Window Treatments to Remove reflected sound

I agree with Dougmc. I have plastic 3 in. regular shutters on all windows. Turned at 45 deg., they provide good mid/high diffusion and light control to boot! Wood might work even better. (Lets, see... maple? (:-))

A previous room had three large windows that were covered with "cellular blinds" and then the windows had heavy fabric over treatments. This proved to be very effective. You could even discern differences that resulted from opening the blinds differing amounts.

Thanks for the good input. What exactly do tuning dots do? There is no explanation of them on the web sit referenced.

No set blinds will have any effect below mid-frequencies and exactly where they will change from dispersing the audio to reflecting it is somewhat unpredictable. The glass is transparent to bass and reflective of HF so, in order to have a nearly equal effect across the spectrum, you need some heavy absorbtion from the low midrange up. I've used velvet drapes interlined with dacron acoustic batting. Since the coverage is adjustable, you can titrate the effect you want.

Kal

This is not necessarily the "best" accoustic solution, but it does have some advantages. Behind the listening position in my rental apartment is a standard two-panel sliding glass door that leads to a balcony. The landlord furnishes apartment-grade, hard plastic vertical blinds, each blind being about 4" wide. I simply set the blinds at a 45 degree angle to the room. In theory, sound waves hitting the slanted blinds will reflect at various angles, depending upon the angle of attack. A few will bounce back into the room, but most will reflect into adjoining blinds or to the glass behind and then reflect into the back side of the other blinds.

Does it work? Aside from the sliding glass doors, my room leans toward the bright side, but I don't experience any noticeable listener fatigue, muddy textures, compressed soundstage or confused imaging.

One advantage of slanting blinds, as opposed to draperies or shades, is that you don't have to banish sunlight during daytime listening. Of course, slanted blinds will work even better when they are made of wood or are covered with fabric. And if outside noise is also a concern, thick draperies or black-out shades would be preferable.

Marigo window tuning "dots". check for these at www.amusicdirect.com

Pleated fabric blinds work well.

If you get curtains, err on the "too much fabric" side. The more folds the better.

I have a related question. Anyone know how to treat "ringing" of large pane windows. I've got a 48"x56" double pane that rings, becomes excited at various voice frequencies. Man, they don't make windows like they used to (thin glass for double panes).

Double or Triple Honeycomb cellular shades work well too.

Your best bet if not using specific room tuning devices would be draperies with 'blackout' linings.

I have what you are referring to as "celluar" blinds behind my listening position. (It covers a large bay window, and two smaller windows, at the side angle points, behind the couch.) BTW, I refer to them as "black-out" blinds, since that is why they have the "air pocket" that you mentioned. It keeps the light from coming in and messing up the picture on the RPTV on the wall opposite of the bay window.

They seem to work very well, IMHO, as it disperses the sound pretty well, and I don't get much in the way of sound reflections from the rear.
(Whether this is the perfect solution, from an accoustical standpoint, I am not sure. But since it does not add rear sound reflections to mess up the imaging and soundstaging from the direct sound coming from the speakers, I am okay with it.)

Perfect? Probably not, but since I am constrained by the old WAF, I don't really have a choice.

My two cents worth anyway.

Good Luck!

Wood slated blinds work better than metal but are very expensive. Fabric blinds/carpets/curtains - heavier the better.