Home Audio Acoustics

**thewire** · **02-02-09, 05:25 AM**

To be fair to others, and since I have been contimplating the idea to move my seats back a foot, here is with the GIK Pillars now stacked on the back center wall onto the 4 other GIK 244's. I moved the left and right speakers away from the walls as well, and moved my surrounds behind the back row.

You can see how the 250Hz area in the decay now results in a better match, and the lower ringing has changed. The ringing is so low that I must zoom into 200ms with the waterfall to observe the decay more closely. This is again with the hush box fan running. The lower ringing now moves to the 20Hz area, bellow my first room mode.

**thewire** · **02-02-09, 06:22 AM**

Some photos also for better understanding of the layout measured.

**thewire** · **02-02-09, 10:32 PM**

This sounds very good also, espicially in the LFE. Simply moving my speakers out however does not seem to be addressing the issues I heard in the front corners in my first post. I'm thinking then it must be related to the subwoofers output, somewhere in the range of 90Hz, - 120Hz, but it also treated much higher for the mains response, and much lower for the subwoofers response. If the problem in the right corner that I am feeling can't be heard, then these traps must be treating very low.

**thewire** · **02-05-09, 10:35 AM**

I isolated my subwoofers on the platforms and the stage using my subdude and put holes in the stage. It seems I now have no need to adjust the trim for the left or right speakers to match. Drilling all these holes without moving the speakers was difficult.

I had to arrange the panels so that reflections from the ports at the bottom of the speakers would be absorbed, and I moved the subwoofers slightly. These measurements were after equalizing the subs.

**thewire** · **02-06-09, 10:43 AM**

Next I might like doing something like this with more trapping. The rear traps I could optionaly place insulation behind. A false wall was out of the question back there because of the sconces. There seems to be a slight bit more bass from the sub on the right wall when in the right seat, and sitting in eather the left or right seat up front which are closer to the walls, the spaciousness seems about lost as more bass seems to come from the speakers closest. Having traps above the subwoofers at the walls midpoints seems to help that but not 100% sure. It just seems to make the balance from the mains to the subs more smoothed out for those seats. That seems to happen at around 92dB or more. It could be something to do with second reflection points but I suspect it's just some sound off the walls moving. More traps would deffinitly help the back wall.

**thewire** · **02-07-09, 11:22 PM**

I'm ordering some Roxul and then I will be adjusting the other room treatments to see what results I can get.

Anyone know where I can get 6 Roxul Rockboard 60 2 inch, Case of 6 for less than $461.44 shipped to area code 65072?

**bpape** · **02-08-09, 06:45 AM**

Roxul - probably not. If you can use IIG, I know I can get some for you for better than that.

I have a commercial FedEx account for my business. I'm getting about $19.50 per box for shipping so that'd be about $117 for the 6 boxes. I'm guessing I could get you the mineral wool for around $300

I used to carry it but have been having QC issues and problems with the warehouse so I discontinued it. I'd be willing to grab you some though and ship to you. We're not that far away - It would be just as easy to meet somewhere in the middle if you have a truck and we can figure out a time.

Bryan

**thewire** · **02-08-09, 07:47 AM**

Quote:

bpape wrote:

Roxul - probably not. If you can use IIG, I know I can get some for you for better than that.

I have a commercial FedEx account for my business. I'm getting about $19.50 per box for shipping so that'd be about $117 for the 6 boxes. I'm guessing I could get you the mineral wool for around $300

I used to carry it but have been having QC issues and problems with the warehouse so I discontinued it. I'd be willing to grab you some though and ship to you. We're not that far away - It would be just as easy to meet somewhere in the middle if you have a truck and we can figure out a time.

Bryan

I'm without any kind of transportation for awhile until we replace my van that just went into retirement. I'm not familiar with IIG. Is that acoustical cotton? For some reason the more coverage I get in the back of the room the better results I measure. It needs to be very thick according to measurements. My projector also just went into retirement and until we can get a 1080P DLP after the tax season and paying off some dentist bills for our family I will be using my 32" flat screen with progressive input and anamorphic sqeeze for the HT. The good news is that I can treat the front wall or the back wall, and move my speakers away from the walls. As they had to be they were 20" from my side walls for the best response, but it landed them right into a null from my axial width modes.

I really need as much as I could get my hands on. Having this room size is espicially challenging and I need to have a live-end dead-end approach to get it sounding anywhere good for movies I think. My front wall and back walls modes are so bad that I have them all the way up into the 120Hz area.

You can see the modes that I am currently after in this image. If I have any left-over but which I doubt I would have there is plenty of room in the ceiling to deal with the third order and first order modes.

When I tried 4' thick pink R19 in the rear of the room I had very impressive results but not down to 57Hz as much as I would have liked. It did very well for the 80Hz area in my mesurements. I tried some Quiet Batt back there also but it didn't sound right for some reason. I tried filling those Helmholtz Resonators with pink also but it did not improve the decay much and it somehow seemed to do more harm than good as they seem to effect the 67Hz first order ceiling mode in a negative way, espicially if I change the volume inside. I had not tried any Roxul in that before, but I see the treatments helping over a more larger area, espicially on the sides of where the GIK 244's are currently back there. The biggest problem I have with those is that they are flanking the back wall some. It actually travels right up the wall through the garage and into my room in the back right corner away from the door. My projector hush-box also has some issues with flanking but that's not as difficult to deal with.

I thought Roxul 60 might work well for a cost effective approach in covering such a large area. If your willing to pick some up for me and ship it also that would be great. I'm still open to other ideas however. I will probobly need to wait until monday before I could order anything over $400, and I need to check what I have in there after some recent expenses.

**bpape** · **02-08-09, 08:08 AM**

IIG is just a different brand of mineral wool instead of Roxul brand.

Rear wall is fine for thicker. Doing too much on the front will skew too much of the boundary effects IMO. Usually we just do 2" on the front in most rooms.

Bryan

**thewire** · **02-08-09, 08:30 AM**

Quote:

bpape wrote:

IIG is just a different brand of mineral wool instead of Roxul brand.

Rear wall is fine for thicker. Doing too much on the front will skew too much of the boundary effects IMO. Usually we just do 2" on the front in most rooms.

Bryan

I see. The MinWool-1200® Industrial Board looks like I would need then. If that is easiest for you to get I will go with that then. I don't really have a preferance for which brand.

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