Altec 600-b cone available?

[guitician]

I have one of these old alnico speakers and the surround has been coated with a brittle film causing it to crack all around. The speaker's voice coil and former are fine, as is the aluminum dust cap. I have done re-cones before, so I'm confident that if I could find a 12" curvilinear cone with a 3" VC opening, I could fix it. Or maybe just a cloth surround? Though I have never seen just the surround sold anywhere. Is there a cone for one of these available? Thanks

[gbono]

LANSING HERITAGE

Official Speaker Repair Site - Orange County Speaker Repair and Sales - SpeakerRepair.com - Home of GLS Audio

and finally....

Great Plains Audio's Homepage

[guitician]

Do you know if they sell parts? Just the cone, or surround?

[guitician]

I found this...
SPEAKER CONE 12" FIT EV, JBL, C-VEGA, PEAVEY,JENSEN, DP | eBay
I asked about the trimmed height and it would be the needed 2.5" for a 3" VC. The fabric surround is like they started using on the D-120>K-120 or 600B>417-B, and I will reuse the coil/former so this may work.

[gbono]

You are brave I wouldn't trust myself to make a cut on a cone like that - you must have a nice scalpel and steady hands.

[guitician]

Now I'm thinking of just using the surround from the cone, if I can somehow remove it with a solvent. The original coil/former/spider are still usable, just the surround is damaged. So, if I can attach a surround to the original cone, I'll be in business.
Oh, yes I'm am very detailed and exacting at my work. I love to take on difficult jobs.

[gbono]

Good luck getting the old surround off and leaving a workable surface. It's always the joints/interconnections on loudspeakers that cause the issues. I'd look for a source of just the surround material.

[jrfrond]

First of all, with aftermarket cones, there's no issue with cutting the neck opening, IF you do it properly and know how to do it. I do it all the time. It's just the way it is in the aftermarket recone parts world. The biggest issue is that your template is the voice coil, and it is not in the position where you can use it as such, when it is installed into the speaker frame.

I place the coil on top of the speaker neck, trace around it with a sharp pencil, and then cut it with a pair of curved sewing scissors. I cut INSIDE the line, so that it is a bit smaller. I can always stretch the cone paper as needed a bit for a good, snug fit over the coil before I glue them together.

From what I see here, you are gaining NOTHING by trying to replace just a cone or surround. In many speakers that age, the spider has been fatigued and sits slightly off-center due to the weight of the voice coil and plain ol' gravity as it sits in the horizontal position for most of it's life. I might be the only one who feels this way, but it's my contention that speakers should be rotated in their mount once a year by 180 degrees to counter this issue. I don't actually do this, just throwing it out there.

You'd be MUCH better off skipping the surgical procedures and performing a complete recone.

[guitician]

If I could get a cone like this, and a 3" paper voice coil former with a edgewound coil, I would recone it. John, do you know if just a fabric surround is available? Thanks

P.S. The cone, spider and coil assembly weigh .925 oz.

[J M Fahey]

I think that a full recone is justified if the speaker is dead or heavily damaged, but otherwise I would *try* to save it, since putting a new edge will affect it much less than anything that touches the Voice Coil.
I mainly fear that a full recone, using modern components, epoxies, etc. will sound very different to the original one, whatever they used.
Probably not bad, but noticeably different.
If there is absolutely no other way to get it, I might send you a spare 12" cloth edge, but consider it only a last ditch option, I'm 8000 miles away.
I would carefully cut the speaker edge, with nail-cutting curved scissors, and a lot of patience, then glue the new edge over the narrow ring the old one would leave.
Trying to unglue it from the paper cone would do more damage than good.
JM2C.

[guitician]

Oh, so they sell just the fabric surround? Where did you get it? Do you have a picture of it? Here is a pic I took of another 600B. A curious thing I found about these speakers is that their paper cone has an extremely thin surround. You can see light through it.

[J M Fahey]

Well, I *do* have a small speaker factory.
Have been making them from the early 70's, already have a few thousand under my belt and obviously have links from importers and wholesalers.
I buy parts in bulk.
The "treated cloth" edges come in 50 packs. (Like most everything else).
I do not have much use for 12" edges, but sure use a lot of the 10" ones in my "10" Ampeg speaker clone"
Here you have both for comparison:

12" edge closer:

detail front:

detail rear:

You'll see that the outer edge is flat (to be glued to the frame) and the inside edge has a slight downwards angle, to better fit the cardboard cone edge.
The thin/see_through edge , is normal in many speakers, to make them somewhat more compliant.
The "brittle coating" you see is brittle because of age.
Without it, that edge would be paper dust by now.
In a nutshell, try to get it in the US; if *absolutely* impossible I might get you one, but remember I live in Argentina.
Although my sister almost got to live in Phoenix, her husband was V.P. in Unocal and when they merged with Philips Petroleum the whole higher staff had to move to Phoenix.
He resigned, they still live in Orange County.
The World is small indeed.

[guitician]

That's what I need. Thanks for the pictures. I have two Altec 600B from the early 1950's that still have sticky "Goop" on their edges. I guess they were treated differently, or kept out of the heat, who knows. But this speaker lost all compliance and bass response as a result. Thanks

[guitician]

Another thing that is important is the cone edge-to-frame distance, shown by the pic. How wide is your surround? Thanks

[J M Fahey]

Your red ruler measures 16mm - 5/16".
The whole fabric ring width is 34mm - 1 5/32".
Consider the mm measures exact; inch ones only a reference.
The whole ring has an O.D. of 299 mm; I.D. 230 mm.
Good luck.