Altec 414Z Surround Ooze

[Mr. Widget]

Well... that's two votes for heat. I was nervous about trying heat, why go organic when you can use carcinogens instead. I guess I'll borrow Mrs. Gadget's hairdryer when she isn't looking.


Widget

[pelly3s]

With the M.E.K. if you use too much it will activate the glue holding the surround down and lift it. I have used the heat method many times and it works good

[louped garouv]

i've used heat as well to remove excess, much in the same way Steve described -- except instead of a dowel, i used the rounded edge of a crab fork

[grumpy]

Widget, let us know how the heat thing (vs. MEK) goes. I've got several
of these I'm going to need to "correct" a bit more than the one in your
photo (appears someone got a bit enthusiastic in "goo" application).

... returning some nice, but empty, Avalon/Carmel cabs to service.

-grumpy

[John]

Well... that's two votes for heat. I was nervous about trying heat, why go organic when you can use carcinogens instead. I guess I'll borrow Mrs. Gadget's hairdryer when she isn't looking.


Widget

M.E.K. is used to thin the goop for application to surround. I have removed excess on a few 15",s with a tooth pick and smoothed it over with a soldering flux brush dipped in M.E.K.

By the way the flux brush application is the way G.P.A. applies the goop to the surround's after the goop is thinned with M.E.K

I would go very easy with the heat!!! Just enought to warm the goop but not enought to cause any harm to the accordian surround.

[Zilch]

Do you (or anyone else) have T/S parameters for those drivers, Mr. Widget?

Have you measured them, perhaps?

Or, if not, would you do that, please?

These are very popular woofers, yet nobody seems to know very much about them.... :dont-know

[Mr. Widget]

Do you have T/S parameters for those drivers, Mr. Widget?

No.

Have you measured them, perhaps?

No.

Or, if not, would you do that, please?

Maybe. If I decide to keep them I will, and I'd be happy to share the data. They were given to me by a friend and I haven't decided what to do with them. I still haven't cleaned up their surrounds, in fact other than applying signal to them to see if they make noise, I haven't touched them.


Widget

[grumpy]

FWIW, I ran two over-gooped (from what I've seen) 414z's through WT-2
and it seems I should indeed un-goop them and remeasure (significant
differences are shown):

Re: 11.5 ohms
Fs: 40, 49.2, 45 Hz
Qes: .29, .36, ...
Qms: 3.51, 2.46, 1.0
Qts: .267, .316, .3
Le: 2.3 mH
Vas: 210, 130, 150 l (delta mass method)
BL: 20, 20, 19.5
Mms: 41g

I've added info for a third unit.

-grumpy

[Zilch]

Thanks, Widget and Grumpy.

That certainly illustrates the problem working with or designing around these vintage drivers, no matter how "good" they are (or were.)

If there were some specs available, we could at least assess the condition of individual units against those.

The situation is much the same with 416A/Z.

I suppose one option is to have them rebuilt "as new" and work from there.... :dont-know

[grumpy]

Yep, most of the "hard" T/S parameters seem to agree (Re, BL, Mms, Le),
it's the suspension-related stuff that varies (no surprise). Testing "freshies"
would give us a reasonable baseline. ... I see sean19's recent post shows
an Altec spec'd Fs of 30Hz for a 414-type unit.

[JoMoCo]

Grumpy, what would you estimate the approx sensitivity 1w/1m to be...

FWIW, I ran two over-gooped (from what I've seen) 414z's through WT-2
and it seems I should indeed un-goop them and remeasure (significant
differences are shown):

Re: 11.5 ohms
Fs: 40, 49.2, 45 Hz
Qes: .29, .36, ...
Qms: 3.51, 2.46, 1.0
Qts: .267, .316, .3
Le: 2.3 mH
Vas: 210, 130, 150 l (delta mass method)
BL: 20, 20, 19.5
Mms: 41g

I've added info for a third unit.

-grumpy