True...what's the RMS rating on the current offerings? I understand that they're reasonably robust.
Well, anyhow, Gary...too much fun. I'm off to see what dear spouse is up to with some of that 'other white meat' (pork roast), as the alien in my rib cage is acting up *L* Consume and watch some '@ Midnight' on the DVR for grins 'n giggles... L8er.
I recall somewhere Nelson Pass commented to the effect that even though they did work they were not practical to mass produce.
There is a project out there that is based on a "Walsh" line driven by a rod connected to the apex driven by a bottom mounted FR driver from below. Seem to remember a treated paper cone and raves (by the builder).
Ahh, the ill-fated Transstar. That may have been the demise for ESS. Cohelo and Co. struggled for a long time with the whole AMT thing. For a very long time, no one got to hear it- they had gold in the AMT driver, but couldn't find a suitable LF section.
I was up there trying to get a job the day Audio Magazine dropped by to see the new Hiel. They got to see it, but were refused an audition. I didn't get to hear it either-
Problem was twofold- the damned thing sounded spectacular, and was extremely efficient.
Meanwhile, their hand got forced when Infinity released the Walsh tweeter.
Remember, back then, the market was partially driven by "technological one-upmanship".
ESS had to act, so they hooked a 10" woofer I think was made by Cerwin-Vega in a bass reflex box and the AMT-1 was born to very mixed revues.
Nelson Pass came up with a novel slot loaded open back woofer array that worked well, but was not exotic enough, so never saw production. One of it's issues was the rear wave was anti-phase to the front wave, unlike the AMT. Needed a big baffle, and in the end had weak low bass. The TS design's front and rear wavefronts were in phase because of those plastic "scallops".
I never learned who came up with the TS woofer design, but it was a nightmare. The amps kept blowing up because of the screwball impedance the array presented.
I never got to hear it- we sat in ESS's demo room for two days at the CES when it was unveiled waiting for a working amp to come down from Sacto for the show. Later learned that they had it working for a few hours one day and the amp blew again.
Ahh, the ill-fated Transstar. That may have been the demise for ESS. Cohelo and Co. struggled for a long time with the whole AMT thing. For a very long time, no one got to hear it- they had gold in the AMT driver, but couldn't find a suitable LF section.
I was up there trying to get a job the day Audio Magazine dropped by to see the new Hiel. They got to see it, but were refused an audition. I didn't get to hear it either-
Problem was twofold- the damned thing sounded spectacular, and was extremely efficient.
Meanwhile, their hand got forced when Infinity released the Walsh tweeter.
Remember, back then, the market was partially driven by "technological one-upmanship".
ESS had to act, so they hooked a 10" woofer I think was made by Cerwin-Vega in a bass reflex box and the AMT-1 was born to very mixed revues.
Nelson Pass came up with a novel slot loaded open back woofer array that worked well, but was not exotic enough, so never saw production. One of it's issues was the rear wave was anti-phase to the front wave, unlike the AMT. Needed a big baffle, and in the end had weak low bass. The TS design's front and rear wavefronts were in phase because of those plastic "scallops".
I never learned who came up with the TS woofer design, but it was a nightmare. The amps kept blowing up because of the screwball impedance the array presented.
I never got to hear it- we sat in ESS's demo room for two days at the CES when it was unveiled waiting for a working amp to come down from Sacto for the show. Later learned that they had it working for a few hours one day and the amp blew again.
The devil is always in the details...
*S* Well, builders always want to rave about their creations...I try to keep a lid on it, since I've yet to post anything y'all could consider and critique', which is only fair. I'm enjoying the fact that, so far, I've been able to make various iterations that seem to make appropriate noises despite their limitations. The handful of people that have heard them are impressed, but I'd hesitate to call any but one a 'serious listener'. But even he asked if he could have a pair....
So I feel I'm making some sort of progress. *G*
BTB, the 3.5's are done. The 'zen' of gluing the cones top & bottom complete; the wait for the adhesives' curing begins. Since I'm tentatively out of town for the next 3 days, that should allow the interval to be relatively painless. Set up, apply wires, and bingo or blotto. Y'all will be the second to know. 😉
So based on your post, I was lucky to hear the TS at all. Lucky me. As for the AMT's, that's what I've heard and read is that they're hard to match up. I guess my 'scattershot' approach with multiple sized drivers and eq isn't too off the wall. Pour enough sugar on it, and even dirt might taste good. *L*
Re 'screwball impedance'...and other curiosities...you 'speak' as one who's been in the industry and likely has more 'depth' that this enthusiastic dilatant...(since your profile is a virtual blank, I can only make assumptions...good ones so far 😉...), I'm interested in your opinion of my concept of 'inverting' a driver. The 'driven magnet within the coil', to be brief. Would the coil present an odd ohm rating, necessitating a transformer or some novel circuitry to not become source of certain amp death? The fellow you mentioned has his approach, which seems fraught with issues to my mind. Total weight of all those parts is first; putting all of them together seems like a new version of a TS woofer is next...
Works great until something goes *foom*, hopefully cheap and not involving the amp. That's never pretty...
Or, to take your advice and stay on the beaten path, and go forward with a 'purpose built' vc/magnet structure? Either becomes 'new ground' to till...
*S* Well, builders always want to rave about their creations...I try to keep a lid on it, since I've yet to post anything y'all could consider and critique', which is only fair. I'm enjoying the fact that, so far, I've been able to make various iterations that seem to make appropriate noises despite their limitations. The handful of people that have heard them are impressed, but I'd hesitate to call any but one a 'serious listener'. But even he asked if he could have a pair....
So I feel I'm making some sort of progress. *G*
BTB, the 3.5's are done. The 'zen' of gluing the cones top & bottom complete; the wait for the adhesives' curing begins. Since I'm tentatively out of town for the next 3 days, that should allow the interval to be relatively painless. Set up, apply wires, and bingo or blotto. Y'all will be the second to know. 😉
So based on your post, I was lucky to hear the TS at all. Lucky me. As for the AMT's, that's what I've heard and read is that they're hard to match up. I guess my 'scattershot' approach with multiple sized drivers and eq isn't too off the wall. Pour enough sugar on it, and even dirt might taste good. *L*
Re 'screwball impedance'...and other curiosities...you 'speak' as one who's been in the industry and likely has more 'depth' that this enthusiastic dilatant...(since your profile is a virtual blank, I can only make assumptions...good ones so far 😉...), I'm interested in your opinion of my concept of 'inverting' a driver. The 'driven magnet within the coil', to be brief. Would the coil present an odd ohm rating, necessitating a transformer or some novel circuitry to not become source of certain amp death? The fellow you mentioned has his approach, which seems fraught with issues to my mind. Total weight of all those parts is first; putting all of them together seems like a new version of a TS woofer is next...
Works great until something goes *foom*, hopefully cheap and not involving the amp. That's never pretty...
Or, to take your advice and stay on the beaten path, and go forward with a 'purpose built' vc/magnet structure? Either becomes 'new ground' to till...
V3.5 first impressions
Returned from our biz trip to Raleigh yesterday and applied the original crossover to the fully cured units, and lit them up. Pleasant surprise, all drivers worked...
...as to how well, mixed bag...
First reaction was to adjust eq with a heavy hand; lots of high through mids, rolling off deeply on the bass. Woofers 'booming' like the bass drums of a marching band. Removed entire array from the wood 'X' supports, meant to keep it all from inadvertently toppling over, and placing directly on floor. Bass immediately tightened up. If placed on a proper enclosure, that could eliminate any need for a sub. But that is just an initial impression....
Output from the mid unit is considerably less than the V.2 units of the relative same size. I'll chalk that up to the size of the magnet structures, which are roughly a third of the V.2's. Sound from them is 'restrained' because of this, IMHO. Considerably more gain has to be applied to get them to 'speak'.
Tweeters work, but are even more restrained than the mid units. Again, I'll chalk this up to their magnet structures, which are probably fine for a typically coned 3". To get them to respond, they ask to be 'cranked up', which starts to generate heat fairly quickly. I monitor this by just placing a finger on the center backside of the magnet. You can easily feel the temp rise gradually....
Above was noted by connecting the xover individually to each element as an initial test. Attaching everything in pairs (T+M, M+W) roughly confirmed my immediate impressions.
Attaching all 3 units together, the woofers are what one hears above all. The response is still 'bassy', but is better when used without the supports. If one damps the surround manually by touch, they 'firm up'; first 'tweek' is to either add damping into the support column or adding additional material beneath the surround to absorb more movement.
Not perfect, but not 'broken in' either. As a test stand, a reasonable start...
More later as I run them more...
Returned from our biz trip to Raleigh yesterday and applied the original crossover to the fully cured units, and lit them up. Pleasant surprise, all drivers worked...
...as to how well, mixed bag...
First reaction was to adjust eq with a heavy hand; lots of high through mids, rolling off deeply on the bass. Woofers 'booming' like the bass drums of a marching band. Removed entire array from the wood 'X' supports, meant to keep it all from inadvertently toppling over, and placing directly on floor. Bass immediately tightened up. If placed on a proper enclosure, that could eliminate any need for a sub. But that is just an initial impression....
Output from the mid unit is considerably less than the V.2 units of the relative same size. I'll chalk that up to the size of the magnet structures, which are roughly a third of the V.2's. Sound from them is 'restrained' because of this, IMHO. Considerably more gain has to be applied to get them to 'speak'.
Tweeters work, but are even more restrained than the mid units. Again, I'll chalk this up to their magnet structures, which are probably fine for a typically coned 3". To get them to respond, they ask to be 'cranked up', which starts to generate heat fairly quickly. I monitor this by just placing a finger on the center backside of the magnet. You can easily feel the temp rise gradually....
Above was noted by connecting the xover individually to each element as an initial test. Attaching everything in pairs (T+M, M+W) roughly confirmed my immediate impressions.
Attaching all 3 units together, the woofers are what one hears above all. The response is still 'bassy', but is better when used without the supports. If one damps the surround manually by touch, they 'firm up'; first 'tweek' is to either add damping into the support column or adding additional material beneath the surround to absorb more movement.
Not perfect, but not 'broken in' either. As a test stand, a reasonable start...
More later as I run them more...
Hmmm....Glo, yeah, the Decware(.com) site. That was one of the sites that piqued my interest in DIY 'Walshing' long ago, back in TX. In retrospect, and almost in a 'snotty' fashion (as my spouse would define my 'tude), Ohm should look into that. *L*
Current thinking on the 3.5's is I'll call the tweets and mids a 'fail'. Drivers too small to be effective. I'll keep 'the guts' around for later improvements. My current drivers blow them away with mere output...
I'll continue to goof around with the woofer, just for educational value...
Current thinking on the 3.5's is I'll call the tweets and mids a 'fail'. Drivers too small to be effective. I'll keep 'the guts' around for later improvements. My current drivers blow them away with mere output...
I'll continue to goof around with the woofer, just for educational value...
I am really jealous of your pvc skills. I am really curios what these sound like in person. hopefully a trip to the Carolinas is warranted soon.
*L* Well, as long as you don't look too closely... 😉 A 'machine shop' I'm not...but they work well enough.
Don't rush on the 3.5s', per my commentary. The existing array isn't going anywhere, either. *G* But if you'd like a slight break from the heat, and a major break in general vehicular traffic, that's an additional pair of inducements. *L*
(...and I'll need to do some 'house cleaning'...*L* Gotta look kinda organized...)
Don't rush on the 3.5s', per my commentary. The existing array isn't going anywhere, either. *G* But if you'd like a slight break from the heat, and a major break in general vehicular traffic, that's an additional pair of inducements. *L*
(...and I'll need to do some 'house cleaning'...*L* Gotta look kinda organized...)
Have you experimented with any paper cones? The lighter weight will make a difference in loudness and high frequency output. Try a 6" diameter paper cone.
Interesting proposal, But...
I agree with that suggestion, Gary. Perhaps the alum cone is limiting the output, esp. with the 'lightweight' magnet structure the 3.5 mids have. I've one other trick I'm going to try before that, however. Currently the cones are under a slight bit of compression, mostly to damp any potential of pistonic motion. I'm going to introduce a tad more height in the support structure to see if allowing more motion will allow more gain. The way they're constructed will actually allow this to be done rather easily. Cheap tricks is us. *L*
They're 3" dia. x 4.5" h. though; going to 6" dia. would require a major rebuild. The V.3 array of 4 that I've been running 'successfully' has 5" dia. x 7" h. cones of the 5 mil alum. If I did anything to them would be to invest in some of the 2 mil alum and mod them a pair at a time to see what occurs.
But going to paper with the 3.5's is a good call. Even if the 'shimming' works, lowering the weight of the cones can't hurt, and they have been built to be messed around with.
If that proves to be an improvement, I can see no reason to not mod the earlier V.2 pair with the larger magnet structure as well. Same size cones; another potential pseudo-surround array. *G* Large in front, smaller in rear...
Gives me a good reason to wander over to Michael's and fondle some of their paper stock. One material that comes to mind is a decent quality water-color paper; they tend to be heavier and a bit stiffer than most, and I suspect will be considerably lighter than the 5 mil.
As for the tweets, they're using the 2 mil you gifted me with. The magnets may just be too weak to adequately drive the cones. But I'll salvage the cones and see what presents itself with larger magnet structures....
The woofers exhibit some odd resonances at certain frequencies. I've been thinking about applying some of the fabric you've mentioned to the exteriors of the cones to nudge them about, a la EnABL. Can't hurt, might help. Since they're meant to be an experimental subject, I may as well get on with it.
This all may well trigger a major 'rewire' of what's driven by what around here. I'm thinking of turning the array over to being driven by the main amp, which has the extra capacity to do so. I'll just have to throttle it down so I don't torch anything...
I agree with that suggestion, Gary. Perhaps the alum cone is limiting the output, esp. with the 'lightweight' magnet structure the 3.5 mids have. I've one other trick I'm going to try before that, however. Currently the cones are under a slight bit of compression, mostly to damp any potential of pistonic motion. I'm going to introduce a tad more height in the support structure to see if allowing more motion will allow more gain. The way they're constructed will actually allow this to be done rather easily. Cheap tricks is us. *L*
They're 3" dia. x 4.5" h. though; going to 6" dia. would require a major rebuild. The V.3 array of 4 that I've been running 'successfully' has 5" dia. x 7" h. cones of the 5 mil alum. If I did anything to them would be to invest in some of the 2 mil alum and mod them a pair at a time to see what occurs.
But going to paper with the 3.5's is a good call. Even if the 'shimming' works, lowering the weight of the cones can't hurt, and they have been built to be messed around with.
If that proves to be an improvement, I can see no reason to not mod the earlier V.2 pair with the larger magnet structure as well. Same size cones; another potential pseudo-surround array. *G* Large in front, smaller in rear...
Gives me a good reason to wander over to Michael's and fondle some of their paper stock. One material that comes to mind is a decent quality water-color paper; they tend to be heavier and a bit stiffer than most, and I suspect will be considerably lighter than the 5 mil.
As for the tweets, they're using the 2 mil you gifted me with. The magnets may just be too weak to adequately drive the cones. But I'll salvage the cones and see what presents itself with larger magnet structures....
The woofers exhibit some odd resonances at certain frequencies. I've been thinking about applying some of the fabric you've mentioned to the exteriors of the cones to nudge them about, a la EnABL. Can't hurt, might help. Since they're meant to be an experimental subject, I may as well get on with it.
This all may well trigger a major 'rewire' of what's driven by what around here. I'm thinking of turning the array over to being driven by the main amp, which has the extra capacity to do so. I'll just have to throttle it down so I don't torch anything...
Yep. the light weight voice coil/magnet doesn't have the cajoles to drive a heavy gauge cone. Also, a 5x7" cone has more than twice the radiating area than a 3x4.5". If you replace the 5 mil with paper it will have about 1/4 the weight.
We have an art supply here called "Blick's". I think the water-color paper is worth a try.
The thing about paper is that it is self-dampening, so you can get by without the treatments that Al foil seems to need (to reduce ringing).
Also, I think you are right about the suspension being too stiff, one place where stiff is not good🙄
You're absolutely right. *L* It's a 'basic physics moment'. 😉 It'll be relatively easy to swap the cones out since I'm not going to have to start from scratch. And forming small cones with the 5 mil is a bit of a struggle, fighting 'spring back' from the material. Paper should be a piece of cake...
I've got one magnet/coil structure hanging around with nothing planned for it. I might try using it to try forming the cone to a minimum 'tip' diameter as was mentioned earlier, just for grins. It's larger than the 3.5's mids, a 'leftover' from the V.1's that got cooked. In paper it should have a better time of it.
I was looking at piezo motors the other night, considering my thought about a different approach to the whole motor issue. Interesting, but pricey for ones that could be strong enough, fast enough, and have the range to be suitable. That, and thinking about inverting the structure of a conventional motor (moving magnet within coil), to determine if that'd be possible at all. One would think that'd it would have been done already if so, so it may just be a great pipe dream.
Been busy with 'real world' activities, so haven't had much 'play time' of late. Been workin' in that coal mine...*G*
I've got one magnet/coil structure hanging around with nothing planned for it. I might try using it to try forming the cone to a minimum 'tip' diameter as was mentioned earlier, just for grins. It's larger than the 3.5's mids, a 'leftover' from the V.1's that got cooked. In paper it should have a better time of it.
I was looking at piezo motors the other night, considering my thought about a different approach to the whole motor issue. Interesting, but pricey for ones that could be strong enough, fast enough, and have the range to be suitable. That, and thinking about inverting the structure of a conventional motor (moving magnet within coil), to determine if that'd be possible at all. One would think that'd it would have been done already if so, so it may just be a great pipe dream.
Been busy with 'real world' activities, so haven't had much 'play time' of late. Been workin' in that coal mine...*G*
I remember Blick's, they have 'the good stuff'...a flashback from one of my earlier lives. *G* There's an art supply shop in downtown ASV that might scope out to see what they've got. As for suspension, I've still got some of the EVA foam at hand so I think I'll just burn it up as a side experiment with the paper cones. See if it's compliant enough for the paper...offhand, I can't think of anything else that would have the characteristics for the application, other than a proportionally thicker paper. We'll see what's out there and strikes my fancy. *G*
Yeah exactly, I look at it like a "Newton's cradle". The voice coil vs cone mass thing.
My grandfathers first job was a coal miner in W. Virginia🙂
I've had good results just using transplanted speaker surrounds. To make life easy, you could get some replacements from PE.