[JohninCR]

I'm finally getting around to tuning my 11' X 20' room.  I've already addressed the low frequencies by constructing the walls and ceiling to form variously tuned panel traps.  I haven't done any finish work on the ceiling and before I start working on dispersion and absorption on the walls, I'm thinking about finishing out the ceiling so it absorbs the high frequencies as well to hopefully result in the effect that there is no ceiling.

Is this a good idea or bad idea?

[JLM]

Seems like a good idea to me, especially if it located at the 1st ceiling reflection point.

[ScottMayo]

I'm finally getting around to tuning my 11' X 20' room.  I've already addressed the low frequencies by constructing the walls and ceiling to form variously tuned panel traps.  I haven't done any finish work on the ceiling and before I start working on dispersion and absorption on the walls, I'm thinking about finishing out the ceiling so it absorbs the high frequencies as well to hopefully result in the effect that there is no ceiling.

Is this a good idea or bad idea?

It depends.

Ceiling clouds are usually hanging traps, which are mounted well below a high ceiling to mess with the room ceiling reflection time. I doubt you need that.

Mounting absorption right on the ceiling is useful if you have speakers that put significant energy upwards, have RT-60 problems, or are really aiming for that anechoic feel. Without knowing more about the room, I wouldn't attempt to guess if it makes sense in your room. You've described yourself as a DIY'er - experiment.

I would recommend treating the walls for reflections first, though. Based on the absorption that gives you, you might decide that doing the ceiling is too much (or at least have a better handle on how much more you want to do.)

[JohninCR]

Thanks Scott,

I guess my question really is whether an anechoic ceiling is a valid idea acoustically.  Since it would be the entire ceiling, then first ceiling reflections are covered.  My room doubles as an HT, so a little on the dead side is fine.  Lastly my goal for music is to not have the room sound like it has the relatively low 8.5ft ceilings that are there.  Can I open up the virtual sonic height using absorption or do I need a more complex reflection/diffusion to "raise my ceiling"?

[youngho]

My limited understanding is that first reflections result in the perception of the creation of virtual speakers located on the other side of the boundary in question, resulting in the relative confusion of imaging, so in this particular scenario, you may actually want the otherwise undesirable reflection off the ceiling, assuming that you've already addressed floor reflections. Alternatively, you might try addressing first reflections from your mains only and seeing what you think. If you like the results, then you could invest the time, effort, and money in a "cloud." As noted elsewhere, a cloud might also benefit bass modes, as well.

Young-Ho

[ScottMayo]

Thanks Scott,

I guess my question really is whether an anechoic ceiling is a valid idea acoustically.  Since it would be the entire ceiling, then first ceiling reflections are covered.  My room doubles as an HT, so a little on the dead side is fine.  Lastly my goal for music is to not have the room sound like it has the relatively low 8.5ft ceilings that are there.  Can I open up the virtual sonic height using absorption or do I need a more complex reflection/diffusion to "raise my ceiling"?

Clouds are hanging devices used to make the ceiling seem acoustically closer. This is useful in churches and other spaces with very high ceilings; it prevents echoes coming back with so much delay that people are thrown off while singing. Not what you are looking for.

The only way to "raise" the ceiling is to use a large amount of diffusion. This puts diffusors near your head, which can adversely affect imaging. Probably not a good idea. You can try to subtract the ceiling from the equation with 2" sheets of 703 across the entire surface, but it shouldn't be necessary to go to that sort of extreme. The ceiling is not the biggest problem in most rooms. Just treat the reflection points (in HT there are a LOT of these, up to 30) and you'll probably be in good shape.