MaxRockbin
Active Member
I just thought this was interesting. I was doing some room measurements with REW and had read something Mitchco said about getting better results from DSP filters if measurements were taken with some offensive furniture removed (in his experience). My listening spot is a large comfy chair with a back that reaches up just to ear level before curving back. So what do the measurements look like with the chair in place and the chair removed? (actually moved about 4 feet back):
1/48th smoothing, measured at listening position. Right speaker + sub. No left speaker.
GREEN = CHAIR IN NORMAL POSITION
RED = CHAIR MOVED BACK
So a pretty apparent difference from about 300hz and up. Audible? Not really something I can A/B.
I had wondered how much damage the large chair was doing to my so very flat Genelec 8030Cs. Probably some of you with big comfy chairs have wondered the cost too.
Here are the same curves with "Psychoacoustic" smoothing applied. It certainly emphasizes different changes. I guess 100lbs of foam and leather has some impact on the lower frequencies when you move it around. I would have moved it out of the room entirely if it didn't require disassembly and a stronger back.
This graph is the better one to look at, I think, for a person who really doesn't want to ditch his/her comfy chair:
(again - green is normal positioning and red has the chair moved back)
So maybe this example gives you some idea of the evil that chairs do and don't. My case may exaggerate the mid and higher frequency effects, or at least them appear more prominent, because I sit relatively close to the speakers. So comb filtering adulterates what would otherwise be a signal dominated by direct sound.
For anyone curious, here's the room layout - top view/elevation view
1/48th smoothing, measured at listening position. Right speaker + sub. No left speaker.
GREEN = CHAIR IN NORMAL POSITION
RED = CHAIR MOVED BACK
So a pretty apparent difference from about 300hz and up. Audible? Not really something I can A/B.
I had wondered how much damage the large chair was doing to my so very flat Genelec 8030Cs. Probably some of you with big comfy chairs have wondered the cost too.
Here are the same curves with "Psychoacoustic" smoothing applied. It certainly emphasizes different changes. I guess 100lbs of foam and leather has some impact on the lower frequencies when you move it around. I would have moved it out of the room entirely if it didn't require disassembly and a stronger back.
This graph is the better one to look at, I think, for a person who really doesn't want to ditch his/her comfy chair:
(again - green is normal positioning and red has the chair moved back)
So maybe this example gives you some idea of the evil that chairs do and don't. My case may exaggerate the mid and higher frequency effects, or at least them appear more prominent, because I sit relatively close to the speakers. So comb filtering adulterates what would otherwise be a signal dominated by direct sound.
For anyone curious, here's the room layout - top view/elevation view