Newly refurbished EPI 100's, they sound AMAZING!

TaddNOhio

Active Member
I bought these EPI 100's from the original owner who purchased them brand new in 1981. Today i decided to do a little upgrading to them ...
I replaced the original crossovers with the ones built by Huw Powell from Human Speakers and i also replaced the original 8" woofers with the Human Speakers PRO 001 woofers .. i installed the original dampening material back in the speakers.
These speakers sound amazing! The upgrades made a really big difference, i thought they sounded really good before but now they sound superb to my ears .. i don't see me ever parting with these

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I wonder who they buy their caps from before they put new heat shrink on them? How much do their caps cost? Those definitely have about the simplest crossovers in the business to update with the single cap on the tweeter. Definitely nice to have those new terminals, too, versus some of the original push versions.
 
I wonder who they buy their caps from before they put new heat shrink on them? How much do their caps cost? Those definitely have about the simplest crossovers in the business to update with the single cap on the tweeter. Definitely nice to have those new terminals, too, versus some of the original push versions.
With those specs I'd bet money they're just Dayton 5% caps.
 
I use a pair of those in my shop when testing/burning in freshly restored units.
Also have other speakers available but these do sound great for small bookshelf speakers.

Bob
 
With those specs I'd bet money they're just Dayton 5% caps.

You would have lost money, i contacted Huw Powell and asked him ..

"Just curious what capacitors you use in the ACC 004 A crossover assembly, are they the Dayton Audio DMPC-10 capacitor?"

And his response ..

"No, they aren't, they are 10 uF, 250 volt capacitors with a very low dissipation factor
that I have custom-made"
 
EPI-100's are terrific small loudspeakers, but I am curious why you replaced the original woofers?
I still have the originals, just wanted to see how good the Human Speaker build woofers sounded ... i am currently replacing the surrounds on the original EPI woofers and will be re-installing those. Going to use the Human woofers in another pair of speaker cabinets i picked up

Here is the Human Speakers PRO 001 8" woofers that are replacements
  • Butyl rubber surround: increased longevity, lower resonant frequency (some early EPI woofers were made this way).
  • Treated cone: seals speaker system better, more attractive, less change due to humidity (most later Genesis woofers were made this way).
  • Treated cloth dust cap: improves linearity, looks better than the exposed wires on most older woofers.
  • Larger diameter "spider" (rear suspension): allows greater linear travel, removes weak link.
  • Acoustically inert "gasket" on front: makes packaging simpler, more attractive.
  • Round magnet structure: identical in weight and function (most later EPI woofers were made this way).
  • Extended pole piece: not visible, but improves linearity.
What's the same and why:
  • Voice coil: the long voice coil winding is critical to linearity, and its high inductance is part of why the woofer does not need crossover circuitry to roll off the high frequencies.
  • Magnet weight and strength, field guide (yoke) plates: again, a critical part of the design
  • Cone material, weight, and density: the exact design of the cone is also part of how the woofer rejects high frequencies on its own.
  • Rear suspension compliance: the larger spider acts exactly like the smaller original one.
  • Free air resonance: although not a "part", the low Fs is important to the extended low bass response.
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...just wanted to see how good the Human Speaker build woofers sounded ...
Thanks for the info - - I know Human Speakers sells very good replacement parts, but I had never looked at these woofers closely. I was unaware that the replacements had rubber surrounds, which is one aspect of my early 100's that I really like, along with the walnut veneer and masonite tweeter.


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I just restored a pair of red ring tweeter versions myself.

Did you change ferro fluid in your tweeters? I'm not sure if yours have fluid. But mine did, and it was a good thing I checked before playing them, it was really gunked up. I used some 100v 10uF Chinese film caps I had laying around from another project. I just refoamed my original woofers. They do sound really good for how simple a design, and hold their own somewhat against the rest of my collection, which are from the same era, and all considerably larger, and more complex in design.

Here are mine
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Not sure
I just restored a pair of red ring tweeter versions myself.

Did you change ferro fluid in your tweeters? I'm not sure if yours have fluid. But mine did, and it was a good thing I checked before playing them, it was really gunked up. I used some 100v 10uF Chinese film caps I had laying around from another project. I just refoamed my original woofers. They do sound really good for how simple a design, and hold their own somewhat against the rest of my collection, which are from the same era, and all considerably larger, and more complex in design.

Here are mine
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E0IEQav.jpg

Not sure if mine have ferro fluid or not?? Here is my tweeters in my EPI 100's
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Not sure


Not sure if mine have ferro fluid or not?? Here is my tweeters in my EPI 100's
View attachment 1301962

You could try asking Human speakers. I'm not sure how to disassemble your tweeters, mine had 3 screws that hold the faceplate to the magnet. Undoing them the whole thing comes apart, and the magnet gap is completely accessible. Mine was filled with so much sludge it definitely would've damaged my tweeter voice coil permanently had I played them as is. The screws also made realigning the tweeter a breeze.
 
I would be very interested in hearing how to replace ferro fluid. I didn't know that was possible.
 
I would be very interested in hearing how to replace ferro fluid. I didn't know that was possible.

it's very simple, buy Ferro fluid, I just use the parts express stuff. Take apart your tweeter, lift the voice coils and diaphragm out of the magnet. Then keep scraping folded post it notes and rubbing alcohol into the gap until ouit cleaned. Fill with new Ferro fluid until the ring closes in the gap. Reassemble.
 
Nope, those are “air-spring” tweeters still in the EPI/EPICURE timelines and universe, so fluid to change in them whatsoever... to change, gunk-up or anything else. :thumbsup:
That is what i was thinking, that the air spring inverted tweeters did not have the ferro fluid .. thanks for confirming. I know i am LOVING these speakers, a friend of mine was over and i had an album playing and he was blown away when he walked downstairs and seen the speakers that the sound was coming from .. he had never heard the EPI 100's and now wants a pair
 
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