Using REW for dual subs pre Audyssey

[meek81]

So I am so confused and hope to get some help here. I have my subs placed in best locations available in my living room by using REW, but I just noticed that messing with the sub distance in my AVR changed the frequency response when I measure with REW? I was under the impression that the sub distance in the AVR didn’t matter before running Audyssey...And now I’m not sure at what distance my subs need to be? So do I physically measure the distance of my subs and enter those distances in my AVR, and then take REW measurements to get a good frequency response? And then run Audyssey? But then I remember that Audyssey will change the distances regardless and am afraid it will mess up the response I had in REW.. How then do I take proper subwoofer measurements before running Audyssey? I hope I’m making sense, help me please..

 

[John Mulcahy]

Changing the sub distance will only affect the response if another speaker is playing at the same time, so the test signal must be going to more than just the sub.

 

[meek81]

Changing the sub distance will only affect the response if another speaker is playing at the same time, so the test signal must be going to more than just the sub.

I see well I am using Java when running REW because I can’t get Asio to work on my PC, but I have the crossover set to the max which is 250Hz on my AVR and I have my left main unplugged when doing the sweeps. So am I doing this incorrectly?

 

[JStewart]

Your procedure is correct.
Assuming your AVR has 2 sub outs, Is only 1 sub on during a measurement? If both, was the distance changed by the same amount for each?
Running a sweep to 1kHz will reveal if another speaker is playing without your knowledge.

 

[meek81]

Your procedure is correct.
Assuming your AVR has 2 sub outs, Is only 1 sub on during a measurement? If both, was the distance changed by the same amount for each?
Running a sweep to 1kHz will reveal if another speaker is playing without your knowledge.

I have a Denon x4500h which has 2 sub outs and I was running both so I could get a good frequency response before running Audyssey, then I thought to myself just out of curiosity wondering if changing the sub distance in my AVR would have an effect on the sub frequency sweeps, and sure enough it changed the response which gots me all confused now.. because to my understanding once I run Audyssey, it is going to change the sub distances I currently have and mess up my current frequency response I have measuring with REW..

Should I run Audyssey first to see what distances it sets my subs too, and then go back to REW turn Audyssey off and do some sub sweeps with the distances Audyssey gave me? Because currently I have my front sub set at 10.2 ft. and my rear sub set at 8.2 ft. which are the actual physical distances of my subs from my main listening position. Sorry for the long rant I just want to do this correctly, thank you for your help

 

[JStewart]

I have a Denon x4500h which has 2 sub outs and I was running both so I could get a good frequency response before running Audyssey, then I thought to myself just out of curiosity wondering if changing the sub distance in my AVR would have an effect on the sub frequency sweeps, and sure enough it changed the response which gots me all confused now.. because to my understanding once I run Audyssey, it is going to change the sub distances I currently have and mess up my current frequency response I have measuring with REW..

Should I run Audyssey first to see what distances it sets my subs too, and then go back to REW turn Audyssey off and do some sub sweeps with the distances Audyssey gave me? Because currently I have my front sub set at 10.2 ft. and my rear sub set at 8.2 ft. which are the actual physical distances of my subs from my main listening position. Sorry for the long rant I just want to do this correctly, thank you for your help

To begin with, as @John Mulcahy said, a single speaker response won't change when distance is changed. If the response is different as a result of a distance change for a single speaker being measured then something is amiss.

In your situation using Audy with 2 sub outs REW will be useful to help confirm the best sub locations for best individual responses. Audy will then do its thing and optimize the sub distances and combined response (IIRC), so optimizing individual distances beforehand won't do anything for you. And to reiterate, it won't matter because changing the distance DOES NOT CHANGE THE RESPONSE.

Where REW can again be helpful is after Audy has done its correction and this will be to ensure the subwoofers to main speakers timing is correct for the smoothest response through the crossover region.

Summary:
Put the subs in the best locations.
Run Audy
Optimize the subs to mains integration at the XO.