[~misfit~[_3_]]

Somewhere on teh intarwebs gregz wrote:
"~misfit~" wrote:
Somewhere on teh intarwebs DecadentLinuxUserNumeroUno wrote:
On Mon, 22 Jul 2013 00:26:27 +1200, "~misfit~"
wrote:

Alas, on getting them home I discovered that the 'rubber' surrounds
of the
12.5" woofers had gone hard


There is no such animal.

You measure the speaker size by measuring the bolt circle diameter,
not the outside rim of the speaker.

I called them 12.5" drivers as that's what Wharfedale call them (as
well as contemporary reviews of the speakers). Also they need about
1/2" bigger holes to mount them than three (so-called) 12" drivers I
have here.

However I agree - and get very annoyed at the way drivers are
'sized' by hole-to-hole - or chassis size. IMHO a cone-type speakers
quoted size should be the diameter of the cone - the same way a
tweeter is sized by the diameter of the diaphragm. Either that or
the size of the hole required to mount them.

So, just for you, they're 25cm drivers. That's the outside diameter
of the cones. Now, can you help me with sourcing (or making)
surrounds for them?

Oh, wait a minute. WTF do you mean by the "bolt circle diameter"? Do
you mean the mounting holes? Because, if you do I've just measured
these and they're *exactly* 12.5" from the centre of one bolt-hole
to the centre of the opposite one. I guess that could be referred to
as the "bolt circle diameter".

(Although *why* anyone would want to use that measurement as a
driver size instead of the cone diameter is beyond me. It's asking
for manufacturers to 'cheat' by having a really wide flange and
spacing the holes all the way to the edge.)

Because that is the size you want to bolt into existing holes. That's
the way I have always gone by.

I understand why they're measured that way for system builders but by far
the majority of speaker-owning and buying people never unbolt a woofer in
their lives. It irks me when a "10" woofer" can have a cone that is smaller
than 7" in diameter. shrug
--
/Shaun.

"Humans will have advanced a long, long, way when religious belief has a
cozy little classification in the DSM."
David Melville (in r.a.s.f1)
[Sent from my OrbitalT ocular implant interface.]