Pan said:
True, true ! The DDD drivers cone are VERY soft when You touch them. It is very easy to make dents in them however it does not seem to effect the performance. It just looks nasty. Thes cone is very soft, like some thin plastic almost.
The principle with bending wave is that it travels along the surface of the cone - it's not working like a piston.
/
"imaging was incredible"
Did you listening inside or outside?
I was very impressed with my DDD speakers for some time, however I got very (as in VERY) tired of the sound in the end.
The problem with omnis is that they iluminate the room with lots of sound which bounce around like crazy and it adds an artificial ambience that some like.. I don´t... not anymore at least ;-).
This result is IMO not imaging, since imaging is about recreate the 3d and spatial clues in the recording. With omnis you get a sort of "sameness" to all records.
Cool project though, admire it.
/Peter
Did you listening inside or outside?
I was very impressed with my DDD speakers for some time, however I got very (as in VERY) tired of the sound in the end.
The problem with omnis is that they iluminate the room with lots of sound which bounce around like crazy and it adds an artificial ambience that some like.. I don´t... not anymore at least ;-).
This result is IMO not imaging, since imaging is about recreate the 3d and spatial clues in the recording. With omnis you get a sort of "sameness" to all records.
Cool project though, admire it.
/Peter
cjh said:
1. Is the Walsh driver or a variation of it available retail?
2. German Physicks seems to mate their version of the walsh driver to a bandpass sub. I was under the impression that bandpass is not really audiopphile.
3. can a small fullrange driver (Jordan JX53/92, Fostex FF85, etc...) mated to a small woofer (5-8") even be compared to speakers like Ohm/German Physiks?
"I had the drivers on each end of the picnic table and I sat in the middle between them."
I take that as a yes to outside? Guess picnic tables are usually used outside
. In such case the relative freedom from reflections and standing waves helps a lot in reproduction of the record. Most speaker performs way better outside... except for the bass which becomes anemic due to no support from the room and cabin gain.
navin,
I´d say no. Jordan is a small direct radiator while the DDD is a 360 degree bending wave transducer. Very different animals.
/Peter
I take that as a yes to outside? Guess picnic tables are usually used outside
. In such case the relative freedom from reflections and standing waves helps a lot in reproduction of the record. Most speaker performs way better outside... except for the bass which becomes anemic due to no support from the room and cabin gain.navin,
I´d say no. Jordan is a small direct radiator while the DDD is a 360 degree bending wave transducer. Very different animals.
/Peter
sure, but in the end we are looking at reproducing sound in our living rooms (something tells me picnic sites are not the general listening enviroment) and given this (living room) enviroment which has a better chance of success.
i agree that one cant compare omnipole sound (walsh driver) to that of a monopole (fullrange or otherwise) one can discuss which might image better, have a more realistic soundfield/freq. respone etc.
However the above question depends on if we can get a Walsh driver retail. I assume the Walsh driver used by Ohm and the DDD used by GP are quite similar and can be directly compared. Are Walsh/DDD drivers available to DIY or does a DIY have to build the driver too? The later option lends many levels of diffculty to the DIY process.
i agree that one cant compare omnipole sound (walsh driver) to that of a monopole (fullrange or otherwise) one can discuss which might image better, have a more realistic soundfield/freq. respone etc.
However the above question depends on if we can get a Walsh driver retail. I assume the Walsh driver used by Ohm and the DDD used by GP are quite similar and can be directly compared. Are Walsh/DDD drivers available to DIY or does a DIY have to build the driver too? The later option lends many levels of diffculty to the DIY process.
I believe the DDD driver is available. I know it was since I used to have a pair. Later I think GP backed out of the DIY market and later the drivers became available again.
IMO there is no discussion about imaging accuracy between omnis and more directional designs. Room reflections and gross combfiltering is distortion. That said there is something nice about the way the DDD sound, but the "samness" to all records become very tiresome after a while.
I´m thinking on using a DDD speaker as L and R back speakers, only adding ambience with good SACD/DVD-A. Once in a while when I feel for it I can use the back channels as mains to get that "big" omni thing.
/Peter
IMO there is no discussion about imaging accuracy between omnis and more directional designs. Room reflections and gross combfiltering is distortion. That said there is something nice about the way the DDD sound, but the "samness" to all records become very tiresome after a while.
I´m thinking on using a DDD speaker as L and R back speakers, only adding ambience with good SACD/DVD-A. Once in a while when I feel for it I can use the back channels as mains to get that "big" omni thing.
/Peter
Pan said:
i would love to know what the DDD's cost and where they are avaialble and are they similar to the Walsh drivers used by Ohm? that said dont we have have room reflections in most live music we listen to?
lastly I MUST CORRECT myself. In a earlier post I had said that the Walsh driver is omnidirectional. I am informed by John Strohbeen of Ohm that the Walsh driver is a monopole. Sorry for passing on incorrect information based on my improperly researched assumptions.
I think the cost is about $3000 or so for a pair of DDD.
As far as I know the walsh/ohm princip is the same as DDD = omni/360 degree driver.
"that said dont we have have room reflections in most live music we listen to?"
Yes, and that is the reflections that should dominate the reproduction if you want fidelity. Add your own room signature and say by by to accurate reproduction of spatial clues and ambience in the recording from the recording venue. An omnipolar transducer is the "worst" in this regards as it iluminates the room at max with energy (think BOSE lifestylesystems..).
Now, this can sound "good" but not very accurate IMO.... well, sure they can sound realatively "accurate" due to that the power respons is more even than for a taditional direct radiator system, and that may be a good or a bad thing depending on how you look at it, room acoustics and so on.
/Peter
As far as I know the walsh/ohm princip is the same as DDD = omni/360 degree driver.
"that said dont we have have room reflections in most live music we listen to?"
Yes, and that is the reflections that should dominate the reproduction if you want fidelity. Add your own room signature and say by by to accurate reproduction of spatial clues and ambience in the recording from the recording venue. An omnipolar transducer is the "worst" in this regards as it iluminates the room at max with energy (think BOSE lifestylesystems..).
Now, this can sound "good" but not very accurate IMO.... well, sure they can sound realatively "accurate" due to that the power respons is more even than for a taditional direct radiator system, and that may be a good or a bad thing depending on how you look at it, room acoustics and so on.
/Peter
While I by myself don't know what I should believe qat the moment, there are different opinions around.
But we localize sound by the initial transient of an acoustic "event", anything that comes later is used to analyse timbre. So it is mainly the direct sound that gives us clues about sound localisation and the early reflections give us clues about timbre.
If our speakers have a heavily frequency dependant directivity the direct sound and the reflected sound have a very different sonic signature. And this is BAD. But I do also believe that in a heavily reverberant room omnidirectional speakers will perform worse than directional ones.
So everything is depending on your listening room in the end.
Regards
Charles
Charles,
The first 10ms or so of reflections affects the imaging a lot.. later reflections (+20ms) may affect timbre more (but this is also true for early reflections) but still affects the imaging and spatial clues.
The less reflections you have in the listening room, the "calmer" becomes the sound and the imaging qualitys is improved. This goes for late reflections as well. I´ve experimented a lot in as big rooms as 100m squared, with dipoles, and boxes. Even reflections as far away as 8 meters or so (16m or more "back and forth") are destructive to imaging. Of course when you treat such late reflections you are maybe dealing more with total room reverberation, but the effect is still there.
/Peter
The first 10ms or so of reflections affects the imaging a lot.. later reflections (+20ms) may affect timbre more (but this is also true for early reflections) but still affects the imaging and spatial clues.
The less reflections you have in the listening room, the "calmer" becomes the sound and the imaging qualitys is improved. This goes for late reflections as well. I´ve experimented a lot in as big rooms as 100m squared, with dipoles, and boxes. Even reflections as far away as 8 meters or so (16m or more "back and forth") are destructive to imaging. Of course when you treat such late reflections you are maybe dealing more with total room reverberation, but the effect is still there.
/Peter
Phase accurate said....
But I do also believe that in a heavily reverberant room omnidirectional speakers will perform worse than directional ones.
So everything is depending on your listening room in the end.
-----------------------------------------
true. we shoud be thinking inside the box (living room) instead of only outside it (speaker).
But I do also believe that in a heavily reverberant room omnidirectional speakers will perform worse than directional ones.
So everything is depending on your listening room in the end.
-----------------------------------------
true. we shoud be thinking inside the box (living room) instead of only outside it (speaker).
Here is a patent describing a cylinder shaped driver. It seems similar to in some respects to the designs discussed in this thread. The patent holder is also the designer of the Quatre Gain Cell amplifiers sold in the late 70s-early 80s. This is a long URL so you will need to cut and paste.
http://patft.uspto.gov/netacgi/nph-...&s1=3939942.WKU.&OS=PN/3939942&RS=PN/3939942"<<img+src=%22/piwdocs/home.gif%22+width=%22120%22+height=%2221%22+border=%220%22+alt=%22go+to+search+page%22<</a<</nobr<<br<
http://patft.uspto.gov/netacgi/nph-...&s1=3939942.WKU.&OS=PN/3939942&RS=PN/3939942"<<img+src=%22/piwdocs/home.gif%22+width=%22120%22+height=%2221%22+border=%220%22+alt=%22go+to+search+page%22<</a<</nobr<<br<
It seems that this thread has died, but I would like to re-invigorate it.
I am very interested in building a "quasi" full range Walsh driver, and would be interested if any of you have attempted it.
In the past, I have built numerous Walsh tweeters, and experimented with a full range version.
If you are interested, please reply.
I am very interested in building a "quasi" full range Walsh driver, and would be interested if any of you have attempted it.
In the past, I have built numerous Walsh tweeters, and experimented with a full range version.
If you are interested, please reply.
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