Headed out for a couple of hours after work. Pulled in lots of coins. The ACE 400 precesses the audio much different then the Garrett AT Series. The AT Series present a modulated audio out of the speaker, meaning, the shallow and smaller targets are louder then the deep ones. On the ACE 400, the deeper and smaller targets get an audio boost, making the deep targets easily audible. There are benefits for both types of audio.