but these remarks are addressed to a certain type of SL's customer who typically has a fetish of a HIGH soundstage imaging specificity
this does not mean that such a HIGH soundstage imaging specificity has anything to do with realistic sound reproduction
Graaf, if by "specificity" you mean realism, yes, that's what we try to "buy"..
But as I said, you might prefer the sound of extra reflexions from everywhere and that's ok. I like them too, but not to the point of listening to reverb only.
Unless your room is critically damped?
this said I haven't built the Plutos yet, only tried with a small FR driver this far.
But as I said, you might prefer the sound of extra reflexions from everywhere and that's ok. I like them too, but not to the point of listening to reverb only.
Unless your room is critically damped?
this said I haven't built the Plutos yet, only tried with a small FR driver this far.
I wouldn't expect any speaker to "work optimally" without EQ. Timbre depends on the direct and indirect sound. Do we know how much to measure this and derive a equalizing strategy from these measurements? I'd say no.
probably would be good to have room EQ
but my point is that the combination of a crossover and carefully chosen drivers for this specific task would form a EQ, or some of it at least
no point in trying to achieve absolute perfection
that always tend to go wrong anyway
99% perfect would be enough
please not this is specificly aimed at omni design only, because of its special design
tinitus,
What happend to Shift and all the punctuation keys on your keyboard? Makes your posts hard to read.
As I've said before, if you don't know what the goal is, you don't know how a driver or crossover or EQ should behave.
What happend to Shift and all the punctuation keys on your keyboard? Makes your posts hard to read.
As I've said before, if you don't know what the goal is, you don't know how a driver or crossover or EQ should behave.
should be able to cope with that in due time
but yeah, this takes 'special measures', and why I said what I did about crossover and driver forming EQ function, as a whole
The ability to localize sound is the highest order of survival engagement. You don't go to a chamber orchestra production to hear garbled modulation envelopes.
The best seats provide best articulation.
Elementary?
Re-read quote of SL in #115
Highly omnidirectional speaker, emulating point source allows formation of uniform wavefront close to speaker, allowing use up close.
SL uses two feet from walls minimum.
I have roughly 7.3m(length) x 4.3m(width) living room. Front wall is virtually all glass, left wall is 50% floor to ceiling brick with fireplace, and 50% floor to ceiling glass as bay window, back wall is solid wood on plaster board with small open doorway to dining room. Right wall is 2/3 floor to ceiling open book shelving with remainder open stairwell to second floor. Floor is wall to wall wool carpet, ceiling is acoustic tile glued to plaster board.
Primary position for speakers is midway up length of room, with floor to ceiling glass end as front wall. Speakers divide width into 3rds, roughly placing each speaker 1.4m from walls and each other. Excellent results in listening at apex from 1 to 2 meters, and is source dependent. Recording techniques render differently. For Pluto type speaker, I often set up mono sub in between speakers. Speakers may be brought closer together, and head moved in, resulting image is perfect, and as expected bobs around virtual aperture with head movement. I can get up and move to alternate apex, and image forms from reflection off back wall, or from primary position speakers may be turned and image forms from reflection off glass. Not surprising, glass reflection and wood reflection have different EQ. High direct to reflected sound levels allow good examination of venue/engineered sound.
Stage width follows apparent speaker aperture. Speakers from primary position may be pointed in at each other. EQ shifts for off axis behavior but image remains the same, and becomes virtually identical at either apex.
Speakers moved to 1.4 meters in front of front wall and directed to listening position form image virtually identical to image from primary setup, with slightly different EQ. Image is behind front wall on patio outside, extending into yard.
Widening physical aperture and backing up listening position to keep same aperture angle maintains image, but details become obscured by decreasing ratio of direct to reflected sound, and shortening in delay of wall reflections. Specificity of instruments/voices/sound elements becomes diffused.
This agrees with SL and with Rudolf observations:
And I concur that many mistake room sound for venue/engineered sound.
Getting 15ms wall reflection to direct sound in my space requires rotating setup 90degrees, and doesn't seem to improve image perceptions, even with full orchestra. Image cues are derived from transient portions of sound, and is primarily from harmonics in 700Hz-4kHz range. Processing time for these is in 3ms range, and is supported by observation of images by reflection, with change in EQ <200Hz as speaker placement approaches wall(s).
SL's two foot minimum works well; where this is necessity, listening triangle is likely small, netting listener about 4ms of direct sound before first wall reflection. Mistake here is expecting high imaging specificity by setting each speaker 2ft off walls with large aperture and sitting at apex.
Morimoto certainly is a knowledgeable guy, and mean no disrespect. His work shows that reverberant tails of sounds remain associated spatially with the sound's localization cues produced at start of sound, even while revealing/illuminating surroundings in which sound is produced.
For multi-way omnidirectional speaker, driver acoustic centers need to be about 1/3 wavelength apart at crossover frequency. Speaker on design axis needs to be flat. A speaker system is fed one signal, and goal is recovery of signal acoustically.
Hi-fidelity is all about being realistic.
Regards,
Andrew
Andrew,
I couldn't agree more with you regarding your description of speaker placement/rotation and listening impressions at different distances along the listening axis.
OT:
Now and then my wife tells me, that I am not realistic. While this could be true in general, what she always means is: I don't see the world in those moments the same way she does
People, who permanently pretend to be in possession of the real realism, are in deep danger to make fools of themselves.
I just try to transport as much of the information, which is in an audio medium, to my ears as possible. If there is a certain degree of precision (of whatever) in the source, I want to get it. This is my essence of Hi-fi. Whether this precision is realistic or not - that to decide is up to my wife
Rudolf
I couldn't agree more with you regarding your description of speaker placement/rotation and listening impressions at different distances along the listening axis.
Uhps ... I didn't mean to say no reflections within 15 ms, but no strong reflections. I'm trying to keep them below -20 dB - but am not completely there yet.
OT:
Now and then my wife tells me, that I am not realistic. While this could be true in general
, what she always means is: I don't see the world in those moments the same way she does People, who permanently pretend to be in possession of the real realism, are in deep danger to make fools of themselves.
I just try to transport as much of the information, which is in an audio medium, to my ears as possible. If there is a certain degree of precision (of whatever) in the source, I want to get it. This is my essence of Hi-fi. Whether this precision is realistic or not - that to decide is up to my wife
Rudolf
On the other hand, "room sound" can deliver what RFZ 2-speaker stereo can't: spaciousness.
A certain (low level) amount of front wall reflections helps the brain to make the spaciousness in the recording (if there is any) more believable. And those reflections must be free of the midrange low pass filter built into all monopole speakers.
Omnipoles (and dipoles) can do this better.
Rudolf
A certain (low level) amount of front wall reflections helps the brain to make the spaciousness in the recording (if there is any) more believable. And those reflections must be free of the midrange low pass filter built into all monopole speakers.
Omnipoles (and dipoles) can do this better.
Rudolf
Front wall? I'd say side wall it is. Didn't you just treat your front wall?
"Best" in my opinion would be a couple of very high directivity speakers. I'm currently prototyping a foam-embedded speaker to get there.
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OK ... lets meet in the front corners.
And I didn't treat the front wall, but the points of first reflection on that wall only. Even looked into how small I could keep the Basotect patch to still work. Just to make sure that I have as many late reflections as possible.
OK ... lets meet in the front corners.
And I didn't treat the front wall, but the points of first reflection on that wall only. Even looked into how small I could keep the Basotect patch to still work. Just to make sure that I have as many late reflections as possible.
How small could you keep the patch and how did you determine the size?
An externally hosted image should be here but it was not working when we last tested it.
Here's a pic of the BeoLab9.
For a given driver, there's a range in which it radiates in an omnipolar pattern. Generally this is when the wavelengths are smaller than the radiator. For instance, a tweeter will be omni below 18khz, and a 15cm midrange will be omni below 2266hz.
So the lens doesn't have to cover a wide bandwidth. In the case of the tweeter in the BeoLab 9, it only needs to cover about one octave, from 10,000hz to 20,000hz. And that's simply to make the tweeter 'omni' in the octave where the diaphragm transitions from omnipolar radiation to monopolar radiation.
Of course, I know you've done your homework, and you already know all of this
Mostly just posting this information for the people reading this thread who are curious about building SAW lenses. They're neat.
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