In-wall or in-ceiling -- what's the difference?

[mstone]

I am doing a major remodel/rebuild and would like to use in-wall/ceiling speakers throughout the house. My question is: are in-wall and in-ceiling speakers interchangable? They look very different, but is there a problem with mounting, for intance, a rectangular RCW-5 in the ceiling? Do in-walls with separate horns sound better than the round RCR-5? Do they project sound differently? If I can fit either of them into the ceiling just as easily (very deep joists in a large volume ceiling), is there a preference?

Sorry for the newbie question. As a bonus question: I am installing a four sets throughout the house, hooked up to a central source. I would like to have volume controls in each room. I assume I will need a separate booster amp for each pair. Is this wired in before the volume switch or after? The whole house is opened up right now, so I have a lot of latitude over the next few weeks as ar as how things are wired.

Thanks for any help, and sorry if the question is silly.

[Guest IVstringer]

As the general trend goes, an in-ceiling speaker has the circular footprint, while in-wall speakers tend to have a rectangular footprint. Given their small and circular footprint, in-ceiling will almost always use a concentric tweeter/woofer combo. Generally, these have completely symmetric polar response and coverage patters because the horns (if applied) are usually circular. In-wall speakers generally are not concentric and have more of a "traditional" tweeter-above-woofer layout as in most freestanding loudspeakers. Generally, the horn geometry is more "flexible" to the designer for an in-wall due to larger footprint, etc.

So, mainly the difference is the physical appearance/footprint, which then in turn drives the rest of the differences. The only difference that does not really fall under this category is that in-ceiling speakers are tuned for a ceiling application. In other words, you tend to assume that above the ceiling there is a larger volume than the wall (think drop-ceilings for example), so the ceiling speakers are tuned appropriately. However, this difference you will probably find to be minor, because a typical home ceiling is not much deeper than a wall. Really, you could put either type in either location, the only difference you will find is in the low frequency response.

In summary, they are interchangeable but somewhat tailored to their "normal intended" placement.

[WMcD]

I'm sure IV is correct. Why argue with the factory guy.

But, he may not have described the physical setting quite enough for understanding.

The starting question is that a speaker in the ceiling and a speaker in the wall have to do the same job. So what is the difference?

Consider that with in-wall mounted speakers, we can pretty much assume that the speaker is on a vertical wall and close to ear level. Similarly, the listener is close to that axis. The listener can move left and right, but that is about all. As a result, the in-walls can be optimized, particularly in the treble range so that they only have to work in that one plane. This is because the listener is alway there.

It is a bit tougher to see, but in-wall speakers also are directional to some extent so that the treble does not paint the ceiling or floor but paint left and right as much as possible.

OTOH, in-ceiling speakers are set up to paint as wide a swath as possible, in a circle. People walk around the room, in what is for the speaker, two dimensions, rather than a plane.

Gil

[mas]

I think we may not be accurately addressing the larger and more important point.

Focusing on the individual products marketed as 'in wall' or 'in ceiling' misses the more substantial point.

The more important issue is how do you design a space for their use - and conversely, how do you use them to treat the space. And in this regard there is a IMMENSE difference!

I will scan a few pages later today and post some information that is pertinent for in ceiling application.

Suffice it to say, everything we have previously spoken about regarding acoustical spaces is literally turned on its head (sorry, no pun intended) for in ceiling installation. So much so that 'in ceiling' installation is typically relegated to distributed zoned systems. (And the prognosis for hi-fi appplications is not a good one for several reasons.)

For 'hi-fi' use, my simplest advice is to avoid in ceiling installation (regardless of the individual speaker chosen) - for some very good reasons. But let me get the materials that cover the subject more thoroughly than I can here at this time, and hopefully you can get an idea of what I am talking about. And also, any subsequenct discussion can focus on some facts rather than simply suppositions and guesses.

To cut to the chase...if you must opt for built in speakers, for all but a truly exceptional application, I would opt for in wall use as opposed to in ceiling installation.

And then with in wall speakers you ideally must address a series of unique and important additional issues as well. that remain with making such in wall systems sound acceptable (and most have nothing to do with the speaker itself!) - not the least is how to remove the wall itself from becoming a very poor performing secondary radiating surface that acts like an extension of the speaker due to the mechanical coupling inherent in their mounting. Typically, the result is a wall that acts as a secondary radiating surface that has the transient characterisitics of jello gone awry! ( Without mechanical isolation from the wall, can we think: poor transients combined with later propagation - in other words, how can we best take a bad thing and make it still worse!

Edit: Sorry for the delay! The files will be forthcoming! I promise!

In the meantime, may I suggest checking out the Genelec website for their 'in wall' soffit mounting instructions. They are not the most advance, but unless you are building the house from scratch, it is difficult to employ the 'best practices' route of mounting the seaker on a non resonant post isolated from the wall and anchored to the foundation. Genelec provide instructions for elastomeric isolation from the wall and a surround seal that will not rigidly mechanically couple vibration to the wall. If you select a good speaker, the mount becomes the most critical.

So except for a bothroom or kitchen where you might simply be satifsfied with the system functioning as a "PA", I would stay with wall mounted drivers. Your ability to hear from above, as well as the soundfield tat is generated by the down firing mounted speakers is NOT optimal (and that is a gross understatement!)

But no need to take my word for this, i will supply the documentation.

[Coytee]

But no need to take my word for this

When did things around here change to inply anyone would? []

inply? sigh...

[:$]

[flatgrass]

I just finished hooking up some ceiling speakers (CDT 5650s) over the holidays. These are in the kitchen ceiling. I had planned on putting some in wall speakers in the high bulkhead between the dining room and the kitchen, facing into the kitchen, but the dimensions of the bulkhead changed throughout the remodel project and I had to resort to changing to ceiling placement.

Now, they sound good, but you can tell when you move from, between, and into a dispersion area of each speaker. I really think that having the speakers on a vertical plane would have produced a better sound field.

FWIW, I have these on a volume control, wired back to the same location as the outside speaker leads. The outside are also on thier own volume control. Both controls have impedence matching settings, dependent on the number of speaker pairs you are running. I use a speaker distribution panel for both sets that connects to a single speaker lead set on the amp.