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Fun experiment to attempt to fix a large mid-range dip.

pollock0424

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I removed some homemade treatments in my office and purchased a new to me RME ADI-2 FS Pro. Moving stuff resulted in a mid-range suck out, which wasn't there before.

no_treatments_thielv1_peq_rme2.png

Notice how the big dip in the 300Hz to 700Hz ?

Here's my homemade 6-inch thick foam based treatment (2ft x 6ft). These used to be positioned at the first reflection points. (with 3 inch air gap). You can see them now in their current position.
rpF43d1Z.jpg


I wanted to see if removing this big panel (2ft x 6ft) was the reason for the suck out. I introduced it back, but with a 4-inch air gap... you can see below what happened.
big_airgaps_thielv2_peq_rme.png

Suck out is not as bad as without the treatment, but it is still there. I wanted to see what happens without any air gap.....
no_airgaps_thielv2_peq_rme2.png


You can see that it got better in the 250Hz to 350Hz region. I can do an immediate A/B with and without PEQ on my RME and the difference is clear.... when I was listening to the CD (Tabula Rasa by Water Lily Acoustics), just for the PEQ part.. I used 5 bands on RME to fix a few other issues.

In my current configuration, I have some issues in the Bass region (70Hz to 150Hz), these will most likely be noticeable with traditional instruments such as Tabla and Mridangam (Hindustani classical and Carnatic music).

Next step is to make these treatments with Rockwool.

Here's how the final response looks like with Psy smoothing.
Left
final_psy_left.png

Right
final_psy_right.png

Left + Right

final_psy_left_right.png


Left, Right, Left+Right (overlays)
fianl_all_psy.png


I still have a sizeable dip between 300Hz and 400Hz in the combined response. This might come off as vocals coming from a bit deeper inside the soundstage.

Left speak to Right speak is 8.143ft.
Left speak to MLP=8.05ft,
Right speak to MLP=8.051,
MLP to RearWall=1.906ft, (behind me)
MLP to FrontWall=9.364,
Right speak to RightWall=3.474ft,
Right speak to FrontWall=2.175, (behind speaks)
Left speak to LeftWall=4.1ft,
Left speak to FrontWall=2.270ft,
RightMid/woof to RightWall=3.4ft,
Rightmid/Woof to FrontWall=2.7ft,
Leftmid/woof to LeftWall=4.045ft,
Leftmid/woof to FrontWall=2.645ft
 

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  • final_psy_left_right.png
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  • fianl_all_psy.png
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