Look into my eye... Fisher XP7 refurb

[Ed in SoDak]

Heheh, where are we, some 4 years and a few months later and I'm still receiving a PM or two about these old Fishers. And new posts to the thread as well.

Sancho, I don't know about the 7C model, but if it follows the B well, it oughta be halfway decent. PICS??

Vinac is a PVA glue (Polyvinyl Acetate) dissolved in acetone. Watered-down white glue is about the same thing, just a different thinner (water). www.bhigr.com is one source, it's commonly used to help preserve fossils.

Since I wrote this thread, I learned more about the "reversed" polarities of the woofers to the other drivers. It does have something to do with the phase of the crossover network as much as DC polarity of the drivers and I've seen it used elsewhere. I guess ol' Avery Fisher would sit down and do the final adjusting on speaker crossovers himself, seated on a chair in front of the speaker.

Mark, good tips on replicating the octopus! Saw pics of that somewhere along the line... Good comments from Nat on the phasing as well.

So, the tweeter surround is just a dust cover, eh? I made mine into a working surround, since I abandoned the octopus. Perhaps no surprise I didn't care for the sound after my fix.

FDwrench, you can make out a faint circle on the metal plate of your tweeter. The outer gap of the voicecoil in your speaker is open to entry by dust and whatever magnetic grit might get in there. I see mine have blanks for the third midrange to make them into the XP9 model, while yours do not. Interesting, maybe they'd run out of XP7 blanks the day mine were made.

I still have these ol' puppies, looking about the same as where we left off with 'em. I have since ordered a big selection of drivers. Might be time to do more experimentin'!

-Ed

 

[soundmotor]

Heheh, where are we, some 4 years and a few months later......

Frankly, yours is one of the more interesting threads on the site. I had no idea Fisher used a proprietary dome tweeter and an alnico one at that! A couple questions -

Has anyone identified it as produced by Fisher or another vendor?

Does it have an EIA identification number on it anywhere?

Is the dome phenolic?

You mentioned early on about finding the woofer wired out-of-phase. Wiring a driver electrically out-of-phase is not uncommon. Some crossover types require it. What the designers are looking for is acoustically in-phase. Under measurement they might have seen better response with the wiring as you found it.

Re: the tweeter, the chamois surround was a neat trick. There are some issues however with replicating the original performances you noted. The voice-coil needs to be both centered in the gap but at the correct height as well. Typically the winding height of the coil must be evenly presented relative to the top plate thickness & top of the pole. Variations on this will not only affect the response but how it performs compared to the other one. In production the manufacturer uses gauges to maintain consistency. All of that info unfortunately is certainly at the bottom of a Long Island land-fill. Still, getting them to play again is a real achievement.

:thmbsp:

(Your thread got me thinking about other rebuild strategies too. A foam-rubber disc sized to the ID of the dome could be glued on top of the pole for example. It could be shimmed to center it on the pole and then dome glued to it. The dome would center upon the foam so the voice-coil would center in the gap. A drill-press (OFF) with a dowel could seat the dome at a consistent height that was verified with a micrometer. Real Wile- E. Coyote stuff but I think it could work.)

 

[Ed in SoDak]

Thanks! All I really did was post my progress as I learned things about the Fishers.

A lot of people seem to like the original XP7, but it wasn't the sound for me. In the end I replaced all the drivers. The only Fisher driver left is the lone woofer from the XP7B cabinet, which I transferred to one of XP7 boxes.

I still have the original drivers stored away. I searched for the tweeters to look for a number, but couldn't lay my hands on 'em. Buried under fresh acquisitions somewhere. The pics show a "T-200" stamped on the face.

I think I read a thread here on AK long ago that Avery Fisher contracted out for these, built to his specs. Not sure if they were the first domes, or maybe he modeled them after AR's. Haven't located that thread yet.

The foam disc idea might be a good one. Might find one already cut at a craft store or maybe as a pre-punched self-adhesive disc at a hardware store. I'd doubt my abilities to make a perfect disc myself from a sheet. Hmm, I'll have to give this some thought and try again to locate my fried eggs.

Just for the historical perspective of recreating it to see how it sounded. My own opinion is that modern domes are lighter, stiffer and more transient in response. The Fisher fried egg tweets seem to me to be a much better mid-range dome than as a tweeter.

-Ed

 

[RaVeN38571]

I know this is an old thread, but maybe I can get a few answers. I just got me a pair of Fisher XP 7's today at a thrift store. Picked them up cause I thought they looked cool and they would go with my Fisher 500-TX. They are a little worn out. What would be good replacements for the speakers etc? Also need it to be cheap. Thanks

 

[Nat]

I think the origin of the dome tweeters has been discussed before, but I believe the guy who founded Phase Tec made them for Fisher. He was out on Long Island at the time, and actually holds the patents on some aspect of dome tweeters -- its hard to believe he could actually patent the dome tweeter since AR made them before he did, so perhaps its soft dome tweeters. He moved at some point to Florida, which is where Phase Tec is.
Warning -- this is all off the top of my rather old head, so specifics might be misremembered.

 

[juan_caliente]

I have acquired a pair of Fisher XP7B speakers, the drivers are in great shape, cone tweeter rather than the fried eggs, but one woofer has no foam. The other has what appears to be a paper acordian edge, does anyone know where I can get a new edge for my woofer?

Thanks,

John

 

[Robmcgill]

Ed

The power of the Internet! This is great and thank you for your thoughtful and generous time. Like others above I picked up these cabinets from a thrift store as a project and I have no idea about the inner workings of speaker cabinets. This thread will be very useful for me over the coming months.

I also enjoyed ed's inner battle of the futility of the postings, overcoming it, then adding a bit more drama to each post before wrapping it up.

Thanks ed!

Rob

 

[13stoploss]

Well, I'm going to be that guy. Old thread!

Seems that you were writing for another time, Ed. Evergreen!

Anyway, I picked up a pair of XP7 recently for $30. Serial numbers are close, but one is walnut colored and one is darker. Mine also have the patched-up cover plate for the un-used driver (XP9?). They also sound like shlt. I have to really crank 'em up to get sound. And that isn't good sound. One speaker sounds better than the other, but it sounds narrow, squashed, flattened, and lacking any kind of detail.

One tweeter was DOA, one is okay'ish. Both have the remainder of the foamy surroundy stuff. I saw that one of the voice-coil leads under the blackened tape on one was severed, so I soldered it back. It now plays sound, but that's an overstatement. Sound also comes out of all four mids and both LF drivers. It appears that my LF driver coils/spiders are fine. No sag or collapsing.

So far, I've built a new crossover board for the bad-sounding speaker. I added two new terminal strips, kept the inductors, and bought new caps (modern caps are kinda big, so I needed wider space). Mine also only have one resistor. Hooked it up tonight and no change to the sound.

The re-soldered tweeter measures 7.0. The mids measure 7.9 and 8.4. The driver measures 4.4, but the cloth surrounds are practically translucent. Was going to try the rubber cement trick to the surrounds to see if that helps. Probably going to take apart the tweeter to see if the octopus rubber thingy is gone, as I suspect it is.

Anyway, thank you for the information!

 

[13stoploss]

As this is the most prominent XP-7 thread on Audiokarma, I'm reviving it yet again. I've (functionally) completed my XP-7 rebuild and took some video tonight to show it off:

When I got the speakers, the tweeters were just about dead. I re-soldered the leads, and it made noise, but not good HF. The mids were flat and lifeless, and the woofers were silent. Because of this thread, I sprayed the woofer surrounds with rubber cement. Then I fixed the bungled crossovers. As for the tweeters, I added MCM tweeters. They have the same frequency response and crossover point as the original tweeters. I like the way they sound. Not overly bright or dominant in the setup--very neutral, and although they look modern, they don't look terribly out of place.

Still working on the cabinets, and permanently mounting the tweeter, but this video demonstrates quick audio comparison of the native iOS video mic, the Zoom iQ5 mic (44.1/16), and the stereo Rode i-XYL mic (96/24). The intervals are unmarked, but there are three videos, each ending around the 54 second mark, starting with iOS, then Zoom, then Rode. The pre-amp gain is unchanged in all three videos, as is the video recording spot at listening position, and the speaker location. The amps are Decware ZKIT DIY, that I've bridged into monoblocks.

 

[Ed in SoDak]

Thread Necro! Might as well wake up this Zombie Fisher thread. Good to see the long-term interest, maybe there just aren't many posts on the Fisher XP7 or XP7B to give it competition.

Not much to add to the discussion. I ended up pretty happy with my mish-mash of drivers and haven't changed a thing after all these beers. I sure don't listen to music like I did a decade or more ago. Packrat that I am, all this old stereo gear is still here, piled in stacks in sheds or corners. I had gotten into a speaker-buying splurge back in 2009, trying and swapping drivers left and right. Probably enough left-over stuff to build a few more!

Someone on another forum posted about AR-1 speakers and that got me all nostalgic. Back in 2009, I was messin' around with speakers and amps till the wee hours. Today, I'm ready for my after-dinner nap! :lol:
-Ed

 

[IheartFisher]

Whats up Ed? Lets keep The Fisher thread rockin! I have a pair of '68 xp-7 my Dad bought brand new in '68. I skipped some of the posts so I didn't catch everything, but the Fisher XP line were the first to use the soft-dome tweeter invented by William Hecht. He created them somewhat by accident because everybody kept touching the earlier dome tweeters at tradeshows and breaking them is my understanding. I believe they were exclusive to Fisher starting in '66 until who knows. Avery Fisher and William Hecht were good friends. I decided to just remove the old Hecht soft-domes and replaced them with Dayton tweeters. Still not sure how I like them. I am about to replace all the capacitors. Thats called a re-cap? Your pics are great, thank you! Not sure yet though. Dark Side Of The Moon and Kid-A will both give you an eargasm on these old Fishers, but you do need to crank up the treble. My Dad was a DJ in Detroit in the late 60's-early 70's and I inherited alot of radio station demo records from him. The right records sound great on these speakers even being all original(except tweeters) But some mixes for sure don't sound great. Should I go for it? Replace the capacitors? How big of a difference does it make and any recommendations for better tweeters than these cheap Dayton Audios? Any help is appreciated! And anybody else restoring old Fishers don't change the reverse polarity on the woofers, and keep them air tight!

 

[Nat]

Recapping sometimes makes a very big difference. Electrolytic capacitors can dry up and go fairly far off spec. Replacing them with film caps - many people are pleased with the reasonably priced Daytons - can make a big improvement. Sometimes, though, the speakers may be brighter than they were meant to be because the equivalent series resistance may be lower than in the original caps. That may, or may not, strike the listener as an improvement.
I would suggest recapping and putting the original tweeters back in and seeing how the system sounds. Crossovers are designed for specific drivers (or they are in more sophisticated speakers) and swapping in different drivers may not produce optimal results. Your cheap Daytons may be perfectly fine, but the Fisher crossovers may be too low for them, or the efficiency may be wrong. Or maybe they will sound great after the recap.
That said, my impression of early Fisher/Hecht tweeters is that the suspensions can harden, and that changes the output. Don't know if anything can be done about this. So it is possible you will want to change anyway.

 

[IheartFisher]

Whats up Nat? Thanks for the reply! I have pretty much already decided not to fix up the original tweeters. My Dad was 20 when he bought these and he said he never remembers the highs being that great. I think I'll start with the caps and see what happens. The sound is balanced very well at high volumes but lower volumes is all mids and lows. Rock on brother!

 

[SOwens]

Wowsers! So I’m not the only one messing with old XP7s. I dug out a pair I bought in 1967 and took a look. Woofer surrounds gone, one tweeter not working. I replaced the surrounds and fired them up. Terrible sound, no mids, bad highs.The speakers got me through college, my 20s, and into early married life. I’ve decided to rescue them. I am going to remove all the drivers and Xover and start over, probably with recapping. The cabinets are solid and I would think they could be made to sound good again. I am aware of the necessity of all the variables that go into speaker building to achieve optimum sound. I do not have the time to delve that deeply into these speakers. Optimally, I’d like to install all new drivers that match the original specs, or at least come close. I would think someone has already done that with satisfactory results. I’ve pored over the XP7 threads here and elsewhere and been amazed at what others have done with these. I know I shouldn’t just install speakers that ‘fit the holes’ and I have found a few suggestions pointing to replacements from Parts Express. Has anyone done a full replacement of drivers (and maybe XOvers) of these speakers that resulted in bringing them back to life?

 

[IheartFisher]

SOwens our old Fishers have real Walnut veneer which is why they look awesome! From what I understand, any break in a seal anywhere will cause premature failure of the surrounds. These babies have to be air tight. Its weird to crank em up with some thumping bass and woofers don't move hardly at all but thats the way they work. The original sealant dries up and air leaks create havoc on old XP's.

 

[IheartFisher]

Update on The Fisher '68 XP-7 refurb. Great news! The caps are all Mylar and are still perfect. I have a cousin, Noel, who is a sound engineer working on them. I bought some Fostex super-tweeters but I might not even use them. Avery Fisher apparently hated highs so there is an 8 ohm pad on the tweeter output essentially cutting the tweeter power in half. See pic below. So Noel is going to bridge those out and lack of highs problem solved! I know Avery Fisher played violin. So maybe he was really bad or maybe hated piccolos. But the 8 ohm pad was put there on purpose, and that is why Fisher XP's have always had incredible mids and lows but weak highs. All drivers are perfect, even the surrounds, except original Hecht soft-domes which I already took out years ago. The boxes are still air tight. After I get them back I am going to see which tweeters I like best, throw the insulation back in, silicone around the drivers, throw the covers back on with something other than the original brads, and crank up some Pink Floyd! And I can't say it enough, you have to keep Fishers air-tight!

 

[Nat]

Don't see mylar caps - see the black and red things that are poster children for why recapping makes sense. If they all read correctly including ESR, then no problem.

 

[IheartFisher]

I honestly have no idea. I dropped the speakers off to him and don't know what the hell he is talking about. He did just send me a text saying "I just looked up the spec sheet for the speaker. My math was a little off, and it does need a cap to fix the crossover frequency back to 2500hz. Those are like 3 bucks and 7 for shipping" He knows his **** and used to make custom speakers and currently does sound for theaters and Amy Grant and stuff like that so I trust him.

 

[Nat]

I'm sure he knows what he is doing.

 

[IheartFisher]

Hey SOwens, I found this (see pic) My 68's are not set up like this. One mid is up next to tweeter and there is no separate containment for anything. I think '66 was the first year for these. Not sure what they looked like in '67, but this can get u pointed in the right direction. Rock out!