[gregz]

"~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.

Greg