On Mon, Dec 31, 2012 at 3:17 PM, Neil <djdualcore(a)gmail.com> wrote:
On Mon, Dec 31, 2012 at 2:57 PM, Charles Henry
<czhenry(a)gmail.com> wrote:
At the ends of the frequency range, the group
delay becomes significant
and
shifts some components of the signal more than
others.
So, the wider the band, the less likely you are to hear the shifted
parts of the signal?
Yes, in general.
In the case we're describing, the top end of the passband is outside the
range of hearing. The phase shifts might still be audible at the low end
of the transducer's range.
However, phase shifts aren't much of a problem by themselves--they're all
over the place in any typical multi-driver system and placement in the room
matters just as much. The loudspeaker crossover introduces the same effect.
Subwoofers are much more prone to phase shift problems. You notice it a
lot when the bass seems to lag behind the beat--and this results from not
having a continuous frequency response that goes down to 0 Hz (the ideal
case) or bad resonance characteristics.
Really clean sounds have a lot to do with the tightness of the temporal
response--but there are of course tradeoffs in any kind of design choice
like these.
Chuck