First noob REW questions....

[Vader]

OK, I just finished my first attempt at getting a FR curve using REW, and have a few questions:

1) I got the measurement level set, but the Wizard asked me whether I was going to be testing a speaker or subwoofer (I tried both). I calibrated to 73dB by setting the AVR to '00' and bumping the measurement level to -17dB. The only difference between the two selections appeared to be the range of requencies present in the pink noise (the bass still came through my mains, but I'm assuming that at my CO the lower frequencies were redirected at my subs). The SPL reading was approx the same between the two (allowing for -2dB in the subwoofer run). Am I correct here? Which should I use, speaker or subwoofer (and can I damage anything by making the wrong selection)?

2) Edit: I guess I am a noob at using the search function, too!

Thanx!

[brucek]

I calibrated to 73dB

Calibrate to 80dB.

Am I correct here? Which should I use, speaker or subwoofer (and can I damage anything by making the wrong selection)?

Yes, you're correct.
If you're testing a subwoofer, select subwoofer.
No damage. Just follow the help file and all will be good.
When testing a subwoofer, don't have your main speakers turned on.

the wizard stopped, and informed me that the input volume was maxed

Your output is too low at 73dB and so the input level rises to compensate and then maxes out. Set your levels to 80dB

brucek

[Vader]

Bruce, the pink noise is at 70dB when I am at the default setting of -20dB RMS and the AVR (Denon 2105) is at MV '00'. I got to the 73dB by bumping the RMS level to -17dB. Is it safe to keep bumping this to get 80dB?

[Sonnie]

Yep.

[brucek]

AVR (Denon 2105) is at MV '00'

Why don't you just turn the AVR up until the RS SPL meter reads 80dB?

brucek

[Vader]

Good point. I guess I just thought of 'MV 00' as the standard for reference. In any case, I finally got it to work, and got my first FR for my HT room. On the one hand, it doesn't look too bad (with no EQ), but on the other hand I probably made about a million mistakes. I'm gonna give it another shot, though (I love this program!). It's not like I can do anything about it right now anyway, as I don't yet have a BFD (or a soundcard with a MIDI interface to talk to it)... Thanx!

[brucek]

Good point. I guess I just thought of 'MV 00' as the standard for reference

No, in this case we're simply using the processor as a volume control to set a proper working level in the REW program so we can take a room response and set up filters. You can ignore the actual level shown on your processor.

It's not like I can do anything about it right now anyway,

Well, many people use REW to help them located the subwoofer in the room to obtain the best response. Sometimes a small change in position helps a lot. Others use it for placing room treatment. Also, if you do a (sub + mains) response test you can modify the response around the crossover frequency by adjusting the subs phase control

I'm gonna give it another shot

Yeah, give 80db a try this time (even thogh REW says 75). This way the meter needle at 80dB will be centered.

brucek