call kicker tech support. They have amazing people that will walk thru it all and figure out the problem

 

As the title suggests, this is a newb question largely about gain settings, but also about diagnosing possible noise issues. I upgraded the speakers and added a subwoofer to my new-to-me 2017 Rav4. Since I'm sticking with the factory head unit I opted for the Kicker Key series of amps- the 200.4 running MTX Terminator6S components up front and Sound Ordinance P-67B Coax in the rear, and the 500.1 running an Infinity Reference 1070 sub.

Getting right to the point, after getting everything wired up and running the Key auto-EQ setup I ran the gain match and found that with the gain levels set "correctly" per the amp software there is an appreciable hiss coming from the speakers at all times. It doesn't matter if the head unit is on or off, and the sound remains constant regardless of the volume setting. From what I've read this is typically an issue of the gain being set too high, and indeed, the hiss volume corresponds to the gain level. So if I turn down the gain to the minimum the hiss is barely audible-if the car is running you can't hear it at all. Also, if I disconnect the inputs at the amp the hiss goes away. Whether or not the sub amp is connected doesn't affect the hiss.

I realize the gain isn't a volume knob, so having it turned down isn't necessarily an issue, but it seems odd to me that the system would be putting out noise with the gains set at or below properly matched levels. So my question(s). Is this normal? Is this a byproduct of running the amps off the factory unit? Should I just run the system with the gains low or is it worth trying to troubleshoot my connections? The only thing I could think of as a possible issue are my long runs of speaker wire going to and from the head unit picking up noise. Is it an issue having these running next to each other especially since they're not shielded cables?

Since I'm not sure what's relevant here are the install details:

8 gauge power off the battery with 60amp in line fuse running to distribution block, 10 gauge from block to the 200.4 wiring harness with 20 amp in line fuse, and 10 gauge with 40 amp fuse to 500.1

8 gauge ground off factory ground point to distribution block and 200.4 harness directly to block. 10 gauge from block to 500.1 amp

Amps and distro blocks are mounted to plastic cargo tray, so no contact with chassis.

All speakers are attached with factory wiring. I spliced into the speaker wires directly behind the head unit and used 9 conductor cable (18 gauge) to run the input and 12v ignition to the amp and the same cable to run output back up behind the head unit. Connections behind the head unit are made with posi-twists and connections at the amp are soldered and heat shrinked.

The front left and right are split at the amps so they run to both the 200.4 inputs and the 500.1 inputs. Soldered connections.

Power wire runs down passenger side and input and output cable run down drivers side.

Any advice or comments welcome!

My opinion is run the gains lower.

 

The easy fix is lower the gains, especially if you still have the volume you’re looking for when you turn it up.

 

If the factory head unit has some high frequency attenuation, then the autoEQ may boost the high frequencies, and this will create hiss. It isn't your grounds or some other thing like that, so don't go tearing your installation apart to find that.

 

I appreciate the feedback everyone. A boost in the high end makes sense- I'm sure the factory HU has some attenuation to protect their crap paper tweeters. I'll give Kicker a call to see what they say, but keeping the gains down is certainly the easy fix and I'm happy with the performance even with the gains turned low--or at least I am now that I turned off the "kicker curve" EQ settings. Supposedly their EQ bumps the bass and rolls off the highs but, to my ear at least, the highs were piercing and the bass bump was overpowering, and I like heavy bass. Some of the issue with the highs might be the factory mounting location pointing straight into the windshield. Or I'm just reacting the limits of some relatively cheap components. I might play around with angled mounts at some point because even with the flat signal the bass and mids sound good at high volume but the highs are harsh unless I turn them down a bit with the HU.

In any case, the sound is drastically better than factory especially for such a cheap and tiny amp. Is it audiophile good, no, but neither are my ears. I do wish there were more post processing EQ options/controls, but I get that the goal is a turn-key system for people (like me) that don't have the tools or experience to properly tune a true DSP. This was my first real install so I figured I'd start with the training wheels on.

 

This is more of a question than a suggestion but can you play around with external grounds for the rcas and head unit? (Adding a wire to connect the rca's together on the amp, or to the head unit chassis, etc)

I know there was a trick was to grounding all head unit rca's together and I also heard of running a ground from head unit to amp or something.

 

This is more of a question than a suggestion but can you play around with external grounds for the rcas and head unit? (Adding a wire to connect the rca's together on the amp, or to the head unit chassis, etc)

I know there was a trick was to grounding all head unit rca's together and I also heard of running a ground from head unit to amp or something.

This is for whining noise caused by ground loops. Not for thermal hiss in components