That sounds viable (small tweeter, no "face-plate").
You could also use a wide dispersion tweeter with absorption at +/-90 degrees, or a baffle large enough to block the intended pass-band of the two tweeters - which is still eminently plausible down to 2k for many designs.
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My generalization applies primarily to above average recordings where introducing any amount of room ambient effects would deteriorate the intended soundstage presentation. I am not in any way saying that dipoles or omni setups are necessarily incapable of providing a reasonable facsimile of a performance venue - I wouldn't have built my HT speakers the way I did if I thought that - but they are less good at it than a speaker with controlled but narrower dispersion.
For answering to Scott & CLS, I use something very close since a while. Back to back dipolar compressions. The working hypothesis is the linear quadripole radiation pattern, that's almost omni (but compared to the drivers size, the wavelengths are probably too short in the high end).
Actually, I use one unit as a two channels central transducer, the common part of the signal is reproduced as a whole intersection of R & L, realizing the supposed LQ pattern, the individual part stays lateralized, all this being also reflected later by the side walls. That's close from the trinaural concept.
For those familiar with the stereolith idea, the width of this unit is 19 cm. My personal opinion has little value, but when I compare with a conventional system I have, looks like this works.
Actually, I use one unit as a two channels central transducer, the common part of the signal is reproduced as a whole intersection of R & L, realizing the supposed LQ pattern, the individual part stays lateralized, all this being also reflected later by the side walls. That's close from the trinaural concept.
For those familiar with the stereolith idea, the width of this unit is 19 cm. My personal opinion has little value, but when I compare with a conventional system I have, looks like this works.
Hi Radugazon,
Up to now I haven't seen anyone else following your astonishing configuration -- stripped compression drivers on shallow WG/OB, and line them into linear quadripole, with complex acoustic characters... Talk about crazy speaker builder, you lapped all others by I don't know how many laps...
No, I mean much simpler and cheaper ordinary dome tweeters, back to back bipole. (no rear wave of each driver, sealed inside each of them)
Up to now I haven't seen anyone else following your astonishing configuration -- stripped compression drivers on shallow WG/OB, and line them into linear quadripole, with complex acoustic characters... Talk about crazy speaker builder, you lapped all others by I don't know how many laps...
No, I mean much simpler and cheaper ordinary dome tweeters, back to back bipole. (no rear wave of each driver, sealed inside each of them)
If I had a couple of Neo 3, I would be very happy to try them in this configuration (open vs closed backs)
What about such an approach:
Did anybody ever run FEM/BEM on such a device?
An externally hosted image should be here but it was not working when we last tested it.
Did anybody ever run FEM/BEM on such a device?
@Radugazon
I think this beast would be better-suited from its max. SPL, but I don't know whether it can be used open back or two back to back would be necessary.
http://www.expolinear.de/images/stories/expolinear rt-10 pro.pdf
I think this beast would be better-suited from its max. SPL, but I don't know whether it can be used open back or two back to back would be necessary.
http://www.expolinear.de/images/stories/expolinear rt-10 pro.pdf
I've tried all manner of reflectors (in this sort of a configuration), but haven't been pleased with the subjective results of any of them.
Smaller reflectors on small domes seem to be the least objectionable. (..the commercial equivalent is the "omni-stat" designs from Mirage.)
OS³-Sat Bookshelf Speaker - Overview
i.e. the tweeter reflector "good", the mid-bass reflector "bad".
Morrison Audio has been doing this sort of design for quite a while now.
Morrison Audio fine audio speakers and electronics.
-it utilizes a 1st order high-pass on the tweeter, which puts some severe restrictions on tweeter spl.
I should also note that *historically* the Morrison has been considered by TAS (The Absolute Sound magazine), to have the most compelling presentation of "images" of any design reviewed by them.
..yes, *imaging* not venue effects (though they thought that was more compelling as well) - this is despite the fact that it's an "omni/radial". (..where "omni's are generally considered *poorer* in this regard, being more diffuse and less "pin-point".)
I think this is mostly due to the small-source tweeter and small reflector for it, with an extended lower freq. response (due to the 1st order high-pass filter).
..yes, *imaging* not venue effects (though they thought that was more compelling as well) - this is despite the fact that it's an "omni/radial". (..where "omni's are generally considered *poorer* in this regard, being more diffuse and less "pin-point".)
I think this is mostly due to the small-source tweeter and small reflector for it, with an extended lower freq. response (due to the 1st order high-pass filter).
On a few, yes.
You can get a pretty good pattern with a good reflector (and a lot less treble loss). I did derive a CSD plot once however (full range radial) - it wasn't pretty. 🙁
BTW, if you are going to experiment further I recommend the "Morrison" approach.
Hi,
As I see the picture of Morrison's speaker, I feel the reflectors are somewhat small related to the dome and cone.
So, in fact much of the sound would 'escape' and more or less up-firing. It seems, the reflectors are configured such that they deflect a (small) portion of energy toward the horizontal plane. No?
As I see the picture of Morrison's speaker, I feel the reflectors are somewhat small related to the dome and cone.
So, in fact much of the sound would 'escape' and more or less up-firing. It seems, the reflectors are configured such that they deflect a (small) portion of energy toward the horizontal plane. No?
I think it's a matter of experimentation - getting the right dispersion pattern for the tweeter with an extended lower freq. response.
This one looks like it might work well:
http://www.zaphaudio.com/temp/SB-Acoustics-SB26STAC-C000-4-FR-offaxis-0-15-30-45-60.gif
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Here is mirage's omnistat measurements:
SoundStage! Measurements - Mirage Omnisat v2 FS Loudspeakers (6/2005)
Bear in mind it's a *2* meter anechoic measurement (obviously for a discreet axis). That treble loss will be far less than represented in the measurement.
You can see however that the problem areas are the mid driver's radiation pattern below 2 kHz and down to as low as 400 Hz.
SoundStage! Measurements - Mirage Omnisat v2 FS Loudspeakers (6/2005)
Bear in mind it's a *2* meter anechoic measurement (obviously for a discreet axis). That treble loss will be far less than represented in the measurement.
You can see however that the problem areas are the mid driver's radiation pattern below 2 kHz and down to as low as 400 Hz.
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Aren't you both saying the same thing? Narrow dispersion speakers open a window into the performance making you feel like you can step into it. The image is sharp and the wall and the speakers in front of you disappear. Wide dispersion speakers bring the performers in the middle of the room. The room and the objects in it are still there while the image of performers is well defined but somewhat soft and holographic.
That's my limited experience so far as well, although a good description may not be possible. I think it's also what Linkwitz concluds from his evaluation of the Behringer monitor.
Every direct sound source should be placed at or around ear height unless very strong first reflections are present that could override the precedence effect.
The masking effect means that the direct sound determines the location whereas the reflections within a certain time window determine the timbre. My experiments with the 8" HX201 confirm this. Graaf with his FE206E with whizzer cone has the image in the middle between speaker and ceiling, same as I had with the 5" HX135.
I think it's more complex. Later reflections do broaden images, smear them in certain directions or even override direct sound localization cues.
Timbre is closely connected to our perception of space. It is best heard when one A/Bs binaural recordings of different spaces. On the other hand our hearing does compensate for these timbre changes. A familiar voice is always recognized in completely different aural spaces.
I believe this solely depends on the radiation pattern and resulting reflections. When I use the reflector on a upward firing B200 the image is wide but not very high. Without the reflector the image gains height.