[Alwayswantmore]

Recent discovery of this GREAT circle has my head spinning  Unfortunately, after reading numerous threads I’m coming up with more questions than answers for my needs 

I’m building a new house with a small dedicated media room (13 x 12, with 9’ ceilings). It’s clear from all posts I’ve read, corner bass traps and absorption at 1st point of reflection will be mandatory for a room this size. 

Questions...

1.) A room this size has ~86 running feet of corners (wall-to-wall and wall-to-ceiling). Assuming I purchase four 2’x4’ bass traps (one for each corner), I will have addressed ~18% of total corners. Will 18% make a significant improvement? On a scale of 1 to 10, how close will this be to an “ideal” amount for corner bass traps?

2.) The ceiling is 9’, yet manufactured traps are typically 4’ high. This means that corner traps cover less than 50% of the corner, and do not address the tri-corner. Again, will 4’ panels in each corner make a significant difference, or will I need to stack them two high or add tri-corners to get good results?

3.) My other big issue is the WAF (cosmetics). Sorry to say, but so far nothing I’ve seen in terms of wall-to-ceiling panels floats my boat.  But I came up with an idea that IMO would look great – but not sure how effective it would be for sonics. So let me know what you think...

Since I have 9 foot ceilings, I could build a false soffit to cover all four ceiling / walls corners. I envision the soffit (or think of it as a trey ceiling) being 10” – 12” in height / depth, and built in a way that it appears to be part of the ceiling (i.e. painted to match). I also imagine placing dense fiberglass behind the soffit for the bass trap.



Assuming this would be effective, what surface material should I use that would not be too opaque? I’m thinking along the lines of smooth acoustic ceiling panels, or maybe 1/4" MDF. 

What do you think? Would this be effective? What material should I use as a substitute for sheet rock? Might this method create too much bass absorption?

Please let me know what you think. Best, Kent

[bpape]

1.  Doing doubles in each corner is more like what you'd need given the small size of the room and the fact that you're almost square in shape.

2.  Yes.  Stacking them 2 high is what I was referring to above.  You can go from the floor up 8' and catch half of the tri-corners.

3.  That is absolutely a valid way to do things.  Just understand that if you use something like drywall or plywood, you'll be 'tuning' the absorber and severely minimizing the broadband nature of same.  You're better off to use a very thin membrane or even something like an FSK facing on it and then covering in cloth of your choice to minimize mid/high absorbtion (saving it for the reflection points and accounting for carpeting) while still providing a nice very broadband bass/lower mid absorber (where most of your severe issues will be in a smaller room like that.

It also leaves ear level somewhat more lively which can be desirable in a 2 channel situation.

Bryan

[Alwayswantmore]

1.  Doing doubles in each corner is more like what you'd need given the small size of the room and the fact that you're almost square in shape.

2.  Yes.  Stacking them 2 high is what I was referring to above.  You can go from the floor up 8' and catch half of the tri-corners.

3.  That is absolutely a valid way to do things.  Just understand that if you use something like drywall or plywood, you'll be 'tuning' the absorber and severely minimizing the broadband nature of same.  You're better off to use a very thin membrane or even something like an FSK facing on it and then covering in cloth of your choice to minimize mid/high absorption (saving it for the reflection points and accounting for carpeting) while still providing a nice very broadband bass/lower mid absorber (where most of your severe issues will be in a smaller room like that.

It also leaves ear level somewhat more lively which can be desirable in a 2 channel situation.

Bryan

Thanks Bryan.

Let's say I start with 8 GIK 244 panels (for the corners) + a one set of 242 panels to do the 1st reflections on side walls (and an extra panel to place on the TV or maybe back wall), then held off doing the soffit idea for a future project.

1.) On a scale of 1-10, where 1 is NO treatments, and 10 is all the GIK product listed above PLUS the addition of the false soffits, how far up the scale would I be with just the four corners and 1st reflections?

2.) And for the corners, if you recall from my first post, one back corner is actually a wall that becomes a short hallway (i.e.) not really a corner. What should I do here? Place the panels across the  opening to the hallway? Put panels at the end of the hallway in front of the door???

3.) As part of the WAF, I might hang curtins in front of the corner panels (to hide them). The curtins could be hung on a diagonal just in front of the panels. I could use a ceiling mount slide that would allow the curtins to be pulled to one side (for critical listening or have access to the closet or hallway). Assuming the curtins were to be closed so they cover the panels (i.e. visible to the listener), how critical is the fabric choice? Would I have to stay pretty acoustically transparent, or would I be able to venture into a variety of fabrics without too much ill effect? [Again, if they are on slides, if the additional fabric is a problem, I could pull them "open" for critical listening if that would help the SQ.]

Thanks again for helping me want to spend more money on this crazy hobby 

[bpape]

Well, first of all, 1 panel on each side wall likely won't catch all the side wall reflections from both front speakers  even to just one seat - you'll likely need 2 on each side wall minimum.

To answer your questions:

1.  I'd say 7 out of 10.  Many of your issues will be length and width related due to the mostly square shape.  Doing the vertical corners will catch the majority of corner related issues in those dimensions.  The soffits will be more general bass control but would certainly help.  Most likely, if you do the verticals, you could get by with only partial soffiting.

2.  As long as the room is oriented with the hall in the rear, I'd start with just the 2 front corners floor to ceiling and 2 sets of panels for the side walls - leaving 2 additional panels to put behind your main speakers to help with SBIR issues that I'm sure you have in a small room.  To me, that's a better way to start out right now.

3.  If you're going to do curtains across the corners, you'll be fine if you follow #2 above.  You'll just add a bit more absorbtion.  I'd however resist doing a lot on the rear wall and across the small hall.  That will give way too much HF only absorbtion - especially since you're starting only moderately on bass control.  On the side walls, do it if you must but I'd again resist it.  If she wants a more complete look, you can do curtains across the whole front wall - just get something soft and hang it so it's hanging 'full' even when closed to cover the whole wall.  I wouldn't worry about pulling them out of the way to listen in that case.

If you want to do a little extra, consider a set of TriTraps - 1 in the rear corner and one back at the end of the hall.  Easy to slide out of the way and the one in the room - let her put a picture, some nic-nacs, whatever on top of to help 'decorate' it.  The Tris will reach deeper into the bass as they're solid absorbtion as opposed to a straddling panel.

Bryan

[Alwayswantmore]

Does the paint finish make any appreciable difference? For example, I'm thinking about doing part of the room in semi gloss and / or maybe some faux finishes (maybe even the ceiling). These finishes are much more shiny than standard interior flat paint.

[bpape]

From an audio standpoint - no - unless you try to paint the treatments - then you'll kill the HF absorbtion.  If you're running video in the room, shiny paint is not desirable as it causes a lot more light to be reflected onto the screen.

Bryan

[srlaudio]

Too much absorption.....check out some diffusion!

Allen Rumbaugh

[bpape]

Sorry Alan - completely disagree in this case.  In a room that small, the ONLY place that diffusion would be marginally effective would be at first reflection points.  BEST case, he MIGHT be 7' from a rear wall diffusor assuming VERY nearfield listening position.  Realistically, he'll be more like 4-5' - way too close for even moderate midrange diffusion to be effective - much less anything low enough to remotely deal with modal issues and buildup of an almost square room.

Bryan

[Alwayswantmore]

Okay, now I've got an  idea for a basic room -- one that I could actually afford with my current budget (stacked 244s in front corners - 6 242s for front and sides - maybe a curtin to cover part or all of the front wall).

If I were to dream of a more 'ultimate' treatment, yet great looking (IMO) - how's this?...

1.) Replace the 244s in the front corners with stacked Tris (greater bass absorption - less obtrusive footprint)

2.) Stay with the 242s for sides and front.

3.) Add a drop ceiling to 8 foot (using suspended tiles). Strategically place fiberglass in the ceiling to trap bass in tri-corners and wall ceiling corners. (Less square room, better bass traps for tri corners and wall ceiling corners)

4.) Add a couple tris for the back corner and hallway.

5.) Keep a light curtin on the front wall to hide the front treatments.

IMO the room could look good. On a scale of 1-10 how good would this be for acoustics?

And even with all the treatments, is the fact the room is small still a significant handicap for achieving great sound?

[bpape]

Personally, I'd not go with the drop ceiling. 

The Tri's will give you more extended absorbtion.

A small room is always an issue.  An almost square room also presents issues.  An almost square small room can be made to sound good but will take a lot of time and effort in careful speaker/seating placement and enough absorbtion to get it under control without making it too dead. 

Bryan

[Alwayswantmore]

Thanks Bryan. Based on your input and pricing I'm leaning toward GIK. It will be a while before the house is done, and the media room will not be the first room we tackle. But at least I can think about budget and how to decorate. Thanks to you, Ethan and others who added their 2 cents. I can't wait to get it done and hear the results!  aa

Almost forgot...  If I can swing the $ for stacked tris for the front, what do you recommend to fit them into a 9' room? Do you make a matching riser, or would it be possible to have them built to 4.5 feet in lenght without breaking the bank???