[Poultrygeist]

I rarely see pictures of room treatments used with open baffles speakers, even in rooms showcasing Pure and Spatial offerings. I've read Linkwitz conclusions and he doesn't appear to be a big fan of them. I know they work great with conventional box speakers but what are your thoughts and experiences as it relates to their use with open baffles?

[radarnyc]

I'm super glad that you posted this as I've been wondering the same thing. You have, no doubt, looked at all the photos on the thread in this OB Speaker thread and Spatial's (https://www.audiocircle.com/index.php?topic=171006.0). I've also watched a lot of reviews of Spatial's. In the videos I've seen a bunch of room treatments but these are rooms where they've had a ton on of gear in and out so the treatments are fixed/established. So, it's left me with the same question that you asked.
Hopefully Clayton and other experts (Anand) will weigh in.
What I've seen is that Clayton may have advised folks to use something like PI Audio Group's "Mr T" behind their speakers (https://www.audiocircle.com/index.php?topic=168813.0).

I'm getting a pair of pre-loved Spatial X3s this week. What I can offer is my plan:

1. Rug and rug pad covering the listening area. Done; I just got a 10'x14' area rug and pad.
2. Layout speakers according to Clayton's suggestions.
3. Listen; adjust speakers; repeat; repeat
4. Measure with UMIK-1 and REW
5. Make decisions on what is needed next if anything (Mr Ts? Corner Bass Traps?)

[mikeeastman]

Here a some pic of my treated room  with my OB super 7s. the panel on right is P I audio the rest are a Jeff Hedback design panels with DYI ceiling cloud and bass trap in upper back left corner. Also all windows have heavy insulated window coverings.

Made a big difference in the sound stage

[ric]

As I've said in other posts, when I bought my first (and only) OB Spatial M3TS, I thought I would not need my DIY Shakti Hallowgraphs--wrong! What these room lenses do for me is help put the soundstage into perspective. At first, I was under the impression that toeing them OUT for larger multi-piece music (classical, jazz etc.) and IN for smaller groups (trio's, quartets) would be preferable, but over time it seems that it depends on the recording (mike placement).
Sometimes it's the three bears affect, trying to find the right lens position, as I have marks on the floor and have them on lazy susan's so that I can point them at reflection points on the wall, or toe them in/out/straight.
To my ears, they are still a necessary tool used in defining the soundstaging. Yes, the bass can be modified slightly because bringing a recording into or out of focus does affect it, or piano can be more defined. As far as the bass goes, it is minor, soundwise, and I prefer a natural sound, which is what adjusting the focus tends to do. If you have carpentry skills, I can send you a template from AudioAsylum posts.
Good luck!

[JLM]

Linkwitz had a very "bright" room with lots of side wall glass - not well suited for treatments, thus his interest in dipoles (open baffles, planars).  Toole described him as a friend, a forthright stereo enthusiast, and a competent engineer but lacked access to a panel of trained listeners to provide meaningful subjective data.  Note that being such a reflective room, dipoles (including bipoles and omnipoles) were well suited as they don't exhibit as much lateral dispersion as monopole loudspeakers and so could maintain proper balance with direct sound (ideally about 5 dB less) in his room. 

Many audiophiles strive to "over treat" their rooms (if the domestic partner allows).  Having a "normally" reflective room actually helps provide a sense of space.  Thin absorbers (less than 4 inches) tend to affect higher frequencies only and thus provide an undesirable timbral imbalance.  Diffusers typically are ineffective in smaller (typical residential listening rooms), however randomly placed semi-spherical designs of 12 inch diameter can be helpful.  Note that according to Toole valid listening tests are the only way to truly evaluate room treatments.  Floyd E. Toole is recognized as a leader in loudspeaker/room research and invented the "spinorama" testing method. 

Most of the treatments I see from your link seem to be addressing reflections off the front wall.  As you probably know, having at least 5 feet of between dipoles and front wall is recommended.  Aside from that carpet or a rug is probably all that's necessary for dipoles. 

By the way ric, Linkwitz is quoted as saying: "The aural scene is ultimately limited by the recording."

[Poultrygeist]

I've seen absorbers or bass traps placed behind OB woofers but can't see the advantage there. Folks do seem to agree on using diffusers.

[AJinFLA]

Many audiophiles strive to "over treat" their rooms (if the domestic partner allows).  Having a "normally" reflective room actually helps provide a sense of space.  Thin absorbers (less than 4 inches) tend to affect higher frequencies only and thus provide an undesirable timbral imbalance.  Diffusers typically are ineffective in smaller (typical residential listening rooms), however randomly placed semi-spherical designs of 12 inch diameter can be helpful.  Note that according to Toole valid listening tests are the only way to truly evaluate room treatments.  Floyd E. Toole is recognized as a leader in loudspeaker/room research and invented the "spinorama" testing method. 
Most of the treatments I see from your link seem to be addressing reflections off the front wall.  As you probably know, having at least 5 feet of between dipoles and front wall is recommended.  Aside from that carpet or a rug is probably all that's necessary for dipoles. 

Agree with all above.
Except..

Diffusers typically are ineffective in smaller (typical residential listening rooms)

That is simply not true..and demonstrable. It probably stems from confusion between statistically diffuse field (true) and perceptually diffuse in small room. I can link a lot of valid listening tests to confirm that. This one is quite amusing http://www.aes.org/e-lib/browse.cfm?elib=16640

cheers,

AJ

[JLM]

I may have interpreted Toole incorrectly. 

[Rusty Jefferson]

@mikeeastman, that's a very interesting listening space/home. Quite yurt-like. I imagine that room sounds good.

The best home listening room I've heard to date is fully defracted on all surfaces with random wood placement. Difficult to implement in anything but a dedicated room I know, but amazing results. The sound of people just standing around talking sounds good in there. They use what could almost be considered an omnidirectional speaker there, and the imaging specificity of live 2 or 3 microphone recordings is simply the most realistic I've ever heard.

[mikeeastman]

It’s call a modified Hogan, a Hogan is a traditional Navajo 8 sided building. I have built several of them in my neighborhood.

This was originally the entire house, we built the rest of the house over the next couple of years and then turned this space into our offices and dedicated listening room

Yes the room with my present set up does sounds incredible.

[Les Lammers]

I rarely see pictures of room treatments used with open baffles speakers, even in rooms showcasing Pure and Spatial offerings. I've read Linkwitz conclusions and he doesn't appear to be a big fan of them. I know they work great with conventional box speakers but what are your thoughts and experiences as it relates to their use with open baffles?

FWIW, I saw a photo of OB Zeniths on AK. The poster hung a couple of crocheted throws behind the speakers and stated that it was an improvement. Another person was using hemp rugs.

https://audiokarma.org/forums/index.php?threads/open-baffle-epiphany.566879/page-192#post-13316945

[Poultrygeist]

I placed heavy quilts on quilt racks behind each of my OB's and couldn't tell any difference.

[sockpit]

I own Clayton’s M5s in an 11 by 14 by 8 room.  I’ve started down the treatment route.

Spoke at length with Mike at GIK, sent photos, etc.  The recommendation in a room this small was their full range Monster Bass traps in all corners and their 244 panels at first reflection points for starters.  My perceived problem has been brightness and Mike promised me that bass traps would clean up the bass and actually enhance it so as to even out the tone across the spectrum.

Knowing OB act differently than box speakers, I ran the entire proposal and all details past Clayton.  He said that Mike was correct and I should follow his plan.  So the bass traps are on order.

I asked about diffusion and neither said it would do the trick in this room.  Apparently room nodes are enemy number one in small spaces.  Such advice is no doubt room dependent but before you just follow the photos of MR. T diffusion, etc. you might want to inquire. Mike says it’s actually hard to deaden such a room.

I think Spatial owners present and future would benefit from Clayton summarizing his philosophy of room treatment on his Circle, with the caveat of course that YMMV.  The choice of absorption vs. diffusion seems too important to leave up to chance.

[Bumpy]

I agree totally. A summary from him would be great. I recently treated my room and misinformation is rife. We've moved on from egg boxes, but not by much. If its of interest I ended up with diffusion behind the speakers and adsorption at first reflection points.

I didn't see the need for bass traps for the following reasons

1. Open baffles are good at not loading the room with bass - many experts fail to know this.
2. I personally have never heard any bass boom in my room
3. UMIK/REW measurements showed no nasty bass loading
4. Bass from a properly executed OB is great but not overpowering

"Mike says it’s actually hard to deaden such a room"  Well I killed the wonderfull OB sound by piling in with adsorption behind the speakers.

"The choice of absorption vs. diffusion seems too important to leave up to chance."  And too expensive!

"My perceived problem has been brightness and Mike promised me that bass traps would clean up the bass and actually enhance it so as to even out the tone across the spectrum." Its my remaining problem too and I would love to hear the science behind this philosophy

[radarnyc]

bumpy and sockpit - is the brightness only a problem at higher listening volumes? that seems to be the case for me and not always (depends on the track of course). At lower listening volumes, I have no brightness in my untreated room. I'm running X3s with an LTA Z10 in a 14.5'x22' room. i haven't measured my room since I got the Spatials...need to do that soon.

Maybe we should post a new thread on the Spatial circle as I'm not sure if Clayton keeps up with this circle?

[Bumpy]

bumpy and sockpit - is the brightness only a problem at higher listening volumes? that seems to be the case for me and not always (depends on the track of course). At lower listening volumes, I have no brightness in my untreated room. I'm running X3s with an LTA Z10 in a 14.5'x22' room. i haven't measured my room since I got the Spatials...need to do that soon.

Maybe we should post a new thread on the Spatial circle as I'm not sure if Clayton keeps up with this circle?

At normal to quiet listening, my system is well balanced. The brightness shows itself at higher listening levels and is most evident on female groups like the Dixie Chicks. Not enough to make me switch off, or get a headache, but enough for me to think I'm not enjoying this as much as I should.

 Here is my system. Sorry its a bit big.

[sockpit]

bumpy and sockpit - is the brightness only a problem at higher listening volumes? that seems to be the case for me and not always (depends on the track of course). At lower listening volumes, I have no brightness in my untreated room. I'm running X3s with an LTA Z10 in a 14.5'x22' room. i haven't measured my room since I got the Spatials...need to do that soon.

Maybe we should post a new thread on the Spatial circle as I'm not sure if Clayton keeps up with this circle?

I have LTA Z10 integrated and SA M5s. My brightness issue is mostly about mediocre recordings, I think! Put on a well recorded piece of music and it's nirvana.  So this might be my relative inexperience with really good gear.  Still, I'm hoping incremental treatment of the room will make more recordings listenable.  A thread on his circle is worth a try.  He's very busy, but I've encouraged him to offer some views on the intersection of his OB designs with diffusers/absorbers.

[Bumpy]

There's not an once of harshness in my system (valves throughout). What I do have is enough transparency to compare recordings.

The brightness I hear is almost certainly the room as the listener end of it is untreated. But do I buy absorbers or bass traps?

[mikeeastman]

I’m about to change speakers in my bedroom system. Right now I have GR Research N2Xs and I upgrading to GR Research Studio Monitors, which have an OB tweeter.

I have only one place for the speakers to go (see pics ). With the N2Xs at Dannys suggestion I mounted the speakers upside down, which has worked well, sound stage is high but other than that sounds good.

Now with the new Monitors I will have 18”-20” from the ceiling to top of speaker. Should I hang the new speakers upside down or mount them right side up and put some acoustical treatment on the ceiling.

The trouble with trying both is I have to have a special bracket made for each way and don’t what to that if I don’t have to.

I'm also posting this in GR Research.

[sockpit]

There's not an once of harshness in my system (valves throughout). What I do have is enough transparency to compare recordings.

The brightness I hear is almost certainly the room as the listener end of it is untreated. But do I buy absorbers or bass traps?

My communications with GIK and Clayton said without a doubt get bass traps in a small space like mine.  Then absorb side reflections.  Only then add diffusion.  I think if you're serious about this, you shouldn't trust opinions on threads, but talk to a couple people who do acoustics for a living.  Sure, they want to sell you something, but you can usually distinguish the BS from a company with a good track record who doesn't even really need your business and are attentive to your concerns.  I felt that was the case with Mike.  He wasn't in the least worried about me sucking bass out of the room. Nor was my speaker manufacturer, for that matter.  Both said the bass would be cleaner and paradoxically stronger in a good way that balanced out the tone across the spectrum.  Also, the bass traps I purchased don't just absorb low frequencies; they are full spectrum. Time will tell if this was the right move.  About 7 weeks.