09-25-2018, 08:05 PM
I'm referring to polarity, i.e., turning the waveform into its mirror image wrt. the time axis. The original wave form and the inverted one would sum to zero, which need not be the case for a phase shift of 180 degrees.
The only way to determine the correct polarity is to listen to both variants, and for this purpose a direct switch would be most helpful (instead of having to reverse the plugs in both speakers).
More concretely, when say a base drum is hit, the loudspeaker cone initially is supposed to move outward. In case of reversed polarity it will move inward instead. Due to the way sound is perceived in the human ear, the difference is audible.
Of course, when a music piece is mixed from several tracks, these may already display different absolute polarities, so for the end result it may be difficult to say which one is the right one. Also, cross-overs in 2- or 3-way speakers can interfere by reversing polarity in some frequency ranges but not in others. Nevertheless, when somebody is singing, one polarity setting should enable the listener to better localize the singer on the sound stage.
[For some recordings it is also beneficial to adjust the phase of one channel separately. Between 1968 and 1970 a number of albums were mastered using the HAECO technique, which allowed to produce a decent mono record from a stereo mix by just combining the two stereo channels. By phase-shifting the right channel by 90 degrees, the components present in both channels are not amplified unduly, however the quality of the stereo mix is diminished. Cream's "Wheels Of Fire" was a prominent victim of this technique, other albums can be found on the net. Fortunately, this effect can largely be reversed with suitable software, and there is no real need to have this available during regular playback.]
-- Jürgen
The only way to determine the correct polarity is to listen to both variants, and for this purpose a direct switch would be most helpful (instead of having to reverse the plugs in both speakers).
More concretely, when say a base drum is hit, the loudspeaker cone initially is supposed to move outward. In case of reversed polarity it will move inward instead. Due to the way sound is perceived in the human ear, the difference is audible.
Of course, when a music piece is mixed from several tracks, these may already display different absolute polarities, so for the end result it may be difficult to say which one is the right one. Also, cross-overs in 2- or 3-way speakers can interfere by reversing polarity in some frequency ranges but not in others. Nevertheless, when somebody is singing, one polarity setting should enable the listener to better localize the singer on the sound stage.
[For some recordings it is also beneficial to adjust the phase of one channel separately. Between 1968 and 1970 a number of albums were mastered using the HAECO technique, which allowed to produce a decent mono record from a stereo mix by just combining the two stereo channels. By phase-shifting the right channel by 90 degrees, the components present in both channels are not amplified unduly, however the quality of the stereo mix is diminished. Cream's "Wheels Of Fire" was a prominent victim of this technique, other albums can be found on the net. Fortunately, this effect can largely be reversed with suitable software, and there is no real need to have this available during regular playback.]
-- Jürgen
(09-24-2018, 11:28 PM)Tim Curtis Wrote: Are you referring to polarity or phase, and how is it possible to know which one or if both were used, or neither were used in the mix/mastering of a recording?
https://www.justmastering.com/article-ph...larity.php
-Tim
