Epicure M602 Speaker Restoration - Bose "shape" Knock-off

[AndrewJohn 10,449]

Some know I have had an affinity for EPI speakers.  I've owned every one of the Burhoe-designed first line coming out in the 70's.  Some say that EPI (Epicure) sold more speakers than any other speaker manufacturer ever.  Thier initial line is in this picture.  Excepting for the simpler designs, all Burhoe's designs (he's still designing speakers) have reflective driver positioning which accounts for the soundstage they produce.  He also used a common driver and tweeter design, changing the models by changing cabinets.  One model, the M602, was designed in a shape similar to Bose 901's, but with fewer drivers.  It was unique, as it was the only one of the original line to use unique drivers with the same physical dimensions, but different impedance (2ohm, vs 8ohm)  

 

Here's Burhoe's original line - and yes, I have a pair of the "coffin" sized towers - and they are glorious.  The only model I have not (yet) heard is the M602, front and center in the picture below.  I have high hopes, and am excited, as they are the third-most rare to find model.

 

[AndrewJohn 10,449]

OK, so what I have are these..., You can see in the speaker on the bottom, that someone has replaced (two - the other one is on the other side) of the drivers with non-standard (junk) Pyle speakers.  These are both 8ohm impedance, and the foam has dried out.  Junk.

 

These speakers I found in an antique thrift shop, with several dozen "vendor booths" that I came across in Wisconsin, while picking up a Denon Turntable..., they were lying among a bunch of junk (not audio stuff).  I made an offer, hoping it would be refused, but upon the person at the counter (these were unmanned antique booths) calling the booth vendor, they took my offer..., That was likely 4-5 years ago, and I'm finally getting around to working on them.

 

Hard to tell in the pictures, but the white crumbs at the bottom of the upper speaker is just dust dirt or maybe white styrofoam crumbs.  The cabinets and grills are in mint condition.  The upper speaker has a correct driver, the lower speaker has the Pyle junk speakers mounted in them - one you can see, the other is on the back..., I'll get some better pictures when I pull these out.

 

[stereo_dog 1,216]

11 minutes ago, AndrewJohn said:

OK, so what I have are these..., You can see in the speaker on the bottom, that someone has replaced (two - the other one is on the other side) of the drivers with non-standard (junk) Pyle speakers.  These are both 8ohm impedance, and the foam has dried out.  Junk.

 

These speakers I found in an antique thrift shop, with several dozen "vendor booths" that I came across in Wisconsin, while picking up a Denon Turntable..., they were lying among a bunch of junk (not audio stuff).  I made an offer, hoping it would be refused, but upon the person at the counter (these were unmanned antique booths) calling the booth vendor, they took my offer..., That was likely 4-5 years ago, and I'm finally getting around to working on them.

 

Hard to tell in the pictures, but the white crumbs at the bottom of the upper speaker is just dust dirt or maybe white styrofoam crumbs.  The cabinets and grills are in mint condition.  The upper speaker has a correct driver, the lower speaker has the Pyle junk speakers mounted in them - one you can see, the other is on the back..., I'll get some better pictures when I pull these out.

 

Nice, will follow this. I have (3) sets of Epicure (EPI) speakers, M201, M400 & 140. I need to get the M400's back out and play with them, again. The cabinets on those look very good.

[AndrewJohn 10,449]

I'm guessing some of you are my contemporaries, and know about the EPI speaker line.  They defined what was known as "The East Coast Speaker Sound"..., not sure what that is, I like what I hear when I play them.

 

OK, so how do you repair Epi speakers?  

 

There is a former employee of the EPI company, in Newberryport, MA, his name is Huw Powell.  He has a website called www.HumanSpeakers.com and has been providing replacement parts and services on old parts (like rebuilding the inverted dome tweeters) for years.  Super nice guy, I like talking to him on the phone.  If you have ever seen the original product catalog, I imagine he was one of the early "hippies" that worked there, making speakers.

 

Did I mention that EPI originally occupied an old mill building in Newberryport (now it's apartments) that prior to being a speaker factory, it was for decades, a "coffin" factory..., which might have contributed to the design of the large towers... LoL

 

True story, not about the M602's, but about me "sneaking into the back door" a pair of the M1000 towers..., my wife drove up, at the precise moment, and I was busted..., without knowing the folklore, she said..., "well, at least you can be buried in them."

 

Back to the M602 project...

 

So, after contacting Huw at Human Speakers, I decided I'd refurbish these in phases.  He had a full "kit" (which he "makes" each time, he doesn't inventory much) that included 6 new drivers, 6 new tweeters, and 2 new crossovers.  His drivers are better than the originals, obviously, as well as his new tweeters.  And he also modified the crossover.  I opted to replace the drivers only, in phase 1 of my refurbish/restore project.

 

Well, the new drivers arrived today!  Yay!

 

 

 

 

[AndrewJohn 10,449]

3 minutes ago, stereo_dog said:

Nice, will follow this. I have (3) sets of Epicure (EPI) speakers, M201, M400 & 140. I need to get the M400's back out and play with them, again. The cabinets on those look very good.

 

I was at max..., and just last month, sold my 201's and my 400's go..., here's a picture of my 400's.  I re-veneered the top with a 4-way bookmatched walnut to restore over wet circles left by a previous owner, flower pot?  I guess.

 

[stereo_dog 1,216]

2 minutes ago, AndrewJohn said:

 

I was at max..., and just last month, sold my 201's and my 400's go..., here's a picture of my 400's.  I re-veneered the top with a 4-way bookmatched walnut to restore over wet circles left by a previous owner, flower pot?  I guess.

 

Thanks for the pic. They look good. I'm determined to get mine out this weekend... 

[AndrewJohn 10,449]

Just now, stereo_dog said:

Thanks for the pic. They look good. I'm determined to get mine out this weekend... 

I miss them, as I put a lot of work in them, refoamed, and new grill-cloth, and refinished the cabinets.  ButI  just didn't have the room for the menagerie of speakers I presently own..., So, I'm whittling the stable down.  The EPI M1000 towers, however, really blow these away.  😉 

[AndrewJohn 10,449]

BTW, someone always asks..., how does Carver power sound through these 70's speakers?

 

Well, pretty good!  I've given EPI speakers a LOT of power, like, for example, driven them with an m1.0t MkII Opt2, or an m4.0t, and even silver 7 monoblocks.  They have produced "gotta' leave the room" sound levels.

 

Huw Powell, writes in a few places on his website that Burhoe significantly under-rated the specs on the original line of speakers.  But, remember, there wasn't a lot of "Carver Clean Power" back then, and what ruins speakers is dirty, distorted power, not necessarily "high power."

[3M_Audio 2,022]

Very cool. Newburyport is only about 8 miles away from where I live. That town does have an interesting history.

 

And I'd like to hear his $75000 InHUMAN towers   Looks like he's working out of Lee NH now and doesn't have a regular retail storefront but does accommodate visitors by appointment. Would be fun to visit sometime.

[AndrewJohn 10,449]

4 hours ago, 3M_Audio said:

Looks like he's working out of Lee NH now and doesn't have a regular retail storefront but does accommodate visitors by appointment. Would be fun to visit sometime.

If you go, please share the experience!!  

 

I'm not aware of those $75k towers..., got a link?  (like I can even entertain such thinking... LoL

[xavionics 2,069]

Curiosity got the best of me and I had to look.

 

Here’s the link AJ…

 

https://www.humanspeakers.com/human/inhuman.htm

 

BTW, I think a digit was missing in Glenn’s post…😳

[3M_Audio 2,022]

3 hours ago, xavionics said:

Curiosity got the best of me and I had to look.

 

Here’s the link AJ…

 

https://www.humanspeakers.com/human/inhuman.htm

 

BTW, I think a digit was missing in Glenn’s post…😳

 

haha - you're correct! I just glanced at it and thought $75K

[AndrewJohn 10,449]

On 3/9/2024 at 1:57 PM, 3M_Audio said:

haha - you're correct! I just glanced at it and thought $75K

 

I understand this to be Huw Powell's idea of humor..., that line array may be in his lab, or living room, but he's not selling them..., unless..., of course, someone actually choked up the cash !! LoL. 😉 

[AndrewJohn 10,449]

OK, back to this project.  Lots of recent distractions..., some good some frustrating.

 

The grills come off, attached by velcro - which is unusual for EPI of this era, they typically used white silicone caulk as glue to permanently affix the grills to speakers in manufacturing.  I didn't have to wrestle these off.

 

I pulled the old drivers out, and remove the old "gaskets" which is really just that white foam, that you find wrapped around new TT dustcovers to protect in transit.  

 

You might notice that there are two pots on the back..., one is to adjust by attenuation the high frequencies going through the crossover to the three inverted dome oil-filled tweeters.  The second one is for attenuating the front panel output altogether.  It's actually a fairly complex crossover.  I'm not going to do anything with the crossover at the moment - right now I just want to get the new drivers in, and see how they sound.

 

I find that the mdf in these old speakers typically is fraying or crumbling where the screws were driven in, w/o pre-drilling.  What I do with this MDF, is try to "tighten up" the screw holes just a bit, as the screws always just seem to crumble it, like it's a triscit cracker or something.  I rub off or cut back any of the "pulling" or fraying of wood chips, with a knife.

 

 

so the frayed sawdust chips come off, leaving a flat surface to mount the new drivers against.

 

 

Basically, this is pretty fragile, and very likely to "bust-out" when the new drivers are installed and the screws are driven back in, so I try to make it more solid, by using this technique..., I use some wood glue, and with a toothpick shove a bunch into the screw-hole, to and let it soak in.  I wet the wood first, so the glue will soak in a bit beyond the screw hole, and attempt to hold the chips together in the area.

 

 

I don't want to drillnew holes, as from two pictures up, you see the tweeter plate overlaps the driver, and this method strengthens the screw hole considerably.

 

When done, the screw holes with the glue look like: 

 

 

When the glue dries, I will reinstall the drivers, turning the screws in by hand, carefully..., I've poked a driver foam with a screwdriver that slipped, before..., 

[AndrewJohn 10,449]

OK, I was able to install the other drivers.  I had a listen, and they sound wonderful!  I'll have to do some comparison with the other speakers I have in the menagerie...

 

But they can crank, loud.  Right now driving them with a simple system setup..., you know, a Lightstar preamp through a Sunfire 600x2 amp 😉  Just to run them through their paces a bit.

 

Here's some final pictures:

 

The flat-wide face, faces the listener.  the binding posts go to the rear.  The angled smaller faces have bigger (8") bass drivers, to fill out the low-end, and deliver it via reflected sound to the listener, creating a sound stage.  Most of Burhoe's designs were this way,   There is a tweeter on those smaller angled faces as well, for the same purpose.  The "shape" looks like Bose, but the design is clearly different.

 

I have a little restorative work do do on the top and bottom of the cabinets.  The photos show it very clearly - it's less noticeable in person.  But this I can do.

 

Note the tweeter on the top, driver's below.  Those new OEM drivers from Human Speakers, sure look nice.  And they are unique..., as noted earlier in the thread - the rear drivers are 2ohm, not typical 8"ohm - I believe unique due to the crossover.

 

What are the pots on the back?  One is to increase or decrease the high-end tweeter.  It's a big fat potentiometer, in the Crossover design.  the second pot is for attenuating the front driver and tweeter, allowing the listener to choose to balance the reflected sound-stage generating of the rear-facing speakers, with the front speakers that are directly positioned to feed sound into the user's ears.

 

 

Which way is up?  Looks like that one, below, is upside down..., actually, by putting the text on the binding post plates so it can be readable, the tweeters are up on the top.  The grill, below, has the EPI logo on the wrong corner..., the oval hole in the masonite panel that the grill cloth is attached to, is wider on the woofer end..., so it's in the right place, but the factory put the badge on the wrong corner.., it may have been on upside down all it's life.

 

the front facing driver is a smaller 6" driver.  I replaced ALL the base and this front-facing mid-range driver - 4 (four) 8" drivers and 2 (two) 6" drivers total for the set (pair) of speakers.

 

In the EPI community..., users that are in love with these and other EPI designs, swear by the inverted dome, oil filled tweeters built on a simple masonite plate.  The magnet on the back of those masonite tweeters is as large as the magnet on the original woofers.  The NEW (better, OEM-replacement) woofers from Human  Speakers designed for these have a round magnet, not square - but guessing by heft, they are the same.  Poing is, those tweeters have a powerful magnet, aboiut 3.5"x3.5"x1" controlling the oil-filled voicecoil.  And, they still work, after ... I'm guessing ... 30+ years.

[AndrewJohn 10,449]

human speakers has a replacement crossover harness they offer, that I opted not to purchase..., I may go back in and refresh the capacitors in the original crossovers..., but I didn't for now - mostly to do one thing at a time, and see if I can tell the difference with each addition/change.

 

The other reason I didn't get Human Speakers replacement crossover is that it was $98, and I think I can update the caps for less than that, should I choose to do so.

 

However, the Primary reason I didn't buy the replacement crossover, is that Huw has taken the design and changed it.  He notes that the potentiometers are a waste, in his opinion, and so he has left them out.  In my opinion, for this model alone due to it's unique design a la bose shape, I think it was valuable to be able to attenuate the front-facing output. to adjust the sound stage to the room.

 

[stereo_dog 1,216]

Nice restoration and write-up. Thanks also for the background to the design of the speaker shape/driver locations. I have never heard this EPI model, but I agree, the ability to adjust the forward and reflected sound does make some sense. I like the EPI speakers that I own, just don't get them out often, anymore.