Thiels , Duntech , Sonus fabers , to name a few , i myself like to use 6 db slopes on the midrange, odd order works best for me ....
You know Scott, people here cannot handle recent circuitry. Most here are stuck with where I was, 40 years ago. IF I put up a modern schematic, all I get is SILENCE.
If you listen carefully, you can hear the drool hitting the floor as we stare at it blankly.
For whatever reason, their published stuff never sounded that good to me; their better commercial speakers often used first order electrical, but were nowhere near first order acoustic.
Back in the late '70s, I was working with Murray Zeligman on a Dynaudio (at that time called SEN Labs) design which used first order electrical and actually wasn't too far from a first order acoustic. It took a five way system and some real crossover complexity to pull it off, but it sounded superb; Dynaudio adapted it later for the Consequence, but Murray's seemed to be just that much better. Years later, he did the same thing for Nova (the Rendition).
I would love to build some of the circuits you post but at present do not have supplies of low noise complementary Jfets - plenty of N channel but very very few P Channel. Hope fully this situation will change soon. Do you think it's worth building with 111 112 174 175's etc.
Seems to me building is a more positive response that just talking
With the n channel devices I can get at present I'm building SE rather symetrical designs.
BTW I did ask a question about the Vendetta diagram that someone posted and I still await a response 🙂
Seems to me building is a more positive response that just talking
With the n channel devices I can get at present I'm building SE rather symetrical designs.
BTW I did ask a question about the Vendetta diagram that someone posted and I still await a response 🙂
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It turns out if you include significant cap load, etc. that simple circuit is hard to make behave with square waves at less than 20dB closed-loop gain. More sophisticated frequency compensation is an exercise left to the reader. 😀
Or use it open-loop, or partially open-loop as someone suggested take the complimentary follower out of the loop if you have 1000pF of cable.
Yep... I know that. That's the reason I only use active filters... there is a lot less tradeoffs with them.
Dear John, I'm not being rigid, I'm just talking about experiences and measurements and basic acoustic theory 😉. Please, excuseme if my comment sounded a bit harsh.
I know about comercial and DIY designs using 6db/oct, and I have used them a couple of times. But they have a couple of "heavy" problems:
1. There isn't real "acoustic first order xover"... only electric ones, at least if talk about high-pass filters applied to mids or tweeters, because every time the filter's first order slope meet the second order slope of the transfer function of the driver, it becomes a third order acoustic filter, so....we need to choose a very high xover frequency, and it adds more problems, let alone that the "perfect transient" behaviour is gone in the acoustic domain.
2. Every xover has phase shifts, so the problems are always there, and this kind of xover isn't doing anything to solve that...
I always ask myself about that: If nobody can hear the transition from first order slope to third one, neither the "not-so-good" HF behaviour of drivers using first order filters, I end believing into psychoacoustics 😉
The original Epos ES-14 ran the woofer with no filter at all, and just a capacitor (and resistor?) on the tweeter.
I would like to present a little history of audio reproduction that might ultimately clarify some to the contention that we seem to have on this thread about acoustic reproduction.
Back in the 1950's, a 'breakthrough' occurred with the Acoustic Research AR-1(2,3) acoustic suspension loudspeaker. It was one of the first speakers that had pretty good bass in a 'bookshelf' sized box. In fact, it NEEDED a relatively small box to work at all.
Before this, people used relatively larger ported boxes or sometimes infinite baffles, usually made by mounting a speaker in a wall or closet door. Of course, there are always tradeoffs with this sort of change in design, and in this case, efficiency was sacrificed for bass extension. This led to bigger tube amps in the process. This was NOT a 'revolutionary' or unique design. It had already been tried and apparently rejected by Harry Olsen of RCA labs, and he broke the patent that AR filed.
There was one real advantage of the AR loudspeaker, it was 'perfect' for stereo when it came to being, and it sold like hot cakes. People became millionaires making these speakers, YET they were not really a 'great' speaker at all. It was over-advertised and hyped in the press, and today mostly forgotten.
Another 'cult of audio excellence' came in the 1960's-1970's from a Dr. Ashley, who interestingly enough, showed the first TP crossover in an article in the AES in the mid '60's. Later, Dr. Ashley put down the AR concept and promoted K-horns instead. He also was a great believer that time and phase information was not important, apparently in contradiction to the TP crossover that he introduced. He wrote another AES paper that I attended in the early 70's, and I remember Harry Olsen getting up questioning his assumptions, which he politely ignored. As with all 'empire builders' Dr. Ashley got on every AES committee he could, and was ultimately responsible for keeping Walt Jung's series on SID from getting into the AES journal. He also became a professor at some university in Colorado teaching audio courses. (sound familiar anyone?)
In the late '70's his empire was brought down by the university who did not give him tenure, and he dropped out completely from the audio scene virtually overnight. So much for interest and commitment in audio. So much for Dr. Ashley, as Richard Heyser, John Meyer, Manfred Schroeder and many others were then dealing with speaker alignment issues and MONAURAL PHASE detection by the human ear.
Now it comes to the next 'takeover' of acoustic principles, by ABX testing. This is where many of you are now 'brainwashed' to blindly believe that what you are being told is the only audio 'truth' and you cannot trust your ears. Well, when a speaker made for relatively low cost completely trumps ALL more expensive speakers, then I will be one of the first to promote it enthusiastically.
Back in the 1950's, a 'breakthrough' occurred with the Acoustic Research AR-1(2,3) acoustic suspension loudspeaker. It was one of the first speakers that had pretty good bass in a 'bookshelf' sized box. In fact, it NEEDED a relatively small box to work at all.
Before this, people used relatively larger ported boxes or sometimes infinite baffles, usually made by mounting a speaker in a wall or closet door. Of course, there are always tradeoffs with this sort of change in design, and in this case, efficiency was sacrificed for bass extension. This led to bigger tube amps in the process. This was NOT a 'revolutionary' or unique design. It had already been tried and apparently rejected by Harry Olsen of RCA labs, and he broke the patent that AR filed.
There was one real advantage of the AR loudspeaker, it was 'perfect' for stereo when it came to being, and it sold like hot cakes. People became millionaires making these speakers, YET they were not really a 'great' speaker at all. It was over-advertised and hyped in the press, and today mostly forgotten.
Another 'cult of audio excellence' came in the 1960's-1970's from a Dr. Ashley, who interestingly enough, showed the first TP crossover in an article in the AES in the mid '60's. Later, Dr. Ashley put down the AR concept and promoted K-horns instead. He also was a great believer that time and phase information was not important, apparently in contradiction to the TP crossover that he introduced. He wrote another AES paper that I attended in the early 70's, and I remember Harry Olsen getting up questioning his assumptions, which he politely ignored. As with all 'empire builders' Dr. Ashley got on every AES committee he could, and was ultimately responsible for keeping Walt Jung's series on SID from getting into the AES journal. He also became a professor at some university in Colorado teaching audio courses. (sound familiar anyone?)
In the late '70's his empire was brought down by the university who did not give him tenure, and he dropped out completely from the audio scene virtually overnight. So much for interest and commitment in audio. So much for Dr. Ashley, as Richard Heyser, John Meyer, Manfred Schroeder and many others were then dealing with speaker alignment issues and MONAURAL PHASE detection by the human ear.
Now it comes to the next 'takeover' of acoustic principles, by ABX testing. This is where many of you are now 'brainwashed' to blindly believe that what you are being told is the only audio 'truth' and you cannot trust your ears. Well, when a speaker made for relatively low cost completely trumps ALL more expensive speakers, then I will be one of the first to promote it enthusiastically.
I prefer to use series & parallel components but not operating at exactly the same point.
e.g. with low pass filter series cap to give 6db point at 3Khz and then an inductor to give an additional 6db at say 4 or 5Khz.
No idea what this would be called but it avoids that exaggerated "knee" that seems to mask detail within it's inherently wobbly uncontrolled nature 🙂
p.s. "wobbly uncontrolled nature" = higher Q
e.g. with low pass filter series cap to give 6db point at 3Khz and then an inductor to give an additional 6db at say 4 or 5Khz.
No idea what this would be called but it avoids that exaggerated "knee" that seems to mask detail within it's inherently wobbly uncontrolled nature 🙂
p.s. "wobbly uncontrolled nature" = higher Q
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Do you mean ABX as a specific test format or all double blind testing where you specifically have to trust your ears?
Then give us a reference , I usually find 24db/octave slopes and speaker that use then incoherent, active or otherwise, throw out some names on what you deem acceptable or good... ?
You mean Sy was not around drooling ...... 😀
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