Getting the full SDA Effect from Polk L800 Speakers

T

tjcinnamon

Audioholic Intern
Yesh. I would contact Matthew. He is a room accoustics expert.


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Update

Method:
I moved everything around in my room. Removed the diffusers, pushed the TV back, removed the bass traps, moved the speakers forward so nothing was in front of them at all, heck, removed all of the couch cushions... I experimented with moving the room treatments behind the TV, behind the speakers, next to the speakers, everything I could think of. Also, a substantial amount of time went into unplugging SDA and testing without. Also, I moved my seat toward and away from the speakers to test the soundstage changes. Then slowly added items back.

Source Material: I used that Cars Stereo Track and Dire Straights Private Investigation test tracks with the Eagles Hotel California Live and a Yosi Horikawa track called Bubbles.

Results: Ultimately I could get the sound stage to be approx 1' to 3' to the right or the left of the speaker vs SDA off. Meaning it's working in some capacity but the speakers are still localizable. However, my expectations could be too high relative to my first impression. That said despite the left/right expanded sound stage it was substantially more 3D. It was a "between the speakers" with SDA and didn't have a lot of the Z axis (between me and the speakers). I don't like using terms like that but that's what the effect offers.

Remaining items: order some additional amps off Crutchfield for testing. I think the Stereo store where it hit crazy good was using a Parasound or a Rotel (I requested one of them). I'm going to ask them to see which one it was. I doubt it's the amp but it's a super easy test. Outright remove the TV from in between (even if it's pushed back). Granted the TV has to be there in the end but it will give me insight. I may even try a dedicated pre-amp for academic purposes.

Questions: The outer speaker is the one that is the SDA, correct (just making sure I have them correct)? Does 1' to 3' seem normal or a touch weak for soundstage?
 
G

Golfx

Junior Audioholic
Wow you’ve done some heavy lifting. Regarding the SDA, yes outer ones cancel. Did you listen to recommended “wandering” test album yet? It’s last track, early in, where the shoes are crunching gravel, was so expansive it sounded very briefly as if it was coming from over my rt shoulder from seemingly my surround rear. The first track bubbles sounded like it was outside my walls. You really should contact Matthew Poes.


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G

Golfx

Junior Audioholic
Wow you’ve done some heavy lifting. Regarding the SDA, yes outer ones cancel. Did you listen to recommended “wandering” test album yet? It’s last track, early in, where the shoes are crunching gravel, was so expansive it sounded very briefly as if it was coming from over my rt shoulder from seemingly my surround rear. The first track bubbles sounded like it was outside my walls. You really should contact Matthew Poes.


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G

Golfx

Junior Audioholic
Edit. I see you did listen to bubbles. Try the last track too.
 
T

tjcinnamon

Audioholic Intern
Wow you’ve done some heavy lifting. Regarding the SDA, yes outer ones cancel. Did you listen to recommended “wandering” test album yet? It’s last track, early in, where the shoes are crunching gravel, was so expansive it sounded very briefly as if it was coming from over my rt shoulder from seemingly my surround rear. The first track bubbles sounded like it was outside my walls. You really should contact Matthew Poes.


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I plan to. We've been in email correspondance. I'm going to run my final checks and then reach out to Matt.
 
T

tjcinnamon

Audioholic Intern
also, irrespective of the SDA effect not hitting it's full potential, the speakers sound fantastic and I'm coming from some Paradigms Prestige which were no slouch. So overall, I'm happy but given their size and cost, I'd like to maximize them.
 
G

Golfx

Junior Audioholic
They are awesome speakers. Congratulations again.


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T

tjcinnamon

Audioholic Intern
Wow you’ve done some heavy lifting. Regarding the SDA, yes outer ones cancel. Did you listen to recommended “wandering” test album yet? It’s last track, early in, where the shoes are crunching gravel, was so expansive it sounded very briefly as if it was coming from over my rt shoulder from seemingly my surround rear. The first track bubbles sounded like it was outside my walls. You really should contact Matthew Poes.


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Just sent payment and I look forward to meeting with him. We've narrowed it that it's likely the distance from my seated position and the rear wall.
 
G

Golfx

Junior Audioholic
Uhoh time to move houses. :)


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T

tjcinnamon

Audioholic Intern
Uhoh time to move houses. :)


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not quite yet! I've been working with Matt Poes from Poes Accoustics on a paid consult and we have some good direction at this point. Now I just need to find the time to implement. It's been really fun because I was an REW amateur before and I'm getting some cool pointers to look at.

With SDA it's a lot of trial and error because it won't show up on the measurements from the perspective of, "is it working"
 

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