Joachim,
You sure are taking your time.
FWIW, I have repeatedly had good success with using ceramic vessels of various shapes for midranges, though they usually are mounted behind baffles. These ceramic vessels have a very high natural resonance that is easily damped and usually are irregular spheroids with very hard and rigid walls.
I find these offer a quality close to solid metal or artificial stone enclosures...
I commonly find them at the local garden centre, where they are known to the great unwashed as "Plant Pots" which denies them their much more noble purpose...
I suspect many of these Plant Pots could also be adapted as free standing midrange enclosure.
Ciao T
You sure are taking your time.
FWIW, I have repeatedly had good success with using ceramic vessels of various shapes for midranges, though they usually are mounted behind baffles. These ceramic vessels have a very high natural resonance that is easily damped and usually are irregular spheroids with very hard and rigid walls.
I find these offer a quality close to solid metal or artificial stone enclosures...
I commonly find them at the local garden centre, where they are known to the great unwashed as "Plant Pots" which denies them their much more noble purpose...
I suspect many of these Plant Pots could also be adapted as free standing midrange enclosure.
Ciao T
Hi Joachim,
I find myself in the midst of building a ZDL type speaker, although I am coming from a different direction with a different goal. But I thought I'd share this with you (and others) and if you are interested and have some time you can find it here.
Demokrit-T
It is a derivate of my omni with a reflector.
If you have any news about your ZDL (and time), let us know.
Otherwise, I hope all is well on your side !
Regards
Oliver
I find myself in the midst of building a ZDL type speaker, although I am coming from a different direction with a different goal. But I thought I'd share this with you (and others) and if you are interested and have some time you can find it here.
Demokrit-T
It is a derivate of my omni with a reflector.
If you have any news about your ZDL (and time), let us know.
Otherwise, I hope all is well on your side !
Regards
Oliver
Sorry, i do not have much time at the moment to contribute much here.
I plan to finish the ZDL i designed nevertheless.
6.283, interesting designs you make. I have to look up your website in detail.
Critofur, i bought the rings from Jan Didden.
You can send him a PM if they are available but i think not. Only a few have being made for friends.
I plan to finish the ZDL i designed nevertheless.
6.283, interesting designs you make. I have to look up your website in detail.
Critofur, i bought the rings from Jan Didden.
You can send him a PM if they are available but i think not. Only a few have being made for friends.
Hello,
This is a very interesting thread and speaker Joachim, but it is a lot to read for someone just discovering it! I have followed a similar path on several speakers and thought some of you might find them interesting. I will post a couple here. Both employ passive crossovers and a somewhat hybrid omnipole approach. Both were very successful and do a great job at expanding the soundstage while maintaining good imaging.
The first is a WMTM configuration with an up and down firing 3” midrange cone, an Aura NT1 tweeter mounted in as small a diameter pvc tube as I could fit it into in order to reduce baffle size and promote increased off axis response. A single up firing 8” woofer was used for the bottom end. Here is a photo followed by the measured frequency response at 0-15-30 and 45 degrees off axis horizontally.
The second speaker was inspired by a Raal creation. Each speaker uses the single Vifa OX20 tweeter, four midrange drivers, one up firing and one down firing in each vertical tube. The midranges are a buyout 16ohm OEM version of the Vifa driver that 6.283 uses in his Demokrit speaker. There are two 12” woofers one firing front and one to the rear in each speaker. These are buyout woofers that are no longer available. The tweeter is mounted in the center side of one of the tubes and fires into the side of the opposing tube.
The tubes create a waveguide that fires equally to the front and rear and provides in excess of 20db boost at the crossover point. The combination of dual 12” woofers, 4 midranges and a waveguided tweeter results in a very dynamic speaker with a lot of headroom. I don’t have any good photos of these, but these will give you the idea. The measurements shown are just on the listening axis of the MT portion. The MT portion swivels a bit so you can toe that portion in or out should you wish.
I can post links to build threads of both of these speakers if anyone wants more detail on how they were built, measurement results, etc.
This is a very interesting thread and speaker Joachim, but it is a lot to read for someone just discovering it! I have followed a similar path on several speakers and thought some of you might find them interesting. I will post a couple here. Both employ passive crossovers and a somewhat hybrid omnipole approach. Both were very successful and do a great job at expanding the soundstage while maintaining good imaging.
The first is a WMTM configuration with an up and down firing 3” midrange cone, an Aura NT1 tweeter mounted in as small a diameter pvc tube as I could fit it into in order to reduce baffle size and promote increased off axis response. A single up firing 8” woofer was used for the bottom end. Here is a photo followed by the measured frequency response at 0-15-30 and 45 degrees off axis horizontally.
The second speaker was inspired by a Raal creation. Each speaker uses the single Vifa OX20 tweeter, four midrange drivers, one up firing and one down firing in each vertical tube. The midranges are a buyout 16ohm OEM version of the Vifa driver that 6.283 uses in his Demokrit speaker. There are two 12” woofers one firing front and one to the rear in each speaker. These are buyout woofers that are no longer available. The tweeter is mounted in the center side of one of the tubes and fires into the side of the opposing tube.
The tubes create a waveguide that fires equally to the front and rear and provides in excess of 20db boost at the crossover point. The combination of dual 12” woofers, 4 midranges and a waveguided tweeter results in a very dynamic speaker with a lot of headroom. I don’t have any good photos of these, but these will give you the idea. The measurements shown are just on the listening axis of the MT portion. The MT portion swivels a bit so you can toe that portion in or out should you wish.
I can post links to build threads of both of these speakers if anyone wants more detail on how they were built, measurement results, etc.
Ah, they look like they would be some sort of commercial product, not custom cut
Thanks.
Joachim,
Thanks. Here are some links:
Soundrounds:
HTGuide Forum - Introducing the SoundRounds
Contrappeso's:
HTGuide Forum - The Contrappeso Project
Thanks. Here are some links:
Soundrounds:
HTGuide Forum - Introducing the SoundRounds
Contrappeso's:
HTGuide Forum - The Contrappeso Project
Kindhornman, i do not talk much about my private life but my house is always open to visitors.
Dan, the one with the metal tubes and the tweeter in between is really cool.
I like that somewhat better then the first one because the source of sound is more compact. The tweeter loading is a strike of genius and the mechanical resonances in that design should be very low. I think i will try that out, just for fun.
Dan, the one with the metal tubes and the tweeter in between is really cool.
I like that somewhat better then the first one because the source of sound is more compact. The tweeter loading is a strike of genius and the mechanical resonances in that design should be very low. I think i will try that out, just for fun.
The tube project (Contrappeso's) is the better of the two, IMO. Improved soundstage, imaging, dynamics, abilty to be pushed pretty hard and very forgiving of different types of music and recording quality, though the resolution is a bit lower with poly drivers and fabric dome than the metal drivers used in the other design. It was a relatively easy project to build, because the tubes were the enclosures and the main construction was the arm between the woofers and MT sections. The soundstage is very immersive, just like I think you were experiencing with the ZDL concept and seems to expand beyond the room.
My mid drivers are recessed a bit, which was a concern, but my plan was to look at measurements to see what significance it acutally had, and if there was detrimental diffraction I would fill in with felt and or raise them to flush. The measurements showed no effect until up in the 8-10khz area and with ~ 4th order acoustic 2khz crossover, that area was a good -50db, so I did not deem it significant. I kind of like how you can't see the drivers straight on when seated.
If you try it with a dome type neo tweeter, I recommend considering the Vifa OT19, which is the brother of the OX20, but in a ring radiator format. It measured much smoother raw in the tube formed waveguide than the true dome, but has a little less sensitivity. I presume that is mostly due to the phase plug helping to reduce reflections at the throat of the waveguide.
I chose to offset the MT tubes from the bass bins and use a 12" dia tube because I wanted to reduce any close, concentrated reflections back up from the downfiring mids and also I liked the idea of being able to alter the placement of the woofers, depending on which you use for left or right, in order to get them closer to the side walls for more boundary reinforcement or away from the side walls for less.
The passive XO's are in the bass bin with the wires to the MT section running up a slot cut on the inside of the curved arm. The slotted wires are covered with small diameter rubber tubing used to secure screens in doors and windows.
My mid drivers are recessed a bit, which was a concern, but my plan was to look at measurements to see what significance it acutally had, and if there was detrimental diffraction I would fill in with felt and or raise them to flush. The measurements showed no effect until up in the 8-10khz area and with ~ 4th order acoustic 2khz crossover, that area was a good -50db, so I did not deem it significant. I kind of like how you can't see the drivers straight on when seated.
If you try it with a dome type neo tweeter, I recommend considering the Vifa OT19, which is the brother of the OX20, but in a ring radiator format. It measured much smoother raw in the tube formed waveguide than the true dome, but has a little less sensitivity. I presume that is mostly due to the phase plug helping to reduce reflections at the throat of the waveguide.
I chose to offset the MT tubes from the bass bins and use a 12" dia tube because I wanted to reduce any close, concentrated reflections back up from the downfiring mids and also I liked the idea of being able to alter the placement of the woofers, depending on which you use for left or right, in order to get them closer to the side walls for more boundary reinforcement or away from the side walls for less.
The passive XO's are in the bass bin with the wires to the MT section running up a slot cut on the inside of the curved arm. The slotted wires are covered with small diameter rubber tubing used to secure screens in doors and windows.
When you mount and measure so much off axis as you do with your midranges defraction artifact are really low so that little edge you have does not make a big difference.
I also found the ZDL speakers throw a tremendous stage.
I certainly will build your arrangement. I think i have some small ring radiators too.
I also found the ZDL speakers throw a tremendous stage.
I certainly will build your arrangement. I think i have some small ring radiators too.
You probably are aware of the Raal Solaja Audio Constellation, see Rocky Mountain Audio Fest Show Report 4 ?
An externally hosted image should be here but it was not working when we last tested it.
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