Well Eric,I gotta say i REALLY love post like this, you are really on your way to becoming audio literate...!!! I really like seeing all of the pertinent information listed just the way you have it... I do hope you learned a lot from your friend helping you with the amp install, we all have to start somewhere...Now, as far as HU settings... once you get the sub and amp back into the mix, you'll WANT to use that 80hz high pass on the deck. This will take the lower range out of the mid-high region, as you have already noticed. It will thin out the sound, but the sub should take over and fill it back in. This is WHY crossovers are used.. Right now you have 2 crossovers working the same thing but set differently. On the deck you have it set to 80hz and on the amp you have it set to ~75hz.... you should pick one or the other, not both... I would turn the "bass EQ" off for gain setting and then after you are done, you can play with it to taste... I cannot tell if you are able to defeat the crossover on the amp (not use it) or not? is that an option? Does it have a switch that looks similar to HP/AP/LP??? If it does, you will want the AP (all pass) setting. If not, use the amp crossover and defeat the deck crossover... Make sure you set the deck sub level output to 0 for gain setting, then you have a range of setting you can put the level to... I use this a lot depending on my mood, i can turn the bass up or down... Do you still have my instructions for setting gain (yes, it means you have to DL a 1000hz (1kHz) and a 60hz test tone, shouldn't be to hard to find) ??? You should consult
http://www.bcae1.com/ on the ins and outs of gain setting, the topic is about 1/2 way down the topics section and has a really good tutorial on it... It's a little work, but it is very worth it...