anybody-but-bush wrote:

"Paul Harris" wrote in message
:
: and one reply was:
:
: "uhh man... thats bad... it does matter whith one!
: your way you could get speakers in phase but running other way around
: (plus to minus) so instead speaker blowing out like this: - D it would
: go like this: - D.
: you probably would notice it as it would produce distortion on high volume.

An age old fuel source for flame wars.
1) the recorded signals of musical instruments,etc are not symmetrical.(fact)
2) some people claim to be able to tell which is true to the source and vice verse.
3) some people claim not to be able to tell is was is true to the source and vice verse.
4) multitracked recordings where a source sound is picked up by more than one mic obscure this
phenomenon .

Thanks to everyone who has shed light on this and apologies for fanning
old flames.

I had not considered symmetry. The "distortion on high volume" got me
wondering if there are speakers that oscillate around a voltage other
than zero i.e. the natural rest position on the cone is different from
the powered but silent position in which case when switched on, the cone
would be seen to jump forward (or back) and hold due to a non-zero
voltage being applied.

Since nobody has mentioned this, I guess there would be no advantage in
such a design - there is no need to "park" a speaker when powered off
like a hard disk drive head.