Speaker placement & other questions

[gsslug]

Maybe this forum is above me because I don't have a home theater but rather I'm building a home entertainment center. It will be in a great room. I have PSB B25 fronts, C60 center, and two CW80R rears to be mounted in the ceiling. The B25s, the C60, and the sub will all be inside enclosures built into the custom home entertainment cabinets which I'm still designing. So some questions.

1. I've read that the sound quality of bookshelf speakers placed in enclosures can be diminished by sound that reflects off the back and sides of the enclosure. Is this true and if so can something be done about it?

2. The fronts will be about 7' off the floor and about 12" from the walls. The walls are actually the 27" deep sidewalls of a niche built into one of the walls of the great room. Would it be acceptable/advisable to angle the fronts inward and down toward the listening position?

3. Above the ceiling is an attic. The ceiling speakers are not enclosed. I have blown in fine cellulose type insulation which I would like to keep away from the speakers. I don't think they would mix well. I thought about covering them with speaker cloth and piling the insulation, about 18", on top. Do speakers get hot enough for this to be a fire hazard? What effect would this have on the sound?

4. The sub is a down firing Boston P-800. It will go in the lower left hand cabinet which will not have a bottom and the sub will sit directly on the tile floor behind the cabinet door. This compartment will not have a front panel across the base and the opening will be covered with speaker cloth. Any problems with this arrangement?

I have attached a drawing. Any suggestions/advice/opinions would be appreciated.

[gsslug]

After posting the above thread I read the General No Nos. Seems like I'm violating all of them. My wife has decreed that no speaker shall be visible. I already have purchased the PSB speakers as part of a package deal with the new TV. While the TV had been thoroughly researched I hadn't started doing speaker research because I thought I still had two or three weeks before purchasing. Then the TV went out prompting an immediate purchase.

Hope someone can offer some helpful advice on how to make do with what I have.

[thxgoon]

First of all I would say that if there was any way that you could lower the left and right speakers in the entertainment center to close to ear level that would give you a huge performance increase. Do the speakers have to be on top? By putting them there not only are you listening to the speakers way off axis but you are introducing room modes induced by their proximity to the ceiling which will likely exaggerate the problems of being in the entertainment cabinet. Why not DVD's or a power center or cable box on top??? Also, to eliminate the resonances that will develope in that enclosed space, line it with some kind of acoustic dampening material. You can find panels from Aurelex from your local Guitar Center or do a google search for other solutions online. Good luck! If it's best performance you are after then position your gear for that as a first priority and adjust from there. Let us know!

[eugovector]

Ditto to all of the above. More to think about. Compressed fiberglass will be less expensive than acoustic foam and more effective. Make sure the speakers that you choose are front ported (which it looks like the b25s are) if they are going in that enclosure, and completely fill the cavity around them.

For the sub, are there other placement options if hidden under a coffee table or behind a couch? Look for other places the sub can be hidden away and try them all.

[gsslug]

eugovector wrote:

For the sub, are there other placement options if hidden under a coffee table or behind a couch? Look for other places the sub can be hidden away and try them all.

The wifes decree that no speaker shall be visible limits my options. The four small squares in the entertainment center in the drawing are my four sub placement options. Unfortunately I have to decide before the cabinets are built. I suppose I could place the sub at those locations and listen but I'm sure it will sound different when it is in the cabinet.

I did get my wife to agree to lower the fronts from the top to even with the center as shown in the second diagram. However that location is about 9" back from center speaker as the shelves on the left and right are recessed.

There is an area rug under the sectional and coffee table. Other than that all the floors are tile with no drapery or other soft surfaces other than the sectional and a leather chair to the right of the coffee table. I do have a cheap Radio Shack sound level meter, an audio setup DVD, and my Denon 3802 has some adjustments for room acoustics. In the end I'm just trying to get the best sound given the limitations of my placement options. I will pack the speaker enclosures as suggested. I appreciate the advice.

[thxgoon]

Looking good! Having all speakers in the same virticle plane is ideal For the sub placement try hooking things up temporarily if it's possible and see what location performs the best. My first hunch would be to put it in the square closest to the wall as that will load the room most efficiently but it may not give the flattest response.

[salvasol]

gsslug wrote:

2. The fronts will be about 7' off the floor and about 12" from the walls. The walls are actually the 27" deep sidewalls of a niche built into one of the walls of the great room. Would it be acceptable/advisable to angle the fronts inward and down toward the listening position?

...

Yes, I think is a good idea ...

Mine are placed at the same height .. what I did is to build a small base for L and R (center came with one) that is angled down to the listening position ...

If you're not satisfied with your sub inside the cabinet (because you can't feel the room or your seat shacking), you can consider adding a pair of buttkickers to your seats ... it will make a big difference ... believe me ...

Good Luck with your project ...

[JCD]

I'm sure I've missed some of the important parts of the thread, but I'm going to throw some ideas out there..

1) If you can, aim the tweeters at your ears at your sitting position. Ideally, this would horizontal, but it's above the listening position, if you can tilt the speakers a little, I think you get the best performance at your "sweet spot". Your off axis areas may suffer though..

2) I'll have to admit this idea may not work, but what about lining the cabinents with something like OC703? And depending on how much space you have, even doubling it up? I'm hoping our resident guru's can comment on this idea.

3) Move the speakers as close as possible to the edge of the cabinent as you can

4) get a new wife that'll allow proper set-up (just kidding of course) -- on the other hand, maybe you can get her a demo of speakers in the right spot as opposed to the confines of an entertainment unit. My wife was similarly anti-speakers, but after listening for a while, she's grown to accept them.

Good luck.

JCD

[kjgarrison]

I just joined HTS and found this thread. Hopefully it hasn't gone stale. I have a very similar "entertainment center" configuration to try to work with as gsslug. I have already garnered WAF to move the L&R fronts level with the center speaker (almost exactly on the same plane as our ears, and just below the display.)

My problem is with surrounds. I have one wall that a wall mounted surround could go on, but it would be higher up above the windows, not in the same horizontal plane as the fronts, probably 5' higher. To make things worse, the room is an "L" shaped room, and the opposite wall for a surround has the additional issue of being 20' farther away. Consequently, I was thinking about going with in-ceiling speakers for the surrounds.

Nobody said anything about gsslug having the surrounds in the ceiling. From the standpoint of acoustic performance, how big of a deal is it to have the surrounds almost at a 90 degree angle to the mains? (Mains "aiming" across the room, horizontally. Surrounds aiming down into the room, vertically.)

In my case if I go with a 7.1 system, the two rearmost surround speakers can be at the same height as the 3 mains. It's just the two side surrounds that are my problem (or surrounds if 5.1.)

[eugovector]

kjgarrison wrote:

My problem is with surrounds. I have one wall that a wall mounted surround could go on, but it would be higher up above the windows, not in the same horizontal plane as the fronts, probably 5' higher. To make things worse, the room is an "L" shaped room, and the opposite wall for a surround has the additional issue of being 20' farther away. Consequently, I was thinking about going with in-ceiling speakers for the surrounds.

Nobody said anything about gsslug having the surrounds in the ceiling. From the standpoint of acoustic performance, how big of a deal is it to have the surrounds almost at a 90 degree angle to the mains? (Mains "aiming" across the room, horizontally. Surrounds aiming down into the room, vertically.)

In my case if I go with a 7.1 system, the two rearmost surround speakers can be at the same height as the 3 mains. It's just the two side surrounds that are my problem (or surrounds if 5.1.)

You actually don't want you surrounds at the same height as your fronts. Rule of thumb tends to be 3 feet above earlevel while seated, +/- 12". Ceiling speakers aren't ideal, but aren't a bad idea, given your setup.

Any floorplan sketches or pictures? Those are always helpful.

[salvasol]

... It's just the two side surrounds that are my problem (or surrounds if 5.1.)

Welcome to the forum

It will be a good idea to post the brand and model of your speakers ... some can be wall/ceiling mounted with backets

[kjgarrison]

eugovector wrote:

You actually don't want you surrounds at the same height as your fronts. Rule of thumb tends to be 3 feet above earlevel while seated, +/- 12". Ceiling speakers aren't ideal, but aren't a bad idea, given your setup.

Any floorplan sketches or pictures? Those are always helpful.

Sorry not to respond for so long. I "subscribed" to this thread but for some reason never got the email notifications. Thanks for the info re: ceiling placement. Should I try to get ceiling speakers that "aim"?

I can try a floorplan sketch. What is a good tool for that?

salvasol wrote:

Welcome to the forum

It will be a good idea to post the brand and model of your speakers ... some can be wall/ceiling mounted with backets

Thank you for the welcome!

I don't have speakers yet. This is still the early planning stage. If it is totally worthless to have speakers deployed in this fashion, then I'm just going to stick with the cheapo speakers that come with the TV.

[eugovector]

kjgarrison wrote:

Sorry not to respond for so long. I "subscribed" to this thread but for some reason never got the email notifications. Thanks for the info re: ceiling placement. Should I try to get ceiling speakers that "aim"?

I can try a floorplan sketch. What is a good tool for that?



Thank you for the welcome!

I don't have speakers yet. This is still the early planning stage. If it is totally worthless to have speakers deployed in this fashion, then I'm just going to stick with the cheapo speakers that come with the TV.

I definitely wouldn't stick with your TV speakers, just about any outboard sound should outperform those.

Directional ceiling speakers would be an improvement, but not a huge one. I wouldn't fret about it too much.

For a floor sketch, MS paint would work fine, though I really like Room Arranger for a semi professional look. Or draw it on paper and scan it.

[JCD]

Another program you can try is Google Sketchup.. I've seen some amazing 3D mockups from people using that program.

JCD

[kjgarrison]

Thank You!