New Home Construction - How big should the A/V room be?

[bpape]

The angled surfaces are a totally different thing in a studio. I'd avoid them if at all possible - it takes away easy places to deal with all dimensions acoustically. Also, do be of benefit, the amount of angle would cause you to lose a tremendous amount of space in the room which you frankly just don't have.

As for the circle, you have to extend out the angled lines to your situation - don't worry about the radius per se.

Bryan

[AverageJoe]

owlfan12000 wrote:

I am curious about the lighting/projector issue - did you need to place it so far back because of some projector constraint or was it just the fact that you wanted the equipment room back there?

It was mostly for looks. I preferred not to have the projector hanging from the ceiling so I tested how far back I could go without giving up too much picture quality, and selected that distance for the equipment room wall (I did hedge my bets a little and ran a conduit to a ceiling location just in case). All the source electronics and the DVD shelves will be in the back room - again, just for looks.

By the way, good decision in choosing acoustic treatments over room size if that was the trade-off. It was a good catch by Bryan regarding the isolation problems with in-wall treatments. I forgot all about that. In my case, I built the walls out to cover the short concrete stem walls, so I had a lot of room to play with above them. I'll still do other rteatments and bass traps, though.

[owlfan12000]

I've seen a couple of references to acoustically transparent screens. Are those significantly cheaper or more expensive than other screens? I've seen theaters built with space behind the screen before but I never realized this was for the speakers. Are there audio advantages or disadvantages to this setup?

I've been trying to figure out where to run wires in the room. I think I can figure out where the speakers would go. I assume that, given my narrow room the back center would be the best location for the equipment rack (saving the corners for potential bass traps). I'm not sure how to accurately place the projector without putting it up and seeing how it looks. I know it will depend on the projector itself, my desired screen size and the screen brightness. I recently read a review on the Optoma HD80 that was pretty impressive. Does anyone have any experience with this projection calculator from Projection Central? http://www.projectorcentral.com/Opto...ulator-pro.htm

I like it because it lets me see how the different components affect each other. It says that the results are based on numbers provided by projector manufacturer so I have no idea if it is accurate.

I'm also wondering if there is some way to sound insulate the projector without causing overheating problems because some of the placements that I come up with are right over the viewing area.

What are the acoustical costs of ceiling mounting some of the speakers? My sister has a new baby on the way so ceiling mounting would have an additional childproofing benefit.

[John Simpson]

Whew, that's a lot of questions, Owl

Regarding the AT screens, certainly they're more expensive. From my research, most are plasticised fabric perforated with little holes: this reduces the gain a little on the screen, but allows most sound to travel through (apparently there is a slight treble attenuation -- not a bad thing probably, as most movie soundtracks are a bit bright).

One brand -- Screen Research -- says they have a special woven screen that hardly loses any brightness, but can still allow the sound to pass through. They also cost a huge amount compared to regular screens. Incidentally, one of their fixed screen range is *curved* to suit the projector's throw... very snazzy indeed.

Regarding projector placement, I intend on building an alcove in a drop-ceiling bulkhead, which should isolate the project from the audience a little without reducing airflow. You should certainly NOT put insulating materials directly around the projector, or you'll be buying new bulbs each month as they burn out (or a new house after it catches fire!). The reason projectors are noisy is the fan keeping them cool.

Finally, ceiling monted speakers are getting better all the time, but a lot of HT purists think they place the soundstage a little too high. Nevertheless, it's again a case of "you get what you pay for"... better quality ceiling speakers will usually perform better than cheaper wall-mounted speakers.

[SierraMikeBravo]

John,

I would avoid the in celing approach. Remember, the higher frequencies above 500 Hz are more linear than lower frequencies which are spherical. So, your speakers, being aimed down, would fire the higher frequecies right at the ground. This would limit the spacious surround envelopment. Plus, you would not get the reflections off the surrounding walls which add to the spacious environment. You want to be able to have some flexibility with your LCR to help alleviate SBIR (speaker boundary interference reflections). I would reduce the size of the screen to say around 100" maximum. At the distance you have your front seats placed at, 100" should be more than enough to project an optimum field of view. If you can't widen your room, I highly suggest you eliminate two seats. With the distance from the side walls you have specified, you are likely to end up with a "exit door" effect at those outlying seats. Basically, the center front is your money seat and the only seat that is relatively optimum in your room with your current design. In addition, subwoofer placement will be limited since much of the side aspect of your theater is taken up by seating. Also keep in mind that placing seats side by side is not usally the best way to go either since you have room modes along the width of your room as well. Remember, I am only a few short hours way!

[John Simpson]

Shawn, there's actually a few ceiling speakers now that have movable centre tweeters (I think one of the brands -- Boston Acoustics? -- protrudes quite a distance downwards to point both the tweeter and mid-range forward).

Not really my cup of tea, but sometimes best for the situation at hand.

[SierraMikeBravo]

Yes, I remember hearing about them, but can't attest to the sound quality since I have not listened to them. Strictly speaking though, unless you get the tweeter to go 90 degrees without interference from the speaker itslef, some of that sound would bounce off the wall and into the floor. You would lose some SPL that way. Plus, the sensitivity isn't all that great either for the BA (89 dB). Like you said, it is an option, but one I would not lean to with other options available. Thanks for the information though!

[owlfan12000]

OK, I'll ditch the ceiling mount for the front speakers at least.

Just to be sure we're on the same page, when I refer to a ceiling mount I was thinking of using the SVS SBS-01 system and using the ceiling mounts that they show at this link. http://www.svsound.com/products-parts-bracket.cfm

I thought about the wall mounts but I didn't think I should be putting the speakers that close to the walls and I thought they might increase the noise transmission to other rooms. I'll only have one story so I'm not too worried about sound transfer through the attic.

What about mounting the rear surrounds on the ceiling with the mounts from SVS? Then I don't have them in my limited side aisle space.

How much space would I need to for reasonable audio performance? I'm still thinking of eliminating the middle armrests and having a couch with two cupholders. With that configuration and the Berkline 088s I would have 32" aisles instead of 18" aisles.

[SierraMikeBravo]

Owl,

Ohhh, I though you were taling about in ceiling speakers. Well, the SVS would be a better option, but it all depends on what you and your room can and will accept. If you don't have the room, then you don't...so go with what works best for you. I would eliminate the couch idea, go with two rows of berklines or whatever you want to use for chairs, and move them closer in to each other. There will be some seperation between the two chairs and that's where the width null should be. Sitting in the center will cause you to sit in the width null. Having only two rows will get the seats moved farther away from the side walls.

[salvasol]

...Just to be sure we're on the same page, when I refer to a ceiling mount I was thinking of using the SVS SBS-01 system and using the ceiling mounts that they show at this link. http://www.svsound.com/products-parts-bracket.cfm

If I were you, I look in the internet for more bracket options ... $75.00 for a pair seems to expensive for me ... there are some that are cheaper ... but I don't know about the quality. I got the Infinity TSS 750 system and the brackets were included.

I thought about the wall mounts but I didn't think I should be putting the speakers that close to the walls and I thought they might increase the noise transmission to other rooms. I'll only have one story so I'm not too worried about sound transfer through the attic.

My speakers are wall mounted, and I don't notice a lot of noise transmission ... except for the bass from subwoofers.

What about mounting the rear surrounds on the ceiling with the mounts from SVS? Then I don't have them in my limited side aisle space.How much space would I need to for reasonable audio performance? I'm still thinking of eliminating the middle armrests and having a couch with two cupholders. With that configuration and the Berkline 088s I would have 32" aisles instead of 18" aisles.

Here is a picture of my sorround speakers installation ....

[Fred33]

Nice pics of the insulation. Seating is a very important decision. It really affects everything.