Date:         Fri, 3 Oct 2008 15:51:46 -0700
Reply-To:     Keith Hughes <keithahughes@QWEST.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Keith Hughes <keithahughes@QWEST.NET>
Subject:      Re: Vanagon, Rear speaker enclosures- I have them!
In-Reply-To:  <20081003221833.56A86638C48@mpls-mf-03.inet.qwest.net>
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>
> Date:    Fri, 3 Oct 2008 15:09:33 -0700
> From:    Mike Miller <mwmiller@CWNET.COM>
> Subject: Re: Vanagon, Rear speaker enclosures- I have them!
>
> Being a long term audiophile, also pronounced 'nut', I'll attempt this.
> Everything degrades with time. But over the lifetime of us, or our vans:
>
> Paper cones degrade whether or not they're used. And that's probably what we
> have.
>
> Plastic doesn't degrade but the glue that holds the spider to the cone can,
> depends on what's used. Same with carbon fiber.
>
> Metal cones don't degrade and sometimes are connected by heat {read solder,
> silver solder, or brazing] and those connections don't degrade but can
> break, but usually not and the glues that are used are pretty permanent as
> well.
>
> Those are the common speaker materials. There are others, oh my many others,
> but they're not used much, if at all, in speakers for our vans.
>
> YMMV
>
> Mike
>
Paper cones are certainly a weak link, and do degrade over time,
especially stored in high heat environments.  But long before I'd worry
about the cone or the spider attachment, I'd look at the surround
material.  Foam is used on 'cheap' speakers, and again, it'll die
whether used or not.  Butyl (rubber) surrounds last much longer, but
still are the weakest spot IME.  That said, a 'plastic' cone with a
butyl surround, stored indoors out of the sun, will last a Long time on
the shelf. So materials of construction are the first limiting factor,
with storage conditions next.  The Boston Acoustics (doped paper cone,
butyl surround) in my van are 13 years old, and still going strong -
well, as strong as a 5 1/4" can.  The same speakers on a rear deck,
exposed to the sun (here in Phoenix), would've been dead many years ago.

Keith Hughes
'86 Westy Tiico (Marvin)

BTW - yes 'he' is named Marvin, after Marvin the Martian.  And he goes
by Marvin or Mr. Buslie (although while replacing the transaxle drive
flange seals yesterday, I found some other choice names for him as
well)  :-)