Placement along the short or long wall? What's "IN"

[JackD201]

Practically all newly built critical listening facilities from recording, mastering and post around the world have ditched live end dead end short wall design in favor of wide wall symettrical construction which require far less room treatment and much less space. A number of speaker manufacturers like Audio Physic and Revel expressly recommend wide wall placement too. Why are audiophiles still stuck to the short wall? What do you guys think?

[hein]

Everybody, please welcome THE TALENTED MR. JACKD.....WS's own US-trained ACOUSTICAL ENGINEER! This guy is the REAL THING, not a pretender. GO AHEAD, TRY HIM with your nerve-wracking acoustical problems.

[timn8ter]

I thought it was better to avoid symmetical construction due to standing waves. I've not constructed a room specifically for audio reproduction, however, in my current room the only parallel surfaces are the floor and ceiling between which there is a 3.35m distance. The speakers are about 2m from the wide wall.

[ichabod]

I used to do it from the short side, but now I'm dating audio physic! I get better response, a fuller sound for such a small speaker in a small room. Who needs those behemoths.

[av_phile]

Practically all newly built critical listening facilities from recording, mastering and post around the world have ditched live end dead end short wall design in favor of wide wall symettrical construction which require far less room treatment and much less space. A number of speaker manufacturers like Audio Physic and Revel expressly recommend wide wall placement too. Why are audiophiles still stuck to the short wall? What do you guys think?

If I recall right there's this article from audioperfectionist.com that recommends placing the front speakers across the shortest wall in a room. Doesn't this have something to do with personal preferrences for near-field or far-field listening?

[JackD201]

Hi guys, well timn8r, symetrical construction refers not to parallel surfaces but the construction materials used for the side walls, my bad, should have been clearer. Ideally for example if you have a nara door on the left you have to have one mirroring them on the right. If you have a window on the left, ditto, one on the right all of the same expensive tempered laminate we love but whose price we hate. True, the ideal would be to have no parallel surfaces at all but in shape the room MUST be as symettrical as an ink blot test that most of us audionuts should take monthly. Look at it this way matched pair tubes, dual mono construction, tight tolerances, cable length to the nanometer lahat pantay kuwarto mo naman hindi. Labo di ba?

The now standard thinking in "get paid to listen" world, av, is that short wall placement is done out of necessity out of "real-estate" limitations and not by choice. Like I said it can work just get your check book ready.You would need a seriosly large room to go wide wall AND far-field. Mid-field baka puwede pa. In the simplest terms using the wide wall practically removes side wall reflections or creates large enough delay times so psychoacoustically you know what is really coming out of the speakers. The most immediately obvious gain will be an increase in soundstage width and depth. It is not uncommon for sounstages to go way past the left and right of your speakers and past the front wall. The more subtle effect which prompted the pros to go this route is improved frequency response due to having much less comb filtering. This allows them to monitor at much lower playback levels which means less fatigue, which means, more billable hours a day AND a much longer career.

Sadly my main room, doesn't allow me to go wide wall. The consequence...GASTOS sa treatment and construction and I'm still far from satisfied! But that's another story.....

[timn8ter]

Very good. I understand your meaning now and agree. I have experienced what you describe.

[hein]

THIS GUY IS GOOOOOOOOOOOD!!!

[jo2]

JackD201,

Speaking of parallel walls, would there be an effect if say one wall is 5 meters and 50 inches

long and the other 5 meters and 57 inches long?

How would it affect the sound or acoustics?

What about if both walls have the same length but of different construction

material...ie...gypsum/gyprock on one wall and concrete on the other?

[timn8ter]

Mike Levigne, who lives nearby here, had a listening room constructed recently. This description was written by the president of our local audio society.

The room was constructed with maple hardwoods and fabric covered fiberglass (1” and 2” thick depending on location). The corners and ceilings were designed as bass traps. The room is approximately 29’ x 21’ x 11’ and all of the walls are non-parallel creating an oval shape. Acoustic treatments are usually expensive, Mike wisely uses treatments that also look great. The semi-cylindrical diffusers at the sides of the room are both attractive and effective. A twofer. The listening and speaker positions were designed to be at 1/3 the distance approximately along the length of the room. The speaker end has a 10’ deep hardwood floor and the remaining floor area is carpeted.
Mike plans to add multi-channel music in the future. However, the room width was for two channel reproduction. The rear speakers would not be in the ideal 110 degree ITU Standard location, but would be equidistant to the listening position.
The ceiling design is excellent and includes 6 chambers, 3 on each side of the room. The center 2 chambers include an ingenious cloud which consists of 8 angled diffusers about 48” x 18” x ¼” maple plywood with 1” x 2” solid maple border mounted on chains.
The Lutron lighting system has several preprogrammed scenes which can be activated by his remote control. With the lights down, we are less distracted and the listening experience is more relaxed. Mike damped all of the down light cans with lead so they don’t ring. The HVAC forced air system is essentially silent. The only noise I could detect was the fan in the EMM Labs DAC6 (which is almost non-existent anyway).
So what does it sound like?
Well… it doesn’t. You can hear everything on the recording… the system and room disappear. And the music just flows. It’s a great thing. Room reflections are the enemy of sound reproduction in the home. Here, the non-parallel walls and distance from the listening position are all greater than 20 milliseconds away, so reflected sound from the speakers do not mix in time with the direct sound (at about one foot per millisecond = 20 feet round trip for a reflection, ideally a reflective surface should be at least 10 feet away). The hard wall surfaces do not absorb sound, so the sound is lively and not dead. There is no image smearing and you can hear the micro detail on the recordings. Usually that low level information includes the original recorded acoustic or venue, which greatly enhances the listening experience. With a virtually zero noise floor, the dynamic contrasts in the recordings are preserved. The only compression is usually what was in the recording. And bass response was natural and extended. The cloud enhances the illusion of image height. A recording in a concert hall sounded like the concert hall.
The classical music pieces were particularly enjoyable as they had great width, depth, layering and scale which I think is the most difficult thing to reproduce convincingly. Frequently suspending disbelief, the music could sound real. Christophe Changnard, a friend of Mike’s who is the music director for the Northwest Sonfonietta (which Mike also contributes) thought that music which he brought and had recorded, was reproduced like he remembered during the original event. You can’t get a better endorsement than that.
What about the music?
Mike played a smorgasbord of tasty music. Such as: Linda Ronstadt Crazy, The Doors Riders on the Storm, Shaggy Hey Sexy Lady, and IZ Somewhere Over the Rainbow/What a Wonderful World. There were male and female vocals, Jazz, Rock and Classical too many to list here. Mike compared identical recordings on vinyl (typically 45RPM reissues) and CD/SACD. One comparison was between the new FIM release of Midnight Sugar by the Yamamoto Trio and the 45RPM vinyl reissue (highly recommended). I usually preferred the vinyl, but hey, well recorded digital was still great, so you don’t have to be a format bigot at Mike’s place because it all sounded great. Just kick-back and enjoy. No analysis paralysis necessary.
Bottom Line?
Mike hits it out of the park! The new room joins a very short list of rooms and systems which define the state of the art in sound and aesthetics in my opinion. I congratulate his achievement because it reveals what is possible. We can learn from and adapt aspects of his design in our own systems and thus we all benefit from his effort. And most importantly, the music was magical, which is the goal we seek. His is truly a music lovers room. Bravo Mike!
Mike Lavigne’s Music System
As of October 2004
Analog source: Rockport System III Sirius,
Lamm LP2 Delux phono preamp
Digital source: EMM Labs DAC6 and CDSD
transport
Pre-amplification: passive Placette balanced
remote volume control and custom Jena Labs
balanced switcher
Power amplifier: Tenor 300Hp hybrid mono
amps
Loudspeaker: Kharma Exquisite 1D
Interconnect Cable: Nordost Valhalla single
ended and balanced
Speaker Cable: Transparent Opus MM 8’
Power: Dedicated circuits with Jena Labs deepimmersion
cryo’d duplex receptacles
Power Conditioning: Shunyata Hydra for
sources
Power Cords: Elrod
Stands/Isolation: Zoethecus all with Z-slab
shelves, SAP Relaxa 1 Magnetic levitation base,
Black Diamond Racing shelf
Room: 21’ wide x 29’ long x 11’ height
Acoustic treatment: see article
Accessories: Walker lead filled pucks, porcelain
cable elevators

[ichabod]

JackD, I like your treatise on the long short wall stories. I'm getting the desired effect you've just described using the AP method. Like the soundstage is the whole wall iteself, wide and deep like I'm thrusted into some space not entirely my room! Yes, less fatiguing, and one can listen at low levels without missing anything. Great to have guys like you here.

[arnoldc]

hmm, based on this post, i think i'm rearranging my room again - to make it more symmetrical. right now i have glass windows on the left, wooden cabinets on the right. i'll turn my gears around so that i'll have the cabinets on the back wall the windows on the front wall and cement walls on left and right.

[johnmarc0]

There is actually another method that makes wide wall projection on small spaces. But it looks ugly aesthetically. You can build your room to be an "anechoic chamber", where you place 45 degree pyramids all over the wall. The biggest challenge in room design is perpendicular planes (90 degree areas) everytime you have a 90 degree portion in a room it creates "sound propagation phase shifts" and reflects back to the point of source/pickup. Once a room is anechoic regardless of size of radiator source (i.e.speaker) or transducer (i.e. mic), the general surround area reception will regard this as an "isotropic point" (it takes a propagation of a sphere) where toeing (the process of finding the least phase shifts) now is not an issue but creates the issue of "directivity".

Further, sound propagation is 3 dimensional, thus vertical coupling becomes a problem (i.e. bookshelve stands distorts the isotropic radiation pattern), wide wall ratios should also take vertical clearance into consideration or make speaker stands as thin as possible without creating a secondary vibrations.

As Mr JackD mentioned it can be a feat in checkbook engineering.

That's why the bookshelf vendors make money, bookshelves simulate small point source radiation diameter. With the advent of thin non coupling bookshelf stands and ascension of audio physic, wide wall projection need no not be the ultimate setup.

[handyboy]

hey jack,

You should check out my condo then. its an acoustic nightmare.

[JackD201]

Why Gagamby? Let me guess, buhos walls marble flooring? Yeah the curse of condo livin. Try false walls of 3/4 inch marine ply and wall to wall carpeting for your listening room.

Hi Jo2, If you mean your long wall and short wall are practically the same length you are in serious trouble. There's only one shape worse than a square and that's a circle. As far as differences in materials, there are always two things that happen when a wave hits a boundary no matter how hard or soft. The boundary will always reflect some of the energy and it will also absorb and transmit some of it (like to the next room). What frequency is reflected and what is transmitted is density and texture dependent. In effect you can have one wall reflecting mids and another wall reflecting highs medjo exag but you get what I mean.

[arnoldc]

... and if i do that, i can put false walls too.

thanks jackd!

[jo2]

Hi Jo2, If you mean your long wall and short wall are practically the same length you are in serious trouble. There's only one shape worse than a square and that's a circle. As far as differences in materials, there are always two things that happen when a wave hits a boundary no matter how hard or soft. The boundary will always reflect some of the energy and it will also absorb and transmit some of it (like to the next room). What frequency is reflected and what is transmitted is density and texture dependent. In effect you can have one wall reflecting mids and another wall reflecting highs medjo exag but you get what I mean.

No, not front,side and rear walls but just the two side walls but with a

difference in length say in 7 inches (5m 50ins-RIGHT wall and 5m 57 ins-LEFT wall ).

Also I thought that two speakers should have the same acoustical environment (and distance) to create the stereo image at the listening spot.

IMHE having one speaker with an acoustical environment different to the other is not right.

I maybe wrong.

[JackD201]

You are ABSOLUTELY correct Jo2, 99.9999% of us mere mortals don't have the good fortune of a purpose built listening room like the most enviable Mr. Levigne. Having less than perfect room acoustics still doesn't mean we can't enjoy good stereo sound though. I wouldn't worry about those seven inches.

[handyboy]

my living are is not a square or rectangular shaped room. its like an octagon with different angled walls. you should see it one time. bad vibes!

[handyboy]

my living area is not a square or rectangular shaped room. its like an octagon with different angled walls. you should see it one time. bad vibes!