JBL MS-* Noise issues (2013 Ford Fusion OEM integration)

I have recently installed a JBL MS-8 processor, after having read many of the reviews and several threads on this very forum. My goal was to bump up the factory output level, fix up the sound stage, and add a subwoofer to the system. To be clear, I wanted to both improve the quality and the volume of the factory gear. Please excuse the long(er) winded post here, but I’d prefer to give as much detail as I can up-front than go back/forth with Q & A over that I’ve seen asked by so many others before.

Anyways – back to the new install issue. The MS-8 seemed ideal for this install - so I set to the task; the MS-8 is installed in the right (passenger) footwell directly in front of/below the glove box. I took the dash apart, and ran 16 gauge twisted pair wiring from the factory radio (SYNC, MyFordTouch, in a 2013 Ford Fusion). I ran the factory front left and front right into the speaker level inputs 1 and 2 respectfully. The connections are made roughly 2 inches from the back of the factory ACM (audio control module) using crimped connectors and wrapped in heat-shrink tubing. Cable length is approximately 20 inches or so, run from behind the ACM down the side of the center console and right to the MS-8.

I ran new 16 gauge twisted pair cabling from the MS-8 through the molex connectors to the (still factory) door speakers. I have the MS-8 channel 1 connected to the drivers woofer, 2 to the drivers tweeter, 3 to the passenger woofer and 4 to the passenger tweeter. I ran channel 5,6 to the left,right rear doors, and the subwoofer (the only channel not using the internal MS-8 amp) is on channel 7. The factory tweeters still have the (passive) crossover via soldered-on capacitor - I'm still unsure of the designed cutover frequency but I wasn't overly concerned as my longer term goal is to replace the factory drivers with an as-yet-determined mid and tweeter. Nonetheless the crossover point is not my issue (sorry - am getting there eventually … promise).Noteworthy that while I ran new wiring directly from each driver in the front doors (because I wanted to bi-amp/separate the mid/tweeters), I ran two more pairs back from the MS-8 and connected the rear speakers from their factory connections in the dash behind the ACM. All said and done, the driver’s door has the longest speaker run with the rest of the cabling well under 3 feet long. The power is connected via a fused (and dedicated) 8 gauge power wire direct to the factory battery, and the ground is grounded to a clean (bare metal) ground on the framework of the dash directly above the MS-8 mounting position on the nut/bolt as the factory ground wire was (still is). The ground wire is approx. 16 inches long, with crimped on ring on one end and fork on the other connected to the MS-8. In short – I do not believe there is a cabling issue anywhere. I work for Ford, and was able to source the wiring diagram in order to correctly ascertain the factory speaker outputs I have triple-checked polarity as well, though as I understand it that should not be an issue anyways using the factory (speaker) high level for the inputs. The factory radio outputs 4 channels full-range at 13 watts RMS, I opted to just use the front left/right. All equalization and tone settings are set to zero, fade is set to full-front.

The problem I’m having is noise. I get an awful amplifier hiss/white-noise at higher volumes. It’s not over-powering the actual sound/signal but it’s more than enough to annoy the average person, let alone anyone who would consider themselves an audiophile to any degree. If I keep the MS-8 volume below -30 it’s barely audible (hiss/white noise that is) but still there nonetheless. The problem therein being of course that my output power is dismal at best too, certainly well below the factory output for sure. I’m not entirely sure of the factory impedance, and I don’t know if that could be a factor at all or not.

I read some other posts about issues with noise (airplane whine sound complaints mostly), and noted that I too had both only measured for the driver’s seat position and that I was leaving the measurement microphones plugged in thereafter; given the relatively difficult access to the input side of the MS-8 I had left the headset plugged in (stowed in the glovebox) with the wire coming through from behind the glovebox. I had also read several suggestions to use the aux input and try that as well. So I have since re-calibrated several times, for both driver and passenger listening positions, un-plugged the headset, and attempted to use my iPhone connected directly to the aux input. Notably, there is no such noise issue when using the aux input – so I’m fairly confident my issue is between the factory ACM (stereo/head unit if you will) and the MS-8… I’m just at a loss for what to do to fix it. I get OK / OK / OK at about 75% volume on the factory unit during calibration, I have tweaked the crossover points here and there a bit, but currently have my sub at 65hz down, and the fronts crossed over at 1000hz. It sounds ok – but not great, appears to be a hole somewhere I can’t quite figure out and I’m assuming that’s a mis-match between the factory passive crossover point on the tweeters and that which I’m configuring on the MS-8 – that problem I can live with until I replace the drivers. Overall though it sounds very hollow-ish, like the early home theatre surround-sound-emulators “hall” mode – not at all what I expected, very much like the whole audio track is being played through either a cardboard sono-tube or a p.a. horn depending on low/high frequency. The soundstage seems drastically improved but the sound quality way out of sync in the process. I was really hoping for a fairly decent auto-tune with perhaps some minor eq tweaking for an ultimately drastic improvement over the stock sound setup – but alas I’m feeling not much more than a huge disappointment. I’m really hoping there’s something I’m missing but I can’t seem to put my finger on it…. Thoughts/suggestions?