TVreplay HT

**TVReplay** · **10-21-09, 05:32 PM**

Well here we go. In a few weeks I will be starting on my basement which will include a HT and I am looking for some guidance/support/kick in the head in a few areas. I will give you info on the room first and questions second.

The room
A blank slate only framed from a previous owner but I am willing to move walls.
17' Wide 23' Long and 8'9" ceilings
No windows
Concrete floor will be carpeted and thick pad
Drywall will be used walls and ceiling
Sound issues are minimal only to bedroom above which is mine. Two sides go to storage, one is exterior wall and the entry wall will be full heavy curtains floor to ceiling and wall to wall.

Projector
Ceiling mounted Panasonic 3000
Future build of an anamorphic lens

Screen
Want between 100"-120"
DIY Open to suggestions
Trying to decide between a 16x9 with masking for 2:35 or a 2:35 with masking for 16x9.
Eventually want to get a electric screen that drops to cover a flat screen that will be on the wall.

Seating
Couch initially then upgrade later to better seating
Single Row

Speakers
5.2 System
Klipsch RF-63, RC-64, RS-52, 2x RW-10d
Fronts and center will be built in wall (I know this is a no-no but the wife has her say) in alcove behind framed speaker cloth like the Tanner Ridge Build but flat wall all the way across.
The 2 subs will be in the room (I did win that battle)
Surrounds hang on wall

Receiver
Eventually able to feed the Projector and a future flat screen, Multizone Video (If there is a cheaper way tell me Please)
Still kicking around which single unit, leaning toward Denon 4310CI or Emotiva when it becomes available.

Soundproofing
Ceiling-Insulation in the joists and Green Glue between two layers of drywall
In Wall-Nothing as there is no adjoining rooms other than storage
In Room-DIY sound absorption on walls

Questions
1 I will have 2 HVAC supply vents and 1 return. I saw in others use flex vent, how important is this? The return uses a wall cavity, how do I sound proof this?

2 When I build the box that the speakers go in is it better to build a smaller box with some sound absorption or a bigger box more?

3 With only one row of seating how high should the screen be off the floor?

4 What am I missing?

I have many more specific questions but will post them in the appropriate areas.

I will post a picture when I figure out how.

Thanks to all that have posted their build threads, I have learned so much from this forum and now believe that I can actually do this.

**bpape** · **10-21-09, 05:41 PM**

Sounds like a nice project and a nice large space.

You really need to fill the walls with insulation. They'll ring like a drum if you don't. Also, no need to do GG and double drywall on the ceiling if you're not doing the walls too. Sound will flank through the walls and up in the gap between the walls and upstairs.

1. Don't use anything but flex. Tin will ring and resonate like mad. If the return is in the wall, it's a huge sound hole. Think about moving it.

2. Box for speakers? PLEASE don't do that. You'd be better of to build a false wall with just studs and cloth to keep them hidden and not kill their performance. Subs can go back there too as well as treatments.

3. General rule of thumb is seated eye level at approx 1/3 up the screen.

Bryan

**TVReplay** · **10-21-09, 06:36 PM**

bpape

Quote:

bpape wrote:

1. Don't use anything but flex. Tin will ring and resonate like mad. If the return is in the wall, it's a huge sound hole. Think about moving it.
Bryan

I will do that for the supplies and the return.
Do I use the same size for both as I have two supplies and only a single return? I could add another but would have to do some reworking of the storage area that is on that side of the wall.

Quote:

bpape wrote:

2. Box for speakers? PLEASE don't do that. You'd be better of to build a false wall with just studs and cloth to keep them hidden and not kill their performance. Subs can go back there too as well as treatments.
Bryan

Can you explain why this is such a bad thing?
I don't quite understand if the speaker is as close to the speaker cloth in front how the "box" behind affects the sound in front. I'm not against building a false wall but haven't considered it.
If I did could I finish the room with walls and carpet and then build the false wall inside of that so if needed I could take it down with out having to redo that entire part of the room? The reason is I'm trying to keep a future home sale in mind.

I tried 3 times to upload a diagram of the planned room but Safari keep failing when I chose the file.
Thanks and I just realized we live close.

**TVReplay** · **10-21-09, 06:47 PM**

Just got it to work

**bpape** · **10-21-09, 06:47 PM**

In general, in a high BTU situation like a home theater (lots of equipment, PJ, many people, etc.) we recommend 2x the return that there is supply.

You can build the false wall after the room is drywalled (and should) so pretty easy to take down.

Building speakers in a wall that are not designed for that will not sound anything like what they're designed to sound like. Part of a good crossover is compensating for the width of the baffle and how far the woofer is from the edge as well as the tweeter. When you build them into the wall, you're effectively making the baffle size the entire wall so the xover compensation is completely wrong, bass response is different, etc.

Building a skeleton wall with just cloth does not increase that baffle effective area, still allows for good imaging depth, etc.

Bryan

**Prof.** · **10-21-09, 07:43 PM**

Quote:

TVReplay wrote:

Trying to decide between a 16x9 with masking for 2:35 or a 2:35 with masking for 16x9.
Eventually want to get a electric screen that drops to cover a flat screen that will be on the wall.

I would go for the 2.35:1 screen, particularly if you're planning on adding an anamorphic lens..
The Pana.3000 with it's auto aspect ratio change will work well on a 2.35 screen in the meantime..

Quote:

With only one row of seating how high should the screen be off the floor?

This will depend on whether you use a 16:9 or 2.35:1 screen..
With the latter, you will need it to be no more than 24" off the floor (mine is 22") to get that immersive feeling..

Also, you can sit a bit closer than you're showing for that size screen with a 1080p projector..
I would suggest a max. of 10'..which would then give you enough room for a second row..

**salvasol** · **10-21-09, 08:39 PM**

Good Luck with your project....

Quote:

Fronts and center will be built in wall (I know this is a no-no but the wife has her say) in alcove behind framed speaker cloth like the Tanner Ridge Build but flat wall all the way across.
The 2 subs will be in the room (I did win that battle)
Surrounds hang on wall

I completelly agree with Bryan, build a flase wall (I'm sure that there's one in Tanner Ridge Cinema); it will look awesome and the speakers will be hiden or if you want you can build the wall around them .....I know that it will be more work, but if you can build some columns to hide the other speakers your room will look cleaner

Quote:

In Wall-Nothing as there is no adjoining rooms other than storage
In Room-DIY sound absorption on walls

I also agree with Bryan, I used a bonus room as HT, all walls didn't have any insulation.... so you can hear everything in the adjacent room....if you can, use insulation to fill the cavities, you won't be sorry.

Also, remember that you need to cover the whole front wall with insulation to kill all reflections.

**MatrixDweller** · **10-21-09, 11:43 PM**

It looks like you'll be about 14' back from your screen. Using this calculator it looks like 125" would be ideal (give or a take a few inches).

Is that a concrete wall on the one side? You most likely would want to insulate that wall. Not just to stop resonance or sound echoing off it, but for thermal reasons. Everyone else is right about the other walls. One of the best parts about soundproofing your HT isn't to keep the sound in the room, it's to keep outside sound from getting in. I can tell you that adds a lot to the experience, especially in suspenseful movies.

**Ted White** · **10-22-09, 02:15 PM**

Back to the questions about the ventilation in the wall: This will certainly cause problems. You have to attenuate the energy in a duct before releasing it into your walls and ceiling.

There is a general misconception that bringing flex duct to a jobsite removes all risk. Absolutely not the case. Send me a PM if you'd like expanded articles on this topic.

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