Acoustic panels - how high?

It all depends on the geometry and the physics. In reality the second reflection points can be worse than the first ones. It all depends on the radiation pattern of the speakers, the dispersion pattern. That's why attention to the placement must be done by ear not some generalized instructions. Otherwise you're only finding the local maximum. Same goes for Tube Traps, you will not find the optimum locations by following the instructions of just plopping them down in the room corners since it depends on where the standing waves are actually located which might easily be two feet from the corner! Hel-looo!

OK, so I've just finished playing - yet again...

A friends place has a 12ft ceiling, so I've been looking at possible solutions.

So I got to thinking about my room with an 8ft ceiling and how a "baffle curtain" might help.

I just happened to have a piece of heavy duty vinyl 2 ft x 6ft and a couple of lighting stands, so I rigged it such that the vinyl hung down from the ceiling like a banner, across the room and tried it in a couple of positions...

1. just behind the speakers...
- There was some improvements in clarity and image
- nothing really to write home about

2. just behind the listening position...
- talk about an OMG moment!
- clarity improved beyond my expectations
- image now easily exceeds the boundaries of the room on most all tracks
- projection of venue acoustics forward now easily envelopes the listener on many tracks
- it's like surround sound with only two speakers
- the improvements can easily be heard outside of the room also, just amazing.

BTW - I also have a couple of 15" x 78"(tall) panels on the side walls behind the speakers to deal with an echo that travelled across that wall behind the speakers

Regards...

I treated the top five feet of the wall behind my listening position with 2" Auralex Studiofoam Wedges, with LENRDs in the corners and accomplished the same effect. An added benefit is being able to listen at realist levels, without overloading the room. Happy listening!

Take Elwoods advice re the mirror and if you wish to maximize your efforts on first, and second,reflection,go floor to cieling with panels in those locations. You cannot go wrong with this simple solution,and it will benefit you. Good luck and let us know your results :) Pete

Eleven little Zilplexes will greatly exceed any benefits of acoustic panels.