Car Audio: LC7I tuning w/ 2 amps.

[Rstutz]

Hey guys, I'm pretty new to this and just starting to learn a lot more about car audio, but am still pretty much an amateur with tuning and installing. I went to Car Toys recently to get my audio system installed in a new car. It's a memphis prx 1.1500 with 2 12" rockford fosgate T1s. I'm not sure if you're familiar with these subs, but they hit hard in my 2013 Jetta. Now in the new car, (2015 Sentra) I'm using a LC7i due to the fact that I'm using the factory head unit. I also just installed a T2652s component set by rockford fosgate in the front recently. Now, my question being: Is it normal for the knob that goes to my subwoofer amp to have to be nearly fully rotated, and there still not be a maximized light on? Ive been messing with it for a day or so now and still have never seen that light come on even if the system is hitting hard. Also, another question. Is static from tweeters with the head unit on 0 volume normal counting the fact that there's a amplifier connected to them and the door speakers? I was told it's normal by Car Toys, as the gain is down on both the smaller amp for components, and LC7i for that channel, it still seems weird that they make that buzzing sound at 0 volume. If I turn the head unit off it goes away.

Also: I haven't messed with the accubass threshould or anything else on the LC7i except the knobs for sub amp and component amp, so they're as Car Toys tuned it.

 

[tracerbullet]

I think you're right that something is not right.

It sounds like for some reason the bass signal may not be making it to the Audio Control unit. It could depend where they tapped it from, possibly from a signal source that is not full range, or maybe it's pre-equalized or crossed over specific to the factory system.

Any noticeable static / buzzing with the sound at 0 also isn't right. You can't always expect perfection but if you can really hear something it's not hooked up correctly. My best guess is there's a grounding problem somewhere.

I get the feeling your install shop has a basic understanding of what to do, but is missing some specific nuances to your car that has ended up giving you these problems. You might have some luck on a Sentra or at least Nissan specific forum where someone has already dealt with this. Or, start looking for some wiring diagrams for your car and see if you can spot anything (or share those diagrams here).

 

[z1ggy]

Check to see how they grounded the amps. If they share a common ground, try splitting them into 2 different ground points. I actually just read about something like this last night when I was looking some car audio things up for my system.

 

[Rstutz]

Thanks for the replies guys! I was just looking at the grounding last night and noticed they used a short 4gauge power wire to the amplifier for my components from my capacitor. Is that normal? Also, the grounding did seem to be in the same-ish place. Which is above spare tire location. One on each side of the trunk.