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What is Phase Angle and Shifting?

A number of threads make reference to phase angle and time domain. I've seen these terms mentioned before in the context of speaker reviews. In addition, and I don't know if this point touches on the question I just raised, but one of the positive attributes associated with Vandersteen speakers is that the various drivers are time and phase coherent. Because I am not an electrical engineer, I would appeciate it if one or both would kindly provide an explanation of these concepts that a layperson could understand.

On an intuitive basis, it seems that a speaker system with various drivers should be designed in such a way that the crossover does not change the time relationship between the various drivers. Or stated differently, the drivers should work in such a way that electrical signal fed to each driver should reach that driver at the right time so as not to change the overall harmonic structure of the sound emited by the drivers as compared to the harmonic structure of the analogue signal fed into the speaker.

Thanks
bifwynne
elizabeth
6,726 posts
 
Can' O Worms!!! man is it ever.
Well the probelm is the basic devices used change the phase. It cannot be avoided. It can be softened, or reduced a bit with some ingenious methods, but basically is is unavoidable.
A Capacitor will change the phase and is also frequency dependent. that is the different frequencies are change at different rates. It is a giant mess.
Amazing anything resembling music comes out the end.
Nearly all circuits have these problems.

The phase is the direction. (in a simple way) so when the waveform is all (for example) positive, like a loud noise. well the lower frequencies in the waveform will be slower, or the 'phase' changed due to wires, capacitors etc, in relation to the higer parts of the noise.
So when it comes out the speaker it is no longer one big perfect (same) noise. The phase has changed it and distorted it. And we can hear it.
All this stuff is a science and an art for a reason.
bombaywalla's avatar
bombaywalla
1,957 posts
 
Bifwynne, I posted my response in the other thread where you asked the question 1st but I'll post it here again:

>http://forum.audiogon.com/cgi-bin/fr.pl?fcabl&1310053833&openflup&20&4#20
ngjockey
1,042 posts
 
Not just the crossovers. the voice coils and construction of drivers have inductance that affect phase. I was building Bessel filters 30 years ago because of group delay characteristics. Then, there's impulse response ...

Huge, complex topic. Sometimes fairly bleeding edge stuff, especially in digital. Lots of opinion about what we can hear and how we hear it. Even the instruments to detect time domain differences to smaller scales are being developed.

I get a little upset when I read "time and phase aligned" as promotional and restated as dogma. Not that I disagree with the principle, the effort and, sometimes, the results. Narrow viewpoint.
mrtennis
3,295 posts
 
do panel speakers have less problems in phase distortion than cone designs ?
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