In-ceiling mounted acoustics

milano

I'm new to this home theater stuff, so why is it that I can just cut holes in my ceiling and mount speakers without an enclosure or other sort of baffling behind them?

Larry Chanin

Hi milano,

The better in-wall and in-ceiling speakers do have enclosures isolated from the wall structure (sometimes also called "back boxes") and specifically tuned for the speaker. Speakers that rely on the wall stud bay for enclosures are not likely to perform as well and may even generate unwanted rattles as the wall vibrates.

Larry

milano

Larry,
Thanks for your response. I still don't get it. The supposedly better quality in-ceiling/in-wall units that I'm seeing, such as Polk LC80i and LC60i, don't have enclosures. What gives? And, if they haven't circumvented the laws of physics, then should I give up on in-ceiling/wall speakers and just go with externally mounted and/or free-standing speakers?

dorokusai

Milano,

You have to realize that a speaker of this type is completely dependent on how and where it is mounted or installed.

The biggest variable, which is always a variable, is the area behind the speaker. An enclosure or free-standing speaker doesn't have this problem due to it's already mounted in the properly tuned enclosure. A speaker mounted in a wall or ceiling has a number of factors working against it to be able to perform as it was designed. Stud channel width and length, resonances from the type of mounting surface, insulation or lack therof...etc. While the problems aren't infinite, they need to be considered.

Polk offers a performance enclosure for the larger models, but this is more of a pre-construction alternative. Larry went forward and did this as an aftermarket installation, that seems to have tunred out pretty well.

I think that a properly set up, or at least somewhat set-up speaker of this type can sound really good. To sound amazing, you are going to need a higher investment.

Sonance, www.sonance.com and Wood Technology, www.crutchfield.com ...make products that can be installed behind the speaker to help with standing waves and performance. One may work better than the other, and one opinion as to install them or not will also vary. I believe it neccesary to implement some kind of resonance and standing wave control. It only took an A/B comparison for me to hear a difference, but choose your own course of action.

Either way they are fairly inexpensive, and should be the very least you do. You can also fill the channel with poly-fill or similar speaker building material found at www.partsexpress.com

What speaker you choose is your choice, but one requires more effort than the other.

Larry Chanin

Originally posted by milano
Larry,
Thanks for your response. I still don't get it. The supposedly better quality in-ceiling/in-wall units that I'm seeing, such as Polk LC80i and LC60i, don't have enclosures. What gives? And, if they haven't circumvented the laws of physics, then should I give up on in-ceiling/wall speakers and just go with externally mounted and/or free-standing speakers?

Hi milano,

Mark described this probably better than I could. It's not an "all or nothing" proposition, nor are we circumventing the laws of physics. For the reasons he discussed, in general Free Standing or On-Wall speakers of equal quality will perform better than In-Walls. Likewise In-Walls with custom-designed enclosures are going to perform better than those without them. The LC80i and LC60is are fine speakers. The LC85i and LC265i with enclosures are better speakers.

To answer your question about "giving up on ceiling/wall speakers," if you don't need In-Wall or Ceiling mounted speakers, then it would be better to use Free Standing or On-Wall speakers. However, obviously other factors beyond performance come into play when selecting speakers. In my own case I'm building a home theater. Originally I planned on putting up On-Wall speakers for my surround back speakers. Then at the last moment I realized that since I was concealing all my other speakers, from an asthetics point of view, it simply didn't make sense to have the surround back speakers showing. So to balance the concern for looks versus performance, I bought the best In-Wall speakers that my budget would accommodate. That happened to be Polk Audio's top-of-the-line In-Walls with enclosures. But I sure wish I had thought about this BEFORE I waited for the sheetrock to go up. :rolleyes:

Good luck with your decision.

Larry

milano

Thanks guys. Mark, (Dorokusai) I will be checking out Sonance, Wood Technology, and PartsExpress for help in properly enclosing my in-ceiling/wall speakers. Larry, I wish you all the best in getting your system just like you want it. Just keep telling yourself, "the sheetrock saw is my friend!"
Thanks again to both of you, and I'll check in later with my results.
Milano