Depend on which DSP you are going to invest, DSP alone or DSP + Amplifier.. To me DSP come with Class D amplifier like 100wrms x 6ch, 100wrms x 8ch or 100wrms x 8 + 200wrms x 2ch it worth to invest coz less wiring, space required & at least can reinnstall to future car (New Car) without hassle.. DSP alone (Alpine H700/701) you need more space & wiring for external amplifier so in the future when you change car maybe those equipment you couldn't install cause limited of space.. last end up in your store or force to sale at cheaper price..