The Meaning of Stereo

[EdGambill]

Tell us in easy to understand language what Stereophonic Sound is and isn't. There seems to be so discourse in another thread on this topic. Explain it like you did Dithering. What a succinct yet articulate explanation. I would try to explane it but it would take half a page.

[Colin Campbell]

Hmmmmmm.... stereo. Seems so simple to me. We have two ears. So when we listen to live music we place different instruments to a certain location accross a "field" in front of us. Our ears have the unique ability to determine the location of a sound by calculating the trajectory of the sound waves as they arrive at our ears. That's why we turn our head toward a sound when we want to hear it better.

So, instead of one microphone (mono) we use two to emulate our two human ears. Then when we listen back we have the same ability to detect the location of instruments or sounds. Now, in modern production this effect of left and right is exploited for effect more than reality. As in old Beatles records where the guitar may be only in one channel. It's not realistic, it's artistic.

Straight voice is inherently mono since we only use one mouth and one mic. We could however add effect to the mono voice track making it stereo in post production by duplicating the track into two channels and delaying one slightly or equalizing it differently in the left and right channel but it always starts out mono.

I suppose it would be fun if we had the time and money to use two microphones for voice and record in stereo. You could do this to add a sense of movement as in walking accross a room but it's much cheaper and easier to do this effect in post production.

[EdGambill]

I thought that was what you would say. So two spaces transducers to pick up the sound to be recorded, then played back on speakers spaced to approcomate the sound field and image we seek.

Mono then is Mono and Stereo is a two eared thing and pseduo sterep is just fakery. I was reading what Jacob E was pointing out about Sterophonic sound in another thread and just want to be sure that what he said was spot on.

[Colin Campbell]

A neat effect is when you have two voices talking to each other. Pan one left about 25% and the other right 25%. Just enough to give the illusion that the two people are in a room conversing. You don't want to pan too much and certainly not all the way. Somone, somewhere will be listening to only one channel or have their balance off and you could "lose" a voice but if you just pan slightly it makes for a neat "realism."

Sometimes in a department store I'll hear an old song I know well and notice some of the instruments are missing. Back in the day they used to use stereo as an effect way too much and when you hear only one of the channels, part of the music dissappears.

[JoeActor]

Ah, but what about "Holophonic" sound?

Below is a 5 minute sample from an old demo cd.

Use your headphones, and close your eyes... Astounding!

How's it done?,
Joe J Thomas
www.JoeActor.com

[Julie Williams]

I've actually used the effect of duplicating my voice on two mono tracks and ever so slightly nudging one track... Sounds very... outer space.

The two mikes on one mouth, Colin, I'm assuming was a joke? Wouldn't there be phase cancellation there?

[Colin Campbell]

Originally Posted by Julie Williams

I've actually used the effect of duplicating my voice on two mono tracks and ever so slightly nudging one track... Sounds very... outer space.

The two mikes on one mouth, Colin, I'm assuming was a joke? Wouldn't there be phase cancellation there?

There could be. I was just illustrating a point.

Now, if you want me to get into phase cancellation, I'll have to come back at another time when my brain is sharper.

[Colin Campbell]

Originally Posted by Colin Campbell

There could be. I was just illustrating a point.

Now, if you want me to get into phase cancellation, I'll have to come back at another time when my brain is sharper.

A lot of times when two mics are used in the same room (usually for two voices) they will reverse the phase (polarity) of one of the mics so that noise present at both is cancelled. This cuts down on one mic picking up the other voice creating an echo effect. It's not done often but was an old trick. Most good preamps have a phase reversal switch for this purpose.

[ChrisMezzolesta]

There is also a difference between stereo and binaural, which is basically dual mono and not quite the same as stereo. The 3D field and location/depth perception is what makes it stereo, just like the Viewmasters and old stereopticons let people see things in 3D, it created a perceived 3rd dimension. Sennheiser and perhaps others used to make dummy heads with small mic elements in the ears to simulate binaural human hearing for various recordings (one place it was used was on Godley & Creme's concept album from 1977 CONSEQUENCES, one section is a rainy burial scene which is heard as if inside the coffin, they shoveled gravel down a stairway onto a board held in front of the Sennheiser head.)

For the voices in different speakers angle, check out some of Peter Seller's records from the late 50s to mid 60s (including his hilarious versions of Beatles tunes), George Martin used that very idea to put one character hard left, one at 50% left, etc. so Sellers could play multiple parts and appear to have them all over the room. And this is with mono and 2-track tape recorders no less! Lots of pre-planning.

Still a bit more offtopic, but to address a point made, the Beatles mixes were hard stereo simply because George Martin used the 2-track deck as a multitrack - recording band on one and elements like vocals or lead guitars, on the other. They were meant to be mixed to mono, but EMI followed a Beatles mandate that they should not mess with the tapes, and reissue them as-is - - meaning what was issued was the hard-stereo between band and vocals etc...Incorrect, but that's what happened.

Now back to the VO forum...

[Colin Campbell]

That is fascinating about the Beatles! I never knew that.

So how exactly does "binaural" differ from stereo? Just that in "binaural" there is no relationship between the two channels?

(..and I'm supposed to be answering questions, not asking.)