RAGE Against the Ground Loop:
05-31-2011, 08:36 PM
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RAGE Against the Ground Loop:
I'm raging for two reasons.
1) My audio install is giving me absolute hell.
2) My ridiculous audio install is keeping me from enjoying my S2000 on the road.
Please help me solve this so I might cruise the roads once again.
I'm going to attempt to organize a decent amount of information into four sections.
//--- The Components ---- \\
//--- Installation ---- \\
Head Unit:
The head unit is currently powering the left speaker, while the JL M6450 is powering the right speaker. I never made it to the second speaker before I hit problems.
The headunit is wired up using a modify harness and everything worked as expected when stock When replacing the passenger side door I rewired everything with 16 gauge wire and simply zip tied the factory speaker harness down.
Originally I had the power line (4 Gauge) running right next to the three sets of RCA's and one set of speaker wire, but have since relocated the speaker wire and three sets of RCA's to run down the center console to get it away from the power wire. I thought this had made a difference, but it seemingly did nothing.
Where the factory spare tire was, I built an MDF platform:
NOTE: This was a mid install picture, the single distribution block shown here is where the negative block now is, and above the fuseblock is the power distribution block. None of my wires are just electrical taped together, at a minimum wires are taped, heatshrunk or crimped, taped, then heat shrunk. I did however use that 12 gauge wire to connect one of the BOSS amps and not the 4 gauge. The other boss amp is 4 gauge, the main JL amp is 4 gauge. The power wire connects to the fuseblock, then the distrobution block. The negative block is of course connected to my chassis brace bolt.
//--- The Problem ---- \\
The bass shakers work perfectly with the stock speakers. Zero distortion from either.
The stock speaker and the now amped JL speaker work perfectly without the bass shakers.
As soon as I plug in the subwoofer RCA from the head unit into one of the BOSS amps, via a splitter or going directly to a single amp I get ground loop noise out of the aforementioned bass shaker and also out of the amplified speaker. The stock speaker as expected always works in this situation.
//-- What I've Tried --- \\
My first instincts told me to get the speaker and RCA cables away from the power line. Done.
My second thought was to reinspect my common ground to the chassis. What's this? TONS of primer around the bolt hole because I was lazy? You bet. 10 minutes later with a wire wheel on a dremel the metal is peeled back and shining!
After both of those failed to even remotely help, I began a frustrating mis-match game. I tried all of the 3 RCA's in the SUB / FRONT jacks in multiple combinations, but nothing changed between them. They were purchased new, Monster Cables approx 10 ft. long I think.
After swapping the RCA cables in and out, I tried disconnecting one of the BOSS amps to see if it helped. It helped somewhat, as I recall but nothing drastic at all. With the second amp out disconnected from both power and ground it then just became like the stock speaker and amped speaker senario and it sounded fine once again.
I also tried experimenting with the ground on the head unit, I tried originally grounding it to the factory harness (Never had an issue with noise before this) and then I tried grounding it in several in-cabin places, as well as tried grounding it to the common ground in the rear, and also the battery. None of which changed the feed back loop at all.
____
So, I think that does a halfway decent job as describing my problem in detail. I can provide more detail upon request.
I'm really out of ideas here.
One more thing I should mention. One possibly important thing, if I take the head unit ground, and ground it on the RCA's - BOOM. Zero distortion instantly.
I don't want, I refuse to install my system this way - if there is any other possible way I'll do it.
Thanks yall,
-Greg
1) My audio install is giving me absolute hell.
2) My ridiculous audio install is keeping me from enjoying my S2000 on the road.
Please help me solve this so I might cruise the roads once again.
I'm going to attempt to organize a decent amount of information into four sections.
//--- The Components ---- \\
- Head Unit: Kenwood Kdc-Bt945U
- Amplifier: JL M6450 Class A/B Six-Channel (45W RMS x 6 @ 4 ohm )
- Speakers: Jl Audio C2-650 Component
- Amplifier 2&3: Boss Audio CX250 x 2 (Rated at "400watts"
) - Subs: Aura Bass Shakers x 2
- TSUNMAI FBWM801-ANL Fuse Block
- TSUNMAI - Solid Distribution block x 2
//--- Installation ---- \\
Head Unit:
The head unit is currently powering the left speaker, while the JL M6450 is powering the right speaker. I never made it to the second speaker before I hit problems.
The headunit is wired up using a modify harness and everything worked as expected when stock When replacing the passenger side door I rewired everything with 16 gauge wire and simply zip tied the factory speaker harness down.
Originally I had the power line (4 Gauge) running right next to the three sets of RCA's and one set of speaker wire, but have since relocated the speaker wire and three sets of RCA's to run down the center console to get it away from the power wire. I thought this had made a difference, but it seemingly did nothing.
Where the factory spare tire was, I built an MDF platform:
NOTE: This was a mid install picture, the single distribution block shown here is where the negative block now is, and above the fuseblock is the power distribution block. None of my wires are just electrical taped together, at a minimum wires are taped, heatshrunk or crimped, taped, then heat shrunk. I did however use that 12 gauge wire to connect one of the BOSS amps and not the 4 gauge. The other boss amp is 4 gauge, the main JL amp is 4 gauge. The power wire connects to the fuseblock, then the distrobution block. The negative block is of course connected to my chassis brace bolt.
//--- The Problem ---- \\
The bass shakers work perfectly with the stock speakers. Zero distortion from either.
The stock speaker and the now amped JL speaker work perfectly without the bass shakers.
As soon as I plug in the subwoofer RCA from the head unit into one of the BOSS amps, via a splitter or going directly to a single amp I get ground loop noise out of the aforementioned bass shaker and also out of the amplified speaker. The stock speaker as expected always works in this situation.
//-- What I've Tried --- \\
My first instincts told me to get the speaker and RCA cables away from the power line. Done.
My second thought was to reinspect my common ground to the chassis. What's this? TONS of primer around the bolt hole because I was lazy? You bet. 10 minutes later with a wire wheel on a dremel the metal is peeled back and shining!
After both of those failed to even remotely help, I began a frustrating mis-match game. I tried all of the 3 RCA's in the SUB / FRONT jacks in multiple combinations, but nothing changed between them. They were purchased new, Monster Cables approx 10 ft. long I think.
After swapping the RCA cables in and out, I tried disconnecting one of the BOSS amps to see if it helped. It helped somewhat, as I recall but nothing drastic at all. With the second amp out disconnected from both power and ground it then just became like the stock speaker and amped speaker senario and it sounded fine once again.
I also tried experimenting with the ground on the head unit, I tried originally grounding it to the factory harness (Never had an issue with noise before this) and then I tried grounding it in several in-cabin places, as well as tried grounding it to the common ground in the rear, and also the battery. None of which changed the feed back loop at all.
____
So, I think that does a halfway decent job as describing my problem in detail. I can provide more detail upon request.
I'm really out of ideas here.
One more thing I should mention. One possibly important thing, if I take the head unit ground, and ground it on the RCA's - BOOM. Zero distortion instantly.
I don't want, I refuse to install my system this way - if there is any other possible way I'll do it.
Thanks yall,
-Greg
06-01-2011, 05:11 AM
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I also tried experimenting with the ground on the head unit, I tried originally grounding it to the factory harness (Never had an issue with noise before this) and then I tried grounding it in several in-cabin places, as well as tried grounding it to the common ground in the rear, and also the battery. None of which changed the feed back loop at all.
-Greg
06-01-2011, 06:17 PM
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Not that anyone was jumping on this, but after another couple hours of playing around I've 100% narrowed it down to two things.
Either all of my monster RCA cables are junk, or the pre-outs on the headunit are junk.
The ground wire to the RCA was in fact a band-aid for a grounding problem at the RCA level.
-Greg
Either all of my monster RCA cables are junk, or the pre-outs on the headunit are junk.
The ground wire to the RCA was in fact a band-aid for a grounding problem at the RCA level.
-Greg
06-03-2011, 07:26 AM
#7
You likely have a bad ground, probably the amp. Even though you scraped the paint off your grounding
point, that point may have too much resistance itself. If you have a multimeter, check the ohms
between your amp's negative terminal and the negative battery clamp (or other factory ground point).
If it's not pretty close to zero, check again from your ground point to the battery clamp - this will let
you know if the problem is between your amp and the ground point, or the ground point and the rest of
the car.
point, that point may have too much resistance itself. If you have a multimeter, check the ohms
between your amp's negative terminal and the negative battery clamp (or other factory ground point).
If it's not pretty close to zero, check again from your ground point to the battery clamp - this will let
you know if the problem is between your amp and the ground point, or the ground point and the rest of
the car.
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06-05-2011, 07:44 PM
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i find the factory grounds, battery to firewall, poor, i ALWAYS upgrade the grounds on the battery, from battery to strut bolt, and other side of engine bay altnator bolt to strut bolt. i have seen a 1 volt increase at amp mounted in trunk, just from doing this
06-05-2011, 08:14 PM
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I have a voltage meter / fuse block form Tsunami and according to it I get high 14.x volts when the car is running, which I thought was pretty good. With music playing is dips to high 12's. But not everything in the system is hooked up yet, so I expect it to go a bit lower.
As for the problem, I believe that the issue is the head unit RCA grounds. From what I've read a short, which I had, can cause the RCA grounds inside the headunit to blow. After this happens, you have to ground the RCA's in order for it to work. But's it's a bit of a hack to an actual problem. Since my head unit is under warranty I'm going to see if they will replace it.
06-06-2011, 07:44 AM
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Well Kenwood said they would fix it, but that it would take 2-4 weeks. =(
Wait 2-4 weeks or cave in an make a ghetto fix.
I was thinking the best ghetto fix I could do would be a large ring terminal around the RCA with a small 3amp fuse attached to the back of the deck...
-Greg
Wait 2-4 weeks or cave in an make a ghetto fix.
I was thinking the best ghetto fix I could do would be a large ring terminal around the RCA with a small 3amp fuse attached to the back of the deck...
-Greg