. mains with a separate crossover for your LFE. I believe even if you don't have this feature that LFE up to 120hz (regardless of your crossover setting) will be fed to your sub with most of todays pre/pros (please someone correct me if I'm off base here). With this in mind you may want to test your sub up to 120hz if you have such a receiver or pre/pro.

If you would like test tones you can go to the BFD Setup page and download sinewaves galore. I would test each sub individually first with 1/6 octave tones.... make adjustments (if you have a BFD) and then test the subs together to see what kind of interaction you get between the two. It's much more difficult to level out two subs than one but you could probably get it close.