What is your source of knowledge that above is "typical"?
How do you know that this can't be a problem of your loudspeakers or your ears?
Rudolf
There's nothing typical about this. I don't have any problem hearing a convincing phantom centre channel including the "ssssshhhss" in the treble, and don't hear what you describe, nor have I ever in any properly working speakers.
Are you sure there isn't a problem with the speakers ? One tweeter connected out of phase with the other, or a significant mismatch between left/right tweeters frequency/phase response for example ? Perhaps a fault in one crossover.
The only time I've ever heard something approaching what you describe is when I accidentally had the tweeter of one speaker connected in the wrong phase, causing left and right to be in phase in the midrange but out of phase with each other in the treble. (As it was a 3rd order crossover there was no big notch in the amplitude response of the wrongly connected speaker - just a very different phase shift at and above the crossover frequency, so both speakers sounded ok individually, but didn't work together)
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Are there any particular requirements for the cone reflector? Specifically, overall size (especially in relation to longest wavelength to be dispersed), proximity to cone, etc.?
This type of construction could lend itself well to implementation as a 3-way, too, no? If a too-large driver is used in order to achieve good bass (without external subs), you might have a power response dip at the high end of the bass driver's passband as it starts to transition into half-space while the wide-range driver is omni at its low end.
The cone should not be larger than the driver. Otherwise there will be too much unnecessary diffraction.
It should not be too small so that it deflects all wanted highs sufficiently.
So same diameter as the driver is a safe bet.
The distance has to be found experimentally and it depends on the driver used. In the example that Rudolf posted somehwere earlier in the thread, the cone sits only 1 cm above the (in this case rigid) membrane. Reflections back to the (rigid) membrane and forth again towards the cone and loading effects are less a concern the greater the distance.
It can be done but I intentionally made it a 2 way to avoid an x-over point above the modal region to get the best possible omni / point source characteristic from the design.
I think also with such a design, you should keep structures as small as possible (see minimizing diffraction above).
Check my measurements of different cone reflectors in this thread. The results are highly unpredictable. It all depends on the driver and how it behaves in the near field.
The last reflector type I've measured is probably as good as it gets if a fullrange driver has to be used. It results in reflections from desirable locations (lateral and height) while keeping direct and reflected sound spectrally balanced.
Yes, the smaller the "baffle", the higher up you can go while staying in full-space radiation.
I don't think the Schroeder frequency matters for full-space vs half-space radiation.
By the way, did you make that cone yourself or did you buy it somewhere?
This referres to what ?
I really like DIY but for things like that I prefer final solutions. Especially if the outcome it not 100% clear
The cones are from Blue Planet Acoustic in Frankfurt.
Diffusor Pyramidenkegel - Lautsprecher Selbstbau by blue planet acoustic
No exactly a bargain but nicely made.
That's actually rather impressive.
It would be interesting to see an average at a typical listening position to suggest what sort of shelving filter it needed in the mids.
You don't have any problem with stereo triangle? Be blessed !
But it is also a curse. Nothing will force you to search for better alternatives.
- Elias
But it is also a curse. Nothing will force you to search for better alternatives.
- Elias
That's actually rather impressive.
You're the first to notice. It's especially impressive when looking at the listening axis (0°, 10°, 20° vertical):
An externally hosted image should be here but it was not working when we last tested it.
... and "ceiling axis" (70°, 80°, 90° vertical):
An externally hosted image should be here but it was not working when we last tested it.
I definitely give it a "thumbs up"!
In fact I'm rather surprised that others didn't note it. ..probably from the glaring alterations in overall linearity for any given axis - but then again it's full-range and it can just be eq'ed - while retaining the marvelous off-axis response. I'd bet that even the linear decay is decent (after eq. of course).
Sorry,
Room Acoustics
Do a Ctrl+F for "Schroeder"
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Anyone with access to a wood lathe could make a decent one, I suppose.
I noticed, but its not very directional, consistant, but with no directivity. I am not sure why you would want that.
Because it often produces a more compelling presentation.
..more specifically it tends to reproduce the venue in context with the performance better than more directional designs, with a near absence in the ability to localize the loudspeaker with regard to music reproduction. Of course it also tends to "give-up" a few other things as well..
I definitely give it a "thumbs up"!
In fact I'm rather surprised that others didn't note it.
but which plot are You talking about?
You have commented the horizontal response plot:
and Markus referred to the vertical plot:
in case of the vertical it was very hard to notice anything because it was very unclear
but what's the use of such reflector as Markus has proposed? flooder doesn't need it and if one wants to make an omni at ear height with such reflector then it brings back the problem of floor reflection
so the question is - who needs it? who else except Markus? of course Markus needs it because He believes in a sound of a flooder coming from the floor
which is obviously not the case as reported by growing number of diyaudio users who tested it OK, I reckon it must be this:
Attached is what you would hear if you balanced the pipe on your nose while laying at your back on the floor (plus reflections from all walls).
Because the vertical response is somewhat fragile you should keep the middle of the cone at ear hight.
What I was saying was not related to half vs. full space radiation but to the reverberant sound field. I don't want to have the x-over's lobing in the pretty strong and many reflections produced by the mids and highs.
Look at the vertical responses. It is all there up to 2KHz and then it is fading out gradually.
Attached is what you would hear if you balanced the pipe on your nose while laying at your back on the floor (plus reflections from all walls).
Because the vertical response is somewhat fragile you should keep the middle of the cone at ear hight.
Sure ! But that already exludes myself, unfortunately
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If the goal is to add spaciousness then strong reflections from the sides and from elevated locations is the goal. The "double cone" I've used is probably the easiest practical way to achive this. The better solution is probably more channels and high directivity speakers.
All other early reflections should be eliminated, otherwise the result is a intransparent, mostly colored but spacious mess which admittedly works well for some music genres. Stereolith, bipole, speaker facing boundaries, objects blocking the direct path, any setup that reduces direct sound and therefore increases the level of early reflections will result in this kind of presentation when used without room treatments and/or careful setup. It has a "whoa" effect at first if one is used to dry, higher directivity concepts but it wears off pretty fast if one also knows how good controlled directivity concepts like yours can sound.
I've heard and measured them all, not like some people (not you) on this board that advocate concepts they've never heard before. Those people just accept their own opinion while ignoring facts and other peoples experience. Right now I'm still exploring what is possible and if and how a broad dispersion concept can be made to work.
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