νομίζω το βρήκα....
είναι στα facts....
HERESY No. 7
There is positive phase and negative phase in music.
This is really stupid heresy. I cant understand why 99 % of people believe it.
The usual test is like this: take a 1.5 V aa cell, apply it to speaker terminals - if the cone moves outward - your speaker produces true positive impulse. Otherwise it is phase reversed and signal is not true because if a drum beats - the speaker cone "sucks in".
WELL, NOT TRUE.
First, lets deal with the driver movement vs. absolute phase of signal. Why moving from idle position towards listener should be "positive" ??? The musical signal is a mix of sine waves. Sine has no beginning and no end. It is infinite and continuous. Low pressure and high pressure of air happen in cycles, no cycle is preferred versus the "negative one". A 1 kHz sound is a low followed by high air pressure followed by low etc. 1 000 times per second. Does not matter which was "first" because we can't discern between the two. Our ear drum being pushed inside our head is no more real sound than our ear drum being sucked outside.
Now lets think of musical instruments. The DRUM (easy to imagine). If the drum kit has the main foot-drum on the floor, is the HIT on it producing positive wave??? How? The hammer (sorry I don't know the vocabulary) hits the drum on the drummer side, hence producing INWARD flexing of the drum skin. This is heard outside in the room as BOOM. Positive or negative? See? And this usually feeds the pressure inside the drum. There is a mike inside this drum. It reads the high pressure by flexing the mike membrane to the left. Or Right. Or In. Or .. Or ... ??? And the electrical signal goes to preamp, console, A/D converter. Is it still positive or negative?
And what if the drumskin is parallel to the floor, like in congas? Is downward hit positive, or upward?
And what if this is a cymbal? Is a flat cymbal hit by the drumstick producing positive or negative impulse??? Anybody answer?
And how about the bass string being plucked? Is positive from left to right or the opposite?
This is truly a stupid divagation. Positive and negative speaker wiring are equal and it is a waste of time using your remote on that Wadia of yours to switch the absolute phase and argue which is more true.
And what if a Jazz ensemble has 5 musicians, all miked in a different way? And what if music is SAMPLED from 10 records by a deejay? Which part of the signal is positive and which negative?
με λίγα λόγια μας λέει ότι δεν υπάρχει φάση και ότι η φάση είναι αδιάφορη....
μας λέει ότι αν κάτι το χτυπήσουμε από δεξιά ο ήχος θα πάει προς τα αριστερά..Αρα? πως έρχεται σε μας?
σε φάση η εκτός φάσης?
με λίγα λογια όλη η θεωρία περι διάδοσης κυμάτων πάει περίπατο ?
