SPL meter subwoofer tuning

SPL meters can get you kindof close but it really takes tuning by ear. When "perfectly" flat response is acheived according to the SPL meter it usually sounds bad. There is a formula for correcting the RadioShack meter that can help (search archives). If you want to measure inroom response you will need a disc with worble tones. This plays a tone that varies within a small range continuously to eliminate the single tone building up and resonating within the room which would give a false reading.
Placement flexibility is the biggest obstacle though. Get a 10meter generic interconnect (less than $20) and place the sub in every livible location.

Good luck!

You'll need a test cd to generate various frequencies. The problem is unless you have an EQ you are only left with crossover frequency, volume, placement and probably phase.

How do the subs sound now? Why are you not satisfied?

There are MP3 pure test tones (from 10Hz to 300 Hz in 1 Hz increments) that can be downloaded from RealTraps website and which you can burn to make a test CD. The digital Ratshack meter is another essential tool with this approach. There is a plot that you can use too. As the 10 second pure tones maximize the room modal response, I suspect that it is best to eyeball the curve and concentrate on taming the broader "bumps" rather than trying to eliminate the inevitable sharp spikes/troughs that you get with a CD with single frequencies.

A PEQ, used sparingly, seems to be another essential tool in practice. (for example It may not be acceptable to install the significant amount of bass traps that might be needed to make an impact on a large room with significant modes below 60 HZ)

I'm surprised you big buck guys don't advocate the use of Breul & Kjear (B&K) or General Radio (GR) sound level meters. Sure the Radio Shack unit might be OK for setting up speakers, but have you ever held and carressed a B&K meter? It's a truely sensual experience that's bound to add to your audiophile enjoyment. And think how impressed your buddies will be when you unload it from it's ever so nice case. Also it can re used with a remote mic and balanced leads. We had both B&K and GR in our lab, but the B&K is a much more emotional experience.

db

Stereo subs get extremly sticky without proper set up. Basically you normally have to run them out of phase to each other due to playing the same frequencies in 2 different corners end up canceling each other out, and then you actually reduce the quality bass load in the room vs. just cranking a single sub up... Now SPL meters are really not accurate in doing subs without a lot of extra knowledge and setup, test CD will be needed that is definate. Good luck

Thanks for all your responses, I have had success with placing by ear, I tried the SPL, it did help, however ultimately my ear was the deciding factor