Don Cox:

> In principle, mixing the channels should reduce
> the noise by about one decibel (the noise in stereo
> will be 1.414 times the noise in mono), but the
> disadvantage of losing spatial separation makes
> this hardly worth while.

1.414 is in fact 3 dB less noise in mono.

I fail to see how there can be "Spatial separation" if a mono signal is
being reproduced in "Stereo".

Due to the HAAS effect it becomes almost impossible to get a stable centre
signal unless you set your head in a vice in the exact centre between the

Moving slightly off centre collapses the sound in either the left or the
right speaker due to the precedence effect, HAAS.

There IS a reason why Bell Labs thought that one should use minimum three
channels, left, center, right, when reproducing sound. This assures that
centre sounds will always appear to come from the center even if sitting off

This is still the practice in film reproduction where the dialogue normally
always come from the centre speaker.

In fact a mono signal should only be listened through one speaker the way it
was recorded to correctly reproduce it as originally intended.

> Since I first bought a stereo record player, I have
> always listened to mono records in stereo. There never
> seemed to be any improvement in the sound when the
> channels are mixed.

I can clearly hear that the amount of distortion, pinch effect, is much less
in mono compared to "Stereo" also the amount of disk rumble gets
significantly less as the vertical component disappears, where most of the
rumble is, entirely when listening in mono.

I think that "Improvement" is an entirely subjective comment as the theory
and my own listening impression entirely prefers mono for mono recordings
and any "Stereo" or two speaker sound reproduction from mono disk records
sounds wrong to me.


Best regards,

Goran Finnberg
The Mastering Room AB

E-mail: [log in to unmask]

Learn from the mistakes of others, you can never live long enough to
make them all yourself.    -   John Luther