On Thu, 09 Oct 2003 23:59:29 +0100, Old Fart at Play
wrote:

Stewart Pinkerton wrote:

Nope. If you look at the volume of air you need to shift at 20Hz to
obtain even 100dB (not a particularly loud peak level), then you need
a *lot* of power! This is why decent commercial subs invariably have
several hundred watt amps, some go up to a kilowatt!.

Can I have a little rant?

This thread was about KEF B139s.

If you look at a B139, not with rose-tinted glasses,
but as the woofer in a domestic hi-fi setup, it is excellent.

Um, it's a decent woofer, but was overtaken many years ago by more
modern constructions, viz KEFs own 'racetrack' woofers in their
current range.

Maybe it doesn't work as an AV sub to reproduce helicopters
and explosions at window shattering levels but in a reflex box
with -3dB at ~32 Hz or a TL with -10dB at ~20Hz it sounds
pretty damn' good on all of my CDs and vinyl.

Granted, it was never designed for subwoofer duties, and comes from an
era when reproduction below 30Hz was almost an irrelevance, i.e. the
days when vinyl was king.

What's more, a B139 still works after 30 years, unlike foam-surround
woofers that are dead at 10 years or other newish materials that lose
their shape and fall off (some sort of Goodmans loudspeaker)

Well, that's true of any other speaker with a rubber surround. In
fact, over forty years or so of audiophilia, and several dozen pairs
of speakers, I don't think I have ever owned speakers with a foam
surround. The 'other newish materials' you sweepingly denigrate are in
the main responsible for great advances in sound reproduction.
Goodmans haven't made a decent speaker in 30 years, so they are hardly
a good target.

So I may buy new speakers, but KEFs will be playing at my funeral. :-)

Ah now, a *real* audiophile would have gone for Quad '57s! :-)
--

Stewart Pinkerton | Music is Art - Audio is Engineering