Set-Up Considerations and Installation
Scenario 3
The final scenario is time alignment between pairs of drivers. When employing multiple
drivers in order to achieve a unified listening experience within a vehicle, it’s usually a
requirement to install the drivers at physically separated locations; for example, your midbass
may be located in the doors, and the midrange and tweeter may be located in the dashboard
or a-pillar. In order to compensate for this, you might choose to selectively delay certain
speakers in the installation so that all of the tones reach your ears at the same time (note that
as previously alluded to, time alignment of your tweeters would be rendered useless).
Amplitude Equalization
An excellent use of today’s dual-mono equalizers and advanced digital signal processing is the
ability to equalize amplitude anomalies between speakers and sets of speakers. In a vehicular
installation, the frequency response of drivers can sometimes be manipulated for the
betterment of the system using independent left and right amplitude adjustment. Virtually any
good car audio system can be made better with judicious use of a minor amount of
equalization. And while equalization will not cure phasing anomalies in a car, usually the
product of vehicular mechanics, they can certainly be helpful in fine-tuning the system to your
own personal taste or in the quest for playback accuracy to the original musical composition.
One important consideration of amplitude equalization (also known in some circles as
“amplitude alignment”) is the ability to tune those frequencies above about 500 Hz that are
not completely affected by time correction. The very best vehicles have some sort of
amplitude equalization between the left and right speakers to account for IID and HRTF. After
your L3’s are mounted and you’re satisfied with them from a tonal perspective, you may wish
to attempt some minor amplitude equalization between the two Legatia L3 midrange drivers to
achieve a more stable image that is not frequency dependent, or perhaps to improve image
placement or stage coherency.
Acoustic Treatment
A considerable benefit can be made to any car audio system with the select placement of
acoustic treatments. The purpose of using acoustic treatments is to reduce the amount of
reflected energy in the hostile automotive environment, and hear more of the direct sound
being emanated from the speaker. It is akin to the signal to noise (S/N) ratio in a piece of
electronics, where the signal could be considered the direct energy coming from the speaker,
and the noise could be considered the reflected waves off of nearby surfaces, such as
windows, hard center consoles and door panels, windscreens, and etc. In our quest to find
the best piece of electronics, one of the most popular measurements to look at is the S/N
ratio, so why not spend at least an equal amount of time developing the S/N ratio of our
acoustic listening space as well? A word of warning though: there is a fine line between too
little and too much room treatment; just as some cars can benefit from some selectively
applied treatments, there is a point where the vehicle can begin to approach semi-anechoic
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