Patient is a 1997 E36M 4 door that had the stock system (Not HK).
I upgraded the system with the following components
JVC Arsenal headunit
Alpine MRV 300 (?) 4x40 channel amp in back fed by a pair of RCA cables run along the drivers side door sills from the headunit
A/D/S 335 separates with a 1" tweeter in the door and a 5 1/4 mid woof in the kick panels running from Crossovers in the trunk with the amp which I put in the stock location.
JL Audio stealthboxes in back running on the Sub/rear channels in the amp. Using high and low pass filter built into the amp, though I tinker with the headunit filters as well.
From the amp in the trunk, I tapped into the factory wires for the speakers. The Antenna is hooked up with an antenna adapter I got from Crutchfield with the install. There was a blue wire on the antenna adapter, that I've never quite gotten a straight answer on what to do with.
The system has been in for several years (5-6?)
Symptoms
The front speakers are dropping out, and I suspect that the wiring is aging, probably in the door connection. Is there a common failure point in these cars to look for? or do I have to rewire the whole system? I'm not quite in the mood to open up everything again, but I suppose if I do it the one time after 5-6 years, there are worse problem areas in a car.
Also, the radio doesn't have great reception, and I suspect a ground problem in the system. I am only running about an 18 ga ground line from the amp to the chassis in the trunk, and suspect I need to upgrade. The headunit is using the factory ground lead.
Finally, the whole system will turn off if I raise power levels too high, though I suspect that the same grounding issue at the amp might be causing sporadic performance.
My course of action:
recheck the amp grounding,
Check speaker connections on the stealth boxes. spade connected, but not soldered. May be a loose ground there?
Look in the door jambs for signs of speaker line wear.
consider opening up the trunk, doorsills, kick panels and doors and just rewiring the whole thing (sigh).
Thoughts?
Marc Plante
E36 M3/4/5 193k
Konis+ Dinan Springs, Understeer SS, Shepott European steering Wheel, ZKW Ellipsoids, ECIS Intake+ ATE Foam filter, Stromung Exhaust, Recaro SRDs. JVC Arsenal Head Unit. Alpine MRV-F300 Amp, ADS 535i components, JL Audio Stealthbox Subs
My Track Rig:
i7700 / 2080 PC with Assetto Corsa and Content Manager, Samsung Odyssey+ VR goggles
Fanatec CSP wheel and pedals, SSH Shifter, recaro seat. Home built cockpit
Mt Pleasant, SC, USA
Fading typically doesn’t indicate a wiring problem. Sudden drop out of sound could be attributed to wiring issues. I’m betting the amp is the cause. Is it new? Also, always solder connections as vibration can degrade spade connections over time.
I just saw youre only using 18 gauge ground wire from your amp. Upgrade that asap. My aftermarket pioneer unit recommended 10 gauge at the minimum. I used 8 gauge.
Sent from my VS987 using Tapatalk
I read thru that setup again. Are you driving multiple subs in addition to front and rear speakers off of one 300 watt amp? What is the RMS wattage of that amplifier?
It sounds like you a over working your amp with insufficient grounding and its overheating and entering a limp mode.
Sent from my VS987 using Tapatalk
I think that XnWarden's points are spot on - 18 gauge way too small and a 300 watt amp for that setup is likely causing overheating/limp mode. Which JL subs are you running? If it's anything above the W3v2, they need sufficient power.
Your Trusted Source For DIY and Parts
FREE SHIPPING over $99 click here
BMW Parts | DIY Tech Articles | Facebook | Twitter | Instagram | YouTube | Promos
888.280.7799 | 6am - 5pm PST
Subs in Infinite baffle (stealthboxes) need very little power to fill the cabin with sound.
Thanks, I have been busy with work and other issues, and I generally run my stereo on low volume playing news when I drive, so it hasn't been an issue, though the door tweets still drop out FTTT (I suspect I have separate issues there).
The amp is rated at 4x50, which is similar to the Eclipse amp I ran in my last E36 with no issues (Same speakers as well).
I'll get some 10 gauge and ground the amp properly.
Thanks,
Marc
Marc Plante
E36 M3/4/5 193k
Konis+ Dinan Springs, Understeer SS, Shepott European steering Wheel, ZKW Ellipsoids, ECIS Intake+ ATE Foam filter, Stromung Exhaust, Recaro SRDs. JVC Arsenal Head Unit. Alpine MRV-F300 Amp, ADS 535i components, JL Audio Stealthbox Subs
My Track Rig:
i7700 / 2080 PC with Assetto Corsa and Content Manager, Samsung Odyssey+ VR goggles
Fanatec CSP wheel and pedals, SSH Shifter, recaro seat. Home built cockpit
Mt Pleasant, SC, USA
You may want to check out the chart on the JL website here. 8 AWG should be fine for power/ground, but if you can run 4 AWG, it won't hurt anything. You didn't mention the size/length of your power wire for the amp, do you know the gauge? It should be the same gauge as the ground as long as their lengths are similar. And get copper wire if possible, it's better than the copper coated aluminum (CCA). Get copper lugs/terminals too.
I'm in the process of rewiring the entire stereo in my E36 M3 and am completely bypassing the stock wiring, and this thread makes me feel good about my decision to start from scratch. Start by properly redoing the power and ground wires for your amp and see how it behaves after that.
A simple rule of thumb is that the amp’s power and the ground need to be the same gauge.
Bookmarks