Having been a vendor for JBL in the past I can tell you that there is little that this giant Harmon International actually makes themselves. They do do some assembly of particular products but most are made up of commodity parts made in China or where ever the best prices can be obtained. Their research budget is less than you would want to believe and I know others on other threads who have worked for this company say the same thing. I would say there is more money put into industrial design than basic research or product design.
When my new designs are ready I plan on offering a version of my designs to the DIY group here and wherever there is a want. They won't necessarily be the lowest cost but they will be the highest quality that I can offer. The only difference between these products and those I plan on selling in final consumer versions will be the packaging. My consumer version will be in a complete package with enclosure and amplification as part of the final product. I will offer the raw frame drivers here for those who want to roll their own final designs.
When my new designs are ready I plan on offering a version of my designs to the DIY group here and wherever there is a want. They won't necessarily be the lowest cost but they will be the highest quality that I can offer. The only difference between these products and those I plan on selling in final consumer versions will be the packaging. My consumer version will be in a complete package with enclosure and amplification as part of the final product. I will offer the raw frame drivers here for those who want to roll their own final designs.
Nothing wrong with repeating it every two years or so
Not all people like "natural" sound , actually I find them to be minority these days. You know many like the sound of their "approved' systems more than the sound of music in concert hall .There could be many reasons but it becomes symptomatic. My nephew prefers the sound of his i-phone to my system , granted that my system leaves a lot to be desired but it's hard to change once acquired taste. Even though Lynn repeats that he is designing the speaker to suit his and only his taste I'm not sure most who are reading this really gets it.
I'm reading again Sound Practices and see all the enthusiasm they had back then , thinking that SET revolution is right behind the corner and we will be blessed by "real-fi " (my friend's phrase ) soon enough and old High-end establishment will be bankrupt in no time . Well, that didn't happen. I think the reason is people in majority prefer processed sound and we lost touch with acoustic music. I bet that among all DIY community registered users here you won't find 3 persons to whom classical music is absolute priority .
Originally, Lynn had a second post below his post, with the first post quoted, and nothing else.
I was just razzing him for a posting mishap.
Well, you have at least one person interested in knowing what you are going to offer. Any links, preliminary details?
ra7,
Right now I have a 6 1/2" long excursion speaker with an underhung voicecoil and a unique cone material that I have developed. It uses a Neo magnet assembly of my own design and has a usable frequency response of 35hz to 2.5Khz. I am also in the thick of development on a beryllium dome tweeter using pure beryllium and again a neo magnet assembly. I also have many 1" entrance small waveguides with a cutoff of 1.6Khz and quite a few mid-range cone driven horns lenses with rear sealed chamber intended for a 6 1/2" speaker. That has a lower cutoff of about 600hz and works well with the small 1" horn lens. I will post some picture soon for those who may be interested. I will produce other sized cone drivers based on this development but I am not spending much time optimizing those at this time.
Steven
Right now I have a 6 1/2" long excursion speaker with an underhung voicecoil and a unique cone material that I have developed. It uses a Neo magnet assembly of my own design and has a usable frequency response of 35hz to 2.5Khz. I am also in the thick of development on a beryllium dome tweeter using pure beryllium and again a neo magnet assembly. I also have many 1" entrance small waveguides with a cutoff of 1.6Khz and quite a few mid-range cone driven horns lenses with rear sealed chamber intended for a 6 1/2" speaker. That has a lower cutoff of about 600hz and works well with the small 1" horn lens. I will post some picture soon for those who may be interested. I will produce other sized cone drivers based on this development but I am not spending much time optimizing those at this time.
Steven
Been thinking about a new center speaker to go along with the new LTO's. As you can see from the photo below, the Panasonic 58" plasma TV is in the middle, with a Dynaudio Contour SCX as the Center speaker.
The Ariels, like the LTO's to come, have changeover switches on the external crossovers, so they can be switched between the Marantz MM8003 and the Karna amplifiers. Both ground and hot are switched, so there is no electrical connection at any time between the 5.1-channel home-theater and the 2-channel all-vacuum-tube system.
The HT system, Blu-Ray player, XBox360, Mac Mini, and a server-grade sinewave UPS (for the TV and Comcast DVR) are plugged into a set of AC outlets on the left side of the picture. Behind the TV there are cable-TV 75-ohm sockets along with Ethernet for the TV, Blu-Ray player, Xbox360, and MacMini. On the right side of the picture, there's a separate set of AC outlets for the Denon 2900 transport, Behringer Ultramatch Pro SRC2496, Monarchy N24 DAC, and the two Karna amplifiers. I expect in time I will have an electrician install separate runs for the HT and audio outlets, going directly to the main circuit breaker panel.
No, I am not going to find a separate room for the audio or video system. Not happening. They have to co-exist together, in the same room, and share the main Left and Right speakers.
So ... the Center speaker has a direct connection to the Marantz AV8003/MM8003 combo, and one of the options for auto-EQ is matching the L & R speakers (which have very flat responses and do not need EQ). But ... I am not completely happy with the intelligibility of the Center speaker. It's OK, I guess, and the Dynaudio is almost certainly one of the best Centers you can buy. I think the problem isn't the drivers (which are real, made-in-Denmark Dynaudios) or crossover, but the side-by-side MTM layout.
I usually sit a bit off-center when I watch movies with Karna, and the arrival time from the pair of midbass drivers is different by a few inches, which I suspect affects intelligibility of movie dialog. I heard plenty of Center speakers before buying the CSX, and trust me, nearly all of them were a lot worse, with atrocious tonality and overall low fidelity. To it's credit, the Dynaudio CSX is neutral, musical, and sounds like real hi-fi, and dialog is reasonably good.
So if I want better, I need to use a different driver layout than side-by-side MTM. As you can see, a vertical layout is not an option unless I want to raise the TV to a ridiculous and visually uncomfortable height (the visual horizon line is just below the upper midbass on the Ariels).
So ... coaxials come to mind. I've auditioned the KEF Uni-Q's. No. I've auditioned the TAD Reference One. No. Tannoy? They won't sell the drivers, and no, I'm not interested in taking my chances with vintage Tannoy drivers on eBay or Audiogon. GPA 604 Duplex? A possibility, but the response is nowhere close to flat in stock form, and I don't want to spend months designing a crossover for a Center speaker that will only be used for movie dialog.
That's when I started looking at the Radian 5312 Neo and 5215 Neo. Hmm, interesting. Pretty flat response with the stock crossover (which I would not use), and they're used in pro applications as compact studio monitors. There's a very nice review by Scott Dorsey in Recording Magazine. I've met Scott at the Positive Feedback get-togethers, and the man knows what he's doing, and has good taste in audio. His favorite is the 12" Radian; point taken.
OK, with the driver selected, what kind of enclosure? My friend Gary Dahl tracked down this source of rounded corners, which can be used for the left and right edges of the cabinet. What kind of bass loading, particularly given that it's going to be used with the 80 Hz highpass filter of the home-theater receiver? That's where Gary Pimm's open-back box, completely filled with Bonded Logic recycled cotton filling, will do the job. His boxes are about 1 to 1.5 feet deep, and surprisingly, are flat to 100 Hz. Unlike open-back dipoles, there's no baffle peak and no requirement for rising EQ below the baffle peak (Gary measured them for me the last time I visited Portland).
This is looking promising. An open-back box filled with Bonded Logic filling, large-radius rounded corners, and a Radian 5312 Neo coaxial driver with custom crossover (most likely using the LTO crossover as a starting point).
The Ariels, like the LTO's to come, have changeover switches on the external crossovers, so they can be switched between the Marantz MM8003 and the Karna amplifiers. Both ground and hot are switched, so there is no electrical connection at any time between the 5.1-channel home-theater and the 2-channel all-vacuum-tube system.
The HT system, Blu-Ray player, XBox360, Mac Mini, and a server-grade sinewave UPS (for the TV and Comcast DVR) are plugged into a set of AC outlets on the left side of the picture. Behind the TV there are cable-TV 75-ohm sockets along with Ethernet for the TV, Blu-Ray player, Xbox360, and MacMini. On the right side of the picture, there's a separate set of AC outlets for the Denon 2900 transport, Behringer Ultramatch Pro SRC2496, Monarchy N24 DAC, and the two Karna amplifiers. I expect in time I will have an electrician install separate runs for the HT and audio outlets, going directly to the main circuit breaker panel.
No, I am not going to find a separate room for the audio or video system. Not happening. They have to co-exist together, in the same room, and share the main Left and Right speakers.
So ... the Center speaker has a direct connection to the Marantz AV8003/MM8003 combo, and one of the options for auto-EQ is matching the L & R speakers (which have very flat responses and do not need EQ). But ... I am not completely happy with the intelligibility of the Center speaker. It's OK, I guess, and the Dynaudio is almost certainly one of the best Centers you can buy. I think the problem isn't the drivers (which are real, made-in-Denmark Dynaudios) or crossover, but the side-by-side MTM layout.
I usually sit a bit off-center when I watch movies with Karna, and the arrival time from the pair of midbass drivers is different by a few inches, which I suspect affects intelligibility of movie dialog. I heard plenty of Center speakers before buying the CSX, and trust me, nearly all of them were a lot worse, with atrocious tonality and overall low fidelity. To it's credit, the Dynaudio CSX is neutral, musical, and sounds like real hi-fi, and dialog is reasonably good.
So if I want better, I need to use a different driver layout than side-by-side MTM. As you can see, a vertical layout is not an option unless I want to raise the TV to a ridiculous and visually uncomfortable height (the visual horizon line is just below the upper midbass on the Ariels).
So ... coaxials come to mind. I've auditioned the KEF Uni-Q's. No. I've auditioned the TAD Reference One. No. Tannoy? They won't sell the drivers, and no, I'm not interested in taking my chances with vintage Tannoy drivers on eBay or Audiogon. GPA 604 Duplex? A possibility, but the response is nowhere close to flat in stock form, and I don't want to spend months designing a crossover for a Center speaker that will only be used for movie dialog.
That's when I started looking at the Radian 5312 Neo and 5215 Neo. Hmm, interesting. Pretty flat response with the stock crossover (which I would not use), and they're used in pro applications as compact studio monitors. There's a very nice review by Scott Dorsey in Recording Magazine. I've met Scott at the Positive Feedback get-togethers, and the man knows what he's doing, and has good taste in audio. His favorite is the 12" Radian; point taken.
OK, with the driver selected, what kind of enclosure? My friend Gary Dahl tracked down this source of rounded corners, which can be used for the left and right edges of the cabinet. What kind of bass loading, particularly given that it's going to be used with the 80 Hz highpass filter of the home-theater receiver? That's where Gary Pimm's open-back box, completely filled with Bonded Logic recycled cotton filling, will do the job. His boxes are about 1 to 1.5 feet deep, and surprisingly, are flat to 100 Hz. Unlike open-back dipoles, there's no baffle peak and no requirement for rising EQ below the baffle peak (Gary measured them for me the last time I visited Portland).
This is looking promising. An open-back box filled with Bonded Logic filling, large-radius rounded corners, and a Radian 5312 Neo coaxial driver with custom crossover (most likely using the LTO crossover as a starting point).
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Problem is it will have an extremely narrow sweet spot vertically- slump in the seat and it'll be bleeagch!
Lynn,
I have found that a narrow polar pattern WITHOUT LOBING is beneficial for a home theater center channel because it locks the vocal position queues to the screen. I had 40 Lambda speakers so….. Our home theater center speaker is a Lambda TD15M crossed LR4 at 1300Hz to a no-rim SB29RDCN dome tweeter which is attached to the TD15M's large phase plug with a piece of bicycle inner tube plus a foam rubber bumper. I have played with extending the inner tube beyond the tweeter dome and creating a short oval shape funky waveguide. ... different ... not better sounding. Simple 50Hz Qts=0.5 bottom ported box built into an oak parsons table that is part of our living room furniture set. THX spec recommends flat down to 80hz.
I think you will be very happy with the Radian 5312NEO, if you can find one. Perhaps you could construct a cabinet that matches the length and depth of your HT “rack”.
Experimenting with a narrow pattern tweeter waveguide for the center channel would be interesting.
I have found that a narrow polar pattern WITHOUT LOBING is beneficial for a home theater center channel because it locks the vocal position queues to the screen. I had 40 Lambda speakers so….. Our home theater center speaker is a Lambda TD15M crossed LR4 at 1300Hz to a no-rim SB29RDCN dome tweeter which is attached to the TD15M's large phase plug with a piece of bicycle inner tube plus a foam rubber bumper. I have played with extending the inner tube beyond the tweeter dome and creating a short oval shape funky waveguide. ... different ... not better sounding. Simple 50Hz Qts=0.5 bottom ported box built into an oak parsons table that is part of our living room furniture set. THX spec recommends flat down to 80hz.
I think you will be very happy with the Radian 5312NEO, if you can find one. Perhaps you could construct a cabinet that matches the length and depth of your HT “rack”.
Experimenting with a narrow pattern tweeter waveguide for the center channel would be interesting.
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I tried the center speaker route for a while - first MTM, then WMTW, above and below the TV.
I finally rearranged my room to where the seating position is very close to center, and now I find that the best sound is with no center channel at all.
The shelves below the center speaker create resonances and the TV above it reflections, so with such a poor environment, I think as a rule, it's best to avoid the center if at all possible.
I finally rearranged my room to where the seating position is very close to center, and now I find that the best sound is with no center channel at all.
The shelves below the center speaker create resonances and the TV above it reflections, so with such a poor environment, I think as a rule, it's best to avoid the center if at all possible.
An externally hosted image should be here but it was not working when we last tested it.
Lynn,
I have built systems in the past with the earleir versions of the 8" Radian coax and I will warn you that you have to watch out for the notorious horn honk we have come to expect from some older horns and compression drivers. It is all in the crossover points you chose and the implementation. Be careful and you can get what you want, sloppy will make you very disappointed.
I have built systems in the past with the earleir versions of the 8" Radian coax and I will warn you that you have to watch out for the notorious horn honk we have come to expect from some older horns and compression drivers. It is all in the crossover points you chose and the implementation. Be careful and you can get what you want, sloppy will make you very disappointed.
You're not likely to hit it by chance. But I assume Lynn know that.Interesting the latest thoughts..
My reference speakers for the time being is a pair of "Onkens" with HempAcoustics co15v drivers. CO15v is basically Radian 5215 with aluminium throat for the compression driver and Hemp for the 15" driver. They perform remarkable well. The Radians are great drivers.
Absolutely no horn honking. Just pure beautiful smooth sound with alot of attack and "space"
My reference speakers for the time being is a pair of "Onkens" with HempAcoustics co15v drivers. CO15v is basically Radian 5215 with aluminium throat for the compression driver and Hemp for the 15" driver. They perform remarkable well. The Radians are great drivers.
Absolutely no horn honking. Just pure beautiful smooth sound with alot of attack and "space"
Lynn,
I thought that co-ax systems were ruled-out completely very early-on in this thread for various reasons - impossible to refine to the level you desired due to the known compromises of the woofer being the horn IIRC. Some excellent drivers were considered at the time but ruled-out.
What has changed? Is it because the application is not 2-channel music-only?
Thnx,
-- Mark
I thought that co-ax systems were ruled-out completely very early-on in this thread for various reasons - impossible to refine to the level you desired due to the known compromises of the woofer being the horn IIRC. Some excellent drivers were considered at the time but ruled-out.
What has changed? Is it because the application is not 2-channel music-only?
Thnx,
-- Mark
Whoa! Hemp Acoustics is still around? And they make a coax based on the Radian 5215? Wow! HA makes great cones, and Radian makes excellent compression drivers. However ... I don't see anything on the Internet about Hemp Acoustics, except a million inquiries about the 8" fullrange driver. Are they still around?
Kindhornman, thanks for sharing your experience with the 8" Radian coax. That model uses the small-format horn and compression driver, while the 12" and 15" use the large-format, 2" exit compression driver, and uses the bass driver as part of the horn flare (similar to Tannoy). The Tannoy coaxial patents expired a very long time ago, so there's no reason anyone can't use Tannoy's woofer-cone-as-extension-of-horn approach.
Part of the reason I'm drawn to the 12" and 15" models is that I haven't had good experiences with small-format compression drivers ... they tend to sound strained in the critical 1~2 kHz region, which makes crossover design very tricky, since the bass driver is at the top of its working range, and kind of tempermental. Plastic diaphragms tolerate working low better than metal diaphragms, which is probably why small-format plastic-diaphragm compression drivers are so popular. If I were forced into using a small-format compression driver, I'd probably choose a plastic diaphragm and cross it no lower than 2 to 2.5 kHz.
Kindhornman, you mentioned you knew some of the people at Radian. Can you confirm the origins of the company for me? I have a 1966 AES paper by J. K. Hilliard and J. A. Renkus (enclosed below), which describes a 4" aluminum-diaphragm compression driver with a Mylar surround. At some point in the Seventies, Renkus left Altec and Emilar, and some time later, Emilar got into financial trouble, and was re-formed as Radian, which continues Hilliard's and Renkus' Mylar-surround technology today. Is that timeline correct? Is there anything to add?
Kindhornman, thanks for sharing your experience with the 8" Radian coax. That model uses the small-format horn and compression driver, while the 12" and 15" use the large-format, 2" exit compression driver, and uses the bass driver as part of the horn flare (similar to Tannoy). The Tannoy coaxial patents expired a very long time ago, so there's no reason anyone can't use Tannoy's woofer-cone-as-extension-of-horn approach.
Part of the reason I'm drawn to the 12" and 15" models is that I haven't had good experiences with small-format compression drivers ... they tend to sound strained in the critical 1~2 kHz region, which makes crossover design very tricky, since the bass driver is at the top of its working range, and kind of tempermental. Plastic diaphragms tolerate working low better than metal diaphragms, which is probably why small-format plastic-diaphragm compression drivers are so popular. If I were forced into using a small-format compression driver, I'd probably choose a plastic diaphragm and cross it no lower than 2 to 2.5 kHz.
Kindhornman, you mentioned you knew some of the people at Radian. Can you confirm the origins of the company for me? I have a 1966 AES paper by J. K. Hilliard and J. A. Renkus (enclosed below), which describes a 4" aluminum-diaphragm compression driver with a Mylar surround. At some point in the Seventies, Renkus left Altec and Emilar, and some time later, Emilar got into financial trouble, and was re-formed as Radian, which continues Hilliard's and Renkus' Mylar-surround technology today. Is that timeline correct? Is there anything to add?
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Sorry I didn't mentioned that. HempAcoustics is long time gone I am afraid. But their coax drivers were great. Probably the Radians also. As I said - the HA drivers are based on Radians. I really cannot understand why they should sound so extremely different? ..
If you get lucky a nice pair come out on the market from time to time.. There are always people that never finish their projects
If you get lucky a nice pair come out on the market from time to time.. There are always people that never finish their projects
Coax drivers can be tricky animals, especially if there's a great big horn right in the middle of the bass driver. I don't even like what phase plugs do to cone drivers, much less a big horn with reflective sides. The cone response gets really goofy with all those reflections, and reflections do not respond well to crossover equalization. (You can't correct a time-domain error with frequency equalization; it makes the time response even worse.)
The Tannoy approach is the right way to go provided you're willing to limit cone excursion. High efficiency and large size can help here, since the bass cone won't need to move as much as a smaller, lower-efficiency cone. The larger cone also helps create a larger horn, which is appreciated since the horn is going to need all the LF extension it can get. Since Tannoy won't sell drivers to OEMs or DIYer's (I've asked the North American distributor), that's off the table.
The potential gotcha with the 12" and 15" Radians is rough response from the cone above 1.5 kHz. A broad, gentle peak at 1.5 kHz, like the Altec/GPA 416 and Tone Tubby 15" hemp-cones, is easy to deal with. What is not easy to deal with is rough, jagged response, which is more common in heavy, high-power prosound cones. The pros don't care because they use digital equalization and 4th-order crossovers; what they're looking for is durability and power-handling, thus the 4" voice coils and aggressive heat-sinking.
The target crossover for the 12" or 15" coax is in the 800 Hz to 1 kHz range, depending on how the horn and cone behave, with a 4th-order LR or Bessel highpass for the horn, and the bass lowpass yet to be decided. The bass might need delay adjustments; Nth-order Bessel lowpass filters should do this adequately.
The Tannoy approach is the right way to go provided you're willing to limit cone excursion. High efficiency and large size can help here, since the bass cone won't need to move as much as a smaller, lower-efficiency cone. The larger cone also helps create a larger horn, which is appreciated since the horn is going to need all the LF extension it can get. Since Tannoy won't sell drivers to OEMs or DIYer's (I've asked the North American distributor), that's off the table.
The potential gotcha with the 12" and 15" Radians is rough response from the cone above 1.5 kHz. A broad, gentle peak at 1.5 kHz, like the Altec/GPA 416 and Tone Tubby 15" hemp-cones, is easy to deal with. What is not easy to deal with is rough, jagged response, which is more common in heavy, high-power prosound cones. The pros don't care because they use digital equalization and 4th-order crossovers; what they're looking for is durability and power-handling, thus the 4" voice coils and aggressive heat-sinking.
The target crossover for the 12" or 15" coax is in the 800 Hz to 1 kHz range, depending on how the horn and cone behave, with a 4th-order LR or Bessel highpass for the horn, and the bass lowpass yet to be decided. The bass might need delay adjustments; Nth-order Bessel lowpass filters should do this adequately.
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