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Path: utzoo!decvax!tektronix!orca!hammer!seifert
From: seifert@hammer.UUCP (Snoopy)
Newsgroups: net.audio
Subject: Re: subwoofers and xovers
Message-ID: <1575@hammer.UUCP>
Date: Sat, 19-Oct-85 14:16:40 EDT
Article-I.D.: hammer.1575
Posted: Sat Oct 19 14:16:40 1985
Date-Received: Sun, 20-Oct-85 21:29:44 EDT
References: <1395@teddy.UUCP> <1556@hammer.UUCP> <1431@teddy.UUCP>
Reply-To: seifert@hammer.UUCP (Snoopy)
Distribution: na
Organization: The Daisy Hill Puppy Farm
Lines: 52
Xref: tektronix net.audio:06559 
Summary: 

In article <1431@teddy.UUCP> rdp@teddy.UUCP (Richard D. Pierce) writes:

> [RDP has built subwoofers] that were measured, anechoically, at being
> -3 db at 25 Hz.

>At the risk of resurrecting the Pierce/Grantges debate again, I should
>point out that very little energy of consequence comes out of organs
>at the fundamental, the vast majority (in the case of pedal reeds and
>open principals, upwards of 80%) of the energy is distributed amongst
>the harmonics.

And early transister amplifiers measure just as good as the tube ones,
and early CD players measure better than LP players.  Sure, a
subwoofer that extends down to 25 Hz will be an improvement over
the 35 Hz of the 'main' speakers, but if I were going to all the
time/expense/bother of buying/building a subwoofer, I would want
it to go to AT LEAST 20 Hz, preferably 16Hz.  Audio is full of
examples of "good enough" not really being good enough.

>>  You can go to larger
>>drivers, but transient response will probably suffer.  
>
>If the crossover limits the high-end cut-off to something like 200Hz,
>and any loudspeaker system can get up at least that far reasonably, 
>transient response will suffer only because of the crossover (neglecting
>the fact that the lower cutoff also affects it as well). 

Perhaps I am using the wrong term?  A larger driver will have more
mass (other things being equal), and will be more sluggish getting
started and stopped.  I suspect that several 10-12" drivers would
sound better than a single large one (18-24-40") for this reason.

>Well, let's note that the poster lives in a small dog house, so bass
>really isn't an issue :-)

Perhaps you have forgotten that the visible doghouse is merely a shelter
for the entrance to the underground mansion.  :-)

>Here is an aside that may be of interest to you sub-woofer enthusiasts.

> [ bit about woofer being mounted in the wrong plane ]

Agreed.  That's probably a significant part of the problem.

Picked up a copy of the October Audio yesterday.  Not that many
systems actually go down to 20Hz or below.  Looks like it would
take $1-1.5k to get something reasonable.  Not including the
fork-lift truck to move it.  Which is really the main reason
I haven't gotten one yet.  I'm still moving much too often.  <grumble>

Snoopy
tektronix!tekecs!doghouse.TEK!snoopy