These filters have a relatively low “Q” thus preventing “ringing”. Ringing occurs when a filter instantaneous- ly receives an input signal and hangs on to the signal for a period of time after it has stopped (see Figure 2 below).
Figure 2: Q vs. Ringing:
1kHz TONE BURST
INPUT SIGNAL
START
1kHz TONE BURST
INPUT SIGNAL
START
INPUT SIGNAL
STOP
INPUT SIGNAL
STOP
All three equalizers have a flat phase response (see Figure 3 below) for accurate sound reproduction with no coloration to your speaker system. This maintains pure stereo imaging without the “comb filter” effect. As your ear passes across the stereo plane of your system, the comb filter effect sounds like “peaks” and “nulls” in the response which can change the imaging dramatically.
Figure 3: Phase Response:
PHASE (Degrees)
180
150
120
90
60
30
0
10 | 20 | 50 | 100 | 200 | 500 | 1k | 2k | 5k | 10k | 20k |
|
|
|
| FREQUENCY (Hz) |
|
|
|
|
| |
Smooth, flat phase response of the Crate Pro Audio equalizers
Example of an extremely bad phase response, typical of some "other" equalizers
4
