REW5, iMac 24", Behringer ECM8000, test date March 13, 2011
The fixture is set to be 4.25 inches from the cone centers, and the measurement mic is 0.75 behind the fabric being measured.
As used in the HT, my RH/LH main speakers are 24" from side wall and 28" from back wall, toed inward slightly.
I measured the midrange @ its center height position (32.0")and tweeter @ its center height position (37.25")
Did the 75db calibration @ midrange position and did not re-calibrate for tweeter position.
Applied 1/3 octave smoothing for all these, if subwoofer then I would have applied 1/12 octave smoothing.
paradigm monitor 9 Crossovers specs:
3rd-order electro-acoustic at 1.9 kHz
2nd-order electro-acoustic at 500 Hz
They graphed like this as baseline w/o any thing between them and the mic:
(Blue is midrange, purple is tweeter)Chart 1 Baseline chart:
1) I always show the "baseline" midrange/tweeter curve for visual compaision on respective charts.
2) I always ran the measurement 80hz - 20khz, and plotted that way also.
3) When looking at the charts, the midrange you should look at the 500-1.9k freq zone, the tweeter the 1.9k and above freq zoneSpoonflower cotton cloth charts
Chart 2a Midrange with spoonflower cotton cloth, baseline and @ 0, 45, 60 degrees
Chart 2b Tweeter with spoonflower cotton cloth, baseline and @ 0, 45, 60 degrees>>My conclusion from the midrange/tweeter charts:
spoonflower cotton cloth is AT and good to go for acoustic absorber panels usage.Charts showing mi-hi freq blockage:
Chart 3a Midrange with kraft paper, baseline and @ 0, 45, 60 degrees
Chart 3b Tweeter with kraft paper, baseline and @ 0, 45, 60 degrees>>My conclusion from the midrange/tweeter charts:
Clearly krafty paper does block significant hi freq, it appears not as good at mid-freq blockage
This show the "freq blockage" of kraft paper vs 3/4" pink foamboard:
Chart 4>>My conclusion from the midrange:
Clearly 3/4" pink foamboard does block significant mid and hi freq compared to the kraft paper
(I forgot to do same test for tweeter kraft vs 3/4" pink foamboard, maybe on Part III will do)
This shows a comparision of tweeter for baseline, spoonflower, and kraft @ 0 deg
This shows a comparision of midrange for baseline, spoonflower, and kraft @ 0 deg
I might re-do these as Part III with the speakers more mid room to more remove any wall interaction from these readings, but my quick experience gained is these fabrics seem more AT than I had guessed they would. But, this is my 1st time doing this so no real frame of reference.
I've not come across anyone else here @ AVS doing these, could be burried in the 200+ page Master Acoustics thread, that thread would be so much more useful if an index was at the beginning...There is great info burried in it, lost, and then re-talked about again. I truly feel for Dennis/Ethan/Terry/Ted/Others for answering q's multiple times.