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Hi all,
I’d like to thank all on this board :T for all of the great insight on gear. It’s been great and I’ve had a lot of fun with the setup. After using some nice gear for a while, the next step is to make sure the room acoustics are maximized prior to thinking about the next steps in upgrades.
I just received my Behringer DEQ2496 and EMC 8000 microphone to use for optimizing the room acoustics and equalizing the subwoofer. All measurements were taken in a stereo direct mode so only the main speakers were active.
I used the Behringer gear as a real time analyzer and got the chart labeled RTA
https://www.htguide.com/forum/attach...tid=6465&stc=1.
The chart was fairly flat above 280 hertz (although I’d like to get it flatter) and there is probably a dB or two of error in the measurements as the level does jump around a bit (for reference I used the pink noise tone played on a CD I burnt using the file track 58 from this site http://www.binkster.net/extras.shtml).
I also used the Behringer gear as an SPL meter (C weighting, slow response) and took measurements while playing the real traps website test tones from 10 to 300 HZ at 1 Hz intervals. That plot is labeled SPL.
I have played around a little with speaker placement and toe in, but I was unable to address of the nasty null points at 160 – 200 Hz. I’d like to get the room dialed in before equalizing the sub since I use the sub for LFE in home theater mode only. The B&W 802Ds are excellent in the pure stereo mode which is the higher priority.
Just a note: I have set the speaker levels using the Arcam functions but have not done any equalization. I’d rather avoid equalization above 80 Hz if I can avoid it.
Background info:
Room size and layout:
Basic dimensions Length = 22 feet 7 inches; Width = 17 feet; and Ceiling height = 8 feet, 11 inches. The room has a deep plush carpet with thick padding over concrete. Walls and ceiling are 5/8 inch drywall, fiberglass filled. Walls have 2x6 studs with exterior plywood sheathing.
Opposite the gear are three leather recliner loveseats arranged in an arc. My prime listening spot is in the center loveseat.
The left short wall has an 11 foot open arch into the next room which has ceramic tile floor. The left short wall has 6 foot wide by 8 foot tall French doors with heavy curtains. In the right front corner are two 4 foot wide by 5 foot tall windows. One on the front wall and one on the right short wall.
I have my gear along a long wall. The speakers are B&W 802D and are located 40 inches from the back wall and 65 inches from the side wall. (distances are measured to the center front of the woofer drivers. The speakers are about 11 & ½ feet apart. I've posted a layout as an attachment. I really can't arrange the room with the speakers along a short wall.
I have a Denon 3910 universal player; an Arcam AV8 pre pro; and Earthquake Cinenova 5 amp (300 wpc at 8 ohm; 600 wpc into 4 ohm). I have B&W 802D main speakers, an HTM2D center, SCMs for surround, and an Earthquake Mark V – 15 subwoofer.
================================================== ==
Now for the tough part - what kind of acoutistic treatment to add?
I am proposing to add some 2" thick Dow Corning 705 rigid fiberglass mounted paper side out at 45 degrees to form a "chamfer" at the back wall/ceiling juncture. At 22.5 feet long this will give about 45 sq ft of absorber. I'd also plan to cover the back wall with fabric over 1" thick cotton batting to give plenty of high bass/mid damping & diffusion. I'm hoping that will smooth out the nulls (especially at 278 Hz) by trapping rear wall reflections. I'm not planning anything for the ceiling since I don't want to make the room too dead acoustically.
But this probably won't do anything to get at that nasty peak in the 30 Hz zone. In fact that peak really surprised me given the left wall is almost completely open. After running some calculations, this has got to be almost exclusively the axial mode at the room width of 17 feeet. About the only thing I could think of would be a panel trap, but the numbers on designing that are pretty daunting since I'd need a really massive (>3 lbs/sq ft) panel. Any suggestions?
Looking at this chart, I'm thinking I DON'T need a sub for movies! :W
Also, I was thinking about laying some bass traps at the bottom of the long wall/floor junction but was wondering if having these behind the loveseats on the floor would significantly impact their effectiveness.
By the way, does anyone know of a pink noise file in 5.1 format? :B Maybe the response will even out with more speakers.
I’d like to thank all on this board :T for all of the great insight on gear. It’s been great and I’ve had a lot of fun with the setup. After using some nice gear for a while, the next step is to make sure the room acoustics are maximized prior to thinking about the next steps in upgrades.
I just received my Behringer DEQ2496 and EMC 8000 microphone to use for optimizing the room acoustics and equalizing the subwoofer. All measurements were taken in a stereo direct mode so only the main speakers were active.
I used the Behringer gear as a real time analyzer and got the chart labeled RTA
https://www.htguide.com/forum/attach...tid=6465&stc=1.
The chart was fairly flat above 280 hertz (although I’d like to get it flatter) and there is probably a dB or two of error in the measurements as the level does jump around a bit (for reference I used the pink noise tone played on a CD I burnt using the file track 58 from this site http://www.binkster.net/extras.shtml).
I also used the Behringer gear as an SPL meter (C weighting, slow response) and took measurements while playing the real traps website test tones from 10 to 300 HZ at 1 Hz intervals. That plot is labeled SPL.
I have played around a little with speaker placement and toe in, but I was unable to address of the nasty null points at 160 – 200 Hz. I’d like to get the room dialed in before equalizing the sub since I use the sub for LFE in home theater mode only. The B&W 802Ds are excellent in the pure stereo mode which is the higher priority.
Just a note: I have set the speaker levels using the Arcam functions but have not done any equalization. I’d rather avoid equalization above 80 Hz if I can avoid it.
Background info:
Room size and layout:
Basic dimensions Length = 22 feet 7 inches; Width = 17 feet; and Ceiling height = 8 feet, 11 inches. The room has a deep plush carpet with thick padding over concrete. Walls and ceiling are 5/8 inch drywall, fiberglass filled. Walls have 2x6 studs with exterior plywood sheathing.
Opposite the gear are three leather recliner loveseats arranged in an arc. My prime listening spot is in the center loveseat.
The left short wall has an 11 foot open arch into the next room which has ceramic tile floor. The left short wall has 6 foot wide by 8 foot tall French doors with heavy curtains. In the right front corner are two 4 foot wide by 5 foot tall windows. One on the front wall and one on the right short wall.
I have my gear along a long wall. The speakers are B&W 802D and are located 40 inches from the back wall and 65 inches from the side wall. (distances are measured to the center front of the woofer drivers. The speakers are about 11 & ½ feet apart. I've posted a layout as an attachment. I really can't arrange the room with the speakers along a short wall.
I have a Denon 3910 universal player; an Arcam AV8 pre pro; and Earthquake Cinenova 5 amp (300 wpc at 8 ohm; 600 wpc into 4 ohm). I have B&W 802D main speakers, an HTM2D center, SCMs for surround, and an Earthquake Mark V – 15 subwoofer.
================================================== ==
Now for the tough part - what kind of acoutistic treatment to add?
I am proposing to add some 2" thick Dow Corning 705 rigid fiberglass mounted paper side out at 45 degrees to form a "chamfer" at the back wall/ceiling juncture. At 22.5 feet long this will give about 45 sq ft of absorber. I'd also plan to cover the back wall with fabric over 1" thick cotton batting to give plenty of high bass/mid damping & diffusion. I'm hoping that will smooth out the nulls (especially at 278 Hz) by trapping rear wall reflections. I'm not planning anything for the ceiling since I don't want to make the room too dead acoustically.
But this probably won't do anything to get at that nasty peak in the 30 Hz zone. In fact that peak really surprised me given the left wall is almost completely open. After running some calculations, this has got to be almost exclusively the axial mode at the room width of 17 feeet. About the only thing I could think of would be a panel trap, but the numbers on designing that are pretty daunting since I'd need a really massive (>3 lbs/sq ft) panel. Any suggestions?
Looking at this chart, I'm thinking I DON'T need a sub for movies! :W
Also, I was thinking about laying some bass traps at the bottom of the long wall/floor junction but was wondering if having these behind the loveseats on the floor would significantly impact their effectiveness.
By the way, does anyone know of a pink noise file in 5.1 format? :B Maybe the response will even out with more speakers.
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