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View Full Version : Looking for suggestions. Replacements for vintage 12" speakers



Ch0jin
April 24th, 2012, 06:00 PM
Well I suppose they've had a good run, but a couple of the speakers in my Vase 4x12 cab have been struck down with pretty severe voice coil grind. When I say "pretty good run", these speakers are over 50 years old! They were made right here in Sydney in the late 50's early 60's.

So I'm thinking I can try and track down someone who might be able to repair them, or I can replace them with something that has the same vibe, or both perhaps.

If I go the replacement route, I'm thinking paper cone alnico's. I can't work out what kind of magnets are in these ones, but given the vintage, I'm thinking an alnico type would probably right, and of course I can see they are paper. I have no way of knowing the wattage, but they were originally used with a 2x 6L6 head.

There's those Scumnico's that might be awesome, but they are pretty pricey, but any other suggestions?

Also, if you had four 50 year old locally made guitar speakers, would you re-cone or replace? (I'm not tossing them, I'd just stash them somewhere)

I don't know if the whole "played in, old magnet" thing is real or not, but if it is it seems a little goofy to replace them with replica vintage.

Anyway, whattya reckon?

Oh I should also mention the cab is roughly "standard" size, but is a little wider as it has a rectangular port or chamber down one side so it's not a fully sealed cab.

FrankenFretter
April 24th, 2012, 07:23 PM
Too bad you live on the other side of the planet, I have a couple vintage alnico speakers in great shape. Sometimes you can find vintage speakers that have been pulled out of old organs (that's where mine came from). Good luck with your search, or re-coning!

Ch0jin
April 25th, 2012, 07:39 PM
Thanks FF! In typically great timing, I have a jam with buddies tonight where I was going to try out my new homebrew JTM45 head with this cab.

I did emergency surgery and removed the offending speaker (the other three feel OK after I gently brushed over 50 years of dust from the cones. The bottom two speakers had around an inch of buildup on the bottom lip of the cones! Eeewwww!) As each speaker is 15 Ohms, I rewired them all in parallel for 5 Ohms total, close enough to 4 Ohms for punk rock :) I've got no idea at all how the 12" hole in the cab will affect my sound at full volume, but I guess I'll find out tonight. If I ever start playing loud regularly I think I might invest in a second cab with speakers not quite so massively rare :)

Ch0jin
April 25th, 2012, 08:29 PM
So I called the local speaker hospital (Yes, that's what the business is called) and they are familiar with the manufacturer, and amazingly, have repair kits in stock for -some- models. They will have to physically examine mine to see if they can be rebuilt with NOS part though, and if not it gets more complicated.

If they can re-cone with NOS parts, it'll still cost me about the same as a Scumico, so I'm thinking better to repair them as they seem to be SUPER rare. The guy I spoke with was fairly adamant I do all four at once to avoid weird phasing issues with new cones/coils and old mixed in the same cab. Also (and quite logically) if one has gone, the rest probably aren't far behind.

Over the phone diagnosis is that the paper coil former has probably slipped free of the coil given how nasty the rattle is.

Funny story.

The reason I originally thought this was an issue with my new amp was that while I was troubleshooting I had two speakers side by side. I plugged into this cab and "rattle", then I plugged into my 1x12 and as I turned it up I could still hear a rattle! Turns out the faulty speaker was vibrating sympathetically (from the 1x12 in a completely different box next to it) and rattling its brains out!

deeaa
April 25th, 2012, 09:59 PM
Hm, interesting.

I'm not buying into that do them all stuff though - how would it be a problem I don't know. I'm big for mixed speakers cabs anyway, I think it's only gonna sound better if one speaker is a touch different. I have two types in my cab and also the old identical ones don't sound identical to me. I don't understand how there could be phasing issues if the wires are just hooked the right way round...if there appears such, just swap the leads to the wrong phase speaker.

I don't think re-coning is a good idea for a working speaker. If there aren't holes etc. what's the issue? A speaker is really simple. The cone is where the sound is after all...I'd even suspect something like they want all the four old cones and replace them with new ones, selling off the old cones as a full set for a good profit...

My speakers are ~40 years old and work fine with no issues other than that the magnet covering plastic or whatever bakelite it is on old Celestions came off due to the glue/resin drying up and letting them loose. They just fell off...but I just epoxied them back in place. They're just cosmetic anyway.

BTW about there being an empty hole...I like that lots. Kinda gives a cab an open-backed vibe without losing the projectivity.

My cab is a 4x12" but had only two 25W celes for like 15 years, I really liked the way the cab sounded, it breathed well and didn't have the issues of open-backs as comes to placement on stage etc. I only put in another pair because 50W total was scary to use with a 100W tube amp :-) and I like it fine also with the full set. I tried, um, four different speakers models from V30 to some Jensens before I found a pair that mixed well with the original Greenbacks - a pair of some Ampeg labeled small-magnet Celestions (35W).

Ch0jin
April 25th, 2012, 11:51 PM
Thanks Deeaa, I tend to agree with you. When the guy I spoke with referenced phase, he wasn't talking abut electrical phase, he was saying that a new (or NOS) paper cone/rubber etc would not perform the same way a 50 year old one would, and there could be mechanical phase issues. When he said it my "Audiophile Bullsh*t" meter started flashing, but I thought I'd see what others though. I have heard of plenty of examples of mixed speakers, especially in 4x cabs.

All speakers have perfect cones. All of them have very small (2mm or so) holes in the felt centers, probably insect related as this box sat in a shed for an unknown time before I got it, but that clearly doesn't affect sound.

The main concern with doing all 4 is that if the fault is that the paper coil former has separated from the coil (which is exactly what it sounds like, the speaker rattles when you shake it which probably wouldn't happen if it was just cone warp causing the coil to rub on the magnet) the others might be close to doing the same.

I think I'll take the single speaker over for them to look at next week and see what they say. If they can repair the single without re-coning that might be enough for now. It would also preserve it's authentic vintage appeal to fix it without changing cones. I don't treat it like a museum piece, but based on the prices I've seen asked for the only other two of these cabs I've ever seen, they can certainly be priced like one!