Setup and Treatment Advice

[Tom Andry]

My wife and I have decided to turn our living room (see diagram below) into a dedicated home theater (yea me ). I will be upgrading all of our equipment and purchasing cinema seating for the room. What I need help with is placement (I pretty much know what I want to do but would like to hear other ideas) and acoustical treatments. I'm mostly concerned with:

1) The open doorways on the two sides of the room (each is about 5 feet wide and 6 feet 9 inches tall) and how they will affect the sound.

2) Treatment placement, type, and of course cost (I’ve convinced her that we need to spend money on treatments but I’d like to keep the costs as low as possible).

3) Integrating the treatments into the room in a generally wife pleasing way.

A few side notes: I was thinking of getting Auralex but I’m not sure how I can integrate them into the room design (perhaps covering them with fabric?). On the other hand, I know that many of the higher-end acoustical treatments are made of fiberglass. I have a friend who has worked with fiberglass for 20+ years and has offered to build me anything I want (within reason). The only problem is I don’t know how those treatments are constructed and even if they can be reproduced on a smaller scale. Thanks in advance to all who respond.

 

[bpape]

Small reality check

Wow, where to start....

First of all congratulations on stepping into this pretty far. Now for a bit of reality.

First, if you can't close it off, it's not technically a dedicted room. The doorways will have a large effect on not only the sound but where you can put seats, etc. If at all possible, serioulsy consider putting in double doors on those openings. To me, this is the single biggest thing that will help this space's potential. You can spend all you want on the rest but these holes WILL cause issues.

Second, wood floors are not necessarily a bad thing. Many recording studios use hardwood floors. The compromise is that if you have hard floors, you should have a soft ceiling. This can acutally be BETTER than a carpeted floor since it does NOT have to be anything you need to walk on!

Third, No matter which end you put the screen/speakers on, you're going to have placement issues with your main speakers. You'll either have them jammed right against a back wall (not good for imaging nor for bass response) or you'll have them so that one side will have its first reflection point in that giant hole of a doorway - but only on one side. This will cause a lot of imaging issues.

Lastly, I personally prefer fiberglass. To me you get a LOT more benefit from less thickness. Also, if you're going to cover it anyway then foam has lost its last advantage IMO (though I personally don't care for it's look anyway in most cases). Making absorbtive covered fiberglass panels is really VERY easy to do. The trick is finding someone who will sell you OC703 or something similar and at a reasonable price. Ethan Winter has some very basic drawings on how to construct panels on his Realtraps site.

Once you figure out what you're doing with the doorways, where your equipment will be, what your equipment will be, where your seating will be, what you're doing with the floor - then I can give you a better idea of specifically what goes where in the room.

For starters, plan on absorbing basically the whole front wall and hitting the first reflection points on the side walls (assuming one of these is NOT right in the middle of an open doorway which I'll guarantee you it WILL be for at least one panel for at least 1-2 seats)

Welcome to the madness!

 

[Tom Andry]

More info

You confirmed my worst fears - those openings are going to suck the sound out of one side of my room. Now for your questions.

Once you figure out what you're doing with the doorways, where your equipment will be, what your equipment will be, where your seating will be, what you're doing with the floor - then I can give you a better idea of specifically what goes where in the room.

1) Doorways: Closing them off is really not an option. The location of this room (next to the front door) would seriously affect the resale value of the house. Plus, my wife is already dreaming of adding on a second floor which would contain a dedicated home theater (with doors and everything!) so any changes would have to be undone at that point. I’m already pushing the limits of our budget with the seating the equipment choices, I don’t see us spending more to add doors which we would just want to remove later to this room. I had planned on purchasing two, four fold room dividers and setting those up in those openings to help contain the sound. I thought that I could line one side of them with acoustical treatments if needed. Would this help or be a waste of money?

2) Equipment placement/Seating placement - I thought that I'd center the HT in front of the window (top of the diagram) with the seating (something like these ) about 3-4 feet from the opposite wall. I'll only be able to fit one unit (center reclining loveseat with a toed in recliner on each side) in the room. Kids will have to sit on the floor.

3) Equipment choices - Most likely will be a Denon 3805 (considering separates but probably can't afford them, may purchase a couple of monoblocs to run the fronts) paired with Axiom's M60ti's, VP150, QS8(4), and SVS 20-39PC+ (though I may consider the EP500). FYI - the reason I didn't include my equipment choices before is because I've seen too many of these posts turn into "Why didn't you consider brand X" discussions. I've been lurking on this site for over a year and have researched nearly every brand that has been advocated. I keep coming back to the Axioms and SVS.

4) Flooring - Still up in the air but my wife has agreed to let me make the decision so I can go with either. I would prefer to have hardwood but I'll do whatever will sound the best.

Lastly, you mentioned OC703. I looked at the realtraps site but couldn’t find any schematics (I’ll continue to look later). I did find (this ).

Thanks for your help so far.

 

[bpape]

Ah... A diffferent story now...

If this is a temporary space, then things change a bit.

The 4 panel dividers won't do a lot to keep bass in but they can certainly help with the imaging part.

If this is temporary, I'd leave the floor carpeted for now and then change to hardwood when you go to a dedicated space elsewhere. This will save you $$$ now on figuring out how to do the ceiling and then later on fixing all the holes to hang stuff! Sounds like a good compromise for everyone both now and later.

The only reason I was asking about equipment was for

1. Screen size
2. FP or RP
3. Sub capability to fill the larger apparent space due to the openings. When you have an open room like that you have to consider the whole volume of space that needs to be pressurized by the sub.
4. Potential location issues for surrounds

The screen size will determine to a point where the seating goes along the length axis of the listening area. Again, you have modal issues to deal with as well as the doorways but you gotta do what you gotta do. Just don't:

1. Put it halfway of the room length
2. Put it right against the back wall - leave at least a couple feet if possible - more is better.

The 703 you found is OK. Usually 1" is more widely used and then just spaced from the wall in some places if you need more absorbtion in the lower mids/high bass. The issue is really getting someone to sell it to you. It's a commercial product and a lot of people won't sell to an individual. Many of the places that will online charge exorbitant prices for shipping because UPS and FedEx consider a box (2'x4'x1') to be oversized even though it is light. I've seen shipping for a box be more than the cost of the box. Maybe you'll get lucky and someone in your local area will sell to you. Check insulation houses, HVAC places, etc. $0.50/sq. ft. for 1" 703 is a good price.

If you make the panels so they are hanging on french cleats, they'll be easy to remove and reuse in the new room when you move there. Just a few toggle bolt holes to spackle and paint.

Good luck.

 

[Ethan Winer]

MR,

> Treatment placement, type, and of course cost <

BP gave you great advice as usual. For your convenience, here's a direct link to my Acoustics FAQ he mentioned:

www.ethanwiner.com/acoustics.html

I'll also point out that with the length and width dimensions being so close to each other you should plan on a lot of bass trapping if you hope to get the low end tight and uniform. This too is covered in my FAQ.

--Ethan

 

[Tom Andry]

Mr. Winer,

Thanks for your response. I've read your article and feel very empowered to create my own panels. I'm thinking of wrapping the panels in fabric and forgoing the wooden frames for now. As you mentioned, looks like I need a lot of bass traps. I'm thinking I should build panels for all four corners and filling the back with bales (or partial bales) of rolled up fluffy fiberglass. I have a few questions (for any that wish to respond):

1) The faq indicated that leaving a couple of inches of air between the panel and the wall is desirable. I was wondering if it was better to mount a 4" piece flush to the wall or a 2" piece with a 2" gap, or would there be a difference?

2) Having only an eight foot high room (plus that crappy popcorn ceiling) is discouraging me from placing treatments on the ceiling. Will the corner traps and wall panels be enough? Is there something else I can/should do?

Lastly, the French cleats idea is awesome. I haven’t done that much woodworking but it looks like even I can do that. Thanks for the suggestions.

 

[bpape]

4" and 2" 2 inches off the wall will perform almost identically.

Don't make the assumption that ALL your absorbtion should be thicker or spaced. A lot of it will do just fine as 1" right on the wall.

One last thing, don't plan on wrapping the glass in fabric directly. To get it tight enough that it won't sag later, you'll crush the edges. They'll also start to just look like crap over time. GOM and 703 is too expensive and hard to get to have to do it over. Take the time and frame it up right. It's time well spent.