Does it need a separate amplifier?

No. The amplifier is built into the enclosure and power-matched to the 10-inch L7 woofer, so you feed it power and a signal and it is ready to play.

Will it fit under a truck or SUV seat?

It is a compact, factory-tuned down-firing box meant for tight locations in many trucks and SUVs, but check the enclosure dimensions against your specific cargo area and leave clearance below for the downward-firing driver.

How does it connect to a factory stereo?

Kicker says it integrates easily with a factory system, typically through a line-output converter or speaker-level input. A remote bass knob is included for level control from the front.

Does it work in a vehicle with start/stop?

Yes. Kicker lists built-in start/stop compatibility, so the amp tolerates the voltage dips that come with the engine restarting.

Can I control two of these from one knob?

Not with the included remote. Kicker offers a separate DBRC remote for running two mono amps or powered subwoofers from a single knob.

Is the square L7 woofer better than a round 10?

Kicker claims the Solo-Baric square design moves more air than a comparable round driver, which is the basis for its output advantage in the same footprint.