COMMON BASE SYSTEM
TECHNICALS
The Common Base System is a popular set-up in many entry level vehicles.
It has 2 channels of amplification for the front speakers and 2 for the rear, all supplied via the head-unit. The bass/midrange drivers run full-range, while the tweeters use a passive 6 dB per octave crossover on the front channels. This creates dispersion and comb-filtering problems, which ultimately limits the potential sound quality from the system.
The Digital Signal Processor (DSP) within the head-unit is used for sound equalization and also provides a roll-off below 60 Hz in order to protect the bass drivers from over excursion.
Due to the configuration of the system, there is limited potential to upgrade the sound at a later date. A vehicle manufacturer might offer a small powered subwoofer as an after-market accessory. An 8” subwoofer, enclosure and amplifier could retail for around $500, and return a profit of around $350.
However, most brands do not bother due to the limited overall sound quality of this type of system.
UPGRADED BASE SYSTEM
TECHNICALS
The Base Upgraded System uses 2 channels of amplification for the bass/midrange and 2 channels for tweeters, supplied via the head-unit. This allows for independent level and equalizer settings for the bass/midrange and tweeter for better integration, tonal balance and voicing. The crossovers between the bass/midrange and tweeter are typically 24 dB per octave, greatly reducing any comb-filtering problems.
The DSP within the head-unit is used for sound equalization, active crossovers, and also provides a roll-off below 50 Hz in order to protect the bass drivers from over excursion.
The Ported Tweeter allows for a much lower crossover frequency than is normally possible, resulting in a wider, much more immersive sound, without the need for rear in-fill speakers.
The 2 x 8” bass drivers deliver a deeper, more powerful bass than the 4 x 6 ½” (lower resonance and greater excursion). The overall sound quality of the system is far superior to the Base OEM System.
*The vehicle could ship with traditional crossover points, but a “Premium” DSP tune with lower crossover frequencies could be available for a fee. This would provide a smoother, much more immersive sound, and deeper bass. This could be implemented as a one time fee, or via a monthly subscription. If the subscription fee were $5 per month, this could add $660 profit over the 11 year life of the vehicle.
**The system could be upgraded later, by adding rear speakers and large powered subwoofer. The vehicle manufacturer could retail the rear bass/midrange, tweeters and DSP amplifier for $500, returning around $389 profit. A 12” subwoofer, enclosure and amplifier could retail for $700, and return a profit of around $500.