Altec 755a's

[scoville]

I was lucky to obtain this single driver in a gift of 2 very large cabinets containing multiple drivers, and horns. The cabinets were way to large to put to use in my home, and not in very good condition to boot. It was hidden under the mixing bowl in the photos, unfortunately it's companion was a Bozak driver. The 3 crossovers in each cabinet were mis-matched along with most of the drivers and horns. Not sure what the proper terminology is of the mixing bowl covers is, but I'd appreciate some insight on those. What I'm really seeking is info on repairing these Altec's . The cone is in poor condition, and they test at 0 Ohms, so I'm assuming the Voice coils are in need of repair or replacement also. I realize these are special speakers, not really shure on what direction I'll be taking with these. I have several systems at the present, and starting to collect some tube gear. I'd love to repair these myself, but have never repaired a VC. I have no problem paying to have this repaired, as long as they can be restored to the original specs. I'm seeing several kits for this repair but I'm unsure of what is really best for this special speaker. I thank you in advance for any insight anybody can share with me on getting this baby up to spec!

 

[RxDx]

The covers isolate the mids and prevent interference between them and the woofers.

The Altec is a fairly unremarkable speaker AFAICT, though I'm sure you're aware of its
huge collector status. You could probably get it repaired correctly and still have a lot of
value. That would probably stop me from attempting my own fix.

 

[scoville]

Is there a name for the bowl like covers? I've never seen anything like them. There are a couple reputable speaker repair companies here in the bay area.

 

[phil-g]

The Altec is a fairly unremarkable speaker AFAICT,

 

[Joe Roberts]

The Altec is a fairly unremarkable speaker AFAICT

Hahaha.

Yeah. He's definitely right. He must have extensive experience with this shitty driver, that people are paying big money for around the world because they are "just collectors."

Western Electric/Bell was such a stupid group of goons, I can't believe anybody let them make a speaker. Their phone system and nuclear defense systems also totally sucked.

Damn, if I knew they were unremarkable, I would be listening to them right now as I type. Maybe I would have a Tang Band instead.

I have been using these 8"ers for 30 years and every time I turn them on I am delighted.

Sadly, there are no exact replacement cones for the 755A. There are some available that will fit but they do not have the multilayer construction of the originals. And they won't sound the same.

I have had patched up cone 755As that sounded excellent but if the VC is open, you will need to find somebody to completely remove the cone and do microsurgery on it. I don't know anybody here who does this work but maybe somebody else does.

I know 755A specialists in Japan but they would surely charge more than that beat-up specimen will ever be worth.

I would sell it as-is to somebody who wants to take their chances with aftermarket cones, or equally likely, fix it up in some underground lab in Asia and sell it as original.

This was almost a major scroe, but not quite, given the massive damage.

As a DIY initiative, the guys I work with in Korea designed, made, and sold ~100 prs of a special speaker cabinet for 755As to members of a Western Electric forum they moderate. Pic attached.REALLY excellent box.

Many fake and shoddily rebuilt 755As showed up in the ensuing rush to acquire the drivers. When demand vastly exceeds supply, prices go way up but also nefarious actors come out of the woodwork. Some amazing counterfeiting and misrepresentation going on, I'll tell ya.

But even without criminal intent as a driver, so to speak, there would be some value in that beat 755A. Somebody somewhere would spend two days at a workbench with a microscope to fix it.

 

[Redboy]

Jeepers Joe, how do you really feel about it all? As the kids would say... "lol".

That cabinet certainly looks interesting! I still need to put mine in boxes, but the real holdup is on the amp front - nothing here with a 4ohm output tap! Well, nothing that currently works, anyway...

 

[EarlK]

. I'm seeing several kits for this repair but I'm unsure of what is really best for this special speaker. I thank you in advance for any insight anybody can share with me on getting this baby up to spec!

Send it to GordonW. .

If it's restorable ( using original cone & coil ), he's the man to do it .

 

[elitopus]

+1 Earl,
GordonW is a woofer wizard

 

[Joe Roberts]

Man, good tip on GordonW...I have a mashed 728B that I haven't had the nerve to try to fix myself. A stray kitten came in through my ham shack window in Austin and decided to use the cone-up 12" high on top of a bookshelf for a bed! I cried.

 

[Tom Brennan]

Well Joe, a friend of mine who was a retired WE sound engineer was mystified by the high fidelity reputation of the 755. He thought it an excellent ceiling speaker but it wasn't his idea of high fidelity. He provided me with a frequency response curve of the driver which I've reproduced here several times, the response isn't half bad but if a Bose had that response people would savage it. No highs, no lows, must be Western Electric. ;-)

 

[elitopus]

Response out to 10khz... pretty good for an 8" woofer

 

[Joe Roberts]

Tom, I have seen that and many other graphs, including some I ran myself . All I can say is it is the best full range speaker I ever heard by a large margin and I tried many, have five or six different models on hand right now.

Did you ask the WE engineer why they made this speaker as they did, and sold it for highly exacting applications, if it is so low fi? I mean WE was a monopolistic cost-plus operation, a branch of the biggest corporation and arguably most technically advanced in the USA at the time. Why did they make such junk?

I only claim to have the authority of someone who has heard 755As in many different settings with many different cabs and amps over decades. And I have mine playing right now and they sound reeeeeeeeeeeeeeeeeeal gooooooooooooood.

And at the moment I am using a pedestrian Dyna SCA-35 I'm rebuilding for my son, nothing super fancy.

Arguments from photos and paper evidence will not sway me. This speaker does magical things in practice. I am listening to it here and now, so why am I to believe otherwise?

I'll say that they are touchy as hell and a bad cabinet or electronics can yield horrible edgy sound, but when well set up, they are crazy 3-D, bells and metallic sounds have incredible lifelike shimmer, microdynamics are the best I ever heard--say on chicken pickin; blues guitar, and vocals have an amazing human quality that not many speakers get.

Bass extension isn't great...that is a limitation to be sure. My Korean partners made numerous back horn designs, with up to four drivers per side, trying to get more bass...and they did, but at the loss of the magic 755 tonal balance such as it is.

Here's a pink noise sweep I just did with my phone at maybe 1 foot...how does it sound to you?

?

 

[Tom Brennan]

You're putting words in my mouth Joe. I never said they were junk and so on. And I'm not saying that you don't like them or shouldn't. I'm saying it's reasonable to hold another opinion on the things. After all, if someone doesn't like them you can't reasonably say they're wrong to not like them.

 

[Joe Roberts]

Unless they have not in fact heard them...

Well set up, I should add, in a serious music listening implementation.

And even then, every set up is different.

This is not an easy speaker to optimize. Many people who have casually tried 755As were swiftly discouraged or generally unimpressed.

Sure, tastes vary. I get to hear a lot of fancy speakers and I sincerely think most of them are very mediocre, but every one has some following, even if only the designer.

Remember, half of all speakers are below average!

Your argument about some random "WE sound engineer" doesn't mean anything to me. He might be arguing from that graph. If that is how he determines high fidelity, that's legal, but no threat to my present experience of musical enjoyment with said 8" speaker.

You know you could be a WE sound engineer and never hear a note on the job outside 300- 3kc, i.e. telephone bandwidth.

This is another long diatribe, but engineers are not always the best authorities on musical reproduction. Some do learn, but this aptitude doesn't come with the diploma, it comes with years of listening and development of taste.
Honestly Tom, I don't see me putting words in your mouth, I'm using my own, but you're putting graphs in my face, Bro!

So got you back!

 

[phil-g]

I own a pair of lowly Es. Someone gave them to me. Possibly the most realistic sound I have ever heard. In 2 cubic ft WE clone cabinets. I did add some tweeters and a touch of sub. Just the most pleasant sound I've heard as I said. I would buy a pair of As, but not for more than 500$.

 

[Joe Roberts]

Yes, the price on 755As is too high. But the 100 guys in Korea I mention compared that with Sonus Faber. Magico, and whatnot and they look almost free!

One thing I like about this forum is that we are a bunch of no-account audio scavengers, and proud of it. In the business, I use $8k custom van den Hul carts and such, demo half-million dollar WE setups on a couple hundred k worth of electronics...but right now I'm listening to jazz on a Shure M91 and loving it. Expensive gear is usually too weird and blingy for my taste...and not always as good sounding as it is imagined to be.

I must report that the C and E versions are indeed nice, easy listening 8"ers but nothing at all to compare with the 755A. Really not much in common sonically at all. The A is super crisp, almost hyper. Not a smooth mellow sound but rather a ruthless monitor sort of sound. Very different from any other speaker I ever heard. Holographic in a way most speakers that chase that phantom never approach. Clearly, I am a huge fan.

I'd buy spare 755As at $500 each, maybe more if I'm feeling rich, and I am a total cheap ass DIYer. Ask anybody who knows me.

To be sure, they were a lot more fun when they were $75 apiece or less, back in the 80s when I first got hip to them., but I'd gladly spend $1500 on a true lifetime pr of speakers, knowing what I know after 30 years in the audio business.

 

[scoville]

Dayum Joe! Don't hold back... Ha! Expatrioted NOVA guy here of over 25 years. HTTR. I'm kind of a hoarder on some vintage audio gear the last several years. Mostly I lurk around for info on this site as I'm still getting educated. I do get lucky on occasion. I do have some carpentry skills and saw that Box in my info search. That is pretty much what I had in mind if I can repair, or get the driver repaired. I have a nice Pioneer SMQ-300 I think it would pair nicely with. Earlk and Elitopus, thank you for the tip, I'll give GordonW a shout out! This driver came out of some really large cabinets, I could barely tip and lift into my F150. I install cabinets for a living. I'm looking forward to sharing the info on the boxes and what was in them in a later thread. I've just been a bit busy putting up hurricane shutters, and removing them, cutting up blown up trees, ETC. I'm thankfully back to work!
Thanks for the great info gentlemen and please feel free to continue your contributions...
All of them of course!
Tony

 

[Joe Roberts]

Hold back? Hell no...Gotta keep my maniac populist literary character in gear. This is a topic near and dear to me, obviously. That speaker has twisted the minds of many very experienced characters who took the time to work with it. It defies explanation and most of us 755A aficionados have given up analyzing it long ago.

I know the top Japanese WE guys from Western Sound, Inc. Last time we met, we spent hours talking about 755As. They have flipped 10000 units over the years and are dialed in on every micro detail of this driver. They too have sort of abandoned analysis and just "do."

There are a few pieces of audio gear across the ages that somehow exceed the sum of their parts and this is a prime example.

The theoretical underpinning of most of my diatribes is that experience trumps abstract speculation. Bad "scientific reasoning" and rehashed forum "knowledge" are obstacles to understanding. In other words, I am a raging intellectual, really.

The "stock" box for these is 2cu.ft. sealed. Any shape will work. I tried many variations of this scheme. The Silbatone box I'm referencing in this thread is a major breakthrough and simple to construct.but 2 cu ft will give you the basic flavor, perhaps with a bit of a "severe" edge. The Japanese go with with a thin resonant wood box like the original Altec cab to take some of the edge off.

My Korean partner has built dozens of 755A cab variants. He calls the 755A a "ten cylinder car." Fast and agile as hell but not always easy to keep it on the road. He has the best audio collection in the world, warehouses of all the best vintage theater gear ever made, but he still loves the 755A like a first son.

I'd strongly recommend tubes with this speaker but I listen to mine with my late 70s Luxman SS and sounds pretty good. The Dyna SCA35 works remarkably well. I might keep it and give my kid the Luxman, at least until he gets a freakin JOB.

I will try to get the OK to go public with the cab plans. I'll put it up on my largely-inactive blog if successful.

The problem is getting a second one for stereo, if you can get that one fixed. Every gear flipper on the planet is looking out for these, for that big dollar ebay flip. They are not rare but, as discussed above, demand vastly exceeds supply.

I left DC/NoVA for Austin in 1991 but now I am back in the belly of the beast aka DC. Even weirder than it used to be...or maybe I'm just getting more normal? Or not normal enough yet?

Good luck with recuperation from the storm, scoville. Nasty stuff.

 

[jeb98]

I have a pair of 755a speakers. I've tried them in a few cabinets, a 1 foot by 1 foot aperiodic cabinet, and a really small old cabinet. I'm still waiting to try them in another cabinet and I'm very much looking forward to making the small cabinet that Joe's friends in Korea have designed. Even in the two cabinets I've tried, they have a very enticing sound that keeps calling me back when I'm using my Altec horns. A really nice midrange, immediacy, and realism. But, I am desperately missing bass in them. I don't like using a sub, but I wonder if there would be a sub that would work with these? Or do you just live without the bass, as they sound great as is in certain applications.

 

[Joe Roberts]

You could try a sub but I think that the typical balance is part of the very special effects these speakers provide.

In a good box, the bass that is there is super tight and snappy. i noticed that I get into head bobbin 'music grooving a lot with these speakers. They have a great sense of forward drive and rhythm. Lots of punch and snap but not much LF vibration. They are their own thing, so to speak.

I suggest getting to know them in the Silbatone box, then reassess your need for bass. Your mini cabs are probably not big enough to get what they are capable of. The small size of the Silbatone box is a plus and the decent LF out of it is a bit of a surprise gift.

I found that in small cabs, perhaps most cabs, the 755A can get a bit screamy. 10 cylinder car.

The other side of that coin is that it is a cone speaker that can give the horn lover the presence and immediacy we need. You won't get that from Magico.