Anyone have OEM Audio Plus installed?

I have a 2020 4runner, so the system came with an extra harness to attach behind the headunit. I got the speaker + amp system, no sub.

When I installed the speakers I noticed a definite improvement, but by chance the way I installed I ended up doing the amp days later.

Once I installed and hooked up the amp, I felt there was NO audible difference between speakers only and speakers+amp.

I've been dealing with OEM Audio Plus on my issue and they have been great, but
I also wanted to put it out to the community as maybe others have noticed something or found a potential reason?

I've done tests as best as I can, having played the same song both with the amp connected and bypassing it (Which is annoying having to go back+forth changing the connections!)

I've tested it mostly with android auto, but have also tried with radio and sirius. I've tried low-ish volume at around 20-25, and higher-than-comfortable volumes at 40 - and I feel there is zero difference in the loudness or my perceived quality of sound between the two setups.

Anyone else have a similar setup? Done any testing? Noticed anything or found any potential issues?

 

Not yet, but it is on my list...

 

There is a noticeable difference with amp vs no amp but I’ve got the sub. I did have to dial in the oem bass, treble and high to my liking though. Had to much bass out of the box