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Discussion Starter #1
I have been posting on AVSforums about how I made a jump from a Velodyne DLS3750 to a new SVS PC12+. I had great room gain and integration with my Velodyne. With this new PC12 plus, I have been reall dissapointed.

This is my first measurement and graph with REW, so let me know if there is something else I should do. Please give me advice on what to do. I have an Onkyo 605 with Audyssey 2EQ...which has no sub filters...in-case you couldn't tell :)

 

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It's best to calibrate REW to 75dB - you're either measuring too low or you didn't run the SPL Calibrate routine.

With respect to the sub, your first line of attack is to simply move the sub around until you realize a better response at your listening position. Place the sub at your listening position and move the microphone around to various positions to test for the best spot, then move the sub there and see how it looks.

brucek
 

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Discussion Starter #3 (Edited)
Thanks, will do. I have actually moved the sub around to every possible position in increments of 1/2feet and they all sill yielded that huge null. The null did move a bit forward on the graph, but did not have an improvement.

Will buying the BFD help this situation? What else can I do if all sub positions yield this huge null?

BTW, when you talk about calibrating the SPL, I have the generic RatShack SPL calibration downloaded and uploaded as the ".cal" file. Aside from that I DID use the "calibrate SPL meter" button, but you are totally correct in that the level was at 64dbs :(.
 

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Discussion Starter #5
I'd say you should try changing he listening position if no change in speaker position yield results.

Do your sub have an Paramtric EQ? Make sure that is not set to maximum cut around 30Hz... I've made that mistake once.
The listening position can not be changed due to the size of the room.

My SVS PC12+ does have a PEQ, but I have I ran REQ with the knobs turned in all settings and it did not make a difference. I have the crossover disabled.
 

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Have you tried playing around with the phase control on the sub? Sometimes even dips that low can be caused buy cancellation due to room acoustics.
 

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Discussion Starter #7
Have you tried playing around with the phase control on the sub? Sometimes even dips that low can be caused buy cancellation due to room acoustics.
I have with the PC12+. I can didn't run REW with the Velo and different Phase settings.

Will every sub produce this kind of "suck out" at that Frequency? Are there any sub eqs that can help this, or will they all yield the same kind of benifit.

I know the BFD is a standard here. Will it benifit that dip around 30hz? I am sure that it can smooth out the curve.
 

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I have with the PC12+. I can didn't run REW with the Velo and different Phase settings.

Will every sub produce this kind of "suck out" at that Frequency? Are there any sub eqs that can help this, or will they all yield the same kind of benifit.

I know the BFD is a standard here. Will it benifit that dip around 30hz? I am sure that it can smooth out the curve.
In general, assuming the suckout is caused by room acoustics, whether modal or more simply reflective), yes, any sub in the exact same location will have the same suckout when listened to from the exact same location. You can't EQ a boost into a suckout that bad, it'll still just get sucked out, and kill your headroom. Unfortunately here, nothing to do mut some good old fashioned placement and acoustics work.
 

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BTW, when you talk about calibrating the SPL, I have the generic RatShack SPL calibration downloaded and uploaded as the ".cal" file. Aside from that I DID use the "calibrate SPL meter" button, but you are totally correct in that the level was at 64dbs
The Calibrate reference was indeed the Calibrate SPL routine you are suppose to run after Check Levels. If it reads 64dB, then you were suppose to change that to 75dB. This tells the REW SPL meter that the level it's hearing when running that routine is 75dB (that you previously set in the Check Levels routine to 75dB with a real SPL meter). Now the REW SPL meter knows what 75dB is (until you change levels and have to run it again).

brucek
 
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