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Multi-Way Conventional loudspeakers with crossovers

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Old 29th November 2012, 09:01 AM   #121
graaf is offline graaf  Poland
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Quote:
Originally Posted by lolo View Post
I don't think so.. from the Master himself:

Room placement

....you will loose quickly in soundstage imaging specificity. Preferably you sit even closer than the classic sweet spot.
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
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Old 29th November 2012, 09:03 AM   #122
graaf is offline graaf  Poland
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Originally Posted by tinitus View Post
I have always thought omnis would need more distance ?
of course, elementary
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Old 29th November 2012, 10:20 AM   #123
lolo is offline lolo  France
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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.
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Old 29th November 2012, 10:46 AM   #124
tinitus is offline tinitus  Europe
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I wouldnt expect omni will work optimally without a crossover equalising the response
though I reckon a raw fullrange in omni might work very well with 'room equalising'
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Old 29th November 2012, 11:38 AM   #125
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Originally Posted by tinitus View Post
I wouldnt expect omni will work optimally without a crossover equalising the response
though I reckon a raw fullrange in omni might work very well with 'room equalising'
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.
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Old 29th November 2012, 12:05 PM   #126
tinitus is offline tinitus  Europe
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Originally Posted by markus76 View Post
I wouldn't expect any speaker to "work optimally" without EQ.
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

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Originally Posted by tinitus View Post
but my point is that the combination of a crossover and carefully chosen drivers for this specific task would form a EQ
please not this is specificly aimed at omni design only, because of its special design
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Old 29th November 2012, 12:14 PM   #127
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tinitus,

What happend to Shift and all the punctuation keys on your keyboard? Makes your posts hard to read.

Quote:
Originally Posted by tinitus View Post
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
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.
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Old 29th November 2012, 12:29 PM   #128
lolo is offline lolo  France
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I did have a cheap DEQ in the chain, yes, but did not do any measurements. Just wanted to see the potential, which was positive.
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Old 29th November 2012, 01:28 PM   #129
tinitus is offline tinitus  Europe
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Originally Posted by markus76 View Post
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
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Old 29th November 2012, 03:15 PM   #130
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Originally Posted by graaf View Post
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
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:

Quote:
Originally Posted by Rudolf View Post
My experience:
At least in my room strong early lateral reflections mess up the stereo scene. They keep me from "listening through my room acoustics" and hearing the room/hall acoustics of the recording environment. I need to keep the first 15 ms free from those reflections to get a solid and structured impression of a large orchestra recording for instance.

Could it be that (too) many people mistake the "spaciousness" generated by early reflections in their room for the hall acoustics of the recording?
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.


Quote:
Morimoto is a knowledgeable guy.
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
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