jj,
I have a set of Burhoe acoustics 'blues (10" 3-way)
the burhoes,genesis, epi (maybe others?)speakers by Winslow Burhoe of that period 70's-80's had woofers left to roll off on their own, straightwired no xo, just a cap and pad on the upper registers.
anyhow point is, the blue with the original woofer in place was one of the most dynamic sounding bottom ends I've ever heard, so it might not be the issue.
I have a set of Burhoe acoustics 'blues (10" 3-way)
the burhoes,genesis, epi (maybe others?)speakers by Winslow Burhoe of that period 70's-80's had woofers left to roll off on their own, straightwired no xo, just a cap and pad on the upper registers.
anyhow point is, the blue with the original woofer in place was one of the most dynamic sounding bottom ends I've ever heard, so it might not be the issue.
Can you supply links to the woofer and kit so I/we don't have to do the footwork?
Here's what I garner about hysteresis from the web. I don't know of a link between it and inductance. Hysteresis results in magnetic materials causing non-linear distortions due to differences in the paths followed during magnetisation and demagnetisation.
Here's what I garner about hysteresis from the web. I don't know of a link between it and inductance. Hysteresis results in magnetic materials causing non-linear distortions due to differences in the paths followed during magnetisation and demagnetisation.
Hysterisis
When using an iron based magnet in loudspeakers, it is not unusual to experience a phenomenon called hysteresis, which is a well-known problem in almost all speaker magnet systems. The magnetization and demagnetization, which happens by the shifting current directions, does not happen at the same time as the demagnetization process is slower than the magnetization process. It occurs because iron is not only magnetically conductive but also very electrically conductive.
The problem with hysteresis is that it introduces an unintended resistance to the voice coil, meaning unwanted distortion. This is dramatically minimized when using the very highly magnetically conductive materials.
" .... Can you supply links to the woofer and kit so I/we don't have to do the footwork?..."
Sure. SEAS A26 Kit and SEAS The Art Of Sound Perfection
This comment from an audiogon discussion:
" ... 09-02-2019 5:09pm
Many of these minimal crossover speakers use mid/woofers with an abnormally high voice coil inductance .The SEAS A26 are an example of that.So to claim there is no crossover on the mid/woofer is arguably misleading.It is just that a first order crossover is built into the voice coil .The mid/woofer in the A26 kit for example [the 26RE4] has an inductance of 3.8mH.Most similar drivers have an inductance of more like 1mH....."
So maybe there is no relationship between hysteresis and inductance, eh? From what I could gather, the relationship (if there is one) would only show up when the speaker had been driven for quite a while, or had been driven hard.
Like I said ..... I don't know. I'm in the dark. jj
Sure. SEAS A26 Kit and SEAS The Art Of Sound Perfection
This comment from an audiogon discussion:
" ... 09-02-2019 5:09pm
Many of these minimal crossover speakers use mid/woofers with an abnormally high voice coil inductance .The SEAS A26 are an example of that.So to claim there is no crossover on the mid/woofer is arguably misleading.It is just that a first order crossover is built into the voice coil .The mid/woofer in the A26 kit for example [the 26RE4] has an inductance of 3.8mH.Most similar drivers have an inductance of more like 1mH....."
So maybe there is no relationship between hysteresis and inductance, eh? From what I could gather, the relationship (if there is one) would only show up when the speaker had been driven for quite a while, or had been driven hard.
Like I said ..... I don't know. I'm in the dark. jj
jj,
I have a set of Burhoe acoustics 'blues (10" 3-way)
the burhoes,genesis, epi (maybe others?)speakers by Winslow Burhoe of that period 70's-80's had woofers left to roll off on their own, straightwired no xo, just a cap and pad on the upper registers.
anyhow point is, the blue with the original woofer in place was one of the most dynamic sounding bottom ends I've ever heard, so it might not be the issue.
I never heard Burhoe (or EPI) speakers. I wish I had. Burhoe had quite the reputation, and from what I gather, quite deservedly so. jj
Here in the UK,I've never even heard OF Burhoe (or EPI) speakers!
And I am more familiar with hysteresis in tyres, particularly motorbike tyres.
And I am more familiar with hysteresis in tyres, particularly motorbike tyres.
Winslow Burhoe brought high Fidelity to the masses for reasonable money (60’s-80’s) with some fairly off the wall engineering. Interesting feller.....I believe he’s still kickin up in New England.
" .... EPI-like woofer-tweeter modules -
Techtalk Speaker Building, Audio, Video Discussion Forum ... "
Well, well, well .... same mountainman bob! You've gone to the well, haven't you? Now you have my curiosity whetted! jj
p.s. He mentions a "mechanical" element to the rolloff. Wonder what that is. Obviously his work took a different direction than this SEAS design.
Techtalk Speaker Building, Audio, Video Discussion Forum ... "
Well, well, well .... same mountainman bob! You've gone to the well, haven't you? Now you have my curiosity whetted! jj
p.s. He mentions a "mechanical" element to the rolloff. Wonder what that is. Obviously his work took a different direction than this SEAS design.
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There wasn’t much love for subjectivity over there! .........not that there’s a whole lot here. 😀
The alternating current which causes inductance is also responsible for hysteresis. In that way, they could be said to be connected.So maybe there is no relationship between hysteresis and inductance, eh?
The alternating current which causes inductance is also responsible for hysteresis. In that way, they could be said to be connected.
Hmmmm. I see ... I think. I'd better stop here before I get in over my head .... if I haven't already. 🙂😱🙂😱 jj
Here in the UK,I've never even heard OF Burhoe (or EPI) speakers!
And I am more familiar with hysteresis in tyres, particularly motorbike tyres.
I found this site. You may wish to peruse it. From what I understand, this man (Huw Powell) had Burhoe as a mentor, and has taken a direction with his own business that resembles Burhoe's to quite a degree. Notice one thing, however: nowhere on this site could I find any response charts. Alarm bell, right there. jj
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Not sure if this is relevant as it’s above my pay grade also.
(PDF) Experimental characterization, modeling and compensation of rate-independent hysteresis of voice coil motors
J.J., I’ve used huw’s stuff and he’s a nice enough feller but his replacements are not up to the original snuff.
(PDF) Experimental characterization, modeling and compensation of rate-independent hysteresis of voice coil motors
J.J., I’ve used huw’s stuff and he’s a nice enough feller but his replacements are not up to the original snuff.
Not sure if this is relevant as it’s above my pay grade also.
(PDF) Experimental characterization, modeling and compensation of rate-independent hysteresis of voice coil motors
Yeah, an old fart like me views this as gobbledygook that's impossible to understand. I did notice one thing, though: the inductance of the VCM that they were measuring was only .5mH. I wonder whether a VCM with much higher inductance would have shown not only different results but the emergence of different problems. jj
No site showing!I found this site. You may wish to peruse it.
No site showing!
Sorry. Try this: HUMAN Speakers: The EPI Story
or the front page HUMAN Speakers: Welcome
Bruno Putzeys' explanation of hysteresis distortion: This Thing We Have About Hysteresis Distortion - PURIFI
Yes, no need to get hysterical over hysteresis! 😀Hysteresis is not so scary.
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