New to rew. Is this ok or normal

[jeff5347]

So I received my mic yesterday and was playing around with placement on my subs. I have 2 jbl pb10 and 1 hsu vtf3 mk3. I found my jbls work best at 1 in the right front corner and the other about 1/3 in from the left corner. My hsu I was moving and so far found behind the couch works. For giggle I left the hsu behind the couch but switched phase to 180 and rew revealed total different results then at 0 degrees. Here are some pics of the room setup as well as rew results. Is it normal that switching the rear sub to 180 increases bass and removes the dips although at 95hz I get a massive dip. Do I worry at 95hz . Not sure if you guys want more info but the room is 26x13x7.5. the hsu sub is roughly 12.5 ft from the TV wall

 

[John Mulcahy]

It is normal for inverting one sub in a multiple sub setup to affect the result, yes, as would changing the distance setting for one of the subs if they can be independently adjusted. To know whether the 95 Hz dip would be an issue you would need to measure with a main speaker as well to see what the combined response looks like.

 

[jeff5347]

Hi John. Thanks for the feedback. So I did a full range measurement one w audessey enabled one disabled. The red is enabled. Seems I still have big dip. I have my sub xover set at 110. One thing I did last night was use rew room sim. My ceiling I measured is 6ft 10 in not 7. Even still I adjusted the room to 12 ft tall and as the ceiling height grew the room sim started to show better results. I'm starting to think it's my room height doing damage. Any advice on getting a flatter response and/ or Lessing the dip at 95 or so

 

[John Mulcahy]

More playing around with positions and phase is probably your best bet. If you have a way to apply individual delays and/or filters to each sub you could try Multi-Sub Optimizer.

 

[jeff5347]

I am running a denon 4400x. So delaying each one I can do, or play with distances at least. Would adjusting a sub distance be the same as delay? With the multi sub optimizer I am guessing I would need something like a minidsp.

 

[John Mulcahy]

Yes, distance is another way of specifying a delay. You don't need a miniDSP for MSO, you could just use it to find the best delay/distance settings for your Denon.

 

[jeff5347]

Awesome. Thanks John. I get started on that and report back. Thanks for the help

 

[jeff5347]

John, I took some more measurements but forgot on keeping the graphs. I experimented with distances for the subs thru the denon but I really saw no difference. A few things I tried did though which surprised me. I have my subs thru the receiver crossed at 110 hz. My mains , surrounds and center I had set at 80 hz and that is where you see that dip at 95 or so hz. So I played with changing the xover points for the M, S and C. I came up with 90, 90 and 100 and it almost elimated the 95 dip and smoothed out a bit more the whole bottom end. I def could tell the difference while watching a movie. Bass seemed more impactful and maybe that's the dip that was fixed. I'm gonna work on some acoustic panels to work on the upper limits. I had no idea that the crossovers would also play a part in bumps and dips

 

[John Mulcahy]

Changing the crossover frequencies changes the relative amplitude and phase through the crossover region, so the signals sum differently. Sounds like great progress.