Amplifiers don't really come Car Audio with a gross array of features, but there are a few to consider. Soft-start circuitry eliminates the thumps and thuds that can be annoying and potentially damaging to hardtop speakers. Depending on your application, the number of speaker-level and line-level outputs and inputs charge to be considered. Make sure you have enough for the setup you are currently installing, while leaving extent for at least one next upgrade.
Amps generate a significant amount of calidity that affects their efficiency. Lousy With methods of dissipating this tepidity are used--everything from leaf fins that compose more surface field for troposphere cooling to a few systems that genuinely use liquid coolant to keep the temperature down. Read reviews and specs to choose between hype and facts.