Re: [ARSCLIST] Absolute Polarity

[Clark Johnsen <clarkjohnsen@xxxxxxxxx>]

On Mon, Oct 20, 2008 at 3:29 PM, Lou Judson <inaudio@xxxxxxxxx> wrote:

> Richard, are you talking about recorded sounds or a comparison with the
> abslute polarity heard in the room with the instrument?


Isn't it a combination? The sound from the speaker(s) must be in the same
polarity as in the room.

>
>
> Think of the sond emanating from the bottom of a piano, and how it affects
> the listener in the same room (and what if it were recorded with mics
> underneath - then which polarity should it have "on tape?" Or snare,
> tympani, literally every percussion instrument? - how much sound comes from
> the bottom?


Generally speaking, the recordist will try to capture the same sound the
audience would hear. The further the mic is from the instrument, the more
its characteristic polarity will be captured. (Up to a point, of course.)

>
>
> Just thoughts on the topic. Makes me smile and think of the French horn.
> Would its attack be positive or negative, since it faces away from the
> audience?


Either way!

>
>
> And contrary to everything Mr Johnson says, every engineer I personally
> know (except two I shall not name) has been well taught the issues and best
> practices for polarity in recording.


Mr. Johnsen sez: Then you might think the matter has been settled. But LPs,
CDs etc. still come with split polarities. So, no. No cigar.


> Myself, I discovered the effects when about ten when putting a finger
> lightly on a woofer cones while listening intensely to a bass. My
> professional education reinforced what was personally observed.


Good story.

>
>
> I am one of those persons whose eyes tear up when presented with out of
> phase stereo speakers.


That of course is a different matter.


> I have been astounded to walk in a room and hear the effect of out of
> polarity speakers being used in "professional" situations, even home
> systems.


Now I'm confused. Do you mean phase or polarity here? If the former, then a
simple switch of one will rectify the situation. If the latter, then the
speakers (or something) must be switched to accommodate variant source
material.


> Maybe some people cannot hear it. Seems like being colorblind to me.


Indeed. For myself, both "phase" and "polarity" are part of sound color.

clark

>
>
> <L>
>
> On Oct 19, 2008, at 12:08 PM, Richard L. Hess wrote:
>
> Here is a start of what the useful list might look like with some of my
> guesses
>
> Piano - compression attack (i.e. positive-going peak)
> Saxophone - compression attack
> Snare - compression attack
> Tympani - rarefaction attack
>
> Are these correct in your experience and what others would you care to
> share?
>