Set-Up Considerations and Installation
balancing distortion and power compression at high amplitude levels. For the casual listener
and enthusiast, we recommend a passband of 200-250 Hz to 6,000 Hz at fourth order filters
(24 dB/octave).
Time Correction
It is our humble opinion that time correction should only be used in three different
circumstances:
1) When the installer recognizes that a vehicle cannot image properly from both seated
positions and it seems more plausible to make the vehicle stage and image well from only one
seated position.
2) To counter the effects of group delay.
3) Time alignment between pairs of drivers.
Scenario 1
The first scenario is rather elementary. If a vehicle is too small to achieve equalized PLD’s, it
doesn’t lend itself well to equalized PLD’s, or the vehicle’s owner doesn’t wish to embark on
physical reconstruction of the car to achieve optimized PLD’s, it is a good use of time
correction to make the vehicle image well from the single seated position. It should be noted
that it is Hybrid Audio’s opinion that it is always better to improve the car mechanically and
attempt to fix mechanical problems with mechanical solutions, than it is use to electronics to
fix mechanical problems. However, we realize that there is the occasion when there is little
desire to try to mechanically optimize one’s listening space, and electronic manipulation is
desired. It is important to recognize that, given the fundamentals of ITD and IID discussed
previously, time alignment is rendered virtually useless for frequencies above approximately
2,000 Hz.
Scenario 2
In the second scenario, the use of time correction is much more cognitive, and shows great
promise for countering the effects of group delay. Group delay is impulse response over time.
Group delay increases significantly at low frequencies, and is considerable in larger
midwoofers and subwoofers. An excellent use of time correction would be to delay the
Legatia L3’s and tweeters with respect to the midwoofers and subwoofers, so that the low
frequency delay of these drivers is synchronized in the time domain with the output of the
midrange and treble frequencies.
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