|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
71.9.0.179
I read somewhere that Omni-directional speakers (such as Ohm acoustics) sound better closer to room boundaries than conventional speakers. From what I understand, these speakers use the reflective surfaces and use them to their advantage, where conventional speakers suffer greatly from the same reflections.
For those of you who have experiance with Omni speakers, what are the differences between these types of speakers and conventional speakers when placed in a problematic small room ( rack between speakers, close to walls etc.)?
Follow Ups:
Headphones are the ultimate nearfield directionsl speakers!
.
.
.
Richard BassNut Greene
"The Floyd R. Turbo of Bingham Farms Michigan"
As noted below current day Ohm speakers are not omnis. But with respect to omnis, I find that caspian@peak.org nails it pretty good with the post below. I used the Ohm F for many years (still own them) and for sure they performed best "out on the floor" and the sound was compromised if placed too close to walls. Ohm Acoustics advised me that they worked optimally 5 ft or greater from any wall, so as to make the room less of a negative factor.
I recall reading (about 15 years after the fact) "The Absolute Sound" review of the F. I recall that the reviewer didn't have the space nor had a clue as to how to have them placed and he had them far too close to the walls.
It is interesting to note that Ohm Acoustics with its current line elected to abandon the very compelling omni virtue so that the speakers would be more easily integrated into more rooms.
Likewise, other quality omnis I have heard such as mbl and Huff (Geman Physik driver) require lots of breathing room.So to directly answer your question, yes, in my experience an omni can perform well in an otherise "problematic room" *if* the owner can manage to "get them out onto the floor" away from room boundaries. If that can be done other room issues, that can adversely effect front firing speakers, such as different acoustic environments for each speaker, how live or how damped the room may be, etc. will have less of an adverse sound on the sound of an omni.
Robert C. Lang
Edits: 01/11/09 01/11/09
I've built a few DIY projects with omni mids and forward-firing tweeters. This approach, also favored by Linkwitz, Dick Olsher, Danny Ritchie, and Dan Neubecker, produces a a very open and spacious soundstage without sacrificing precise imaging.
I find that such speakers work best with LOTS of open space around them. Too close to reflective boundaries, and there is insufficient delay between the arrival of the direct and reflected sound. Ideally you want at least 10mS delay, so the ear/brain mechanism can sort out the difference. Too-early reflections can smear and muddle the direct sound; when they are delayed, they contribute to the illusion of a wider, deeper stage. So I pull my omni speakers well out into the middle of the room. The walls are covered with a variety of diffractive and absorbtive materials, which reduce and break up the reflections.
The exception would be in a surround channel application. An omni speaker, right against the side wall and somewhat behind the listening position, has a diffuse radiation pattern ideal for surround channel information.
Interestingly, these kind of speakers sound wonderful with NO nearby reflective boundaries. I listened to one of my pairs out in the back yard a lot last summer, and they threw an incredibly deep stage when that information was in the recording.
Whether you prefer an omni speaker or one with a more focused pattern in a particular room could vary.
Since omnis are going to intentionally bounce sound off the rear and side walls, that would suggest that the rear and side walls be approximately the same on both left and right. I've got a room with a 7' wide opening in the side wall by the right speaker. The left speaker has a conventional door opening that is on the side wall, but slightly behind the speaker. The reflections patterns are completely different from side to side.
I've owned omni-directional Ohm Fs, bidirectional Maggie 1.6QRs and several other speakers. In my current listening room (described above) I fare much better with the tighter, directional focus of my Spendor SP1/2Es. Sure it is a small sweet spot, but I'm the only "serious" listener in the household and that spot seems to be big enough for me. If I'm up wondering about in the room, then I'm not listening intently anyway. The lack of a precise image elsewhere in the room is not an issue for me.
Others listen differently and have different priorities. But, since the "problems" in problematic rooms can vary widely, what works best is going to depend heavily on the specific room in question and the preferences of the individual involved.
I've owned the OHM 100's M3 for about 2 years now. Prior to that I had some Dynaudio DIY 2 way for 20 years and a set of BIC 6 for about 10. I much prefer the OHM's to the more conventional speakers for lots of reasons. IRT soundstage and imaging the OHM's are much more real. My speakers are only 1' from the wall 3' from a corner. There's a TV in the corner facing out into the room at 45* and the speakers are on either side opposed at 90*. It's a very odd configuration but because the tweeter is aimed at the inside corner of each speaker it actually works.
From most places in the room a wide deep soundstage is percieved. With direct radiators there is only one spot where there was a soundstage and that was a very small focus. This is most apparent in large orchestral works. In a live concert (as opposed to a dead one) the music comming from the stage is not tightly focused, although you can "place" the instruments if you close your eyes. But its' not pinpoint as a direct raditor setup provides. IMO the OHM's do the best job of this than any other speaker I have heard.
When I was auditioning speakers 2 years ago I listened to the Gallo's, which at the time were going for about 3K. Thery were very nice but even in a "perfect" enviornment (High End Audio Salon) the sweet spot was very narrow. Only one chair had a great seat with excellent imaging. Move to the left or right 3 feet, as on a sofa, and the soundstage collapses. That seems a high price to pay for a single listning enviornment.
That's my story and I'm sticking to it!
******************************
It's the MUSIC Dummy!
Keith is correct. While certainly the current Ohm line descends from the original Walsh concept (I still have a pair of Ohm F's packed away in the basement), the back of the current driver is affixed with absorbing material so that the system radiates sound horizontally about 180 dgrees; not 360 degrees as with the orginal. Sound does not emanate from the rear (or all around) as did the F. The Walsh line sure sounds spacious, though.
Robert C. Lang
t
Omni's can create a pleasing effect.
The "problems" are that it does that to all recordings, everything sounds spacious and just like your room, regardless of how or where the recording was made. Worst, it's an effect one can't turn off.
If one chose to judge "accuracy" based on your ability to understand words, then one finds that the higher the direct sound level is compared to the reflected the more words you can hear.
For "hearing and preserving information", either spoken words or recorded stereo image, then the directional speaker which produces a lower level of reverberant sound is vastly better.
Best,
Tom
You stated:*****Omni's can create a pleasing effect. The "problems" are that it does that to all recordings, everything sounds spacious and just like your room, regardless of how or where the recording was made. Worst, it's an effect one can't turn off.*****
One could also say that front firing speakers "sound less spacious and constricted----just like your room, regardless of how or where the recording was made." Of course, this would be a fallacy.
Likewise, your sweeping statememt as it applies to omnis is also a fallacy. I can only conclude that your experience has been with poorly designed and/or poorly implemented omnis. As with any other speaker type all omnis are not created equally. Any good speaker, omni or other design type will accurately (for a loud speaker) reproduce the contents of the software. I have certainly found this to be true of well designed omnis I have heard.
Of course, *all* speakers, regardless of design type or expense, will impart its sonic signature, good and bad, on all recordings.
Robert C. Lang
Edits: 01/12/09
Perhaps an explanation is in order.I have heard a number of omni speakers, a friend was a salesman for Ohm and another less well known brand of omni’s. I have heard several models in my room and others and some as set up by the factory.
I have also heard them when setup outdoors where there is no room to help out and this reveals what the speaker alone can do and how much the room contributes.
If you have never done this, when weather permits, set your stereo up outdoors and listen to what the speakers alone can do (true for any type of speaker).
What you hear without the room is a thinner representation, less bass BUT preservation of the stereo image is vastly better without the reflections. Do try it if your skeptical.In my job function, I design loudspeakers often used in larger rooms with poor acoustics, often wide dispersion speakers are what is being removed when ours go in. My comment on directivity is an accepted fact in architectural acoustics, if you want to preserve the signal, directivity is your friend, omni’s are the worst choice in that use. Lastly, keep in mind that the typical shoebox with cones and domes has only slightly more directivity than an omni speaker and the room still plays a very strong roll on what you hear.
“Of course, *all* speakers, regardless of design type or expense, will impart its sonic signature, good and bad, on all recordings.”
True but typical hifi speakers in a room are still pretty far from what can be achieved, the designs ignore most of the problems which make the speakers have a sonic identity.
FWIW, Here are some comments from a home hifi person using our commercial speakers in a home.
http://www.audioasylum.com/forums/hug/messages/13/139739.html
Best,
Tom Danley
Edits: 01/12/09
my experience would be similar. also somewhat poorly recorded lp's and cd's sound better.
In my experience, very directional monopole speakers -- I'm thinking horns/waveguides here -- are your best bet for near wall/corner use. They don't tend to splash as much acoustic energy onto the front and side walls, preserving directional cues. They can image like an sob as a consequence. Roy Allison also found that placing the woofer at the floor/wall boundary would minimize reflections that would otherwise cause audible mid-bass suck-outs.
Other than that, very wide but shallow conventional boxes like the old Boston Acoustics A-series or very anti-diffraction designs like the original Snell A were designed for near/on wall use.
I had the original Gallo Reference speakers for awhile and never could get them far enough from room boundaries to sound right to me.
Last comment: I talked to Winslow Burhoe (you might remember him as the designer of the EPI/Epicure/Genesis/etc. speakers) some time ago about this very issue. One of his first commercial products back in the 60's was an omni based on the use of 4 of his "Burhoe modules" in a huge tower called the EPI1000. He said that the preferred placement of these monsters was, assuming a rectangular room, on the centerline of the long room dimension, with each speaker 1/4 of this dimension away from the nearest short wall. In other words, about as far from any boundaries as possible. I can only imagine the WAF of that layout.
is basically the placement recommended by Audio Physic.
It has a couple of advantages. It ensures that the first reflection paths tend to be long relative to the direct sound path so it weakens the first reflections, and it also puts the speakers in locations where they minimally load a lot of the room's modes. The end result of those two things is that this placement minimises the impact of the room on the sound probably as much as can be achieved without acoustic treatment.
You would minimise the room's effects more with a true nearfield setup but with normal sized speakers rather than monitors, and the listening distance required for the sound from the different drivers to integrate properly, you're probably not going to be able to sit close enough to the speakers to achieve a genuine nearfield setup. In a quite small room this placement would probably yield a true nearfield setup but you'd have to use monitors designed for close listening.
This is basically the setup I use in my room which is awkward because it's L-shaped. As far as the WAF goes, my wife had agreed that I could set up a room as I liked for the system so that wasn't a problem. If you don't have that freedom then I think the mildest way of expressing things would be to say that it is not a living room friendly setup :-) It does give very good results in my experience.
David Aiken
A few years ago, Winslow Burhoe was selling a wall positioned speaker under Direct Acoustics Silent Speaker. Although the website is still active I think he stopped selling them in part because production of the tweeter he was using was phased out. Most recently I htink he's been designing for Zvox.
JM Reynaud sells a speaker designed to be positioned against the wall.
And lastly Amphion's Krypton2 uses a cardioid pattern which supposedly allows the speakers to be put against the wall. Soundstage did an interview with the proprietor of Amphion where he explains this but I can't find it at the moment.
If you want to put them in the corner then I believe you are looking for a pair of Klipschorns.
on soundstage video
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: