Ceiling Treatment?

[RUR]

OK, so I've got the front wall and side wall first reflection points treated for absorbtion, and the corners bass-trapped. I'll insert some type of diffusion/abfusion on the rear wall once I figure out the best product/approach. Which leaves the ceiling......

How important are the ceiling first reflection points when using ML's? What improvements have folks experienced when treating those points? What did you use and how did you attach it?

If I do this, I'd like to keep it as attractive as such a thing can be, short of insetting OC705 and covering a portion of the ceiling with fabric.

[DTB300]

I have a dropped ceiling so I stuffed it with 5.5" Acoustical Cotton instead of fiberglass. For me, the room sounded better after stuffing.

With vertical dispersion pattern the ceiling and floors do not come "directly" into play as much - unless panels are extremely tilted.

The reflections from other surfaces which may then hit the ceiling right above your listening seat could be an issue. Think about the covering of a TV which may sit right between speakers. Sound does not directly hit the front of the TV
screen from the speakers, yet putting absorption across the front of the TV changes the sound. To me this is a reflection of a reflection being absorbed.

Maybe Ethan will drop by to address as I have seen this discussed in other forums.

[RichTeer]

MartinLogans have limited vertical dispersion, so I don't think treating the ceiling would be anywhere near as important as the walls (and it sound like you've got that one, err, covered!).

Would RealTraps' RFZ Panels have an acceptable WAF?

[JonFo]

Yep, the ceiling is not as critical with line-source speakers, at least for the mids and highs.
So ceiling is the last item to get addressed in a ML rig.

One treatment I have found to help is to address the vertical mid-bass / bass mode just over the speaker itself.


As seen in this picture (http://www.martinloganowners.com/~tdacquis/forum/showpost.php?p=87970&postcount=144), where I’ve deployed two Minitraps over the main speakers


This improved the area around 160hz a good bit, taming a vertical resonance formed by the ceiling height.

[DrJRapp]

MartinLogans have limited vertical dispersion, so I don't think treating the ceiling would be anywhere near as important as the walls

I've found that just a small amount of diffusion on the ceiling is usually adequate in most situations with just about any speaker. If your ceiling is smooth gypsum board, then the application of "knock-down" (a construction technique for textureing) will do a decent job...the heavier the texture, the better. OBTW, "knock down" on the walls, especially the front wall, works well also.

[DTB300]

I've found that just a small amount of diffusion on the ceiling is usually adequate in most situations with just about any speaker. If your ceiling is smooth gypsum board, then the application of "knock-down" (a construction technique for textureing) will do a decent job...the heavier the texture, the better. OBTW, "knock down" on the walls, especially the front wall, works well also.
At what frequency did you find the textured walls to help with?

My guess is a very high frequencies due to the small differences in the textured depth.

[DrJRapp]

At what frequency did you find the textured walls to help with?

My guess is a very high frequencies due to the small differences in the textured depth.

High and upper mid frequencies...due to randomness of depth and angularity of the surface.

[Bernard]

Yep, the ceiling is not as critical with line-source speakers, at least for the mids and highs.
So ceiling is the last item to get addressed in a ML rig.And of course it is even less critical with higher ceilings.

[RUR]

Seems that everyone's confirming the conventional wisdom i.e. ceiling HF absorbtion isn't de rigeur for line source speakers. This being the case, I guess it's time to arm myself with REW and start experimenting with additional absorbtion in various other locations, as well as selecting a rear diffusion/abfusion solution.

[Ethan Winer]

Seems that everyone's confirming the conventional wisdom i.e. ceiling HF absorbtion isn't de rigeur for line source speakers.

Yes, that's my understanding too.

--Ethan