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Coax project using 6.5" car audio drivers ESB 4.6C
- Thread starter ppataki
- Start date
- Thread Starter
- #23
I could only perform in-room (in-corner) off-axis measurements, not sure if those would helpAre you able to make some off-axis measurements? I'm curious to how bad the interference is
But anyway the speakers are already on their way back
Well, I'm not at all surprised by the results... Too bad I wasn't proven wrong
I will be eagerly awaiting your next pair of victims
I will be eagerly awaiting your next pair of victims
What about the KEF Q350 driver? The price of a pair of loudspeakers is at a low; the Q350 has been replaced with the Q3 Meta. I have both and there is little difference in the two. What I did was to purchase the systems and simply remove the transducers and stack up the enclosures et al. in my office. I have black and fake oak.
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- Thread Starter
- #27
Wooow, that is brutal!!!
Congratulations on your system, really impressive!
Are you planning to devote a separate thread to it here? I would love to see the measurements and also watch a video about how they sound
ppataki
I just got my UMIK-1 mic and REW to work yesterday. I am using a miniDSP FLEX HTx and so far I like it. Once I get the mic and REW issues resolved, I will order and download a 8-channel DIRAC license from miniDSP for the HTx. The Q3 Metas are powered by a Topping LA90 and the other 6 channels are powered by FOSI V3 Mono's. That Topping is something else. If I turn the volume all the way up and press my ear to the KEF Al dome tweeter(s), I cannot hear anything, no audible hiss at all! I am posting reports on my project(s) on LinkedIn, https://www.linkedin.com/in/steve-mowry-0959176/. I am retired now and I go slow. This is my hobby.
Bellow is a sketch of my #2 Flower system concept. I have everything and I will start this month. This one uses the Radian coaxial with complementary low frequency transducers and is a more compact implementation.
I just got my UMIK-1 mic and REW to work yesterday. I am using a miniDSP FLEX HTx and so far I like it. Once I get the mic and REW issues resolved, I will order and download a 8-channel DIRAC license from miniDSP for the HTx. The Q3 Metas are powered by a Topping LA90 and the other 6 channels are powered by FOSI V3 Mono's. That Topping is something else. If I turn the volume all the way up and press my ear to the KEF Al dome tweeter(s), I cannot hear anything, no audible hiss at all! I am posting reports on my project(s) on LinkedIn, https://www.linkedin.com/in/steve-mowry-0959176/. I am retired now and I go slow. This is my hobby.
Bellow is a sketch of my #2 Flower system concept. I have everything and I will start this month. This one uses the Radian coaxial with complementary low frequency transducers and is a more compact implementation.
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thewas
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thewas
About 12 years ago, I worked closely with Ilpo from my office in Phuket for about three and one-half years and before he passed away. Our major projects included the Racetrack woofers used in the ONES and the design and development of a new coaxial that utilized only one Neo magnet and was manufacturable. I visited GENELEC in Finland twice and I have stories. They really liked the performance of the spider-less old patented GENELEC coaxial. The design engineer had passed away by then and they mentioned manufacturing issues. I asked the managing director how many units could he build per day. He was actually honest and replied, "six (6)" and only one operator was capable of building their coaxials. I almost fell down! At that time, GENELEC's focus was signal processing. They did not even have the FEA tools to perform motor, suspension and diaphragm simulations. The staff hated me at first. I am in the tropics and they are in the artic. One of my visits was during 21 June and it did not get dark that day.
Another story relates to when we were working on the racetrack woofers, Ilpo indicated that some folks in the company wanted to just mount round woofers on the sides of the enclosure. However, Ilpo had blocked that approach and claimed that they had researched side mounted woofers. Ilpo claimed that it did not sound right. As you know, the 8381 has woofers on the sides of the enclosure. Their first product to do this. It was Ilpo that claimed that directivity was everything.
There's more, much more but Ilpo had asked what if we go for a coaxial with a planar tweeter. GENELEC's first systems had planar tweeters and Ilpo liked planar. At that time, I was concerned with the manufacturability. So we went with two coils within one motor. Using nonlinear AC FEA, appropriate shorting rings were implemented. Why isn't their new coaxial patented. Because I blocked that. It was not new; Harry Olson did it, not to mention I am for open source. I dislike patents. It's just bean counters restraining trade. Having said that, the Radian coaxial has a bit of a special meaning to me.
Ilpo and I discussed the Flower array but he wanted the 4 x midbass drivers mounted inside the waveguide. I cannot remember what happened with that but Ilpo had cancer and that certainly had to compromise things. In retrospect, GENELEC's 4 x midbass drivers should be inside the waveguide and get those woofer off the sides!
Finally, why aren't there more "good" coaxials? My call is that they are more difficult to design and to manufacture. When I first look at a loudspeaker, if I cannot identify the acoustic center, I typically loose interest. Moving the mic to find the best position is cheating at best. I now concur, directivity is everything.
About 12 years ago, I worked closely with Ilpo from my office in Phuket for about three and one-half years and before he passed away. Our major projects included the Racetrack woofers used in the ONES and the design and development of a new coaxial that utilized only one Neo magnet and was manufacturable. I visited GENELEC in Finland twice and I have stories. They really liked the performance of the spider-less old patented GENELEC coaxial. The design engineer had passed away by then and they mentioned manufacturing issues. I asked the managing director how many units could he build per day. He was actually honest and replied, "six (6)" and only one operator was capable of building their coaxials. I almost fell down! At that time, GENELEC's focus was signal processing. They did not even have the FEA tools to perform motor, suspension and diaphragm simulations. The staff hated me at first. I am in the tropics and they are in the artic. One of my visits was during 21 June and it did not get dark that day.
Another story relates to when we were working on the racetrack woofers, Ilpo indicated that some folks in the company wanted to just mount round woofers on the sides of the enclosure. However, Ilpo had blocked that approach and claimed that they had researched side mounted woofers. Ilpo claimed that it did not sound right. As you know, the 8381 has woofers on the sides of the enclosure. Their first product to do this. It was Ilpo that claimed that directivity was everything.
There's more, much more but Ilpo had asked what if we go for a coaxial with a planar tweeter. GENELEC's first systems had planar tweeters and Ilpo liked planar. At that time, I was concerned with the manufacturability. So we went with two coils within one motor. Using nonlinear AC FEA, appropriate shorting rings were implemented. Why isn't their new coaxial patented. Because I blocked that. It was not new; Harry Olson did it, not to mention I am for open source. I dislike patents. It's just bean counters restraining trade. Having said that, the Radian coaxial has a bit of a special meaning to me.
Ilpo and I discussed the Flower array but he wanted the 4 x midbass drivers mounted inside the waveguide. I cannot remember what happened with that but Ilpo had cancer and that certainly had to compromise things. In retrospect, GENELEC's 4 x midbass drivers should be inside the waveguide and get those woofer off the sides!
Finally, why aren't there more "good" coaxials? My call is that they are more difficult to design and to manufacture. When I first look at a loudspeaker, if I cannot identify the acoustic center, I typically loose interest. Moving the mic to find the best position is cheating at best. I now concur, directivity is everything.
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For example and with respect to the GENELEC ONES (Ilpo's designs), the 8381 topology could have been coaxial. Then with GENELEC's DSP resources, the directivity could be made outstanding. Two woofers up / two woofers down plus the Flower but with drivers inside the waveguide for GENELEC's coaxial!
Now in a 3-box setting, the above topology is something Ilpo might have considered.
Can anybody identify the Industrial Design, that GENELEC was famous for, in the 8381?
Now in a 3-box setting, the above topology is something Ilpo might have considered.
Can anybody identify the Industrial Design, that GENELEC was famous for, in the 8381?
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thewas
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While I of course do not disagree that directivity is very import, do you want to say that such is compromised on the 8381 and if yes, can you show it in their measurements? For example side woofers aren't a real problem when crossed low enough so their distance is less than lamba/4.
My statement was based on a comparison to the development of the ONES. Clearly it would have been mush easier to OEM some round woofers and side mount them. However, Ilpo blocked that concept. He then started the development of racetrack woofers as his desired concept and thus maintaining the coaxial topology. The racetrack woofers and the coaxials are manufactured in Finland and thus must be designed for manufacture.
Having said that, GENELEC is very strong in signal processing and I cannot evaluate any design compromises. However, I can identify a bit of disrespect for the deceased Founder and former Chairman. The GENELEC R&D team was and is well aware of Ilpo's thumbs down to side mounted woofers. Then how is side mounting an improvement to their coaxial arrays? So, I cannot identify the compromises but can you identify any benefits other than it's easier that way.
Having said that, GENELEC is very strong in signal processing and I cannot evaluate any design compromises. However, I can identify a bit of disrespect for the deceased Founder and former Chairman. The GENELEC R&D team was and is well aware of Ilpo's thumbs down to side mounted woofers. Then how is side mounting an improvement to their coaxial arrays? So, I cannot identify the compromises but can you identify any benefits other than it's easier that way.
While on the topic of coaxials, here's a link to the old GENELEC coaxial US Patent, https://patentimages.storage.googleapis.com/2e/f9/51/9578c0ab9b3b33/US8660279.pdf. Now coupling this coaxial to the GENELEC front baffle waveguide with the hidden racetrack woofers and applying a bit of Industrial Design, resulted in the 8351A with performance at high standards. Unfortunately, the low frequency coaxial transducer's voice coil cannot be gauged. The leaking around the voice coil that has been identified is related to gaugability and is a major issue in coaxial design. So as time progressed, and in the limit the value of this concept was negative to the company. It became a problem rather than a solution. It was not manufacturable, thus the 6 a day situation. This can happen when engineers with their typical egos, manage the transducer development project.
Here's a link to a dated discussion on the topic of who should manage the transducer development project, https://pearl-hifi.com/06_Lit_Archi...Mowry_Steve/Who_Should_Manage_The_Project.pdf.
Here's a link to a dated discussion on the topic of who should manage the transducer development project, https://pearl-hifi.com/06_Lit_Archi...Mowry_Steve/Who_Should_Manage_The_Project.pdf.
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If they're anything like my line of work, they patent the stuff they don't use (to thwart second-to-market wannabes) and leverage trade secrets hard to render the actual product and process as abstruse and inscrutable as possible for any potential imitators.
Um... there's more industries that do this than you think lolIf they're anything like my line of work, they patent the stuff they don't use (to thwart second-to-market wannabes) and leverage trade secrets hard to render the actual product and process as abstruse and inscrutable as possible for any potential imitators.
I published a discussion of various coaxial transducers in 2014 and there seems to have been little change in the last 10 years. I was hoping to see some EMI concept(s).
https://pearl-hifi.com/06_Lit_Archive/14_Books_Tech_Papers/Mowry_Steve/COAXIAL.pdf
https://pearl-hifi.com/06_Lit_Archive/14_Books_Tech_Papers/Mowry_Steve/COAXIAL.pdf
A decade and no innovations? Sad. So what in your estimation then is the most performant coax on the market? The ones @RickS is using in his current design, made by Sica, look real promising ( https://www.audiosciencereview.com/forum/index.php?threads/sica-6-5-coaxial-speaker-build.61464/ )
