[Bumpy]

I am very pleased with the sound of my system and room treatments. I have left the walls directly behind the OBs untreated to preserve the rear of the dipole. The OBs are 4ft from the facing wall, but, out of necessity, close to the side walls for a broad soundstage.

Recently I have been running-in a pair of new midrange drivers at volumes where I cannot stay in the room for long. From outside the room the sound is clear and undistorted but in the room, particularly up near the OBs, and with female vocals, there is a very nasty glare (echo?). This very occasionally invades the normal listening experience.

So do I need to treat the walls behind the OBs and if so, what with.

[Bumpy]

Looking again at my picture, and with the OBs angled in a bit, the rear dipole actually fires into a corner. In retrospect this may not be a good thing as it creates a 'horn' type echo area.

[mick wolfe]

Yes, I'd certainly experiment by placing diffusion panels behind the speakers at or near the corners. If that center diffusion panel is actually 2 panels, I'd use those for the experiment. If that's to your liking, I'd then place an absorbing panel behind the equipment rack in place of those previous diffusors. Now this is nothing more than an experimental starting point, so in the end, your ear will be the final arbitrator.

[radarnyc]

Yes, I'd certainly experiment by placing diffusion panels behind the speakers at or near the corners. If that center diffusion panel is actually 2 panels, I'd use those for the experiment. If that's to your liking, I'd then place an absorbing panel behind the equipment rack in place of those previous diffusors. Now this is nothing more than an experimental starting point, so in the end, your ear will be the final arbitrator.

That’s interesting as this is opposite of what Clayton (Spatial) and GIK had told me…i.e. absorption in the corners and diffusers in Btwn the speakers. I’ve only done absorption and it sounds great.

[mick wolfe]

I've done both in combination. I started with absorbing panels only on the front wall. Yes, most effective at or near room corners. This with diffusion panels on the back wall. In the last year, I've started to incorporate diffusion panels on the front wall as well. Ended up liking diffusion in the corners with absorbing in the middle. Now this applies to my system and room, not anyone else's. In regard to the OP, open baffle and panel owners usually opt for diffusion on the front wall behind the speakers. Box type speakers seem to favor front wall absorption. ( for starters anyway) Bottom line is that one has to find his or her own solution in regard to room treatments. One size doesn't fit all.

[Bumpy]

Just randomly throwing some cushions in the space behind the OBs has started to make an improvement.

I think in general I would agree that every system has to be judge in isolation. There is a lot of misinformation out there, particularly from people trying to apply room treatments from box speakers,

[Bumpy]

Tried bringing down the high lever diffuser to the wall behind the OBs. Changed the perspective on the sound but no change to the nasty distortion behind the OB.

Returned the diffusers to the high level and replaced them behind the speakers with 1200x600mm GIK bass absorption panels. That did the trick

Wouldn't necessarily recommend this if OBs are close to that facing wall, but at 4ft it works great. I think 'corner' placement exacerbated the problem for me.

All good now

Thanks for your help guys

[Tyson]

Every room corner acts as a horn, magnifying problems with the room.  Treating them is a good idea.

[Nsm1979]

This has been my best setup so far.  Dispersion on the front wall and at first reflection side wall points.  DIY base traps in front corners.  Rear wall is covered with absorbing room darkening drapes.

[Tyson]

Those are some very nice subs you have there

[BobM]

What I've heard, and found to be true, is ... for cone/box speakers you absorb on the front wall (behind them) and diffuse in the listening space. For dipoles you diffuse on the front wall (behind them) and absorb in the listening space. The side walls also need tabsorption at first reflection points if your speakers have a wide dispersion.

Here's what I did. Look at the wood dowel construction I made behind my speakers. I also found that absorbing the center space was better than diffusion there.



That construction was based on one I'd seen at an audio show. The best part was they cost me about $100 using Home Depot dowels and a little stain and paint and elbow grease, as opposed to the $4000 the originals cost from some buddist-named company that you've all probably heard of before. Here's the look of the originals.

[rockymystic]

What I've heard, and found to be true, is ... for cone/box speakers you absorb on the front wall (behind them) and diffuse in the listening space. For dipoles you diffuse on the front wall (behind them) and absorb in the listening space. The side walls also need tabsorption at first reflection points if your speakers have a wide dispersion.

Here's what I did. Look at the wood dowel construction I made behind my speakers. I also found that absorbing the center space was better than diffusion there.



That construction was based on one I'd seen at an audio show. The best part was they cost me about $100 using Home Depot dowels and a little stain and paint and elbow grease, as opposed to the $4000 the originals cost from some buddist-named company that you've all probably heard of before. Here's the look of the originals.

Could you please share the details how to construct these diffusers? Links or plans will help...Thanks in advance

[BobM]

Pretty simple. Plans aren't necessary. Get a bunch of different sized dowels from Home Dopey, stain and poly them, then construct a top and bottom piece and arrange them randomly with a single screw through the header and footer into the center of the dowel.

[Bumpy]

I took some advice from GIK Acoustics and their recommendation was to concentrate on the first reflection points. My acoustics are unbalanced with a steel heating radiator on one side and window on the other.

I bought a pair of 4ft panels and placed them at those reflection points raising them temporarily on a couple of stools to cover the mid and tweeter drivers.

Now this has made a profound improvement and as important as the adsorption panel in the corners behind the speakers.

[richmain]

 Adding wall treatment to the side walls made a big improvement for me better then placing behind the baffles.

[SinSilla]

Have you ever tried a combination of Diffusion/Absorbtion behind the speakers?

I'm a huge fan of Binary "Abfusers", they have been working really well for me.