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I have extensive acoustic treatments (and even Dirac) in my setup with Maggie 1.7's. My setup is:
12'X23'X8' room (kind of - room actually has a bulge in it so the width is 14' for about half the room, and 11' for the rest.
Speakers on short wall, 10' into room. Equulateral setup with seating position 8.5' to each speaker and between them.
Here's the question...anybody else find that acoustic panels placed behind the speakers creates the best sound? I have 3X 2'X4'X2" 705 corning fiberglass arranged in a semicircle to dampen the back wave. Sounds great.
Follow Ups:
Yep. As you describe but with mild diffusion in the center (between speakers).
Turned out pretty good! I couldn't get my hands on majesty palms so had to 'settle' for the Kentia. The panels on the wall behind the speakers are made from a line frame and wrapped in a cotton fabric with a thin layer of poly batting behind it.
Sorry for the dark photo, this was taken last night on the phone. To give you some brearings, the taller palms are about a 18" behind and to the outside of each speaker and the shorter Kentia palms are about 18" ahead of the speakers.
The imaging is startling, and the instrumentation and vocals have improved breadth. I was expecting to have a greater stage width, but there is a greater depth instead.
I'd love to get another pair for the rear of the room, but my wife has to get used to this congestion first :)
Opinions don't affect facts. But facts should affect opinions, and do, if you're rational..
- Ricky Gervais, 2012
Looks very interesting. Good ideas all round.
Are those OB subwoofers?
Thanks, it's frustrating being limited to how much I'm able to treat the space. The few thing I've done have made music more enjoyable to listen to.
The subs are isobaric, not OB. OB was what I really wanted to do but just don't have the space for four 15s per side :). These use 8" drivers and are ported; currently crossed at 30hz LR2 and just barely detectable by ear, but what they do for stabilizing the sound stage and giving a foundation to the major instrumentation and vocals is quite nice.
Opinions don't affect facts. But facts should affect opinions, and do, if you're rational..
- Ricky Gervais, 2012
Ahh Isobaric subs. How cool. My first meet with IsoBs was the KEF 104.2 and that was such a shock it brought tears to my eyes. Made my then JBL Centuries sound like they were stuffed with sheep.
I used my Vandy 2C carcasses to make bipole sealed subs by replacing the 8" woofer with an Aura 8" driver and the 10" with an Aura RPM 10 car sub driver that used to be popular in the blast off competition circuit. Don't really need them. But they do the bottom octave very nicely.
Curious why you chose a bipolar design... was it just to make use of the 'carcass'?
This little subs are something else. Granted, I'm still not finished the integration with the Mags yet as there are some things that aren't quite right; but, for their size they 'fill' very nicely. What's crazy is that even when the system is running at high levels (95db peaks) the woofers are barely moving.
I had bipole in mind for extension. With the woofers facing forwards and back it was either dipole or bipole, since dipole would have cancellation I choose bipole. It makes for a more percussive bass as well, which complements the maggies which don't produce that kind of bass kick.
I run 75-80's db average, which on large orchestral works and big band jazz I listen to comes out to top peaks in the 105-115 db range.
Which Mags do you have and where are you crossing your bipole bass bins at?
I run a TIV/Neo8 and the subs were run for a short while cut in at 30hz 3rd order symmetrical with the bass panels. Did not really seem that useful even in the less bassy equidistant arc configuration, but gave me punch that would otherwise not be there. When I started experimenting with wall loading the bass panels the subs became superfluous entirely as I am at 0 db relative to the mids at 20hz and there is a broad hump 30-50hz 4-6 db above midrange levels with wall loading.
I took that target curve from the Focal Nova Utopia as it seemed to do things very right in the bass (rising genty to +3-5db 20-40hz in room) as opposed to the big Wilsons with their center humps at 80-100 hz. Yet when we played the 20 and 25 hz warble tones on the wall loaded TIV the owner of the Focals was asking "what's that?". I didn't manage to get the bass to be as smooth as it is on the Focals and overshot the target at 30-50hz but it gives you a good Fletcher-Munson compensation which is good for LP and CD EQ - but makes SACD sound too bass heavy; as it is typically mastered with the bottom octave boosted 6db relative to CD releases on classical..
Anyway, with wall loading the TIV bass was sufficient and all I got from the subs was extra TT rumble and a whole mess of extra wiring..
I had four 6' by 2' by 2.5" (Roxul) panels hung on the front wall of the listening space with my previous speakers which were boxed monopoles. It improved the clarity, imaging, and staging.
When I brought in the 2.5R, I had a heck of a time trying to get things to sound right. There was a weird 'phasing' going on where the outer soundstage was big, wide, and open, and the centre was very flat. A friend that owned Mags suggested to remove the panels, and wouldn't you know it... the staging and imaging became more cohesive.
I put these four panels horizontally up high near the ceiling to help mitigate the rooms reverb.
My space is a a 1150sqft condo, with the living space being about 900 of it, and 11' ceilings. Most of the surfaces are hard and reflective and when the music gets turned up you can really hear the room start to dominate. I had considered QRD for the front wall, but for me a factory made option is cost prohibitive and I don't have a space to DIY, so recently we purchased two 5' high majesty palms and I tried these in various locations near the speakers:
First was against the front wall and between the speakers; this shrunk the stage in all dimensions.
Then between the plane of the speakers; better, it soften the hardness of the room without the deleterious effect above.
Along the front wall at the on-axis point of the rear wave; not so great.
On the outside of each speaker, perhaps a foot ahead of it's plane; quite nice, brought a nice shimmer to the ribbon and widened the stage
Just today I picked up another two palms and will these between the speakers to see if there's an additive effect.
Opinions don't affect facts. But facts should affect opinions, and do, if you're rational..
- Ricky Gervais, 2012
I think each room is idiosyncratic, so you have to figure out what works best for you; there are also corner base traps, which you cannot see in the photograph.
This really is a good looking room, Slapshot.
Thank you...only took several decades to get to this point.... :)
I also have 1.7's that are in a room now about 12.5' x 20.5' x 7.75'. I tore out the original paneling and ceiling tile and stuffed the walls and ceilings with Roxul. The front wall has 4.5" to 12"; the ceiling 6" and the rear wall 6". I did this originally to reduce outside noise and for thermal insulation.
Afterwards I noticed that I could hear the quite parts of classical music better at lower volumes along with a general improvement in detail and soundstage across a wide variety of classical and jazz. There was dramatic reduction in what I call "choral-soprano-screech". REW showed dramatic improvement in waterfall decay. I decided to add 6" of Roxul on the sidewalls coming out 30" from the four corners for more bass trapping which resulted in more improvement on the REW waterfall and in my ears for timpani and kick drums and electric and acoustic bass. (The rest of the sidewalls are new sheetrock with or without book shelves and a glass window on one side. The floor is concrete covered with a thin Berber carpet with no pad. Subwoofer is a Rythmik F15HP with crossover at 40 or 60 HZ depending on music.)
I had my 1.7's about 1/3 the way into the room and for giggles decided to move them about 2' from the front wall keeping them at 40 degrees and now facing the corners. The rear sound then hit Roxul on both the front and side walls. This improved soundstage and detail and bass decay time even more.
I plan to cover the Roxul surfaces with Owens Corning 703 wrapped in acoustic fabric for appearance. Since I am crazy I decided to make up some 3" thick floor to ceiling 703 panels to go between the edges of the 1.7's and the front and rear walls just to see how that sounded. Again more improvement in detail, soundstage and REW bass decay time. Before I decide to keep these panels I am going to do some more testing with different speaker angles and corresponding listening positions keeping the speakers near the front wall.
This has led me to discount the clichés about "dead", "anechoic" and Maggie rear sound contributing to a sense of spaciousness. The sound is good everywhere in the room but when I move off of axis there is now a more noticeable drop in volume than pre-Roxul. So now I have Maggie box speakers. Heresy!
Some of the best improvement came with English early music recordings in spaces with natural reverb. The vocalists are now more upfront, clearer and louder. I can more clearly hear the acoustics of the recording spaces. I don't have many recording of jazz-pop vixens licking microphones but the ones that I do have don't show as dramatic an improvement. Joni still sounds like Joni but sometimes I feel like I can now reach out and touch her guitar.
I also hear more detail in more complex music like Beethoven and Mahler symphonies. Having said that there is obviously less "sound" in a way and that may be a shock to some. Your mileage may vary.
That is rather extreme.I have not tried anywhere near that much absorption, but at much less than that I got to the point of having too dry a sound with too little reverberation to it, at least to my taste. I also observed an improvement in clarity as the stuff piled up but thought things started getting clinical and artificially overly present individual instruments. The orchestra did not seem to gel together that well. My walls are all bookcases and stacked junk so perhaps they were already sufficiently absorptive and diffusive. So perhaps your "raw" room less the absorption is rather lively relative to my attic like junk room setting.
In most zen vibe empty listening rooms I do suggest a fair deal of diffusion and absorption but I prefer that to be provided by furniture and other "useful" items that do something beyond their acoustic impact.
Extreme? Well bless your heart. That's the nicest thing anyone's said about me for a while. :) I definitely prefer the detail and much improved soundstage. I suspect that the standard Maggie wisdom for speaker distance off front and side walls is less useful as a room gets smaller. If I took my current speaker/listener triangle and moved it to a larger room I might be able to get as good or better detail and soundstage with less absorption.
This link http://www.hometheatershack.com/forums/home-audio-speakers/70413-official-2-500-speaker-evaluation-home-audition-event.html has an mdat file for a 1.7 listening test in a much larger room than mine. I have a flatter frequency response curve but their file shows lower reflections in the first 30ms above -30db. I have also noticed that the lovers-of-reflections, Floyd Toole and Linkwitz have much larger listening rooms than me.
There is also a link on YouTube of a drummer playing a few beats after he installs each set of absorbing panels in a small room and another by Real Traps for treating a very small room for recording. Both have before and after music that illustrates what I heard in my room.
Other clichés that did not pan out to my ears and REW are
1. First reflections. 703 panels made no difference on the side walls.
2. TV and rack in center had no effect on soundstage or anything else.
3. 20 square of glass on one side wall had no effect though it is all from 5 to 7 feet off the floor.
4. A side wall with large openings made no difference depending on where the openings were relative to the speakers and listening position.
When I finish covering the panels with fabric I plan to build a large QRD for the rear wall to see what I hear. I expect that the less there is to diffuse the less diff it will make but the trip will be interesting either way.
Thanks for the details.
Yes, for really small rooms or when there is no way to get WAF to have the speakers well off the walls I do suggest thorough absorption, but your room is long enough, and so long as you don't use too much toe in, the sidewalls should be in the null and not participate much in close up reflections.
Your results definitely don't show an overly damped room so it seems you did good despite the unusual amount of damping.. Good to know.
Is your setup along the long wall?
This room is just for music and movies. The speakers are on a short wall. I set the triangle up so that the speakers are perpendicular to the triangle sides with tweeters on the inside. For REW testing the mic is centered on the intersection point of the middle of the tweeters and I move it up and down the height of the triangle a few inches either way looking for the best frequency response curve. I have settled on three positions, a short isosceles triangle close to speakers for near listening, an equilateral triangle and a taller isosceles triangle. The corresponding speaker angles from the base of the triangle are about 45 degrees for the near position to about 30 degrees for the farthest. I tend to sit a few inches in front of the ideal REW spot. I also have comfortable office chairs with wheels, height adjustment and tilt. There is really no bad place on the centerline of the room. If I don't have my ears nearly inline with the tweeters I loose too much detail on some classical recordings. The sweeter spot for soundstage for the middle and far positions is two chairs wide and for the near only one chair wide. It is important to have a near perfect triangle and have the speakers plumb. I don't measure off of walls to layout the triangle as the room isn't perfectly plumb level and square.
So you are more of a nearfield listener. Are you trying to get more of a front row orchestra kind of perspective or is it just the increased clarity in fine detail that you are after?
I find my balance of clarity vs. reverb field being closer to the equilateral triangle, but I sit close to the wall and absorb the back wall.
I finally have my room sounding great but it took a lot of trial and error (and money!) The room is about 24 x 14 x 9 with the speakers on the long wall and a small office area all the way on the left side. There's a weird bump out in the wall behind my right speaker and a wall of glass all the way on the left short wall that's not in the pictures that I can look out of when I'm at my desk. I ended up with 3 Stillpoint Apertures on the front wall, 1 more on the right wall, and 2 more on the back wall for a total of 6. Then I've got a pair of 16" tube traps in the corners behind the speakers and 3 more 11" and 2 more 8" on the rear wall behind my couch. And to top it off I ended up with a bunch of Synergistic Research gear that really made a difference; 20 HFT's, 3 FEQ's, and 2 Black Boxes. Plus I've got everything up off the floor on 4" maple plinths with brass spiked feet and I built a 5" high platform under the couch stuffed with R19 insulation that gives the room a sort of stadium effect. But the best part is the oil painting of a 1951 Ford F1 Pickup truck that sits on the floor right between my speakers. I had to keep it there no matter what its doing to the sound. Actually I think it helps because the room sounds fantastic!
Looks like you don't trust your floor much. How is it constructed?
I generally either use very short speaker cables on monoblocks or bury the wire under carpet to provide physical damping.
Guess I got hooked on near field because my first real listening room was pretty small. That's when I got into Quads and really enjoyed listening close. I do love the detail and experience of being immersed in the music with near field listening. With the Maggie set up in the pictures, I've got the back of my couch about 18" from the rear wall with the speakers out from the front wall about 5 1/2 feet and the listening seat about 7 1/2 feet from the front center of the panels.
The center image appears to float just in front of the front wall about 3' or 4' or so behind the plane of the speakers on most vocal recordings. I'm also getting a pretty wide soundstage with images several feet outside the speakers.
The floor is poured concrete with wall to wall wool carpet. Years ago I got ahold of a Mapleshade catalog and bought a pair of maple amp stands because I was afraid I'd burn my house down with giant tube amps sitting on the carpet. Then after numerous conversations with Pierre Sprey, the founder and head engineer of Mapleshade, he convinced me to put plinths under my speakers as well. I have since tried my speakers with no spikes, just Mye Stand spikes, spiked plinths with no Mye Stand spikes, and spiked plinths with Mye Stand spikes. By a huge margin, the double spiked plinth set up in the picture easily beat every other option. Its an amazingly lively, detailed, but very full sound.
The couch platform was the final frontier. I mostly did that to get my ears more aligned with the center of the speakers since they were now a good 8" off the floor. But it also seemed to just help disconnect me along with everything else, from the walls, floor, and ceiling, of the room. The effect of all of it is a feeling of being immersed in the music, in about the 3rd row, with detailed images that seem to just resonate out of nowhere and float in space.
This set up is probably not technically correct by any means, but I'm enjoying it and listening sessions have become extremely addictive. If I'm out of town or just don't have time to listen to music, I can feel withdrawal setting in after a couple of days. By 3 days, with no music, I'm a mess.
I've attached a link to the Mapleshade plinths.
Well, you wouldn't want to be in my shoes, I had flooding when the sump died and am still drying out the room trying to kill the mold. Its been a few months. I only did one short listen and all seemed intact but for a possible rattle on one bass panel which may be delam.
I don't have enough clearance in the room for tall speaker platforms because of the acoustic ceiling. But I have a slab floor as well, obviously and had to face the realty that it transmits bass quite well into my turntable when both the stand and the speakers are spiked to the floor. so something had to get unspiked. The bass panels ended up with rounded spikes and sat on a rug.
Also lifted my chair on blocks - did not occur to me to build a stuffed platform. I think the barka is stuffed enough for isolation.
I have been trying to imagine what the maple platforms do to the sound of the speakers. Can you describe that in more detail as to particular audiophile SQ characteristics?
I also like the close up front orchestra perspective but am not sure about the nearfield so much. The instruments can appear hyped up. Besides, how do you get to nearfield with a TIV?
So sorry to hear about your flood. What a horrible moment that must have been to find water in your room! I had that once in a different house when a builder who was working on the kitchen upstairs left water running all night. Ended up filing a huge insurance claim and sending a bunch of gear back for repair. Not much fun.
The platforms under the 3.7i's seem to open up the speakers and the sound flows more effortlessly with a certain nimbleness to it. They just seem lighter on their feet, faster, more detail, and more clarity. But not lean by any means. Behind the speakers I've got a pair of REL G2's that are not spiked and not on plinths. I've tried the subs on spikes and it just wrecked the sound. They became dry and thin and the decay in the notes was sort of chopped off.
Also, the rack I'm using is a Merrill 450 lb cast iron monstrosity that is also spiked. On each shelf, I've got another 2" maple slab under each component on Herbie's Tenderfeet to isolate the slabs from the rack. The rack, being cast iron, has a ring sound and the shelves are slippery but the Tenderfeet with maple have eliminated both those qualities plus I've got all that weight for stability. My TT is rock solid on the top shelf and I've painstakingly leveled the platter with the floor spikes of the rack.
Your right about hyping up. Sometimes its like being smacked in the face with a drum stick, or I've even found myself gripping the couch during a huge orchestral crescendo and holding on for dear life to get through it. Intense but I love it! But then on more quiet pieces, the textures and delicacy of the notes are just sumptuous.
Same here. It almost seems the more the better. Though I did find that completely isolating the back wave was undesirable. I left the top 2 feet behind the speakers uncovered.
I also have panels at first reflections (side and ceiling) and in all corners.
I'm now using Dirac as well. It's a great sound, all included.
is to diffuse the rear wave not attenuate it...
But if you are happy, don't mess with success.
"The hardest thing of all is to find a black cat in a dark room, especially if there is no cat" - Confucius
Right, that's what I've read. My testing did not prove that out, though. Just wondering if anyone else found the same results as me.
Once put will hangings behind my speakers (4.5'). Basically destroyed the sound stage. Did not work for me.
I use a mix of tube traps (diffuse side forward), T-Fussors (Auralex) on the back wall behind my 1.6's. The Tubetraps help with absorbing the room nodes & diffusing the rear wave. I've tried absorption and it killed the 3D aspect of the sound.
"I see sound waves"
Exactly
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