Speaker Service refoaming an Altec Lansing Woofer

Speaker repair

[@ronwilgenbusch1961]

I’m in the process of redoing the surrounds on some old 1973 Sylvania AS-225A woofers. They’re Rola/Celestion 12”. I picked up four of these speaker cabinets for $25 us, the other drivers and cabinets are solid, just need some oil on the walnut veneer. Hope they sound good when I’m done. I’m not out much….

[@user-ug6jr7ql9i]

Altec 305 most likely. 200mm diameter cone. Looked everywhere and as far as I can see, all the foams sold out there supposedly for the 305 are for smaller cones and don't fit ... 194 or 197mm. I've tried 197. Nope! There are some larger foams for 203mm cones (sold for KEF woofers) but they don't have enough inner diameter to provide a decent overlap for glueing.

[@markmarkofkane8167]

Interesting! I like speakers. I used to take them apart for the magnets. (Not good expensive speakers of course). I never had the opportunity to rebuild a speaker. Which I know requires great skill.

[@jeffadams5510]

Reading comments below, it's simply a matter of what your used to using=especially if you do it on a regular basis. I prefer the white speaker glue (basically Aleene's tacky glue in the brown bottle) as I have all the time in the world to work with it. Had nothing but excellent results that way. I've also used the black silicone based glue which sets up FAST so just be ready for that and if your any good you'll get it right :)

[@coyote_den]

I have a Mirage Omnisub 10" I had to repair. Aluminum cone and a heavy rubber surround, not foam. Puppy wrecked the cloth grille and put a hole in the surround. Rather than try to find a replacement, I slapped some gorilla tape over it and used silicone sealant to make it airtight. Not quite as flexible as the good part of the surround but it doesn't seem to affect it much down below 80 Hz, which is where I have it crossed over.

[@zx8401ztv]

It didn't take you long to fix that, great another saved speaker 😀 Oval speakers must be a pain in the arse.

[@hugobloemers4425]

Thanks for sharing this with us. It looks so easy in this video but I guess you have to refoam quite a few speakers before you can do it that fast.

[@12voltvids]

I have done a grand total of 9 including this one.

[@johncopley974]

I’ve done quite a few of these including JBL ads and pioneer. Pretty difficult to avoid getting blue on the foam. The finished product looked good to me

[@12voltvids]

Damn near impossible to do it without getting some glue on the foam. At the factory the surrounds are attached before the cone spider and voice coil are set. Those that are making comments about how they would have done it without getting glue on it I've never done the job and most are trolls. Johnny send check was such a troll about 6 years ago. Making disrespectful comments on every video he found himself band from my channel as he's found himself banned from several other channels so now he continues to harass us by sending comments and take down request to Google for every video that myself and others that he has his sights on such as Fran lab and eevblog. I don't ban people for nothing people get banned if they post spam, such as the invest with so-and-so and the porn links. every single one of those people and anybody who makes a reply to them will find themselves on the band list there is no 3 strikes you're out. other people have to really piss me off to be blocked from posting. John send check was such because he logged in with multiple accounts using variations of letters and numbers in his name and I'm sure that he's got an ALT that he comes on now and still stirs up shit. He'll probably complain about this saying that I'm revealing his identity and tell Google that I have to delete this comment or try to get my video taken down again as he does every time. Actually he already has about 30 take down requests came through this morning for this one because he sends multiple requests. As you probably know when you reform a woofer part of the process is hooking into an amplifier and giving it a low frequency sine wave. The constant up and down motion of the woofer at 40 or 50 hertz centers the foam to the cone and to the bracket and in the process glue is going to ooze out at the edge of the cone. You actually want this because that way you know that everything is glued down and you're not going to have a surround buzzing away. Nothing's more annoying than a speaker that buzzes. The guy that owns this one tried to do it himself and he ended up with a buzzing speaker. First thing you did when he got the speaker back was pushed the cone down and release it to make sure it wasn't rubbing they gave me the thumbs up so he's fine with a bit of glue on the phone because again he's a normal person that runs his speakers with the speaker grill on so you don't see the driver or the surrounds anyway.

[@jkmacgyver]

I made an attempt, didn't have proper stuff to work with. JBLs, replaced them with some polypropylene MTX 10s got from kid Walmart lot 25$ I guess dumping them because 8ohm... I can't believe how deep and punchy they sound!

[@AllboroLCD]

That woofer has a 1989 mfr date FYI. Would love to know what model this came out of. Ive refoamed eight of these things out of 2 seperate sets of towers (model 501 & 512). Loctite clear multi-use glue worked best for me. Being its a single woofer, was this possibly from the model PSW10 sub? Either way, restoration well worth the $. These woofers sound amazing against anything modern and thats impressive given the modest size magnets and stamped baskets.

[@Jammerk40]

The best way to get glue all the way around evenly is you put power to the speaker not much, it will raise the cone and you can get the glue spread evenly then disconnect the power the cone drops and nice contact all around!

[@12voltvids]

Except putting DC to a speaker to raise the cone is not good for the speaker that DC voltage will start to heat the wires up and melt the glue on the voice coil and then bad things happen even if it's only a low voltage for a few seconds it will still heat the wires up speaker to decide to operate on AC for the audio waveform where the current is not constant is constantly cycling up and down back and forth and the pumping action of the coil moving up and down actually helps keep it cool

[@craignehring]

Nice work, thanks I see that adhesive is no longer available?

[@12voltvids]

I just bought it this year.

[@12voltvids]

It's available at Walmart online Lee's electronics. That's where i got it. 15.00 at Lee's.

[@jkmacgyver]

I have got away with black RTV, but was non critical small speaker repair. Could maybe use rubber cement or spray a gasket... If cannot find good stuff, dunno?

[@12voltvids]

@@jkmacgyver this is proper speaker cement. Same as the factory uses. It is great adhesive. Unlike some glues will not damage the cone or surround and can be used to repair tears in the cone.

[@HF-7DXM-6DXW-12]

Great job.

[@cougar1861]

How does one get the cone separated from the old foam without damaging the cone? (Apparently the client did this already.)

[@12voltvids]

It's not that difficult from the speaker itself you can typically just pick it off with your fingernails carefully. When dealing with carbon fiber drivers such as this you can use some IPA to help soften the glue a bit. The guy that owns this obviously used a grinder on the metal portion which I would never bother with just glue the new foam over top of any remnants you're not going to hear it.

[@zulumax1]

I am sure that they apply the glue and foam to the backside of the cone before the voice coil, spider, cone is installed into the basket at the factory. I have refoamed a set of Pioneer DSS-9D 12" woofers with the foam attached to the rear of the cone. You just can't see well when doing a refoam this way. I saw someone else use a DC power supply to move the cone outward to give some more room, but I have not tried that myself.

[@12voltvids]

Yes I am sure they have the surround on the cone before aaaembly into housing. They would shim the voice coil and then glue the spider and outer foam.

[@davidbkelly]

You are using the wrong size foam, look at the cone all wrinkled up.

[@12voltvids]

I didn't buy the foam. It was supplied with the woofer by the owner of it. He ordered it and brought it to me to install. Guess how much he paid me to do it? That's right zero, zilch, nothing. So I really don't give a shit if he brought the wrong one because i did it as a favour for a friend and he said it sounds fantastic.

[@chaseleim4773]

you really should have pulled the dust cap and shimmed the coil, there's no need to play a sine wave during a repair,the glue allover the foam was indeed avoidable

[@Poppinwheeeeellllllieeeeez]

Shimming is stupid. Just use s 1.5v battery.

[@chaseleim4773]

@@Poppinwheeeeellllllieeeeez that's stupid because dc current destroys the voice coil

[@tacofortgens3471]

​@@Poppinwheeeeellllllieeeeezgood way to destroy the voice coil

[@madpom2]

Why use foam again instead of rubber Foam won't last long

[@12voltvids]

Mine have been on 20 years still good

[@solitaire5142]

Rubber will alter the drivers Thiele-Small parameters by stiffening the cone assemblies compliance. FS will likely increase and it wont sound as designed.

[@12voltvids]

There is a reason that foam was used. Rubber is too stiff and alters the sound.

[@paulb4661]

​​​@@solitaire5142 Not really, it's more about cone termination, rather than compliance and fs per se, about 4/5 of the compliance is down to the spider actually, with only the remainder offered by the surround.

[@marcparsons1726]

Stick to troubleshooting that Refoam was an Abomination! Shoddy work man!

[@12voltvids]

Works fine wasn't paid to do it.

[@norcal715]

First!

[@brettprave98]

Would work better if your glue wasn't dried out

[@12voltvids]

My glue isn't dried out. That's how it is.