heytonyman

Some quick background, 2018 STX Sync 3 6-speaker. Pioneer TS-A6996 6x9's in front doors, TS-A1606C 6.5's in rear doors with the tweeters in the dash. JL 500/1 on a 10W7 fed from the LF channel thru a LOC. Pretty happy with the system, just looking for a bit more volume and detail. I like bright highs and full midrange.

The wife picked me up a Kicker Key amp. It will take high or low level inputs as well as run 4 channels from only 2 channels input. You can also use it as a regular 4 channel or bi-amp the front stage. I'm running several scenario's thru my mind on how to hook it up and would like to get your input.

Scenario 1: Hook it up leaving the high-level as is and amp all 4 channels. Seems kinda wasteful amp'ing the rear door speakers with the **** signal that they are getting from the ACM... be it by design or limitations of the system, they sound like crap. I would have to move my LOC inline between the ACM and the Key as I would cross them over at 60 or 80hz. This would keep highs coming from both my front doors and A-pillars. It would give me less accurate time correction thru the Key tho.

Scenario 2: Stay high-level and bi-amp the front speakers only. Leave the rear speakers powered off the stock deck. This would give me more accurate time correction from the front but none at all from the rear. It would also crossover the door speakers at 3200hz and move all the highs to the dash only. Not too sure how I feel about that. All for the benefit of having more power per speaker, being "Active", and being able to adjust the gains for mids and highs independently.

Scenario 3/4: Change to low level and power via either scenario above. Problem is I am not sure of the rear channel output quality when set to low level. If it is a full clean signal, I can send it to the Key on the front channels and use the rear channels to send to the sub amp and eliminate the LOC. This seems to be the "cleanest" way to go as removing the internal ACM amplification as well as removing the LOC could help eliminate noise sources. It would also let me use the fader as sort of a bass control. If the rear channel is still band-passed (for all intensive purposes) at low level, then it pretty much eliminates any benefits to going low level. I wouldn't have anywhere to get a signal to the sub without splitting a low level signal and all the problems that can come from doing that.

So what's your opinion? Is going to low level worth the cleaner sound? Would there be sound benefit to sending full range to the rear doors? Or even amp'ing them at all? Or getting rid of them all together? Are the rear channels just as clean and full as the front if you change them to low level? Is it worth losing the front door highs and rear door amplification to bi-amp the fronts?

In case you're wondering, yes I over-analyze **** way too much. lol

HushCarAudio

Look into forscan. I used it to flatten the signal to my amps. The OBD2 tool only costs $20-30 on Amazon. Some say you can get full range signal out of the front channels only and forscan isn't needed. I haven't tested this before so can't say if that will work or not. I can only tell you what I did on my truck and few others.

heytonyman

Yeah i've had forscan for a while. Thats how I would change to low level. Question is, is the rear low level a full range output? Or is it just as jacked up as the rear channel high level?

dhmcfadin

Rear channels have a 70hz highpass filter with or without forscan. No way to defeat that. So no, they aren't full range but they aren't intended to be. Rears are for ambiance and fill.

heytonyman

Have you verified that on a RTA? I'd prefer to go low level and simplify the system but if the fronts are the only usable channels and I have no preamp output, my hands are tied.

dhmcfadin

Yes, and it's well documented.

Your hands are tied??? The rears are simply a duplication of the front channels except they have a crossover on them. Music is recorded left and right not front and back. The front left and right are full frequencies and all you need for input into any amp or dsp. Even if you are just adding a sub, the fronts have what you need. You don't need the rears for anything. They add absolutely nothing to the completeness of the signal. If you want rear fill, you split the signal to the rear channels on your amp or dsp and set the proper crossover. Easy.

I'd also ask, why do you want to go low level vs high level? Kind of an unnecessary step considering the factory headunit doesn't clip until volume level 29. There have also been reports of turn on pop and unwanted noise when using forscan to go to low level. Keep it simple. Use the FOR-11ck harness and speedwire. You will have an incredible sounding system. I promise.

slodat

I echo everything dhmcfadin said. My system is running off line level outputs from the front. It sounds incredible.

heytonyman

The Key has no pass-thru output and I can't use a 70hz high-passed signal to a sub. I need 4 channels of full range output and only have two. I've had bad experiences in the past with RCA splitters adding a ton of noise to the system. If there are no other differences from the front to the rear other than the 70hz crossover, I guess I could run the rear high-passed channels to the Key and the front full-range channels to the subamp. It seems ghetto but it would work.

heytonyman

Just weighing options like I explained. If I can get a better sound with less noise without going thru the internal ACM amp and getting rid of the LOC then I'll do it that way. The problem with only having 2 channels of full range signal with no pass-thru from the Key amp remains either way. At least with high-level, I can keep using the LOC between the ACM and the Key.

I have a CarAV 12-240 harness coming on the slow-boat from Hong Kong. Need to pick up some Speed Wire to put it all together. This Key is plenty small enough to mount up under the dash so I think just 3 or 4 feet will be plenty.

dhmcfadin

I think you might be confusing yourself. You don't need to use rca splitters. You would being going high level into the amp. You can split that high level (speaker level) signal before the kicker amp to your sub amp. Very simple.