I know there are some that think all quality amps of the same power are equall but I have a 2000 Mustang with Alpine SWX-17REF Front Stage Powered by Alpine PDX4.150, Alpine 9886 Head Unit, 2- 10" Alpine Type R's powered by an Alpine PDX1000.1.
I decided to Swap out the PDX4.150 for the Soundstream VGA400.2 that has the same rated power as the PDX4.150 and I must say my Midbass came alive. I read about the lack of midbass in Car Audio with the PDX amps and they were not kidding because on Full Range Mode on the PDX it put out very little but clean Midbass but with the Soundstream in Full Range I had a ton of clean Midbass and AWESOME sound clarity coming from the front.
I am not saying that amps are the reason for Midbass but it sure seemed like it when changing the amp out. The Soundstream is a Class A/B versus a Class D Amp.
Thought some would find this interesting!
Note: I have no EQ in the car as of yet.