Axiom Home Page Forums General Discussion Advice from Axiom Owners multiple subs

When trying to calibrate a sub by ear a person will most times have the sub about +10db to hot. As far as the sub is concerned this is your problem, you will need to calibrate the sub to get it right..

Then after spending several hours, days or sometimes weeks of getting it calibrated and dialed in to a 'T' with the spiffy SPL meter ... we'll invariably reach back there and crank it up just a notch or two the first time a movie comes along with what we believe are not enough LFEs to suit our needs. Problem solved.

A lot of folks do set their subs a bit hot, normally around +3db for movies.

Wid, glad you brought back your VU meter, I was getting worried man, that is classic and all Wid.

Lately I calibrated all of my subs/speakers to 78dB's. When all subs are turned on, I get an average of 83dB's or 5dB's higher than the other speakers, seems to work well for me.

I use a +6db hard-knee house curve on my subs and that works for me too.

Gotta have the meter

Went out last night and bought an SPL meter. Came home and set everything up at 70dB. Not sure if I did this correctly or not so I want to throw it out.

Set the SPL for 70 (radio shack digital). Set all speakers as close to 70 as I could (a couple of speakers were fluctuating b/w 70 and 71. With Denon 3806 could set speaker level individually. Everything sounded good but the sub. Seemed way too loud and boomy. Scaled that back to about 64 and seemed to blend in much better. Also didn't seem so localized.

So.....did I perform this test correctly? Never used an SPL before.

You seem to have deep placement issues causing some frequencies to be much louder and some much lower. The pink noise being the sum of many frequencies, it is just a guide. Try the tones from the following link (with your SPL meeter).

http://www.realtraps.com/test-cd.htm

That might give you a more accurate picture of what is really happening with low-frequencies in your appt/house and also a more precise tools to see exactly how moving subs and furniture around (and also playing with x-over) will influence/improve things.

But you made the best first move: get an SPL meeter! Now the fun begins!

You certainly did the channels right, but Eric's probably on point here--you need to move your sub.

Thanks for the link. I have moved my sub down to a side wall just behind the main seating area and lowered the volume a bit. The bass has leveled out and is matching much better as a whole. There doesn't seem to be as much localization as before. I am still thinking of a second sub to help smooth out peaks and nulls more.

Thanks to all that have helped. Hope to someday return the favor.