Old Shearer Horn, Altec, VOTT Found, And Question

[Flamingo]

I am new to the forum, but have lurked on and off over the years. My company is finally updating a sound system (a ten-year process!) in a 1941 Navy base gym. One of the requirements is to remove the old sound systems, which was as far as we were told was a basic Soundsphere-TOA affair.

In the process of establishing conduit routes a few years ago, I see the first picture attached (could not get directly to it, just on a ladder from about 10' away). I thought, "cool, we'll have to check that out if we ever get this contract."

Long story short, we started work last week, and finally got into that loft. Sitting there for who knows how long are one of the single Shearer Horn modules (A4), its two old 415 bass drivers, a 288-8G HF driver on I think a 45x60 horn, a single A8 and a singe 816A. No multi-cell horns though...

We will fulfill our contract obligations and remove these old sound system parts as well :) I'll make sure these items get to good homes who can restore them properly, put correct cones on the field effect drivers, etc. The only thing I'm not sure about is the actual plywood horn - is that worth getting out of there for someone to work with? For sure I'd want to get the dividing network and schematics, but the logistics of getting the big horn down are significant.

To see this stuff in the wild, some with 80 years of dust on them but still surprisingly intact blows my mind. Reading up on the history of these again makes me realize just how we stand on the shoulders of giants, Hilliard and Olsen in this case.

We're installing Danley GH60 and TH212 with SM60F for center and sidefill. I feel like we're maintaining a respectful legacy by installing the current generation of horn-loaded goodness, but I can't help but wonder what it was like for the sailors and shipyard workers to come into that big gym to watch Casablanca or Bambi, or The Flying Tigers on the big screen and big speakers!

[Flamingo]

Her's the main question - is there anyone in the Puget Sound region who would want this A4 for the cost of what it will cost me to get it out in one piece?

Of course if anyone is interested in the other items, I'll be selling them. I couldn't ascertain from my first read of forum rules what the appropriate place is for that, so I apologize if I'm out of turn here.

I am just in awe of seeing a real Shearer bass horn in person, and how the high sensitivity of the system with efficient amplifiers could actually fill up the 2500-seat gym and its balcony!

[4345]

Do I see a paper label on the wood cabinet? If so, that would make it absolutely a factory made cabinet. That is not a A4 211 enclosure, which is fairly common. That is an older folded horn enclosure. I think one like that is much rarer and would definitely be worth the effort. PLEASE try to save it. I am sure you can sell it. Maybe some other members know more than I.

[Flamingo]

Do I see a paper label on the wood cabinet? If so, that would make it absolutely a factory made cabinet. That is not a A4 211 enclosure, which is fairly common. That is an older folded horn enclosure. I think one like that is much rarer and would definitely be worth the effort. PLEASE try to save it. I am sure you can sell it. Maybe some other members know more than I.

Thanks for the reply 4345! Yes, those are actual little blueprint papers on the back inside of the folded horn. The model number on those says 30W5, and I believe it is one of the bass horns shown in this picture. I have the rear cover with the elongated slots in it, as well. I don't see any of the baffle wings, but the pedestal to get the horn to the height of the opening is sitting upside-down on top of it in one of the pictures in my first post.

[Earl K]

Calling Steve Schell :bouncy: ( one of the originators of this site ).

Great stuff there !!!

The woofers will easily sell ( highest $$$ most likely from the Asians ).

Thanks for the pics ( BTW ).

:)

[4345]

I hope you can sell it to someone from the forum. I wish I had the space. I am not sure if both cones on the 415 woofers are bad. I would not rip out the cones. Just preserve them as best you can exactly as you found them and do let any surface (like the metal of the magnet area) get scratched or scraped. Do not have them re-coned or attempt a repair at all. Let the buyer do that. Since they are field coil drivers you need a power supply for them. If you see that, it is important to keep it together. The wiring looks really nice. You should preserve all the pieces associated with the cabinet exactly as it was. Do not just cut wires and trash them etc. Those things are important to collectors. I would also try to sell the woofers with the cabinet. At least keep them together at first. I think it is nice to have the original woofers that came in that exact cabinet.

[Flamingo]

Calling Steve Schell :bouncy: ( one of the originators of this site ).

Great stuff there !!!

The woofers will easily sell ( highest $$$ most likely from the Asians ).

Thanks for the pics ( BTW ).

:)
Thanks for the pointer to Mr. Schell, hopefully he can chime in with some regional contacts who would be interested in the components or better yet restoring the system.

Does tagging work in the threads, hopefully this gives Steve Schell a direct notification :)
Steve Schell (http://www.audioheritage.org/vbulletin/member.php?199-Steve-Schell)

[Flamingo]

I hope you can sell it to someone from the forum. I wish I had the space. I am not sure if both cones on the 415 woofers are bad. I would not rip out the cones. Just preserve them as best you can exactly as you found them and do let any surface (like the metal of the magnet area) get scratched or scraped. Do not have them re-coned or attempt a repair at all. Let the buyer do that. Since they are field coil drivers you need a power supply for them. If you see that, it is important to keep it together. The wiring looks really nice. You should preserve all the pieces associated with the cabinet exactly as it was. Do not just cut wires and trash them etc. Those things are important to collectors. I would also try to sell the woofers with the cabinet. At least keep them together at first. I think it is nice to have the original woofers that came in that exact cabinet.
Thank you for the reply and the confirmation of my gut instincts, 4345! I agree wholeheartedly it should be preserved intact, but I may even have to take parts of it off to keep them from being damaged during the removal process. If I have to do that, there will be copious pictures taken, and all original screws and nails kept. The plywood is in reasonably good shape, I've seen touring road speakers in much worse!

Both 415s are torn, but they are otherwise intact. I know enough about reconing to know these are not a typical size, and I would want them to be done by someone with specific experience with this vintage of Altec.

I'm guessing like most on this forum, I've been fascinated with audio for a long time. I've had more than a few chances to hear the unique sounds of well-restored vintage equipment - that is, put into as close to original condition as possible, without trying to "improve" it - but rather to let it speak accurately for its place in audio history.

How many of us have heard one of these horns in action? I know I want to! I feel I have something of an obligation to help make that happen somehow, but I'm not in a position to do it myself at this time.

[Flamingo]

Thought I'd give everyone an update. Over the last couple of months, I've been doing a ton of research on the field coil approach and the specific 415 drivers and 30W5 cabinet. All of that only made me want to get this thing out of the loft even more!

We had tried to manipulate the horn by hand into the specific orientation to get it out the hole, but it was just heavy enough and awkward enough to not be safe. So I went ahead and brought in one of our baby 1/4-ton chain motors, rigged it from the steel structure overhead in the stage house (it was about 55' up, not the 40' we thought earlier), and connected it to a long spanset we wrapped through a 15" hole and around the horn. We figured there was a possibility of the cabinet not being strong enough for that, and it might pull apart, but we also figured this approach was the last best option to saving this cabinet from the dust of obscurity. So, worth a shot.

It pulled up and away just like we'd hoped, and the horn section in the cabinet didn't even flex! These were well made! We now have it out on a motor case ready to bring back to our shop in the truck (wouldn't fit in the utility van) later this week.

Here are some more pictures. First, the schematics inside the rear of the cabinet. I took them out (along with the junction box and cabling) to prevent them from possibly being damaged in the lift.

[Flamingo]

Pictures of the 30W5 getting out and on the ground:

[Flamingo]

So now we have the cabinet, two 415 drivers, and the 220V cabling / low voltage signal cabling coming out of the junction box. that was attached. It looks like the 220V supply was cut off inside the box (I'll post a couple of pictures of that later) when it was taken out of service.

The three 220V twistlock connectors are there, as well as the three low-voltage signal pairs. No horn or 287 driver, or any mounting hardware for that to be seen. This was definitely mounted horizontally on top of the stick frame base in the first set of pictures - there was a slight curve cut out of the "bottom" side (the open "right" side in the new picture) where the staff had set up a hinged rail assembly to protect people from falling out of the speaker loft, but still give them access when needed. Halves of that are still attached to the wall and the stick frame base, but it's interesting how they just used the mass of the speaker as part of the guardrail system :)

Now that the parts are all out of the loft, is there anyone interested or can point me to anyone who would be able to restore this as a unit again? I noticed Mr. Schell hasn't posted since almost a year ago - I hope he is well, because I've come to really appreciate his posts in this and other forums during my research.

Any insight at all as to what should be done with this wonderful piece of history is welcomed!

[4345]

I think it would depend on what you plan to do with it. If you plan to keep it for a long time and have a place ready for it, then it might be worth getting the woofers repaired. If you want to sell it, I would sell it as is. If you want to just try it out, you might look for a pair of later model permanent magnet models that would work well in the cabinet. I think either a 515b or 416A. However, ask other members to be sure which is best. You also want to make sure the screw holes are in the exact same location.

Fixing the 415 woofers is delicate I am sure. I think Bill at Great Plains Audio might have similar but not exact parts. Exact would only be the original cones from 1941. Keep in mind, a purest might not want them repaired at all. Always best to leave it to the buyer. I think trying to fix them in any way would be a mistake if you want to sell it. I think the real value is in the historical nature of the item. It is huge and will not compare to todays speakers. You will also need to power the woofers. I hope others can chime in.

I would love them along with most other old Altec/JBL speakers. However, I already a have bunch of extra speakers I just look at.

[Flamingo]

I've been meaning to do this for a while, but haven't had time until now, since my business is shut down for the foreseeable future :(

Thanks for your advice earlier,4345 (http://www.audioheritage.org/vbulletin/member.php?144-4345) and your idea about substituting the 415s for something permanent-magnet based. I have to admit the process of learning about it and its history has made me go down the rabbit hole a little. Okay, a lot.

1. Restoring this as an original field coil system was more than I had money / time to collect everything for;
2. But to still hear the horn in something similar to what it originally sounded like was something I really, really wanted to do.

With that in mind, I've been able to sell the two 415s and wiring box to a fellow AH member, script56 (http://www.audioheritage.org/vbulletin/member.php?16505-script56), who is working on his own field coil project. We had several good chats about the technology, and in the process of answering his good questions helped give me direction for next steps. With his permission, I'm posting more pictures of the 415s posterity.

3. The A8 cleaned up very nicely, and sounded great. It was barely used, if at all, before it was stored It went to an old-school analog recording studio in the Everett area (Soundview Analog Recorders). He had one already, needed another for his studio playback monitors. He already has a nice pair 612 (with real 604 in them) for actual control room monitors, so it was the perfect home! https://www.instagram.com/p/B7Pu-_iprpQ/. I'll post some pictures of the inside of that one, too.

4. I was able to reassemble the 816A bass cabinet and MR64 horn and put an OEM Altec-Lansing binding post on the 288H-8 driver. Unfortunately this didn't make noise, so I investigated further, and whenever the original binding post got smashed, part of it pressed a hole in the diaphragm and separated the voice coil wire from it :eek: Just to try and get it all working, I replaced the diaphragm with a Simply Speakers replacement. Seems to be okay, after aligning it (it was rubbing a bit on the first installation, so I took the driver off and used the low-volume/low-frequency sweep method to get it aligned without rubbing). Using the N8500-8 network in the 816A, I just hooked up the 288 from the HF output posts on the back of the 816A. The MR64 horn's mounting holes lined up with T-nuts installed in the front-top of the 816A, so that assembled up like it was originally installed in the old gym. I've been listening to it in the shop a lot as I've been working on other things. Definitely a "horn" sound, and there doesn't seem to be much above 6KHz? Not sure if that's the driver, the horn, or the N8500. I'll have to run some tests on it during my COVID-19 vacay.

5. 4345 (http://www.audioheritage.org/vbulletin/member.php?144-4345) - After researching, I found the 515B was the definitely preferred driver for horn-loaded boxes like the 30W5. I found a probably mid-1950s AlNiCo pair on eBay from a gentleman who had GPA recone and re-gauss them for a project he never completed. He gave me a good deal on essentially brand-new drivers in a close vintage that would give me a representative sound.

6. I found locally (Seattle area) an H515 tar-filled horn, from the same vintage (1939 - 1943) as the 30W5 bass horn. It came with a brass 30172 dual-throat adaptor for 288 drivers. I plan to put a plank-foam plug in half of it, and use the 288G-8 driver from the MR-64 setup to test it.

7. I already have some really nice QSC, EV and Ashly solid state amps, 96KHz DSPs (I personally have a strong dislike for the Behringer/dbx Driverack level of gear), so I can make decent noise. Not tube noise. Not original noise. But close, and with the ability to hear the the system's horn-loaded design in a similar fashion to how it would have sounded almost 80 years ago.

Pictures to follow!

[Flamingo]

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I thought it was interesting there were QC marks and touch-up paint at this corner. A piece of wood look like it had chipped away before it left the factory. The scuffs and dings from sitting in a loft for 40 years were much worse, lol.
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[Flamingo]

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[Flamingo]

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[Flamingo]

Here's a few pics of the horn and dual-throat adaptor. One question I have is, since the horn has already been painted (when it went into the theater in Seattle where it lived all these years until recently), and since it is showing some surface rust - should I mist it with some really good Krylon flat black to keep the rust from spreading? Or leave it for some unknown future collector to deal with? I know the preferred answer, but I'm also a decent painter and can do this with no runs - unlike the theater tech's pain job :)

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[Flamingo]

You might have noticed the caster plate we built and put under the 30W5 horn. It doesn't actually attach to the original horn, but the 2x2s keep it from sliding off as we move it around the shop. I've since painted the caster plate black, and put together a top plate for the H1505 that sits in the bottom (now the top) of the horn. We had to put it upside down on the caster plate, because the original "bottom" was cut up (butchered, really) by some Navy contractor in 1942 to attach the loft's safety rail assembly to the horn. The top horn plate drops down into that hole and makes it level again with inner boards to keep it from sliding off. Those pictures and the 415 pics have to wait until tomorrow!

[srm51555]

Thanks for sharing with us

[Mr. Widget]

Thanks for sharing with us+1

Yes, please keep them coming... very cool haul.


Widget

[JeffW]

I think I'd just leave the horn as is. While it'd look better painted, it wouldn't match the bass bin - it might look like somebody tried to just slap some components together, worn patina on the bass bins and spiffy new horn. Let the collector decide how he wants them to present. Unless you intend to keep it, then just do whatever looks best to you.

[Flamingo]

Hi JeffW (http://www.audioheritage.org/vbulletin/member.php?407-JeffW) - After looking at the practicalities of even a simple anti-rust job on the H1505, I have to agree with you that it would look too "new", especially on that beat up 30W5. No part job on it for now, and I'll just keep an eye on the rust.

[Flamingo]

The 30W5 as mentioned was cut up by the Navy contractor tasked with building a safety rail for the loft where the speaker resided. Not quite enough room, so what's the answer? Cut out a notch in that big ugly box messing up my rail project. I may go back to the gym and take that railing off to include with the horn! :D

This was not a problem for decades, and no one fell out of the loft. The 30W5 sat horizontally on a little raised platform, so there wasn't really a top or bottom. The side cut into is actually the "open" bottom of the cabinet, whereas the top is solid plywood, so whatever horn assembly chosen had a good place to sit.

Fast forward to now, and space requirements in my shop mean I have to do the vertical orientation, and the top became the bottom sitting on the caster plate. I've had a piece of plywood veneer sitting in the shop for literally decades, inherited from my dad. It's a nice piece, but it was 1/2" thick on one end, 5/8" thick on the other. A manufactured oddball that got set aside.

It found its home on this project. Because of the cuts in the 30W5 cabinet, it's about 5/8"lower than it's supposed to be on the face, but the back edge of the framing 2"x4" is only 1/2" above the edge of the side plywood. Voila! I now have a nice level flat top to mount the H1505 on. Sure the veneer with a fresh coat of Danish oil is overkill, but at least it's protected, and well, classy in a weird way.

Note: First couple of pictures were before cleaning the 80 years of dust off - just water and rag, over and over again.

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[Flamingo]

Only five pictures per post, so here we go.

script56 (http://www.audioheritage.org/vbulletin/member.php?16505-script56) now owns these. I hope he can post a thread with his project and plans for these.

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[Flamingo]

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[Flamingo]

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[Flamingo]

I thought it was pretty strange to see such low DCR on the voice coils, and was worried at first. But wen you look at the schematic, you see the 415s are wired as a 3 ohm load...wow. The VCs still floated very nicely on their phenolic spiders, with no rubbing...

[Flamingo]

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[Flamingo]

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I've never packed artifacts before, so we mounted the drivers on plywood, bagged the serial number tags in little parchment "teabags", and double-boxed them.
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[Flamingo]

I couldn't figure out what if any serial numbers were on the two 515B drivers I picked up. It sure looks like a S/N on the one basket, but there is no such number on the other driver. What do the little marks in the square mean?

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[Flamingo]

​I've had some quarantine time to work on this project. Finished cleaning the H1505 up, figured out how to build and mount it onto the top plate so it doesn't actually modify the 30W5 while still fitting securely, and putting together semi-old hardware for adjustment capability. The bolts are mounted through the plywood veneer for strength, this horn-plus-driver-plus-plywood weighs north of 150 lbs.

Attachment parts are not original Altec-Lansing, but neither is the top plate. My goal here is to be able to assemble a working system so I can hear its basic sonic signature, leaving the original parts intact for a future collector.

I built the gaskets out of new cork rubber, found some old 5/16"-24 bolts for the throat, and some old '60s vintage fiber-rubber gasket material that matched the horn flange thickness exactly.

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[Flamingo]

I use SMAART 8 for and a couple different reference mics (mainly earthworks) for general measurements, so that's what I set up to work with the 816A/MR64 combo as well. I only have the one 1980s vintage 288-8G driver that came with the MR64, so I'm sharing this driver between the MR64 and the H1505 for now. Bolt it on, do some measurements, move it to the other one when needed.

The original Altec-Lansing diaphragm was pretty dinged up from when someone broke a terminal off - magnet sucked the nut right into it. Needed a replacement. As mentioned earlier and in an effort to save money, I bought a Simply Speakers replacement diaphragm, thinking it would be good enough. Feel free to say "I told you so", but I've had problems with it.

It actually rubbed in the gap the first couple of times I installed it, even after re-centering it (using the low-level 250 Hz sine wave approach). I think the VC just goes out of round when it overheats, which doesn't take much current to accomplish. As long as I don't get too loud, the HF just seems a bit "raspy." I think the SS "stamped surround" vs. the original hydroformed spiral makes a difference in the sound quality, so I've ordered a replacement GPA diaphragm, and I expect the HF will be as smooth as the LF on both systems. Is this a reasonable expectation?

For processing, I'm using a QSC PLD 4.5 four-channel amplifier with good DSP on each channel. Up to 48-dB/octave crossover filters, 5-band PEQ, delay, and limiters are all employed on the speakers. The 4.5 is a pretty beefy amp, so I attenuate the output levels down 16 or 18 dB to get us in the ballpark.

[Flamingo]

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[Flamingo]

Once we got the H1505 and top plate assembly rigged, we rolled the 30W5 under it and eased it down into place. For once in my life, something I built fit very well on the first try!

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[Flamingo]

More to come later today, including working to get the phase alignment right.

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[Mr. Widget]

Damn, that is a beast! Keep it coming!
I'll make more popcorn.


Widget

[Robh3606]

Really keep it coming we love this vintage stuff being measured with modern test equipment. Shows you just how good the engineering was back then! Those guys really knew what they were doing!

Rob:)

[srm51555]

This is such a cool find, thanks again for sharing. Those guys really did know what they were doing.

[Flamingo]

I ordered and received an 8-ohm diaphragm from GPA and installed it on the 288 over the past weekend. The issue I was having was a breaking up - VC rubbing sound using the replacement Simply Speakers diaphragm.

Unfortunately, I'm still having that problem with the new GPA, and in fact I'm also getting the edges of the little plastic spacer imprinted into the new diaphragm, grrr.

I've cleaned the gap.

I've assembled it and used a swept sine to listen for rubbing / vibrations, but not really getting any. In fact this process with the GPA was the first time I didn't have to move the dia around and tighten it down to get rid of VC rubbing, as I did in the SS dia. I assumed the SS dia must have gotten formed out of round, or God Forbid, the center pole of the 288 was off.

Bolted it back onto the H1505, fired it up, and it sounded good for a minute or so. But as it warmed up, the scratchyness returned. I then pulled the dust cover off while connected, and that's when I noticed the imprint of the plastic asterisk on the dia. Not deep, but noticeable. I loosened diaphragm screws, and moved it around while listening to music (just the HF output) and found a spot where it seemed to be smoother.

Put everything back together again, and listened some more, but it still ended up sounding like it was occasionally rubbing or distorting. I'm kind of at a loss, now.

I've been involved with audio for 30 years, and replaced a few diaphragms, but never had this much trouble. I also confess to not knowing what the purpose of the "plastic asterisk" in between dia and phase plug. See, I don't even know the right word for it besides "plastic asterisk"! Can I get away with not using it to see if that hitting the diaphragm is the problem?

Here are some pictures, I didn't get one of the imprinting. My question is, how important is that asterisk spacer? Is there anything I need to make sure of during assembly? I'm _pretty sure_ I'm keeping the leads from the terminals to the spades on the dia to the sides of the diaphragm when installed, but can't be 100% sure. Is this even possible for what the symptoms are?

Any and all help would be appreciated!
Brad

[JeffW]

You might call GPA, but I think that's just packaging protection, I can't imagine it being mounted between the diaphragm and phase plug.

I only found one other pic, no mention of installing that in the driver

https://images.reverb.com/image/upload/s--YL3o4tlg--/f_auto,t_supersize/v1549238863/k4wpir9b7bgel50xjk9g.jpg

[Earl K]

That plastic shim doesn't permanently live inside the diaphragm/magnet assembly.

That plastic "asterix" is simply a VC spacer that's used to help achieve the best alignment of the coil within the gap.

It's insertion is only temporary ( like when a woofer is reconed ).

From what I can see, you can't even use it on your older alnico magnet type 288 .

Here's a snipet of the directions for it's usage ( it has the important points ) .

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=64173&stc=1&d=1421248788

The shim is meant to be used with the newer drivers ( ceramic magnet types ) that have diaphragm locating pins that are themselves adjustable.


:)

[Flamingo]

Well, this is the part where I go to the corner stool and sit with my pointy hat on :crying:

The spider shim was installed between the old dia and phase plug when I took the driver apart. My initial search of what it was for turned up nothing, so I put it back in like I found it. Which also means it must have sounded like crap when it was actually in service back in the late 1970s/early 1980s.

That extra 1/32" of material in there totally explains why I always felt like the HF was hit and miss (randomly blocking phase slits), and the VC actually rubbing probably all the time.

Thanks very much, Earl K, I will let you all know how a slightly marred GPA diaphragm sounds in a 288 after I put it back together correctly this evening.

Sheesh! I will probably frame it, and title it, "Spider Shim Of Shame."
Brad

[Flamingo]

I feel like the guy who bought a used Servodrive sub and posted on the LAB about his problem with only getting one tone out of the sub no matter what he did.

Turns out the speaker connection used a 120v twistlock connector, so he made an adaptor and plugged it into the wall. It just sat there, reproducing 60 Hz all day long until someone (I think Fowler) finally sorted out what was happening.

Lol.

[Flamingo]

After installing the diaphragm back into the driver without the shim, the HF sounds amazingly....normal. Thanks for the installation page, Earl K (http://www.audioheritage.org/vbulletin/member.php?21-Earl-K).

https://i.pinimg.com/originals/d3/a7/38/d3a738413b1b9c65333276c89ed82476.gif

I'll set up the SMAART rig again and take some measurements and play with the crossover again. I had set it up pretty high (800-ish) because it was buzzing below that, and I thought it was some physical limitation of this driver. Actually, it was - it had a spider stuck in its throat.

Because I haven't replaced an HF diaphragm in years (my EAW and DAS Audio boxes have great limiters in the built-in amps), how severely do you think I damaged the GPA diaphragm where it left a little edge on it from one of the spider legs?

Once something like that happens, is it essentially stable, or does it cause progressive degradation over time?

[Earl K]

The spider shim was installed between the old dia and phase plug when I took the driver apart. My initial search of what it was for turned up nothing, so I put it back in like I found it. Which also means it must have sounded like crap when it was actually in service back in the late 1970s/early 1980s.

No wonder you thought the spider shim was meant to go inside the driver ( since you found a shim there when you removed the original diaphragm ).

Yep, face-plant time ( too funny ).

Hopefully you haven't done much damage to the new diaphragm ( measurements will tell the story ).

Depending on the model ?? you bought from GPA, the most HiFi version is made from softer aluminum that does in fact "work-harden" over time ( especially when used industrially within large horns ).

- That's why Altec eventually developed the pre-hardened model ( for extended working life ).

:)