doesn't require an amp, but it works very well with one, especially as the rear output can be used for a sub. That's what I've done, with a wee 8" under the false floor. Phone calls are awesome, very clear. Need to move the mic to the top of the driver's a-pillar, that is still to be done. The EQ and DSP is astounding for a €130 head unit... the app is important but it works pretty well. Phone sits rock-solid (we did some backroad stuff last Friday with the new tyres to scrub them in and it the Nokia 7.2 sat securely in there the entire time). Very happy, not played with EQ properly yet, just begun to get it dialled in and the sub HP / door LP set nicely.