Acoustical Treatments Master Thread - Page 353 - AVS Forum
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post #10561 of 10571 Old 12-09-2014, 08:48 AM
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You're right to be concerned about the usefulness of insulation within the wall/ceiling. It would contribute to keeping the room quiet, which is important for having a good sounding space, but it won't change the behavior of sound within your room. This is the difference between the thread (acoustic treatments) and another thread in this forum - the soundproofing master thread.

There are differences between the products, but the differences among them are much smaller than the differences in implementation. So let's deal first with what goals we might have for improving your space, and then determine what characteristics to look for in products.

The hardest to fix with treatments will be bass, so here's my recommendation without seeing exact details of placement and performance. Make sure the subs are in different portions of the room. Add absorptive treatments to any corners that you can (though it looks like that will be tough in your space). Then make sure they are properly set up for delay and phase at the main listening position. Last, apply some mild EQ to flatten the response at the main listening position.

The left and right mains are pushed into corners by the large screen. I'd need to see anechoic measurements of those speakers to be sure, but I bet they are designe to sit out farther from the walls (probably three feet or more). When that's the case, the nearby walls will reinforce the low-end sensitivity and you end up with an overpowering bass response. EQ may be necessary, but you should also try some thick absorption on the side walls next to the speakers to mitigate the boost.

In the rear half of the room, near the seating, I'm less certain. The diffuse character you get from your surrounds is probably a good choice given the proximity to the seating, but there is probably still some troubling flutter echo between the side walls. A few simple panels to the sides of the seating is probably adequate.

For the corner bass treatments, you want as much material and space as you can sacrifice. If you can get to thicknesses around a foot, you should focus on a low density product, like common batts of insulation. But if you will be limited to less, I'd recommend a rigid rock wool panel about 6 pounds per cubic foot.

For the panels near the mains, I'd recommend the same 6 pound product at four inches thick or six inches if you can manage it.

On the side walls b the seating, a 2" panel of the same is probably a reasonable compromise, given the space constraints. Thicker would be better.

This should be a good start. There are other worthwhile approaches, but this is where I would start. Remember to run you auto calibration after any of these changes.
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post #10562 of 10571 Old 12-09-2014, 09:03 AM
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This should be a good start. There are other worthwhile approaches, but this is where I would start. Remember to run you auto calibration after any of these changes.
Thank you so very much!! I can't tell you how helpful this is!!

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post #10563 of 10571 Old 12-09-2014, 11:01 AM
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Got it. Home Depot doesn't seem to have R80 in stock online or in stores so I'll see if they can special order, or drive further to Lowes.

If I ever rip apart my walls again, should I put R60 in between the studs? It's a dedicated basement home theater and I can't figure out how having insulation behind the wall would make much difference for reflections other than as a harder wall. Would this be the right order for sound deadening?

1. On-wall treatments and in-wall treatments
2. On-wall treatments
3. In-wall treatments

In addition, I'm not entirely clear on the benefits of R40 v. R60 v. R80 for bass management. Some people say R40 and some say R80.
I am not sure either... I was told to use R60 for the bass traps as it was better for bass traps, and to go at least 8" thick so we went 9" thick (3 layers of 3"). Our first reflection points are all 4" thick (2 layers of 2")... Originally we were just going to go 2" thick, but I was told to go 4" so I ordered more.

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post #10564 of 10571 Old 12-10-2014, 06:10 AM
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Originally Posted by HopefulFred View Post
You're right to be concerned about the usefulness of insulation within the wall/ceiling. It would contribute to keeping the room quiet, which is important for having a good sounding space, but it won't change the behavior of sound within your room. This is the difference between the thread (acoustic treatments) and another thread in this forum - the soundproofing master thread.

There are differences between the products, but the differences among them are much smaller than the differences in implementation. So let's deal first with what goals we might have for improving your space, and then determine what characteristics to look for in products.

The hardest to fix with treatments will be bass, so here's my recommendation without seeing exact details of placement and performance. Make sure the subs are in different portions of the room. Add absorptive treatments to any corners that you can (though it looks like that will be tough in your space). Then make sure they are properly set up for delay and phase at the main listening position. Last, apply some mild EQ to flatten the response at the main listening position.

The left and right mains are pushed into corners by the large screen. I'd need to see anechoic measurements of those speakers to be sure, but I bet they are designe to sit out farther from the walls (probably three feet or more). When that's the case, the nearby walls will reinforce the low-end sensitivity and you end up with an overpowering bass response. EQ may be necessary, but you should also try some thick absorption on the side walls next to the speakers to mitigate the boost.

In the rear half of the room, near the seating, I'm less certain. The diffuse character you get from your surrounds is probably a good choice given the proximity to the seating, but there is probably still some troubling flutter echo between the side walls. A few simple panels to the sides of the seating is probably adequate.

For the corner bass treatments, you want as much material and space as you can sacrifice. If you can get to thicknesses around a foot, you should focus on a low density product, like common batts of insulation. But if you will be limited to less, I'd recommend a rigid rock wool panel about 6 pounds per cubic foot.

For the panels near the mains, I'd recommend the same 6 pound product at four inches thick or six inches if you can manage it.

On the side walls b the seating, a 2" panel of the same is probably a reasonable compromise, given the space constraints. Thicker would be better.

This should be a good start. There are other worthwhile approaches, but this is where I would start. Remember to run you auto calibration after any of these changes.

I too have very limited space for proper bass traps. Would a 3 feet thick rockwool at the whole frontstage top v wall (triangle) trap work? Or, is it too thick? I am using rockwool 80kg/cubic meter. It's a huge bass trap that spans the entire left to right, top of the wall... it extends down 3.5 feet and out 3.5 feet and triangular in shape.
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post #10565 of 10571 Old 12-10-2014, 11:08 AM
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Originally Posted by ellisr63 View Post
I am not sure either... I was told to use R60 for the bass traps as it was better for bass traps, and to go at least 8" thick so we went 9" thick (3 layers of 3"). Our first reflection points are all 4" thick (2 layers of 2")... Originally we were just going to go 2" thick, but I was told to go 4" so I ordered more.
When ever possible, thicker is better.
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post #10566 of 10571 Old 12-16-2014, 12:44 PM
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Could someone tell me what to look for when comparing Linacoustic rc to other products? Is it the NRC number or is there more to look for? Is higher the NRC better?
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post #10567 of 10571 Old 12-16-2014, 12:49 PM
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post #10568 of 10571 Old 12-16-2014, 01:26 PM
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Do I compare the NRC number or all of it?
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post #10569 of 10571 Old 12-16-2014, 02:15 PM
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Bob has organized the absorption coefficients for each material. The higher the coefficient, the greater the absorption. Presumably, if you're installing an absorber, you want the most absorptoon. But you should be thinking about the frequency ranges you need most absorption in.
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post #10570 of 10571 Old 12-23-2014, 12:34 PM
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Quote:
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Bob has organized the absorption coefficients for each material. The higher the coefficient, the greater the absorption. Presumably, if you're installing an absorber, you want the most absorptoon. But you should be thinking about the frequency ranges you need most absorption in.
Right and just to add you want to focus on how low in frequency the product works. If you put something that only absorbs upper frequencies you run risk of the room becoming unbalanced. Meaning low end is still bouncing around but upper frequencies are dead. Makes low end sound muddy/unclear.

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post #10571 of 10571 Old Today, 08:28 PM
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Originally Posted by HopefulFred View Post
In the rear half of the room, near the seating, I'm less certain. The diffuse character you get from your surrounds is probably a good choice given the proximity to the seating, but there is probably still some troubling flutter echo between the side walls. A few simple panels to the sides of the seating is probably adequate.
Not my room, but out of curiosity, do you reccomend these side panels near the seating position to be floor-to-ceiling, or floor-to-just above ear height?

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