22 x 14 - Vaulted - Acoustic Treatments Help Please

[dgshtav]

Hi,

Am building an HT (Music/Movies 60/40).

A little bit about my current setup
* 7.2
* Near full range (28Hz and above) rear ported towers all around (Note that the surrounds are direct radiating towers and not bi/dipoles. Even If I change speakers in future, I will still be getting direct radiating speakers for surround. I am not too much a fan of (I think!) dipoles.)
* 2 subwoofers with each having 15" driver (Front firing and front ported).
* Room is 21'5" Long x 14'1" Wide and is on 2nd Floor of a single family home.
* Room is acoustically coupled to a foyer that extends from ground to roof.

I will eventually (soon) get Line Arrays (About 8' high I think) for music only.

Some comments on the room:
* Vaulted Cieling and associated flutters (Terrible - A Clap echoes 6/7 times before it dies out)
* Will have layered seating (3+4 or 4+4 if I can accomodate 4 in a row in the current width with rear ported towers)
* Am open to woofer placement anywhere in the room as long as it doesn't interfere with seating space.
* Lot's of window glass (18' length) on one side of room and wall openings on the opposite wall mirroring windows. Wall openings open into Hallway/Foyer.
* Windows and Wall Openings will eventually be covered with full height curtains.
* TV will be wall mounted higher than it's current position.
* Please ignore the "furniture" in the room pics. We had just moved in and everything is make-shift!

Pics attached for more details.

I was planning on the following acoustic treatments:
Width Height
Left Front Corner 2 9
Left Rear Corner 2 9
Right Front Corner 2 9
Right Rear Corner 2 9
Right Ceiling & Wall Corner (Running Length of Room) 2 24
Front Left 2 9
Front Right 2 9
Left Side Wall (3 panels Horizontal under windows) 2 4
Right Side Wall (2 horizontal panels, 1 under each opening) 2 4
Rear Wall (3 Panels) 2 9
Ceiling (Length Wise) 2 8

Insulation Material in Mind:
* OC 705 2" (Backfilled with OC R-30 in the corners), OR
* OC R-30 pink in the corners and OC705 for all other panels
* Open to OC-705 equivalent from other brands as long as it offers good bass absorption with 2" (OF course I would backfill the gaps with OC R-30)

It's difficult to find the acoustic product in SFO East Bay Area. Do please let me know contact details of any vendor that you know of around SFO Bay Area. (And am open to travel to other side of bay too if required).

Unfortunately, all my local searches for OC, JM, FBX turned out to be dead-ends. The only option that seems to be easily available (and will probably perform acceptably) is OC Fluffy Pink R-30 9.5'. Compressing 9.5" to 4" will "increase" it's density but would be a challenge to get the panel maintain shape on the front face.

Any guidance on any of the aspect (Room Acoustics, Materials, Vendors) would go a long way.

Thanks for your patience with the post. Your guidance will be much appreciated.

- DGS

[dgshtav]

Note that the surrounds are direct radiating towers and not bi/dipoles.

If I change speakers in future, I will still be getting direct radiating speakers for surround. I am not too much a fan of (I think!) dipoles.

(Sorry, newbie here and I have to get my post count up. Edited the original post as well to reflect the comment about Direct Radiating surrounds.)

[bpape]

Welcome to the forum.

The overall plan sounds good - though I would recommend OC703 instead of 705 and frame it for a nice clean look. 703 will work just as well or better for 1/2 the money.

I'd also plan on killing the upper corner where the sloped ceiling meets the right side wall or you'll get a focusing effect from that. It will be distracting and shift the image.

You might try SPI for materials. www.spi-co.com I think they have one in SFO area.

Bryan

[dgshtav]

bpape wrote:

The overall plan sounds good - though I would recommend OC703 instead of 705

Thanks Bryan for the feedback. The reason I had 705 in mind was because of it's better bass absorption properties.

Bass is currently very boomy and I get a range of 10db on the SPLs for the bass across various spots in the room. This is without the second sub connected though. With 2nd one connceted and configured, I hope to even out the bass response of the room a bit.

But I hear you. Maybe I could do 703 everywhere except the corners.

bpape wrote:

703 will work just as well or better for 1/2 the money

Can you please elaborate on the "Better" part?

bpape wrote:

I'd also plan on killing the upper corner where the sloped ceiling meets the right side wall or you'll get a focusing effect from that. It will be distracting and shift the image.

I plan on the following:

"Right Ceiling & Wall Corner (Running Length of Room) 2 24"

Will that address it? It will be backfilled with OC R-30.

Any experience with FBX? (The 1280?) If so, how would you compare it with 705?

Thanks again for your feedback.

- Dinesh

[dgshtav]

Also, note that the surrounds are rear ported. I would like to move those as close to the wall as possible.

So am open to a different material behind these. Any recommendations on this specific aspect?

[bpape]

1280 is fine. Again, if you go thick enough, 1240 will work just fine.

For reflecitons, 703 will work better than 705. Also, for bass duties, if you can only do 2-3" thick - yes, 705 is SLIGHTLY better. However, 4" of 703 will WAY outperform 2" of 705 for the same money.

The upper corner comment was meant to be in addition to the front corners.

Bryan

[dgshtav]

Was thinking about 2" thickness, more so on the side and rear walls. But will consider 4" as well. (Not much options if I have to compress the pink stuff if I cannot find the boards locally for a reasonable price)

bpape wrote:

The upper corner comment was meant to be in addition to the front corners.

I am still not getting this part.

#1. Where the ceiling meets the right wall along the entire length (all the way from front to back) of the room, am planning a 2 x 22 length panel slant mounted with one long edge touching the ceiling and the other long edge touching the right wall. The gap behind the panel will be filled with R-30 pink stuff.

#2. Where two walls and the ceiling meet - I wasn't planning on this because:
- The left front and rear corner panels will extend all the way to the top (and will be slanted for flush install with ceiling)
- For the right front and rear top corners - Not needed (in my opinion, but please guide) because of the long panel in #1 that will be flush with the front, right and rear walls and the ceiling.

[bpape]

I was referring to number 1. What you have planned will work fine - though 4" of 703 with fluffy behind will be slightly better.

Front corners address different isues than number 1. What you had planned for the front wall/wall corners is fine.

Bryan

[dgshtav]

Bryan, Thanks a bunch for your inputs.

Will try SPI (again). An email to them couple of months back didn't receive any response. Guess I will have to call in.

Am still hoping I will get a response here on where JCD bought his JM boards.

[bpape]

If you can't find it, let me know via PM. I can get it for you.

Bryan

[dgshtav]

bpape wrote:

If you can't find it, let me know via PM. I can get it for you.

Bryan

sent you a pm.

[tenzip]

dgshtav wrote:

Also, note that the surrounds are rear ported. I would like to move those as close to the wall as possible.

So am open to a different material behind these. Any recommendations on this specific aspect?

If you're using a sub, the port probably never even gets used, so putting it right up against the wall, or putting acoustic treatment right up against it should have zero effect as far as the port is concerned.

As long as you're running your surrounds as small. If you leave them as large, then you may want to consider the port clearance.