If you do, I was wondering what levels and which features you use...

I have 2 subs and all stock interior speakers...

Right now, I am trying to keep the sub level on zero, and using the bass engine at 1-60 +7 and treble at 1-160 +2

Unless someone had the exact same speakers as you, then there'* not much to be had by comparing.. Level adjustments are all about getting everything to work in different accoustic environments in cars.

I had my 9856 setup with a little forward Bias to strengthen the soundstage, had my gain setup properly on my sub, so I could use the internal controls of the alpine to adjust bass between tracks.

My unit doesn't have time adjustment, so I never got into that.

I try to keep processing down to a minimum, there are so many things available in modern HU that adjust the sound and after a while you have to tweak them all so little to work with eachtother it'* nuts IMO..

I am just throwing some #'* out there because this HU does not have a high pass filter, so I am trying to get the right amount of bass to go through without distorting the inside speakers, but still giving me a good bass sound from my subs. I realize everyone'* is going to sound different, but the different types of setups could be compared, maybe not technically a +5 to a +7, but a recommendation on trying to turn the sub level up and the bass down, might be something someone else might know.

The options my alpine has is, a center frequency for treble (75, 100, 125, 150)khz and bass (60, 80, 100, 120) hz; a loudness option, bass level (-7 to +10) treble level (-7 to +10) and input sensitivity on the amp if needed. I also have bass blockers on the positive ends of the inside speakers to keep bass from them...(I think they work). I also have a low pass filter on my amp.

My better question is: if anyone else has a HU without a high pass filter, what'* the best way to get the most bass out of the subs, without blowing or distorting stock speakers inside the car?