Does subwoofer recalibration needed after EQ applied?

[skool]

Hi guys, this is my first time playing with the REW software. I must say, it's very interesting and quite useful if used correctly. Anyway, I have a huge peak (10+ dB) in my room around 38-40 Hz. I was wondering when you calibrate the system to 75 dB using the internal receiver's test tones, what frequencies does it play for the subwoofer? I'm wondering if the 40 Hz peak would affect my subwoofer calibration by using these test tones? If I tame that 40 Hz peak using my eQ.2, do I need to recalibrate my subwoofer?

[Nuance]

skool wrote:

Hi guys, this is my first time playing with the REW software. I must say, it's very interesting and quite useful if used correctly. Anyway, I have a huge peak (10+ dB) in my room around 38-40 Hz. I was wondering when you calibrate the system to 75 dB using the internal receiver's test tones, what frequencies does it play for the subwoofer? I'm wondering if the 40 Hz peak would affect my subwoofer calibration by using these test tones? If I tame that 40 Hz peak using my eQ.2, do I need to recalibrate my subwoofer?

The receiver uses pink noise, so it's not just one or two frequencies. After I EQ'd my sub I had to re-level match, but I used REW and my SPL meter because it uses the calibration file and corrects the meter's slightly inaccurate readings.

If you have a 10+ dB peak like I did, you'll most likely needs to re-level match when your finished EQing, but be sure to use the gain on the subwoofer and not the channel level in the receiver.

[skool]

How many dB did you have to increase to compensate for the sub after EQed? How exactly did you use REW to level math the sub? I assume once you loaded the calibration file for the mic/meter setting, that should take care of the Radio Shack SPL meter compensation, correct? Afterward, you just turn on the SPL input reading (red button on middle top) and just level the speaker and sub? Anybody else have comments? I would appreciate further comments because I worry I would run the sub too hot.

[brucek]

REW uses a band limited pink noise signal for sub calibration with a low cut of 30Hz and a high cut of 80Hz.

Yes, if you removed a peak in a sub, it would require level setting after EQ'ing.

It's easiest to level set your sub and all other speakers in your system with your receivers internal test tones.

brucek

[skool]

Thanks Brucek, you're as helpful as usual in this forum.

[Nuance]

skool wrote:

How many dB did you have to increase to compensate for the sub after EQed? How exactly did you use REW to level math the sub? I assume once you loaded the calibration file for the mic/meter setting, that should take care of the Radio Shack SPL meter compensation, correct? Afterward, you just turn on the SPL input reading (red button on middle top) and just level the speaker and sub? Anybody else have comments? I would appreciate further comments because I worry I would run the sub too hot.

I think the subwoofer ended up being 3 or 4 dB less than the mains, so I ran the test tone on the receiver and used REW's SPL meter readout (with the calibration file loaded) to get them equal. I have them within .1 dB according to REW. Oh, and I used the subwoofer gain to level match, not the receiver's channel level, as REW recommends the former.

I suppose you could use the "calibrate" button in REW and select the subwoofer tone for bass calibration, then the speaker tone for speaker calibration. But like Bruce said, using the receiver tone is just easier.

Hope that helps. Best of luck to you sir!

[skool]

Got it! Thanks a lot.