how can I make the back wall transparent?

I guess this hobby (obsession) is a series of discoveries and this is just my latest...

Even after finding the correct speaker position (posted above), there were a few very annoying tracks that failed to impress me and always sounded very "confused".

I started thinking about my room and how sound might be bouncing around.

This brought me back to my initial room treatment - two 15" x 78" screens. I remembered that when I was experimenting with the screens, it was the height of the screens that contributed the most benefit.

Thinking about my room...
- 15 x 12 x 8 feet - audio system/speakers on a short wall
- the long wall on the left has a double open doorway
- the long wall on the right has a sofa and pictures(no glass) on the wall
- the short wall behind my listening chair(s) has a large bow window with very light drapes that do not have any effect on sound when closed
- in the corner to the right of my chair was a tall bookcase loaded with vinyl.
- floor is hardwood mostly covered with an area rug

So with all those soft furnishings in the lower half of the room it seemed logical to me that if there were any reflected sound waves bouncing around - they should be occurring in the upper half of the room.

Armed with a 2' x 6' heavyweight vinyl "curtain" and two large extendable stands I thought I'd try some different positions in upper regions of the room

1. a centralized location behind the speakers
- this offered very little relief on a couple of tracks, but not enough to make me declare it was a success.

2. a centralized location up against the wall behind the listening position
- the curtain dropped below the frame of the window by about 12"
- The resulting effect was immediately noticeable, pretty much an OMG moment!
- clarity improved beyond my expectations
- an image that now easily exceeds the boundaries of the room on most all tracks
- projection of venue acoustics forward of the speakers which now easily envelopes the listener on most tracks
- it's like surround sound with only two speakers
- the improvements can also easily be heard outside of the room also, with significantly more clarity, simply amazing.

Basically - all walls are now transparent - yes GONE!

What really surprises me is that I have no "treatments" on the wall behind the speakers - other than the two screens that are actually more on the side walls into the corners.

I then tried a couple of variations...
- curtain right up against the ceiling
>>> provided the most benefit
- leaving a foot of space above the curtain
>>> resulted in the sound becoming a little muddled and
quite bassey
- shorten curtain to 15" but right up against the ceiling
>>> a little less depth in the image than the 24" deep curtain - but still excellent

Achieveing so much benefit from treatment in the upper 15"-24' of the room is what surprised me the most.

I think I am very fortunate that I do not need to cover large areas of my walls in acoustic tiles - the mere suggestion of which sent the WAF scale dipping well into the negative.

She will now be very happy if I simply replace the vinyl curtain with a purpose made roller blind to fit the entire window. :-)

And, I figure there may be more benefits to be had if I cover the glass completely :-)

I'm not saying that all rooms only require treatment of the top 15"-24", especially if your room has solid side walls.

But it is where I'll start - next time :-)

But one last question: Has anyone out there found that the installation of cove/crown mouldings improved the SQ??? - thanks

Hope you find this useful :-)

Great post !

Williewonka, thats some really nice effort you have been putting in.
Give the ASI Liveline resonators a try. They essentially do exactly what you are trying to achieve, they make the room disappear! And they are extremely small in size, like a match box each. The big deal about them is, their effect is like the walls have disappeared but the musical energy which should be present in a small room remains with great open-ness. They not only improve focus and soundstaging but also greatly help in improving the immediacy, dynamics and timbral accuracy. Every wall (and for that matter every item) in the room would be adding or taking away something from the tone, the ASI makes the wall disappear in the most graceful sense, as in tonality and frequency response is also corrected. Talk to Frank Tchang and give a basic set of resonators a try if possible. Your wife wont even know you have added something to the room, they are that small.

Achieving so much benefit from treatment in the upper 15"-24' of the room is what surprised me the most.

That's the way Peter(Pbnaudio) treated his rear wall; absorption along the entire upper wall. It's even more effective in his case since he has space between his listening position and the wall.

I'd like to do that, but my setup is in a living room.

Lowrider57 - my setup is also in the living room, so the 24"× 60" piece of white vinyl currently supported by two stands is a bit of an eyesore right now.

However, I've just ordered a 92" × 78" vinyl roller blind ($215) that will fit behind the drapes and is almost invisible when retracted. High on the WAF scale :-)

Perhaps you could mount a similar blind with a white valance to "hide" it
-after all, it will be up against the ceiling (retracted) - no one looks up there :-)

If it's a plain wall you could put an outrageous work of art under it to divert peoples attention?

Possibilities are endless :-)

$215 is not the cheapest tweak I've implemented, but it has been the most effective to date.

Even my wife thinks the system now sounds amazing :-)

Cheers