john@mddc.UUCP (John Pletikapich) (12/27/83)
I was reading in an audio magazine about the Hafler circuit. A third
speaker placed behind the listener connected to both positive terminals
of the amp creating a "spatial, airy effect".
What I did was run a wire from the + connecter on speaker A to speaker
X- and another wire from the + connecter on speaker B to speaker X+.
Right now I do get some sound from speaker X but it is very faint -
inaudible in comparison to the main speaker pair. (It's not the speaker,
I tried some car speakers in its place.)
Does anybody have any ideas ? I don't know what I'm doing - is my house
gonna catch on fire ?
thanks in advance,
john
...{decvax, ihnp4 + others}!cbosgd!qusavx!mddc!johnspoo@utcsrgv.UUCP (Suk Lee) (12/29/83)
You have the Hafler circuit set up
properly. The sound is faint for
two reasons: the amount of out-of-phase
information is less than
the amount of in-phase,
so the third speaker
(which is playing out-of-
phase stuff) is quieter
and
your third speaker could
be less efficient than
your main speakers.
However, it's not too important that
the third speaker is quiet. The way
to adjust the Hafler circuit is to
wire an "L-pad" in series with the
third speaker (so that you can adjust
the volume), and decrease the volume,
with the main speakers playing,
*JUST* until you can't hear it from
your usual listening position. You
may find that the Hafler circuit
doesn't seem to do anything when you
set it up this way, but try disconnecting
it while the music is playing: the
sound field "collapses" back to
ordinary stereo.
Concerning safety: as long as the third
speaker isn't of terrifically low
impedance, everything should be okay.
Good listening.
From the pooped paws of:
Suk Lee
..!{decvax,linus,allegra}!utzoo!utcsrgv!spoordg@hpcnoa.UUCP (01/02/84)
#R:mddc:-29500:hpcnoa:30200006:000:880
hpcnoa!rdg Dec 30 11:22:00 1983
I used the Hafler circuit in my system for about 6 months.
It does not do any harm to your system, except if you have
a certain kind of amp: I forget what the complaint was, but
it was in an article in Stereo Review and Audio somewhere around
the summer of '82.
It does make a difference, a noticeable improvement, especially
for ambience and showing up sounds you didn't know were there.
I stopped using it when I bought new speakers though; I found
that having the extra 'hafler' speaker also caused degradation
of imaging, not to mention more noise - yes! some of those sounds
you weren't hearing before are noise! The new speakers reproduced
ambience and detail better than the hafler circiut could with
the old speakers.
So, try it out, and decide whether or not you like the effects.
It is quite interesting, I do admit.
Rob Gardner
{hpfcla,hp-pcd,csu-cs}!hpcnoa!rdg