Alright, here goes the short version.

Using an Alpine PXE-H650 Imprint tapped off the front speaker leads prior to BOSE amp (gone) and into the AUX input on the Imprint.

Works fine, gains on amps aren't high, but I cannot tame out some brutal sibilance and harsh guitar frequency. Have the Imprint set to max volume so I can use HU controls (never above 20).

Curious if I need a LOC to amp the signal prior to the Imprint or SSI in case I'm missing some frequencies by only using the front speaker outputs.

Have swapped mids/tweeters up front, same frequency pain occurs. Current are Image Dynamics NX30s and Dynaudio MW160GT crossed at 2k (have tried many CO points)

TL;DR - Can a LOC fix sibilance that may come from a poor HU signal?

 

Okay, I've been doing a little research and I'm not sure if wiring in the RCA to speaker leads is the issue.

I basically bared wire on the front speaker wires before the BOSE amp and spliced into (soldered) Acoustic Research PR-131 RCA into the Imprint. It's shielded and I don't notice any noise, but someone that's RCA'd into an amp or DSP with experience would be appreciated.

 

The Bose headunit outputs a differential balanced signal, otherwise, it is a clean signal. I gave the product page a look, doesn't look like converting balanced to unbalanced is one of its features, so it is probably doing some really strange things to try and compensate, since a clean balanced signal looks like a really bad unbalanced one.

This post would be of much use to you.
https://g35driver.com/forums/audio-v...-stock-hu.html

 

Very good to know, thanks. I'd spliced in this way based on some successes on the board with similar setups. Is there a better method I should explore? I could always wire directly into the speaker level inputs and go through the signal flattening procedure on the Imprint, but figured that was pointless with a clean signal.

That thread is where I got the information on the RCAs. I used to have a JL 500/5 that accepted differential balanced, but the Alpine does not and the staging created by the Imprint is hard to beat. I loathe the idea of pulling the dash apart to add a LOC to RCA in so I may have to go through the ANTeq setup to try that.

 

If you're that concerned about quality audio, I'm surprised a new headunit isn't 1st on your list. That'll definitely open up your options on amp and processor. Plus, since the factory headunits are so failure-prone, it's a good way to prevent failure in the future.

 

Certainly a valid point, but an extra $1000 for HU and finisher, plus taking the dash apart does not sound like a project I'm willing to take on. Pre-kids, would have been no problem