Some interesting posts in my absence.
My impression is we are all conveying our experiences and understandings of technical audio concepts. But without context how can we compare apples with apples and make sense of it?
The particular usage - near field monitoring from home studio recording
- home stereo two channels playback in a living room.
- home theatre
- barn / garage sound
My impression is we are all conveying our experiences and understandings of technical audio concepts. But without context how can we compare apples with apples and make sense of it?
The particular usage - near field monitoring from home studio recording
- home stereo two channels playback in a living room.
- home theatre
- barn / garage sound
On those Harman Curves Sean Olive revealed (excuse the pun) that he can on board after it was determined that Harman or whoever was in charge at the time wasn’t happy with the consumer reviews JBL consumer were receiving.
From that point of view the research by Toole & Olive was a commercial decision to try and push back on the leverage that consumer reports held by being purely subjective at the time.
John Atkinson has revealed in a relatively recent interview that a consumer review is never an easy job. His explanation is that the reviewers job is to understand the loudspeaker designers goal and then assess whether those goals have been achieved.
The technical reports by Atkinson then either support the reviewer’s findings or not if possible.
Has Harman been successful?
It depends on how you look at it?
Market share of consumer loudspeakers?
It’s too early to say. People are talking about it on audio forums. As a design practice off axis response is now an accepted goal with visibility in “some” but not all consumer reports.
If the JBL imaging control wave guide was seen as a development of Toole & Olives work then franchising it across every model in the consumer range seems to be working.
But l don’t think Harman have succeeded in telling the hifi publication industry how to play its game.
There is absolutely no doubt consumer reports influence sales. The big issue provoked by Harman is the context in which subjectivity plays a role in consumer reports. I think John Atkinson answers this by saying it’s up to the reviewer to report if the design or designer goals have been successful.
From that point of view the research by Toole & Olive was a commercial decision to try and push back on the leverage that consumer reports held by being purely subjective at the time.
John Atkinson has revealed in a relatively recent interview that a consumer review is never an easy job. His explanation is that the reviewers job is to understand the loudspeaker designers goal and then assess whether those goals have been achieved.
The technical reports by Atkinson then either support the reviewer’s findings or not if possible.
Has Harman been successful?
It depends on how you look at it?
Market share of consumer loudspeakers?
It’s too early to say. People are talking about it on audio forums. As a design practice off axis response is now an accepted goal with visibility in “some” but not all consumer reports.
If the JBL imaging control wave guide was seen as a development of Toole & Olives work then franchising it across every model in the consumer range seems to be working.
But l don’t think Harman have succeeded in telling the hifi publication industry how to play its game.
There is absolutely no doubt consumer reports influence sales. The big issue provoked by Harman is the context in which subjectivity plays a role in consumer reports. I think John Atkinson answers this by saying it’s up to the reviewer to report if the design or designer goals have been successful.
On the diy front l am going to compare a system using horns with dome mids in the upper midrange over the next few months.
This will be implemented using a removable support baffle in a JBL 4343 style enclosure.
The dome will either be a JBL 903Ti, a Visation, a Dayton dome mid or the Sarori mid dome.
An appropriate dome tweeter will also be used.
The crossover from the cone lower mid or the 15 inch woofer will be part of the comparison.
Some new compression drivers and wave guides will also form part of the comparison.
This will be implemented using a removable support baffle in a JBL 4343 style enclosure.
The dome will either be a JBL 903Ti, a Visation, a Dayton dome mid or the Sarori mid dome.
An appropriate dome tweeter will also be used.
The crossover from the cone lower mid or the 15 inch woofer will be part of the comparison.
Some new compression drivers and wave guides will also form part of the comparison.
Attachments
The Consumer Reports being referred to was a specific publication available at the time.
"Perhaps the only ones of any practical note are the loudspeaker reviews in Consumer Reports, published by Consumers Union (CU), starting about 1970. Based on a comparison of subjective and objective data, a method of processing sound power measurements was developed that resulted in a percentage accuracy rating [14,15]. Products are rank ordered in quality according to this rating. Over the years, it became a bit of sport, within the audio community, to be critical of this process, alluding to examples of loudspeakers that were believed to be better or worse than the CU ratings suggested. New knowledge about the acoustics and psychoacoustics of loudspeakers and rooms suggested that the CU method was flawed. Still, a viable alternative computational model has been lacking … until now."
It's a controversial topic at best. I personally don't think Harman has made a dint in how the HiFi industry has worked with magazine reviewers. JBL simply didn't or doesn't have market leverage.
As a document (attached above) it's quite a complicate read to communicate and I don't believe they have yet distilled it down to what it means in one sentence to a HiFi enthusiast. What matters it how it sounds subjectively at the point of sale. Who in their right mind wants or needs to be a trained listener to appreciate a researcher's findings?
Let your ears be the final arbiter.
What actually happened with JBL was it was JBL's own Hi end systems that really improved to the point of being likened to HiFi with the likes of the Project S9800 in early 2000's. It was the latest 0435Be compression drivers that were more advanced technically and that was the product story. They were still developing their CD horns so they didn't sound like horns back the early 2000's.
But was this what their brand loyal customers wanted in Japan? No not necessarily. This imho was a dilemma for JBLs' Japan division so they split ranges between the blue baffle traditionally voiced systems and the Hifi voiced S9800 and what followed. I heard them in Tokyo. They were distinctly different ranges. For rock and popular music the traditional blue baffle systems tend to win favour with long time JBL owners. They have a more bold character and a bigger bass presentation. The S9800, S9900 are nicer and more polite. The JBL Array 1400 images like nothing else on the planet. But that was the decision by Greg Timbers to put a JBL Synthesis horn with a horizontal diffraction slot in vertical orientation that made it work. None of the horizontally oriented JBL consumer horn systems image anywhere near as well.
What is interesting is that it was Greg Timbers efforts in his own garage that (which I visited ) that scored the big home runs for JBL's product market historically. He then had the task of convincing the marketing department. He said he put his own license subjectively on how he wanted his designs voiced.
In recent times it was Charles Sprinkle and Alexander Voishvillo's work on the M2 that has bought a wind of change for JBL'a product market portfolio. Voishvillo is an outright genius and the man behind the D2 dual annular diaphragm compression driver. Sprinkle also a brilliant engineer left JBL after 15 years and now works for Kali Audio designing budget priced near field monitors.
https://pro.harman.com/insights/har...tlight-alexander-voishvillo-jbl-loudspeakers/
https://www.audiosciencereview.com/...charles-sprinkle-about-studio-monitors.52528/
So I kinda go yes there's the theory but its the innovation in the product that your actually taking notice of. And that is a subjective reality that your ear's immediately identify with. There's nothing subjectively subtle about it.
The M2 wave guide was and is the real answer to Toole and Olive's research. That was 20 years in development.
As a document (attached above) it's quite a complicate read to communicate and I don't believe they have yet distilled it down to what it means in one sentence to a HiFi enthusiast. What matters it how it sounds subjectively at the point of sale. Who in their right mind wants or needs to be a trained listener to appreciate a researcher's findings?
Let your ears be the final arbiter.
What actually happened with JBL was it was JBL's own Hi end systems that really improved to the point of being likened to HiFi with the likes of the Project S9800 in early 2000's. It was the latest 0435Be compression drivers that were more advanced technically and that was the product story. They were still developing their CD horns so they didn't sound like horns back the early 2000's.
But was this what their brand loyal customers wanted in Japan? No not necessarily. This imho was a dilemma for JBLs' Japan division so they split ranges between the blue baffle traditionally voiced systems and the Hifi voiced S9800 and what followed. I heard them in Tokyo. They were distinctly different ranges. For rock and popular music the traditional blue baffle systems tend to win favour with long time JBL owners. They have a more bold character and a bigger bass presentation. The S9800, S9900 are nicer and more polite. The JBL Array 1400 images like nothing else on the planet. But that was the decision by Greg Timbers to put a JBL Synthesis horn with a horizontal diffraction slot in vertical orientation that made it work. None of the horizontally oriented JBL consumer horn systems image anywhere near as well.
What is interesting is that it was Greg Timbers efforts in his own garage that (which I visited ) that scored the big home runs for JBL's product market historically. He then had the task of convincing the marketing department. He said he put his own license subjectively on how he wanted his designs voiced.
In recent times it was Charles Sprinkle and Alexander Voishvillo's work on the M2 that has bought a wind of change for JBL'a product market portfolio. Voishvillo is an outright genius and the man behind the D2 dual annular diaphragm compression driver. Sprinkle also a brilliant engineer left JBL after 15 years and now works for Kali Audio designing budget priced near field monitors.
https://pro.harman.com/insights/har...tlight-alexander-voishvillo-jbl-loudspeakers/
https://www.audiosciencereview.com/...charles-sprinkle-about-studio-monitors.52528/
So I kinda go yes there's the theory but its the innovation in the product that your actually taking notice of. And that is a subjective reality that your ear's immediately identify with. There's nothing subjectively subtle about it.
The M2 wave guide was and is the real answer to Toole and Olive's research. That was 20 years in development.
Integration of the SATORI MD60N in my 475L project :
... Awaiting listening tests ! 😀 😉
T
... Awaiting listening tests ! 😀 😉
T
It would be interesting to see anyone's attempts with MTM arrangements using mid domes and their resulting vertical off axis response curves. I've see some good results doing this with Morel MDM55s and a CAT378 crossing at 3.5k with CTC spacing of 1.25 x WL. The VC isn't offset with the drivers all being mounted flush in the baffle. The midrange HP is capable of being pushed down to 700 hz, which is at least another 150 hz lower than typical xovers designed for the MDM55. The resulting dynamic range is impressive used with a decent sized LF driver.
As more AMT drivers enter the market, I’m finding them to be the most articulate or clear transducer technology currently available. Subjectively, for all of their other faults, Mylar dome tweeters did the same thing….produced a clarity that silk and the like couldn’t achieve. Low mass domes certainly outperform cones in this regard. AMT mids have the hurdle of size…..with limited vertical response, it becomes challenging to effectively cross them to HF devices currently by I suspect we’ll see more AMT type mid tweeters extending higher. I’m not that demanding in this regard…..one driver that can do 500-15k is just fine by me. The GRS copy of the BG planar mid tweeter comes close.
Best of the best available right now?….i‘d have to say if high SPL isn’t a system goal a mid dome paired with a true ribbon tweeter or small AMT is where it’s at currently…….at least for those who appreciate the clarity…..some find it fatiguing and prefer the cohesive nature of the french fried 2 way……because who doesn’t like french fries?
I bought a pair of the ESS Heils after reading here that there’s an incredible sale on em. I’ve been prototyping with them for a few weeks now but not much progress as I’m a summer guy and there’s much to do outdoors this time of year. I suspect the love of audio is a seasonal thing too……much of the best gear, active DIY and high end consumption seems to happen in places that have very short summers and long, dark winters…….music can soothe that savage beast!
A pair of LRS+ have been at our country place since February….haven‘t done much with them other than listen when we’re there……the plan is to tackle the poor low end response this winter with a very specific subwoofer system……but lord knows I hate the cold so not sure how many trips up north i’ll take.
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@mayhem13 The characteristic sound signature of specific midrange driver emissive materials and motor design can be hard to categorize if the diaphragm material is a synthetic polymer material. Large AMT drivers can suffer from standing wave modes across the vertical plane (along the fold peaks) depending on the polymer chosen. Kaladex is the newest offering with the best internal dampening vs. rigidity. It doesn't handle nearly as much heat as kapton but has a much smoother, yet extended sound. An area where AMTs can have higher 3rd order HD is the lower mids and this depends on how well the folded diaphragm is dampened in the vertical plane. Some manufacturers use silicon coatings to dampen the diaphragm ie Mundorf premium models. The back chamber on the premium monopolar Mundorf AMTs is a bit more refined. Many of the budget AMTs don't have any special treatment or diaphragm materials and sound rough. The only exception I've found are most of the Aurum Cactus AMTs. The Dayton models are rather peaky in the upper mids and lack that extra refinement. The Beyma TPLs are very good for the price but require special attention to get the cleanest performance from. They're definitely designed for the pro market and work well in that application, but aren't quite equal to the higher end Mundorfs in stock form.
I've found that fabric mid domes vary greatly in sound just from the type of fabric and coatings they employ. ScanSpeak has the advantage in the fabric dome market with the most experience in materials and production methods, giving their domes an edge over the others, even Dynaudio and Morel. Problem is most fabric domes run in a softer, broader range breakup mode as opposed to metal or composite domes which stay pistonic longer, but then break up suddenly and very sharply. The SS D7608 has a better fabric dome composition and shape compared to most other larger domes. IMO, the D7608 has a cleaner sound while being more relaxed, specifically in the 2k+ range where most fabric domes start to go soft. Its closer to an Alu dome in nature but retains its balance in character longer, making it a good match for planar tweeters without having that abrupt change in sound at xover. The narrow vertical pattern of a planar compliments the large mid domes directivity as opposed to a non WG dome tweeter, which suddenly goes wide at crossover. The resulting change in midrange to treble tonality shifts abruptly over the listening distance, unless an appropriate WG is used on the tweeter.
The so called french fry type 2 way is a ubiquitous design these days, but some of them are exceptional. These days, with the modern materials we have access to, you can do an exceptional 7" cone and 1" alloy dome 2 way. The rohacell composite cones from Morel are pretty amazing in their pistonic range. Many 2.5 way systems can now outdo 3 way systems. I know alot of people like Aluminum cone drivers, but the sharp breakup can be hard to eradicate from their response curve, even with a notch filter. There are times, despite the careful crossover work, you can still hear that metal cone sound signature. The neighboring driver can partially excite the resonance, which is usually structure born in the front baffle. The most effective solution is decoupling the woofer and tweeter from the front baffle. This should be done on mid drivers like the M74A and other alloy domes.
Many people love Beryllium and believe its the perfect diaphragm material, but it can often mask details like silk and other fabric. Be is a great material for larger domes which have some of the breakup up top but with less of a peak. To my ears, Be sounds very close to fabric more than it is to alloy. Titanium can be hit or miss depending on many factors ie dome shape, geometry, thickness, size, embossing, etc.
So for my taste, a large mid dome like the SS D7608 has the best balance in sound which delivers the right amount of even order HD, clarity and sound stage usually not heard in 2 way designs or even 3 ways with more advanced cone drivers. Planar drivers come close, but are unfortunately not always as smooth and relaxed that listening fatigue doesn't take over. The area between 1k and 4k can be challenging to play without ear fatigue while truly being analytical but not doing so using extra added harmonics giving that false impression of higher detail and resolution. Alot of speakers are designed with midrange peaks to give that fake impression of sounding detailed and open.
I've found that fabric mid domes vary greatly in sound just from the type of fabric and coatings they employ. ScanSpeak has the advantage in the fabric dome market with the most experience in materials and production methods, giving their domes an edge over the others, even Dynaudio and Morel. Problem is most fabric domes run in a softer, broader range breakup mode as opposed to metal or composite domes which stay pistonic longer, but then break up suddenly and very sharply. The SS D7608 has a better fabric dome composition and shape compared to most other larger domes. IMO, the D7608 has a cleaner sound while being more relaxed, specifically in the 2k+ range where most fabric domes start to go soft. Its closer to an Alu dome in nature but retains its balance in character longer, making it a good match for planar tweeters without having that abrupt change in sound at xover. The narrow vertical pattern of a planar compliments the large mid domes directivity as opposed to a non WG dome tweeter, which suddenly goes wide at crossover. The resulting change in midrange to treble tonality shifts abruptly over the listening distance, unless an appropriate WG is used on the tweeter.
The so called french fry type 2 way is a ubiquitous design these days, but some of them are exceptional. These days, with the modern materials we have access to, you can do an exceptional 7" cone and 1" alloy dome 2 way. The rohacell composite cones from Morel are pretty amazing in their pistonic range. Many 2.5 way systems can now outdo 3 way systems. I know alot of people like Aluminum cone drivers, but the sharp breakup can be hard to eradicate from their response curve, even with a notch filter. There are times, despite the careful crossover work, you can still hear that metal cone sound signature. The neighboring driver can partially excite the resonance, which is usually structure born in the front baffle. The most effective solution is decoupling the woofer and tweeter from the front baffle. This should be done on mid drivers like the M74A and other alloy domes.
Many people love Beryllium and believe its the perfect diaphragm material, but it can often mask details like silk and other fabric. Be is a great material for larger domes which have some of the breakup up top but with less of a peak. To my ears, Be sounds very close to fabric more than it is to alloy. Titanium can be hit or miss depending on many factors ie dome shape, geometry, thickness, size, embossing, etc.
So for my taste, a large mid dome like the SS D7608 has the best balance in sound which delivers the right amount of even order HD, clarity and sound stage usually not heard in 2 way designs or even 3 ways with more advanced cone drivers. Planar drivers come close, but are unfortunately not always as smooth and relaxed that listening fatigue doesn't take over. The area between 1k and 4k can be challenging to play without ear fatigue while truly being analytical but not doing so using extra added harmonics giving that false impression of higher detail and resolution. Alot of speakers are designed with midrange peaks to give that fake impression of sounding detailed and open.
No, exactly the opposite, the bends are the strongest point and the hardest to excite of the whole diaphragm. If there are building standing waves then it's where the pressure is the highest and the stability the lowest, the surfaces 90° towards the front and back. In the big ESS AMTs it's actually the diaphragm frame which needs the most attention (and is the most neglected point).
Kaladex is not a good substitute for Mylar because it's not bi-axial oriented. At least for AMTs. You're improving one direction by neglecting the other.
The folding is ofc important. Though: The 3rd order HD comes actually mostly from how the diaphragm is glued to the frame and which properties the glue has.
@ICG My data regarding the construction challenges of AMTs comes from R&D I've done with a company back in the 90s, trying to find better materials. Kaladex was preferred as it had better internal losses. Kapton was too resonant anf mylar was to weak. The directionally of grain on these plastics wasn't so much a problem for the processing and cutting but it had to be considered when folding it permanently so it wouldn't fracture. The diaphragms were cut via sharp stamping tools and the cleanest folds could be done with kapton. It definitely mattered where the folded diaphragm assembly was supported in the vertical plane, otherwise it would cause multiple resonant modes. Drops of RTV silicone were applied randomly to the vertical corners. If you look at Mundorf AMT diaphragms, they were designed with random termination points. Mylar was chosen due to its low cost and availability, but it didn't sound as good as the Kaladex. Infinity had lots of delamination issues with Mylar as did Magnepan. Apogee had to repair alot of midrange panels on the Diva model because of delamination of the aluminum.
The downside of Kaladex is that the tensile strength deteriorates stronger in one direction and loses flexibility too, being less flexible to begin with - which is a requirement for an AMT. Mylar is keeping its properties better over time. I have ~50 year old AMTs here which still work perfectly with the original diaphragms. Kaladex was invented 1980, Mylar 1952 so it's hard to tell which material in a tweeter in an actual real-life situation lives longer.
You are forgetting that it was a matter of the voice 'coil', mainly a matter of glue which lead to the 'wires' not keeping attached to the Mylar and not an issue of Mylar itself having material problems. Kaladex is facing the same problems unless you use the appropriate glue. I have to admit though, I don't know which glue is the right one and which is not.
The use of Mylar was not because it was cheaper (not really an argument because of the tiny ammount needed for a diaphragm in relation to the costs of magnets and iron) but because it was available in thinner sheets and with less tolerances, mainly because of its much longer production time and production volume. That thickness argument changed when DuPont cancelled the thinner sheets (and was the only company which produced them in the thin thickness) a while back, so Mylar might not be the best choice now but there were very good arguments back then and there are nonetheless still good arguments "pro Mylar" today.
@profiguy
It‘s hard for me to follow along with the whole false detail thing…….i find most folks that follow this mantra pray to the gods of sighted listening using FR as a road map. Measurements will only get you so far…..response, phase and impedance plots won’t tell you much with complex music…….the actual behavior of the transducer is nothing like a sweep or burst. At some point personal preference and subjectivity become the variable in the equation. By choice and occupation, I probably do more near field listening than most……..which is very enlightening over time. All transducers will exhibit some poor behavior under a specific condition…..end of the day, it’s still a motor.
It‘s hard for me to follow along with the whole false detail thing…….i find most folks that follow this mantra pray to the gods of sighted listening using FR as a road map. Measurements will only get you so far…..response, phase and impedance plots won’t tell you much with complex music…….the actual behavior of the transducer is nothing like a sweep or burst. At some point personal preference and subjectivity become the variable in the equation. By choice and occupation, I probably do more near field listening than most……..which is very enlightening over time. All transducers will exhibit some poor behavior under a specific condition…..end of the day, it’s still a motor.
Can someone please tell me which mid domes are in these JSE speakers? Thanks.
Look very much like peerless 2" silk domes from the 1990ies
...and very good Peerless mids designed after the second gen Philips. These were extremely flat and neutral on larger baffles.