-CGL- said:
Sorry CGL, my fault!
Meanwhile I done my homework and found the original thread where this link was posted - at audioasylum
So you are using the 18S XT1086 + BMS 4552ND in a project, right ? Sure I would like to hear and see more about that.
best,
LC
Thanks for the interesting polars. These look more like what I would expect and a far cry from what 18 sound posted on thier web site. They probably normalized the axial response (bad idea) and smoothed things in frequency and angle. The angles are obviuosly 10 degrees each line.
Because my devices are axi-symmetric they have a bit worse axial response. I've often thought about going to an elliptical mouth and this is planned for some future updates. Foam plugs in an ellipitical shape would be tough to cut.
As far as a "group buy", I'd only consider this if I got one payment and shipped to one address. I could do $200 each for 20 and $150 each for 100.
Because my devices are axi-symmetric they have a bit worse axial response. I've often thought about going to an elliptical mouth and this is planned for some future updates. Foam plugs in an ellipitical shape would be tough to cut.
As far as a "group buy", I'd only consider this if I got one payment and shipped to one address. I could do $200 each for 20 and $150 each for 100.
Hello, this might be an off-topic to the current discussion although it's probably the best place to ask.
Mr. Geddes, I've noticed a statement in another thread in which you considered the 200-1Khz region less critical than the 1Khz and up. This is due to phase problems, psychoacoustic differences and so on. So this lower band it's good for compromises but the +1Khz has to be perfect.
My question is what if I'd want to try a waveguide in this band using a 4" throat, 6" diafragm Emilar driver or a 3" throat JBL driver? Off course assuming that the crossovers problems would be resolved and assuming I'd source a compression driver to go this low. How a waveguide would perform in this conditions?
The advantages I see in this configuration are linked to the fact that actually this is the "music band" and I wonder how the increased dynamics would affect this compared to a direct radiator. The idea camed from all those exotic horn users that are praising the virtues of horn loaded lower-midrange. A waveguide would cure those inherent problems of horns and enhance this even further.
Mr. Geddes, I've noticed a statement in another thread in which you considered the 200-1Khz region less critical than the 1Khz and up. This is due to phase problems, psychoacoustic differences and so on. So this lower band it's good for compromises but the +1Khz has to be perfect.
My question is what if I'd want to try a waveguide in this band using a 4" throat, 6" diafragm Emilar driver or a 3" throat JBL driver? Off course assuming that the crossovers problems would be resolved and assuming I'd source a compression driver to go this low. How a waveguide would perform in this conditions?
The advantages I see in this configuration are linked to the fact that actually this is the "music band" and I wonder how the increased dynamics would affect this compared to a direct radiator. The idea camed from all those exotic horn users that are praising the virtues of horn loaded lower-midrange. A waveguide would cure those inherent problems of horns and enhance this even further.
...So you are using the 18S XT1086 + BMS 4552ND in a project, ..... Sure I would like to hear and see more about that.......
Yes, back in 2004 I made a version with a 12" woofer. It was so nice that I´m going to do two new versions of it, one that goes down a little lower, and the other to be used with a subwoofer. I´ll post more as things get going (hopefully next week).
Other than that, the XT1086 is worth a try if one can handle the cross-over. It´s the best off-the-shelf horn, and costs ~40 euros...
Yes, back in 2004 I made a version with a 12" woofer. It was so nice that I´m going to do two new versions of it, one that goes down a little lower, and the other to be used with a subwoofer. I´ll post more as things get going (hopefully next week).
Other than that, the XT1086 is worth a try if one can handle the cross-over. It´s the best off-the-shelf horn, and costs ~40 euros...
The cost of these WGs sits in the mould and the labour, not really the materials cost.
For such a production run an aluminium mould is probably the way to go as it'd when waxed release beautiful parts consistently and last long.
For medium production runs hardwood is also an option, though the stability is probably not ideal, which is why I have in the past used machined Alu threading into hardwood for the first ~20mm and then post-machined the remainder in CNC. Here in maple terminating for something different (note change of colour dependant on angle).
For such a production run an aluminium mould is probably the way to go as it'd when waxed release beautiful parts consistently and last long.
For medium production runs hardwood is also an option, though the stability is probably not ideal, which is why I have in the past used machined Alu threading into hardwood for the first ~20mm and then post-machined the remainder in CNC. Here in maple terminating for something different (note change of colour dependant on angle).
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Member
Joined 2003
Earl,
Several people are interested in using "Hi-Fi" domes in waveguides, but results are mixed and (I think) the issue may be the throat.
The OS type transition necessary for compression drivers seems unnecessary, or maybe even undesirable, for the Hi-Fi domes since they are not designed to operate in a confined space. My hypothesis is that a proper WG for these tweeters is a conical flare with a "knife edge" ending at the outside of the surround cavity (plus a large mouth roundover for diffraction).
At some point (I'm assuming) you have likely worked with Hi-Fi domes and waveguides. What are your ideas for the best solution? (No fair saying compression driver+OS
)
Also, what are your thoughts on the best dome shape? concave/convex?
Thanks,
Paul
Several people are interested in using "Hi-Fi" domes in waveguides, but results are mixed and (I think) the issue may be the throat.
The OS type transition necessary for compression drivers seems unnecessary, or maybe even undesirable, for the Hi-Fi domes since they are not designed to operate in a confined space. My hypothesis is that a proper WG for these tweeters is a conical flare with a "knife edge" ending at the outside of the surround cavity (plus a large mouth roundover for diffraction).
At some point (I'm assuming) you have likely worked with Hi-Fi domes and waveguides. What are your ideas for the best solution? (No fair saying compression driver+OS
)Also, what are your thoughts on the best dome shape? concave/convex?
Thanks,
Paul
Paul W said:Earl,
Several people are interested in using "Hi-Fi" domes in waveguides, but results are mixed and (I think) the issue may be the throat.
The OS type transition necessary for compression drivers seems unnecessary, or maybe even undesirable, for the Hi-Fi domes since they are not designed to operate in a confined space. My hypothesis is that a proper WG for these tweeters is a conical flare with a "knife edge" ending at the outside of the surround cavity (plus a large mouth roundover for diffraction).
At some point (I'm assuming) you have likely worked with Hi-Fi domes and waveguides. What are your ideas for the best solution? (No fair saying compression driver+OS
Also, what are your thoughts on the best dome shape? concave/convex?
Thanks,
Paul
But the best solution IS a compression driver. The foam plug that cuts down on HOMs also reduces sensitivity dramatically. Combine that with the fact that hifi tweeters are ALREADY compromised in the power handling and the power compression department and you come to one conclusion:
Dome tweeters are 2nd rate.
Hmm, I was having the exact same thoughts as Paul - domes might produce much more like a spherical wavefront that would favor a conical flare, and in spite of the efficieny disadvantage, the restricted radiation volume will get you up to 8-10 dB gain here. Compression drivers are always quoted on horns already, this is partly why their efficiency is so high. Also, precisely because of their uncompressed "exit", domes might actually be at an advantage HOM wise.
I had just started thinking how to shave the OS mouth off my prototype waveguide.
I had just started thinking how to shave the OS mouth off my prototype waveguide.
I have not followed the thread so closely but may be this has not come up yet...
Please look at
http://www.aadsound.com/products/Loadspeaker/Silver/silver.htm
There is a AAD Sound speaker where the WG has a kind of pullet plug in centre. What are the toughts on this. The measurements results in last Stereophile magazin seem quite good....
Regards,
Ergo
Please look at
http://www.aadsound.com/products/Loadspeaker/Silver/silver.htm
There is a AAD Sound speaker where the WG has a kind of pullet plug in centre. What are the toughts on this. The measurements results in last Stereophile magazin seem quite good....
Regards,
Ergo
Member
Joined 2003
Paul W said:Earl,
Several people are interested in using "Hi-Fi" domes in waveguides, but results are mixed and (I think) the issue may be the throat.
The OS type transition necessary for compression drivers seems unnecessary, or maybe even undesirable, for the Hi-Fi domes since they are not designed to operate in a confined space. My hypothesis is that a proper WG for these tweeters is a conical flare with a "knife edge" ending at the outside of the surround cavity (plus a large mouth roundover for diffraction).
At some point (I'm assuming) you have likely worked with Hi-Fi domes and waveguides. What are your ideas for the best solution? (No fair saying compression driver+OS
Also, what are your thoughts on the best dome shape? concave/convex?
Thanks,
Paul
The fact is that there is no way to optimally match a waveguide to a dome. A waveguide can be perfectly matched to a flat piston and the first waveguides II made used these and they work great.
I simply would not recommend a dome without a phase plug - but thats another level of complicated engineering to consider. I simply don't get the desire to use a dome. But if you must use a conical waveguide with a mouth radius. Won't work that well, but its the best that you can do.
augerpro said:
I havet to agree, this IS a novel solution -
But from a marketing standpoint. If I were *selling* a speaker, I would do anything I could to make my product standout. Using a planar ribbon is undoubtedly a clever way to do so.
Besides the arguments offered up by Dr Geddes, there are a number of interesting threads about the superiority of compression drivers that have been posted on Audio Asylum by Tom Danley.
If I had a formal education in this stuff (I'm in software, not speakers) I could probably do a better job describing this phenomenon. Perhaps someone will correct me? But here goes, anyways -
In a nutshell, Danley describes how the drooping frequency response that you see with a compression driver is *preferable* to the flat response you see with a dome tweeter. This behavior has to do with the motor superiority of a compression driver, and it also affect it's phase response.
... hopefully someone will chime in with a better explanation of this, cuz I'm babbling now
...