Should Measure Be Mono?

[Kenryan]

I think I finally got a good graph (used the on-board cheap soundcard (SoundMax) instead of the expensive E-MU (go figure). But I wanted to know if a measurement from one speaker is how this is supposed to work. I still only have the right speaker/channel hooked up as per the help file. Since that isn't how audio is listed to in this room, does that not affect the accuracy of the result?

Thanks.

Ken

[brucek]

I think I finally got a good graph (used the on-board cheap soundcard (SoundMax) instead of the expensive E-MU (go figure).

That's usually the way it is. The cheap card has no features to confuse and mess things up, and a cheap cards frequency response is easily corrected by REW.

does that not affect the accuracy of the result?

It's debatable. Once the sub is equalized and then a single speaker added, the mono signal is fine since the sub and main would handle their own bandwidth above and below the crossover. The shared frequencies would be manipulated by the subs phase and distance settings to achieve a proper mix.

But if you added two mains, the signal to those mains would be mono and while it would provide the opportunity to see how each main reacts with the crossover, there is the issue of cancellation between the two mains that may not be present when using a proper stereo signal.

I vote for using the two mains.........

brucek

[Kenryan]

Thanks! I actually don't have a sub. All was done with just the 2 speakers. And I did select that option in REW.

Ken

[Wayne A. Pflughaupt]

I dunno – unless you have the mic perfectly centered between the two speakers, you have a time alignment problem, which typically does nothing good for response measurements. But it’s easy enough try it both ways and compare the two. If the two-speaker reading looks significantly different than the single one, I’d stick with that. Personally I did it both ways and didn’t see a problem, but it’s good to be aware that there could be.

Regards,
Wayne

[Kenryan]

Thanks Wayne!

Ken