Also, how far away do the sofas go? :)

November 27, 2008 3:18 PM

Blank slate "home" theater setup needs audio advice. Details of space and existing gear inside. Help!

Since everyone I work with seems to be a movie buff, we're recovering some underused storage space in a studio/office by turning it into an as-needed screening room of sorts. We're drowning in capable video minds, due to the nature of the work, but nobody's confident about audio switch and speaker requirements or the right way to do placement of the five (six? eight?) speakers required for good "home" theater audio. Since tomorrow is cheap-electronics day, this seems a good time to buy a present for ourselves. :)

The room is a pretty blank slate: it's a big one, 25 x 25 feet square with high, raftered ceilings that look about 18 feet off the ground to me. Walls are easy to get behind for cable runs as needed, and there's even crawlspace under the floor, so cables will be easy to hide no matter how long.

Existing gear: the screen will be a plasma, probably the 54" Toshiba that's currently hanging behind the reception desk (we'll replace that later, it's underused). It'll be connected to (at minimum) a PS3, an XBox 360, and a Mac Mini or Mac Pro (salvage from someone's desk, they get an upgrade). Other than occasional Blu-Ray on the PS3, we'll use the Mac and Front Row (or XBMC) for movies, mainly from a server full of ripped DVDs we already have.

But how to do audio to handle all of these things reasonably well? The screen has an SVGA input (for the Mac) and two HDMI's (for the games) which is all lovely so I think video is covered already, but I need to get my head around the audio side: What kind of audio switcher/decoder box do we need here, and what type/number/location of speakers to provide a reasonably good movie experience while also being good for big-screen videogaming? (Note: digital cable / television is not a factor. No TV, no need, no thanks.)

Ideally: one switchbox/remote would be better for both A and V, but we can live with "change the screen input with existing remote, change the audio to match with this new remote" too.

Ideally, most/all speakers would be hidden (wall mounted?) or otherwise discreet -- we'd like to avoid "speaker standing in middle of room at precise angle" so that the floorspace of the room remains pretty wide-open for times we need the room for other functions, like when we need to throw together ad-hoc cubicles to gear up for a big short-term project (we've used the room this way before, other times it sits empty.)

Wireless is not necessary since we can hide long runs of cable under the floor or behind the easy-access wall panels. I also don't trust wireless AV stuff much, myself.

What do we need to buy, here, and where do we put it?

posted by rokusan to technology (4 answers total)

This is a hard question to answer because there are so many variables involved. Speaker manufacturers generally have a recommended setup configuration, but it varies from speaker to speaker. It also depends a great deal on the room--it size, shape, and even what the wall material. Carpeting vs tile floors can make a big difference for example.

A 25' x 25' room with 18' ceiling is pretty big. You'll need a fairly beefy amp to fill that space. The number of speakers depends on the amp you get. You usually see numbers like 5.1 or 7.1 surround. 5.1 surround would mean two speakers on either side of the TV, a center speaker above or beneath the TV, two speakers behind the listening position, and a subwoofer (the .1) in one of the corners.

I have more experience with stereo than surround sound. With stereo sound, you generally want to start by positioning the speakers six to eight feet apart from each other, and the listening position centered about eight feet from the front of the speakers--so the front speakers and the listener roughly form an equilateral triangle. The speakers should be positioned something like one or two feet from the back wall. Distance from the wall is especially important for rear-firing speakers (the hole in the cabinet) because it has a huge impact on bass.

Also, free standing speakers will tend to sound much better than in-wall or wall mounted speakers. You should consider at least having your fronts out in the room.

Googling for "surround speaker placement" should give you lots of info. Also, avsforum.com is a good resource for this kind of stuff. A few minutes of research should give you an idea of a reasonable default setup. Then, it's just a matter of having one person make slight adjustments to the speaker positions while the other person listens.
posted by paulg at 6:48 PM on November 27, 2008

To start with, a good receiver with enough digital audio inputs for all the devices should be sufficient. An outboard amp would certainly help with sound quality, but probably isn't necessary if you're using smallish speakers.
For receivers, I like Pioneer Elite, Denon, Yamaha really well. They're each fairly easy to use.

As for speakers, there are several companies building in-wall and in-ceiling models, but more traditional stand-mounted or floor-standing speakers may perform better. Probably one of the biggest advantages to these types of speakers is placement. They allow you to properly position the speakers for optimal acoustics. On the other hand, in-wall speakers don't get in the way. Also, many of the nicer receivers have an automatic calibration system that can adjust for room/speaker acoustics to get the most out of the components and space.
For that size of room, I'd probably try to go 7.1 for the speaker system. That's Left-Center-Right up front, Left-Right surround, and Left-Right rear. I also strongly recommend getting a subwoofer since most smaller and in-wall/ceiling speakers will not be capable of reproducing frequencies below 70-80hz. Even though it'll sit out in the room you can put it in a corner which will actually increase its volume by a few db.
posted by nickthetourist at 8:43 PM on November 27, 2008

This JBL guide has some good information on home theater sound, and some plugs for their products. In a room this large, I'd consider small commercial box-type speakers, such as the JBL Control stuff, mounted on the walls using brackets.
posted by Monday, stony Monday at 9:39 PM on November 27, 2008

If you are using the system primarily for movies and games, I'd actually go with one of the high watt theatre-in-a-box systems like the Onkyo HT-S990THX 7.1. Although lacking a abit in absolute performance, similar systems are probably the best compromise in terms of biggest bang for the buck without going through the hassle of matching different components that work well together. These are already matched, and you can upgrade piece by piece if need be.

Otherwise, you can get downright ludicrous with the amount of money you can throw at this ("and when you die, they can bury you in it!"), and I'd really suggest buying used at that point.

And as mentioned by others, speaker placement is probably worth more than some incremental gain in specifications. There are various test CDs to assist with speaker placement, and even software so you can get a better idea of what changes can be made that will have the greatest impact.

Finally, I'd let your ears be the final guide in how much you spend where. The difference between a $500 receiver and a $300 receiver is slight in most instances, and if you can hear no difference, why bother?
posted by quintessencesluglord at 12:22 AM on November 28, 2008