If it were your room...

[Youthman]

We met again with the builder to go over the floor plan for our custom house that we will begin building in May. I need your help. Take a look at the attached floorplan. The top left is where the HT will be. I REALLY want to have rear access to the A/V rack but am unsure where to place it. I know that I do not want it in the front of the room due to the lights being distracting. That leaves the side or back wall. Would it be best to add a partial wall in the back of the room with a curtain leading into a narrow hallway type area to have rear access? I would prefer to have the A/V rack flush mounted.

What about the dimensions 15' wide x 25' long x 10' high. Any problems there?

Not sure if I will have theater chairs or a sectional type furniture so the layout of furniture might change.

I value all of the wisdom from this forum. What would you do if it were your room to design?

Speakers will be RF-83's, RC-64, RB-61's. Not set on receiver, amps, projector, screen yet. Working on one piece at a time.

Stevens Main Floor Plan 4th Revision.pdf

[Youthman]

Here is the room layout (subject to change).

[mas]

A couple of thoughts.

1.) The dimensions : all exact multiples of one another - Coincident room modes. At the risk of being a smart aleck, you won't have trouble identifying them!

2.) If you want rear access to equipment, place the rack in a closet with dual access from another room as well.

3.) In your picture, I would not want to be sitting in the seats on the rear wall for a numberof reasons. You need to be cognizant of the side/rear surround speaker placement relative to the seating.

[Youthman]

Thanks for the input Mas. I had contacted a local A/V Specialist and I sent him our floorplan and when he plugged the dimensions of the HT into his software, he said those dimensions would work out great. LOL. What's up with that? Why wouldn't they know about the dimensions being multiples of each other. I value your opinion so if it were you, what dimentions would you setup the room to be?

I agree with the back row. I told him I was looking at 6 seats. He thought I could fit a few more than that but I would hate to have the rear seats that far back. As stated, the furniture is likely to change. Haven't decided whether to have 6 theater chairs or maybe some form of sectional so that it can serve as a sitting area, meeting room or theater room.

I thought about the rack extending into another room. It cannot extend into the bathroom so that only leaves extending into the top left bedroom. Would have to move the closet to the top wall in order to make that happen. Thx for the suggestion.

[oldtimer]

Is it possible as in will you pay for it to put in false walls so that the actual sound chamber is more theater/concert hall-like? Or would this be unnecessary mas? What i mean is why go with a rectangle if you can build it any way you want?

[Youthman]

What i mean is why go with a rectangle if you can build it any way you want?

I'm just going by what most HT's look like. They are usually rectangular in shape. I'm open for suggestions.

[mas]

A/V specialist????? Nope

Theater seating saleperson maybe...I would hope that he does something to earn his money!

He hasn't a clue. And I AM beoing polite. I seriously suggest finding another, as if he doesn't understand such a fundamental and simple concept, he has no business being in business. But then, don't expect too many of the shops to have a clue. The onus is on you to do your due diligence; and I would NOT rely on a shop to magically do all of the work for you. You have just received a very fortuitously cheap lesson!

Regarding the perfect dimensions, there aren't any.

What there are are optimal relationships between the 3space dimensions.

Attached you will find an image of one of the myriad room mode calculators available. While there is nothing spoecial about it, it does display some of the ratios that distribute the modes to the greatest degree, thus avoiding the superposition of mode frequencies and the summing of mode, thus making them more difficult to treat. But even if you achieve an ideal ratio, you will STILL have room modes that need to be treated, so don't get too obsessed with achieving an ideal ratio. But you would be VERY wise to avoid room dimensions that are even multiples or which have common denominators of one another.

[mas]

Is it possible as in will you pay for it to put in false walls so that the actual sound chamber is more theater/concert hall-like? Or would this be unnecessary mas? What i mean is why go with a rectangle if you can build it any way you want?

If you have the option, splaying the sidewalls outwards from front to back ~6 degrees each, and splaying the ceiling upwards from front to back ~12 degrees will solve much of the room mode issue as well as redirect early reflections away from the 'sweet spot'. And while not eliminating surface treatment o some absorption and diffusion, it will definitely be an asset.

Room partitions have a very nasty problem...the create mutliple tuned spaces with various resonant modes that sum. These tuned spaces will not be your friend. And in order to address the results, you will have to have the room measured an the results will be complex. Unless you are comfortable with such a process, I would avoid them like the plague. On the other hand, it is a good reason to invest in RPlusD and start learning about room measurements - it WILL easily pay for itself many times over in savings and resultant quality (the total cost is about $350 in addition to a mic, audio I/O and your computer).

[oldtimer]

OK to get my definitions straight, the space between the inner room ( and i envision a separate room within) and the outer room walls that one would see from outside the room will create mulitiple tuned spaces? Is this true if you use state of the art soundproofing construction techniques?

[mas]

Building a room within a room will afford little benefit for a home theater in any respect. It provides NO positive impact on internal room response and relative to the added cost, it is using a sledgehammer to solve sound transmission issues if such extremes are not absolutely required.

If they are worried about sound transmission into adjacent spaces, more prudent construction techniques that cost MUCH less are in order.

[oldtimer]

Great! So the idea is to splay the inner walls of the ht while using good anti-sound transmission construction techniques.

[mas]

Depending upon the use, the nature of the family, etc., you may not need to deal with sound transmission at all.

Splaying the walls addresses room mode issues, minimizing but not eliminating them. And this only addresses low frequency boominess.

You still need to address the specular reflections and their arrival times, levels and diffusion via treatment.

Also, in dealing with transmission, in addition to walls, various flanking pathes such as air gaps, doorways, ductwork, and AC outlets will be of even greater importance. Think of sound like water in the case of transmission issues and that you are in a boat, where leaks result in the boat sinking. If air can get in or out, so does sound, and it negates the benefit of perfect walls.

[oldtimer]

Thanks mas, i will need to deal with transmission issues because my wife hates it when I crank it up when she is there (in the house). So acoustic treatment plus anti-sound transmission will be what i'm after, as much as possible. That and locating the ht to the least frequented part of the house should do the trick.

[mas]

I didn't realize that you were talking about your needs as well...sorry!

When you need it, give me a holler and I can provide diagrams of the most effective wall (etc.) construction techniques for transmission issues - and you don't need the 'magic' treatments so often pushed on the web. []

[Youthman]

I'll talk to the builder about splaying the walls. I have heard of that before. Wouldn't that make the back side of the house "crooked" or at an angle since the walls will not be parallel to the rest of the house?

I mentioned to the builder I wanted to do staggered studs but that's all that we talked about so far so any ideas or documentation on isolation is more than welcome. I know my wife does not want to hear the theater room when she is trying to sleep. I told her that probably would not be possible. []

[DrWho]

It would probably be cheaper to make the room a bit wider so that the exterior of the house is square, and then you can have the drywall slant inside the room (so basically making the room smaller in the front). The other advantage of this approach is that you end up with some dead space in the front corners of the room which can be used to all sorts of good effect - whether it be insane subwoofage or flush mounted mains, etc... It's also a good way to hide acoustical treatment too.

[oldtimer]

Yeah I thought it went without saying that the exterior makes no difference. You are merely using the interior walls for effect. In my case I was thinking of a timber frame, which gives you relatively limitless possibilities for interior room construction.