am i crazy or is does this make sense?

So tell me if this is me just being crazy or if I actually have a legit problem I gotta take care of. I'm an installer so no opinions/advice will confuse me. So I just installed everything in my car... Here's my setup Rockford P1000-1BD Mono sub amp (1000w RMS at 1ohm) going to two 12" alpine Type-R subs (obviously running at 1ohm for the amp) in a sealed box. I have two sets of Infinity Kappa Perfect 6.5" (their a component set), both being powered by an Alpine MRP-F300 (which does 50w RMS by 4). The sub-amp is powered by 4gauge wire, and the 4-channel amp is powered by 8gauge. The radio is an alpine CDA-9886 with the Imprint Processor box hooked up to it as well. SO... here's where I'm confused if I'm going crazy or if this is something that actually makes sense. Assuming I have my gain on my sub amp at about 8 1/2 out of 11, and my 4channel at about 7 out of 11, and my subs turned up to 15 out of 15 for the gain on the radio, here's what happens. It seems to be that when I have my radio at lower volume (setup with the gains I listed above) I get a ton of bass from my subs, pretty much overpowering the music from the speakers. Which makes sense because of how I have the gains setup. However, I turn the volume up, and my music gets louder from my speakers, it seems almost as if the bass from my subs is going down. Its definitely more noticeable if your doing it the opposite way, going from a high volume to a lower volume. Is this possible or am I just crazy? It seems to me that it could either be a couple of things... 1. My ears are just hearing more all around sound at high volume and when its turned down my ears can pick up more of the bass (this seems unlikely because its kinda a pretty noticeable difference) 2. When I turn my system up louder its causing more of a strain on my charging system and there for decreasing the voltage going to my sub/amp HENCE why I'm not getting as much bass at high volume. (this is the one that seems to me to make the most sense, I obviously could probably check this out with my meter just haven't had a chance to yet) So my two questions are which reason do you think it could be (if its something different lemme know) and two, what thoughts do you have to fix it? I have not done a big three upgrade (I AM planning on it, just not an easy process as my alternator is not to easy to get to), and I do not have a capacitor. I'm kinda thinking as much as I know capacitor's aren't really the problem solvers people think they are, it might be useful for my application. Because if option 2 is the culprit, than having an extra storage of voltage for the amp should be beneficial right? Anyways thanks for any ideas/thoughts you guys might have!

I'd say your sub amp gain is up way too high. You are reaching the maximum power output of your amplifier early so when you turn the volume up even more, all the other speakers get louder and the subs stay the same (seem to get quieter). The fact that your explanation describes the exact location of the gains indicates to me that you didn't set them correctly. As an installer myself, I adjust gains on quite a few amplifiers. I couldn't tell you where any of the gain knobs are on any of them, including in my own vehicle. I never rely on the markings on the side of the amplifier. I'd start by setting the gains correctly. You can find an explanation on how with a search of this site.

Where is the Imprint getting it's "information"? Is it possible that the installed curve within the Imprint is doing this? I'd look seriously in that direction. The human ear is more sensitive to higher frequencies than lower frequencies at higher SPLs. And a cap will do ABSOLUTELY zero for you in this case (in ANY case, truthfully)... Don't go there!It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Hey Aggro, Not that I can discount your craziness, but that sounds very unlikely (no pun intended). I reckon I can discount #2 - the drop in system voltage - with reasonable certainty. However, apart from as above re Imprint and limiter effects, I too support the info about (h)earing dynamics - ie, "bass is 3x louder than treble" (sic, but you know what I mean(?) etc etc), and about adding NOT a cap. [IMO a small AGM aka Recombination battery has far greater effect at a fraction of the cost, though its isolation when the vehicle isn't charging is the norm.]

Check the subwoofer output settings on the deck. It will be a menu option thats labeled subwoofer sys 1 or subwoofer sys 2. I forget which is which, but I know one of those setting will adjust the sub output from your deck with volume, the other will not.