610 Stereo versus mono; etc.
Date: Wed, 12 Jun 2002 16:15:42 -0500
From: "Frank G. Williams" <frankw@MAIL.AHC.UMN.EDU>
Subject: Re: Stereo versus mono; etc.
Dave and Friends,
> A couple local people have stated that stereo is not good for
> a dance setting, as the audio interference patterns can cause
> a bad sound. This makes sense from the laws of physics, as
> when one is not in the dead center, there will be interference
> patterns which are frequency dependent.
In your home, your car, your dance hall... anywhere there is
a source of sound and also a surface that can reflect that
sound, you have the potential for interference. The reflected
sound arrives at your ear later than the direct radiations, and
depending on the frequency, can either cancel the wave (softer)
or reinforce the wave (louder) or degrade the apparent sound.
As somebody who designs and builds his own home hi-fi equipment,
let me comment further on the issue of acoustics that Dave raised.
The issue of stereo in a dance hall is complicated, but no more
so than getting good stereo in your home. Much depends on speaker
placement, sound dispersion and the particular difficulties
posed by reflections in the room itself. There are no rules that
apply universally. The original purpose of stereo was to add a
sense of location and enhance the apparent 'reality' of music
reproduction - to re-create the effects of each musician needing
his/her own space in which to play. Maximizing the peceptual
effects of that additional channel of information requires that
you be the same distance from each sound source. When you're
dancing, of course, that is usually not the case. But usually
there is lots of reflected sound that also degrades the sonic
clarity of the original signal. The job of the 'sound-guy' is
to minimize the negative impact of several competing forms of
distortion. It's all a juggling act - you can never attain
anywhere near the sound quality you can get with earphones.
My preferred 'stereo' setup: A) position the speakers at opposite
sides of the floor so that they face each other, B) blend the signal
for each channel so that is is about 50% 'mono' and about 50%
'stereo', C) use the graphic equalizer to knock down any
frequencies that are harsh. I use both a frequency sweep test disc
and music for the testing source...
One eventually realizes that each of us derives the
feelings of the music in different ways. Some people don't
care much about fidelity (gasp!). Some people hate artifacts
like clicks and pops, but other issues of sonic realism aren't
so important. I have played with noise reduction algorithms
enough to know that 'noise reduction' really means 'music
reduction'. The old microphones gave precious little resolution.
There is very little 'headroom' for separating music from noise.
The oldies can be improved, but only up to a point. Removing
ALL the noise will render some of the instruments almost
unrecognizable.
Re: Steve's comment about re-synthesizing the music with much more
resolution... lovely in theory. However, anybody who has tried
to add 'live realism' to a MIDI file knows how labor intensive
that is, and tango musicians have SO MANY 'tricks' for manipulating
the sound of their instruments! I'm not holding my breath that
we'll ever experience the original dynamics of Troilo and his
contemporaries. It must have been breathtaking! Yet, if you
ignore the lack of realism in some of the old music - just let
it wash over you as best you can - I hope you notice some pretty
compelling feelings!
Those feelings, IMHO, are the 'real' reason to listen and dance.
Frank in Minneapolis
...who needs to remodel just to make the stereo sound better!
Frank G. Williams, Ph.D. University of Minnesota
frankw@mail.ahc.umn.edu Dept. of Neuroscience
(612) 625-6441 (office) 321 Church Street SE
(612) 624-4436 (lab) Minneapolis, MN 55455
(612) 281-3860 (cellular/home)
Date: Wed, 12 Jun 2002 16:48:20 -0500
From: Stephen Brown <Stephen.P.Brown@DAL.FRB.ORG>
Subject: Re: Stereo versus mono; etc.
Frank Williams wrote:
>Yet, if you ignore the lack of realism in some of the
>old music - just let it wash over you as best you can
>- I hope you notice some pretty compelling feelings!
>Those feelings, IMHO, are the 'real' reason to listen and dance.
I agree completely with Frank's comments about why we use older recordings
at milongas. The sonic qualities may be inferior, but we find the classic
performances to be more compelling than the more recent recordings.
Why? We find the music more emotionally satisfying.
Let me offer a non-tango example: I listen to Miles Davis, Kind of Blue
and Billie Holiday, Solitude much more than I ever listen to the audiophile
recordings of the Paul Desmond Project (which does not include Paul
Desmond) because I find the musical content is greater.
The same is true for tango...
The number of tango recordings made during the golden era was much greater
than those made during the past 20 years.
To give you some numbers, Rodolfo Biagi had more than 100 recordings;
Carlos DiSarli had over 300 recordings; Juan D'Arienzo had nearly 1000
recordings.
When one has so much material to cull through, one is more likely to find
great music.
In addition, through the influence of some of the great tango musicians,
such as Astor Piazzolla and Horacio Salgan, tango music took a turn away
from a dance sound toward a concert sound. Most of today's contemporary
orchestras continue to play on the same sound pallette that was developed
in the concert era. Stage dancers have adapted to this style of playing by
emphasizing drama in their dancing over connection.
Frank also wrote:
>Re: Steve's comment about re-synthesizing the music with much more
>resolution... lovely in theory. ... I'm not holding my breath that
>we'll ever experience the original dynamics of Troilo and his
>contemporaries.
I would not hold my breath either. In fact, I was not trying to claim that
one could use today's technology to achieve a reconstruction of the music
from the golden age through the synethizing strategy. Rather, I was trying
to emphasize how far we were from restoring live sound from vintage
recordings. Frank is clarifying my point.
With best regards,
Steve
Stephen Brown
Tango Argentino de Tejas
https://www.tejastango.com/
Date: Wed, 12 Jun 2002 16:36:11 -0400
From: Tanguero Chino <tanguerochino@NETSCAPE.NET>
Subject: Re: Stereo versus mono
Dave Schmitz <dschmitz@MAGELLAN.TEQ.STORTEK.COM> wrote:
>A couple local people have stated that stereo is not good for
>a dance setting, as the audio interference patterns can cause
>a bad sound. This makes sense from the laws of physics, as
>when one is not in the dead center, there will be interference
>patterns which are frequency dependent.
There will be dead spots whether it is stereo or mono. The dead spots occur when two wave patterns of the same frequency but opposit amplitute meets at the same spot. So, theoretically, there will be more dead spots if you play in mono, since both speakers will be generating the same sound at the same time. Whereas playing in stereo will reduce the number of dead spots since there are different sounds coming from the different speakers.
However, none of the above is important in a milonga. The sound frequency keeps changing (thus we have music), and people's position keeps changing (caused mostly by dancing).
The stereo vs mono debate is still interesting for the milonga though. Depending on speaker placement and the recording quality, sound quality in one part of the dance floor may be quite different than other parts.
From my personal experience though, I can't say I have a really high demand for sound quality when I go to a milonga. I do notice when the volume is cranked right up and the amp/speaker combo starts distorting the sound. I notice when the speakers are placed low, and I have to pass right in front of them when dancing. Otherwise, as long as the sound is evenly distributed over the dance floor, and the music selection is right for my mood of the night, I'm happy.
Good sounding tangos to all.
T.C.
Date: Sat, 15 Jun 2002 12:40:49 -0700
From: Robert Hauk <robhauk@TELEPORT.COM>
Subject: Re: Stereo versus mono
Hello everyone,
There is one detail in the stereo vs. mono debate that many people may
be unaware of. To make a pseudo stereo sound from an originally mono
recording it seems that it is common to send more bass to one channel,
and more treble to the other. The overall effect is a 'separation' of
the instruments in the different sound ranges.
We had some trouble with the speakers at the venue for our Monday night
milonga, and I couldn't seem to get the system to sound good no matter
what I did with the tone controls. Finally I realized that one of the
suspended speakers was not working, it happened to be on the channel
that had more treble. When I set the system up to play mono the sound
improved dramatically. I always run the system in mono now and even
though the speaker is fixed and working I find the sound more consistant
in the room because the two overhead speakers are putting out the same
thing. The system has two large cabinets on the floor with big bass
speakers. If the system is in stereo, these big bass speakers overpower
the one overhead speaker that has most of the treble.
The best sounding setup I have worked with has four speakers, one in
each corner of the room, and you guessed it, the system is run in mono.
Each speaker puts out the same sound, and none have to be too loud. The
overall sound level in the room is good for dancing and the sound is not
overly loud near any of the speakers. Moving around the room I rarely
hear any interferance effects between the speakers. There are so many
reflections in the room that most of the interference pattern one would
expect is gone.
I am constantly surprised when people complain about the sound in a room
when they are sitting between big bass speakers. When the speakers are
at one end of a room the sound quality can vary dramatically from place
to place in the room, and is often not pleasant right up near the
speakers. The DJ booth is often completely across the room from the
speakers so it is natural that the DJ might adjust the sound system to
sound good from the booth. It is hard to keep up with the changes in
the room as it fills with people, completely changing the sound
reflectivity of the floor area.
In all of this debate I completely agree that one should try to use the
best sound system possible to make the music sound good. Unfortunately
we usually deal with sound systems that are compromises. The kind of
system required for DJs is very different from that needed for live
bands. When you use a venue you get what you get.
More good sounding tangos to all,
Robert
