[Audio Empire]

On Tue, 29 Nov 2011 15:27:46 -0800, Arny Krueger wrote
(in article ):

"Audio Empire" wrote in message
...

What I have found is that two subs are always better than one,
however.

I would trot out a little logic of rhetoric and point out that
any such global statement is more than a little suspect.

Perhaps I should have stated it as this is what *I* have found to be
the case....

I've heard two subs sound worse than one, and I've hard more than
a few cases where two subs and one sub sounded different, but could
find no preference for either.

........ and that's how you have found it.

I know that the conventional wisdom has it that a single sub,
with all of the system bass below about 200 Hz or so summed to
one channel, is sufficient because low frequencies are
non-directional,

That's way off, because it is well known that subs crossed over
much above 85 Hz can generally be located in the room.

I never believed it was fact even though I have read it often enough!
The fact that it doesn't seem to be true was my main reason for
bringing it up.

I have tried my two subs in all possible combinations: both subs
summed as one, one-channel (first the left, then the right)
operating only, and stereo bass. Stereo bass ALWAYS sounds
better in my listening room whether I'm using one of my woofers
monaurally or both of them monaurally.

Well, if you are crossing them over at 200 Hz, no mystery.

Where did I say that I was doing that? I merely stated that
conventional wisdom is that frequencies BELOW about 200 Hz are said to
be non-directional.


Come back after a
few weeks of listening with them crossed over at say 50 Hz.

Been there, done that. My crossover point between my main speakers
and my subs is chosen by a DSP program that has me using a microphone
placed at various points in the room while the system plays
calibration tones through both my main speakers and my subs. The
crossover frequency and the turnover and slope are chosen by the
computer. I suspect that it's somewhere around 80 Hz. THis system not
only optimizes the crossover between sub and main speakers but it also
(supposedly) contours both to the room (at my listening position).

It's weightier (as one might expect) and is more articulate and
more spacious. I have also noted that even though most of the
imaging cues for bass instruments originate in the bass
instruments' upper harmonics, that having the lower fundamentals
originate on the same side of the soundstage as the harmonics does
help with low-frequency placement.

Again, an obvious artifact of what seem to me to be very strange
choices of crossover frequencies.

Again, I never said that my crossover frequency was 200 Hz. You're
jumping to conclusions.

I've long had subwoofer crossovers that allowed me to move the
crossover point around, and speakers that allowed me to do so
without creating obvious artifacts. No surprise - moving crossover
frequencies down and using the right slopes make most of the
obvious artifacts go away. I would say that everything listed in
the paragraph above namely

"...more articulate and more spacious. I have also noted that
even though most of the imaging cues for bass instruments
originate in the bass instruments' upper harmonics, that having the
lower fundamentals originate on the same side of the soundstage
as the harmonics does help with low-frequency placement."

are easily dismissed as being artifacts of suboptimal choices.

Nobody has made a "suboptimal choice", here. Perhaps you
misunderstood my argument?

It seems to me that if the bass viols, for instance, are on the
right side of the orchestra (standard practice) and the harmonics
for those instruments originate in the right channel while the
fundamentals originate summed in the left channel, this cannot help
but confuse the image somewhat.

Again, something that looks very much like an artifact of
suboptimal choices
of crossover frequencies.

Again, your conclusions are not supported by the facts. Actually your
conclusions seem to based solely upon your misunderstanding that:
1) I believe the oft stated "wisdom" that frequencies below 200 Hz
are non-directional, and 2) your incorrect assumption that I am using
200 Hz as the crossover point between my main speakers and my
subwoofers. Since neither supposition on your part is true, then your
conclusions are likewise in error.

The viol WILL be more solidly anchored on stage right if BOTH the
fundamentals and the harmonics emanate from stage right.

Which is possible with appropriate choices of speakers, crossover
points, and crossover slopes.

I suspect the notion that summed bass is acceptable comes from the
old stereo LP practice of summing all of a recording's bass to the
left (lateral) groove wall in order to make a mono-compatible stereo
LP.

Because of the well-known bass dynamic range issues that are
inherent in the LP, the effective crossover points for bass summing
were generally too high. Besidies the amazing amounts of audible
jitter, the vinylphile acceptance of the audible problems
associated with bass summing at too high of frequencies raises a
lot of questions in my mind.

The wisdom here was that if bass, with it's large groove
excursions were kept out of the vertical component, then a
stereo record could be traced with a mono cartridge without
harming the record.

Only part of the story. It's no secret that vertical tracking was
a far tougher nut to crack than horizontal tracking. After all, you
can wiggle the stylus back and forth quite a bit, but if you try
to move it up and down too much, you either punch a hole in the
disc or send the cutting edge flying into the air. In one case
you tear the stylus off of the cartridge, and in the other you
have nasty clipping.

While what you say is certainly true, it is irrelevant to the point
of my comment which merely addressed the fact that for many years
during the LP era, audio types were told that a single sub, on the
left channel only, was sufficient because low bass was non-directional
and that LPs were cut with all bass summed to the left.

This allowed the record companies from the early 60's
forward, to eliminate the hated "double inventory".

Only part of the story.

Perhaps, but it is THE only part of the "story" that I'm addressing
here.

While cheap mono phongraphs continued to be sold
during the stereo era, the cartrdige manufactuers started building
mono cartrdiges with vertical compliance.

Again, while you are correct, it is, once more, a point irrelevant
to this discussion.

I know that record companies did this for years.

But the reason was a desire for trackability and low distortion,
not mono compatibility.

While improved trackability was likely a welcome side benefit, the
desire to stop pressing dual-inventory WAS, without question, the
overriding business reason for the move. Think about how many
millions the record companies saved by eliminating the need to have
TWO different versions of every record title produced on sale at the
same time!

What I do not know is whether this practice continued into the
CD era.

I'm sure that many mastering engineers knew that they could often
clean up messy bass with a little LF mono summing. If it works, it
has far less adverse audible effects than simply rolling off both
channels in the bass.

And I'm sure that many early CDs were mastered from analog and digital
tapes originally mixed for LP cutting and therefore had the bass
summed to the left channel for that reason. But that's not to what I
was referring. I meant was bass summing a practice that continued even
after LP stopped being a major part of commercial recording?

They may have kept the practice because so many
systems are set-up with subwoofers connected only to the left
channel because it was "traditional" to do so.

Never heard of such a thing.

Oh, well, that answers it. If you haven't heard of it, then there's no
chance that such a thing was ever even considered. 8^)