So I finally finished up my install.

ID ctx65cs
MB quart q.80 amp
Dayton 10" classic sub in a box.

Power is running down the drivers side, amp is grounded to the bolt just above and left of the fuel pump in the trunk.

RCA's and speaker wire are all running on the passenger side. I have the cross overs screwed down to the carpeted board I made for the amp and distribution block. Wires are run for a change to active crossover sometime. mini dsp looks interesting... I didn't end up running speaker wire into the doors. I just spliced back into the factory harness post amp. Too much hassle and I'm not running that much power anyways.

I spliced RCA's onto the pre-amp signal and got the remote turn off off the factory amp remote wire.

After all of this I have alternator whine.


Time to do some trouble shooting I guess. Should I just try a ground in the trunk with a self tapping screw somewhere?

Other issue is that the sub adjustment on the HU seems to have almost zero effect. When I turn the sub off on the HU I can hear it turn off, but almost no difference from -6 to +6. Normal, or did I just hook something up wrong?

Man, I hate dealing with electronics. I am so much better with mechanical stuff.

 

I'm dealing with the same issue with noise after installing an amp. However, I have narrowed it down to only the left side and I'm stumped as to what to do next.

In your scenario: Are you using the rear speakers? Are you using the stock amp for anything? Does your amp accept balanced inputs?

When I originally took the pre amp signals the whine was worse and on all channels. After I took it post amp thru a LOC the noise was only coming from the Left side. I don't think my amp would accept the balanced signal from the head unit.

 

If you used the same signal for the front and rear channels of the amp (assuming that you bridged the rears of the q.80), then the sub control would not work at all. The sub control from the HU only controls the sub channel. You could connect the sub channel to the rears on the q.80 and regain that control.

 

I still have the rear and center hooked up through the stock amp. I'm not sure about the balanced inputs. I don't recall it saying anything special about balance inputs.

I'll play with this a bit more tonight. Hopefully I can track down where its coming from. The noise is a constant static that doesn't vary with volume but pitch that changes with RPM.

 

Did either of you do your big 3?

 

I have not but might do it at some point. In my case I don't think that would help since the noise is only coming from the left side and is there if I connect back to the OEM amp. I'm thinking I nicked a wire or somehow damaged the amp, head unit or connector to the amp. Thoughts?

 

Sooooo I did some testing

Car on ACC, no motor- no buzz

Taped RCA cables- still buzzing (Read a thread where the ends were grounding)
pulled RCA from amp- no buzz
ran RCA outside car- still buzzing

So near as I can tell the buzz is coming from the source.
So are the pre-amp lines really balanced? I found a circuit online that will convert from balanced to unbalanced. Would that be causing the buzz? Since the amp didn't buzz with the RCA's removing, I'm guessing there is no problem with the amp itself.

Side note- My amp went into thermal protection mode on the way home from work. Realized I had some switches set wrong (They wanted me to bridge channels 3 and 4. I had bridged 1 and 2.) Swapped that all tonight. see if it happens again.

 

No, but I only have one amp. 4x80. Not a ton of power.

 

If you unplugged your amp from your HU and the alternator whine went away then the issue you are fighting is most likely a ground loop between the HU and the amp. This can be caused by the ground reference of the HU and the amp not being at the same potential.

I'd first see if the amp ground is responsible; the fuel pump ground point is not the best for audio applications. Disconnect your existing ground and use a longer large gage cable and run the amp ground back to the battery and see if the whine is still there.

If the whine is still there, then I would try and only connect the + pre-amp output to the amp's center connector. You are correct, the TL's HU outputs are balanced and the MB Quart amp is expecting a single ended input. That is the Quart's outer or ground input connector is expecting to be at a nearly constant ground potential. If you have this connected to the pre-amp output - signal then the Quart is not getting a constant ground reference and could be the path for the ground loop. In fact some RCA cables do not connect the ground or shield at one end of the cable in order to prevent ground loops through their shield.

Good Luck.

 

Yah, after a bit of reading I'm pretty certain I need a balanced > unbalanced converter. Wish I had read a little closer and just bought an amp that handles balanced input to start. RF-BLD seems to be the cheapest way to accomplish this.

 

Don't just shotgun solutions. Do some troubleshooting first.

You can check and see if the issue is with the balanced interconnects. The balanced pre-amp output signals (the + and - legs) are mirror images of each other. The balanced converter will just invert one of the legs and sum it with the other. This way any noise picked-up that is common to the two signal legs will be canceled. If you just disconnect the - leg of the pre-amp output and run only the + signal to the amp you will not have the common mode rejection of a balanced connection and your signal strength will be half of the balanced connection but it should work and with the amp's ground disconnected from the HU you will minimize the chance that the cable shield is the return path for a ground loop.

I still recommend that you try both finding a better ground for your amp and the cable.

 

u said u have ur ground on the spot near the fuel pump? my friend had the same alternator whine on his system when he grounded his system at that spot too. try somewhere else

 

Are you getting a buzz or alt. whine that increases as you move?? I believe I'm grounded to the same place that you are and I'm sure you've heard about my troubles.

Kinda worried now b/c I just picked up the MB Quart q4.150...if they don't like our signal then I might be SOL. I'm doing the big 3 this weekend and likely running wires to the trunk for an active setup.

My plans are:
1. Run active wires to trunk and hook up amp like Normal (If noise then #2)
2. Run new RCA cable to amp (If noise then #3)
3. Run RCA cable outside of car to check for interference (If noise then #4)
4. Hook RCA's up to "post-amp" connection (If noise then #5)
5. Go to gun store and purchase shotgun....

 

Both buzz and whine. The buzz is hard to describe, but its not white noise. Its like there is a ticking to it. Then there is a whine that changes pitch with engine speed. Sounds pretty much like a ground loop issue.

I've done 1,2,3. Considering 5.

 

Haha yeah, 5 is looking VERY good to me lately.

Have you tried hooking them up post amp? I know they are already crossed but what can ya do. I would try post-amp and if that doesn't work then use and LOC on the pre-amp connection. The "ticking" you say sounds like what I have. It's a clicking/ticking sound that I have also....check this out!

http://www.youtube.com/watch?v=nzBzCYSHPYY

Is this what yours sounds like?? Turn it up as it's faint in the video but not in person

 

I'll give it a shot. I just need to buy one of those RCA extenders. I have a cable I can hack the negative conductor out of.

If the balanced thing doesn't check out, I'll move it. However without the RCA's disconnected the buzz goes away. That would seem to mean the amp itself is grounded okay. Otherwise I'd still be getting the buzz.

 

Here's what might help someone else to figure out the problem...thought this was weird:


- Alpine PDX4.100 w/ Ground Loop Isolator (and without for that matter)
Ticking/Clicking/Noise: YES


- PPI Art a600.2 w/ Ground Loop Isolator
Ticking/Clicking/Noise: NO

- PPI Art a600.2 without Ground Loop Isolator
Ticking/Clicking/Noise: YES


Does this mean it's most likely a ground issue?? I might move my grounds to another place as being near the fuel pump/tank or being grounded along with a stock component might not be the best place.


BIG 3 being done this weekend also so that will take out that variable

 

That would be the same ticking that I have. I'm really trying to avoid post amp hookup. I don't want to have to deal with the cross overs and EQ that goes on inside. People have completely ditched the stock amp, so I know I can make this work. The difference seems to be they are running processors that all have the ability to take balanced inputs.

 

Yeah, the people with MS-8's and 3sixty.2's, etc seem to be fine with their SQ. Would a nice LOC work for us? One that isn't a POS and won't hinder SQ a ton. Or a line-driver?

I'm still a little unclear about the whole balanced/un-balanced signal thing? Ours is a "balanced" signal and that's the problem?? We are taking the signal before it reaches the factory amp so removing the factory amp wouldn't have any effect correct?


As shitty as this sounds...it's very nice to know that someone else has the same problem as I have right now. We can work together to fix this

 

Well don't need a LOC. That's for speaker level to line level. Pre-amp you *might* need a line driver. Some amps can take the low voltage, some can't. The Q4.150 can. 200mV is its limit and we should have 900mV.

For balanced>unbalanced conversion, the cheapest option I've seen is the rockford fostgate RF-BLD. On top of being a line driver, it also will convert a balanced signal to unbalanced. The next option up ($150ish) is a mini-dsp balanced kit. Its a processor that can do all sorts of EQ, time alignment, active crossover, etc, etc. It also will convert from balanced to unbalanced. Third I've seen is just buying a balanced amp. The amps that support it seem to be twice as expensive for similar power. Last, is the processors like the 3sixty.2, etc.

As for balanced vs unbalanced, RBeachTL explained it well. In a normal rca, the + connection carries the signal and the - is just a ground. In a balanced signal, there are normally 3 wires. + signal is the same. - signal is the same as positive, but inverted. (Like you set a speaker out of phase) Then there is a ground wire. We don't have a ground in the TL. It uses a common ground I guess, but the + and - signals are still inverted. This normally allows the connection to reject noise better than a normal RCA.

Since we don't have a ground wire, the ground on the amp, and a ground by the HU are being used. That means if there is a potential difference between the two grounding spots, you'll get voltage flowing through the ground and causing noise. Typically ground loop stuff. The difference really is we have two signal wires instead of a signal and a ground.

 

I'm not buying another amp lol. I read somewhere that they said the PDX line accepts a "balanced" signal..and that definitely wasn't the case with mine. Just a thought..

So our options are:
1. Rockford Fosgate BLD (looking at pricing now)
2. Mini-DSP (not sure what this is..)
3. Processor (most $$)

I think I'll look into the #1 or #2. If the mini-dsp can do everything a processor can, why would people spend the extra money on a processor. Eh..guess I need to just check it out and see.

 

1) $70ish
2) Check out http://www.diymobileaudio.com/forum/...ternative.html It'll give you an idea. They are talking about the unbalanced version, but I've gone through the manual of the balanced version to confirm it will convert.
3) yeah...The whole rest of my system wasn't that much.

Like RbeachTL said- do more testing before spending money.

 

The miniDSP looks VERY nice. A little complicated in what I would need to set it up other than a laptop but still very interesting. It's a nice processor for roughly $200 to your door. Awesome customer service, all the processing bells and whistles and will work with balanced signals.

Are you going to go with the MiniDSP or RF soon?? I need to order some 14 or 16 ga. speaker wire from Monoprice and I'm wondering if I should order RCA's too. Might need another pair since we've cut the ends off ours lol

 

I sort of wanted to get a mini-dsp anyways to play with anyways... This may be the excuse I need. I'll try to rule out the other issues first though. Due diligence and everything.

 

Oh just one other thing on the mini-dsp.
http://www.hometheatershack.com/roomeq/
Can automatically build parametric EQ files for the mini-dsp if you choose to go that way.

 

Would this work?

http://www.monoprice.com/products/pr...seq=1&format=2


Damn, this little Mini-DSP looks awesome!! Are you ordering one Geeky?? I'm really interested to see if it works, etc. The processing alone is worth it lol. You can buy many of these for the price of a bit.1

 

How would you connect this to the speaker wire going into the OEM amp? It looks like there are 3 prongs.

 

It's got a (+), (-), and ground wire. I'm wondering if you can cut it and use it like normal but ground the 'ground' wire somewhere near the amp. If this would work..you'd need 2 cables obviously (just for reference)

http://www.rane.com/note110.html

 

Cut the negative wire to the RCA this morning to test the balanced issue.

+ I still have audio.

- I still have the buzz/whine. I think it may be a little louder.

Next step?
Maybe try grounding the rca - wire. I'm not sure which end to ground it on though.

Thing that sucks is I'm leaving on a long car trip tonight. It'll be a long ride with this noise.

 

You would need to ground the end going into the amp. No idea if it is risky for your amp though.

 

I've read this thread and thought I'd post my experience. I could never find my source of alt. whine on the front pre-amp signal so I re-wired to a LOC post-amp. While my amp does accept down to 200mv, the signal to my sub (again, pre-amp) is so weak, I'm getting a poor output level. I've also lost the ability to control the output level on the HU. So, I'm going to a LOC on the post-factory amp sub signal also.

It might not be ideal but being able to boost the signal of the source made a considerable difference on the front and I am hoping the same for the sub. I might lose some low-end frequency output (with a LOC) but having the ability to by-pass the balanced signal input and gain more control over the sub at the HU is more important to me at this point.

Good luck to everyone. Like any car audio, it's always a fun challenge.

 

Well that's a bummer. Check my thread in a second about the Audison amp...

I've got my sub on pre-amp right now and it doesn't sound nearly as good as when it was post amp (w/o LOC though). The post-amp signal sounded cleaner, tighter, and dug lower. Weird...I know. I just think the signal is too weak. My PDX1.1000 has a switch for .2v-.8v too and the gain still needs to be up high quite a ways.

I'm still able to fully control the "sub" control though, even when I'm on the pre-amp signal. Not sure why you cant...

 

I bought a nice balanced line driver and it works great. No noise and no degredation of sq like the LOC does. I'll have to check when I get out to the car but I think it was RF brand. Very nice unit. It has enough range to where #2 on the factory HU is extremely loud. You should never set it up this way but just showing it will really boost the signal if you want it to.

 

Definitely check for us. It looks like RF makes something they call the "BLD" that takes a balanced/unbalanced signal and also acts a line driver. $75 though

 

Just went out to my car with my phone and a cable directly into the amp- no hiss. Quiet as hell though. Probably doesn't help. Just verifying I can play *something* with the engine on and no buzz.

 

Wait what? What'd you do?

 

I got one of those 1/8 TRS(headphone) to male rca cables. You know for hooking up a ipod, etc to a stereo. Unplugged the rca from HU, and plugged the phone directly into the amp and played back a mp3. No control from the HU of course, but no buzz either. Previously I just disconnected the RCA from the HU. This time I added a signal to make sure there wasn't some auto-mute function or something going on. Other than the low volume, it worked like I expected.

 

Im sorry I wasnt able to read through the whole thread but the issue I ran into after installing an aftermarket mono and 4 channel amp was the mic in the rear of the car. Before disconnecting it I was getting a really bad whine. All I did was pull down the rear dome light disconnected the green harness and it got alot better. Idk if that helps but hopefully it does. I believe its called a noise cancellation mic.

 

Only TL-S ('07-'08) have this

 

Found this elsewhere...

1. TO BEGIN: Be sure that system is correctly designed and matched for compatibility.

2. INSPECT VEHICLE: Verify ground from negative battery terminal connections to the fender and/or chassis. Upgrade as needed. This connection must be capable of handling all the current flow requirements of the system. ASSUME NOTHING, oversize as needed.

3. CHECK VEHICLE ELECTRICAL SYSTEM: Battery, alternator, etc. Make sure your alternator can adequately supply the sound system as well as other vehicle systems (alarm, lighting, etc.) AMPS/VOLTAGE NOT OK: See service technician to have system repaired or upgraded.

4. PROPERLY MOUNT COMPONENTS:
4.1 Electrically isolate them from the chassis.
4.2 Mount away from vehicle harnesses, computers, etc.
4.3 Do not hesitate to use a factory wiring diagram if needed. DO NOT GUESS!

5. PROPERLY RUN ALL CABLES:
5.1 USE CORRECT GAUGE WIRE. If in doubt, go larger.
5.2 Ground all components to a central point and/or use a "ground sniffer" to locate a quiet area.
5.3 Run power and signal cables down opposite sides of vehicle.
5.4 Properly terminate all connections (double check!).
5.5 Use a relay to provide clean power to accessories if needed.
5.6 Use the same gauge wire for power and ground.
5.7 Check signal cables for continuity and repair any open shields or cold solder points.
5.8 Ensure that the shield of signal cables, especially RCA ends are not touching the chassis.

6. HOOK EVERYTHING UP: Follow the instructions provided with the component and be sure of polarity. Make sure everything is working and set all line levels. If noise exists, please continue...

7. IGNITION NOISE: Check for noise in each of the following switch positions:
7.1 IGNITION ON, CAR NOT RUNNING: It is possibly related to an Electronic control module, digital dash, or possibly fuel pump. Do not attempt to filter an E.C.M.! Re-route cables away from control unit or fabricate a shield.
7.2 ACCESSORY POSITION, CAR NOT RUNNING (All accessories off): Substitute an isolated signal source (such as a walk-man CD, tape player, or home CD player), if the system plays fine, the head unit needs to be checked.
7.3 ENGINE RUNNING: Make certain no ground loops exist between components (if they do, see next section.).

NOTE: Pulse Width Modulated headlight switches (like some Honds cars use) can cause a whining type of noise when on, verify this type of problem by turning lights on and off while listening for noise. If this is the problem, the headlight switch may need to be replaced with an alternate type.

8. GROUND LOOPS AND/OR RADIATED NOISE EXIST: Check resistance of all ground cables; consider using central point grounding. Resistance needs to be as low as possible (around .2 ohms) on your meters lowest scale. If not, re-do or upgrade cables. If it is not possible to get the resistance's this low, try to get them all at an equal value (all the same resistance.)

TIP: Use the combination of a DVM and a ground sniffer to find the best ground point. Remove the positive cable from the vehicles' battery and check resistance's from:
A. Ground point of all units with connection point on chassis.
B. Connection point on chassis with the negative terminal of the systems battery.
C. Battery negative terminal with the chassis connection point.

8.1 RADIATED NOISE: Place head unit next to amplifier and plug directly in (or use an isolated source such as a Discman or Walkman) and turn system on. Listen for noise. If noise is gone, please continue...

Muting plugs can be used to systematically troubleshoot the point at which the noise is entering the system. Muting plugs consist of a male RCA end with the positive and negative (tip and shield) connected together (a dead short). Open RCA ends can become an antenna radiating noises into a sound system. By inserting muting plugs into the inputs of each component in your system one at a time the source of the noise can be found.

This is a process of elimination starting with your amplifiers. Insert the muting plugs into the inputs of the amps. Turn on each amp (with the muting plugs inserted) one at a time and with the car running listen for noise. If none is heard, the amps are OK. If all amps are OK, connect the next piece in the signal path upstream of the amps (typically the crossover) by connecting its outputs to the amp inputs using normal RCA cords. Now insert the muting plugs into the inputs of that product and turn on the system. If noise is heard now, power the component with an external power supply. If the system is now quiet, the noise is probably entering through the components' power supply. If no noise is heard, insert the plugs into the next component upstream in the signal path and check it the same way. Keep working your way upstream all the way to the head unit. Once the problem is found, you can stop.

9. ANTENNA NOISE I: Unplug antenna from the back of the head unit and listen for noise. If noise is eliminated, see section 13. ANTENNA NOISE II. However, if noise remains:
9.1 With head unit powered up and all speakers connected, slowly pull head unit from dash cavity and check for noise:
A. Noise Remains: Noise is entering on one of the power lines; ignition or memory. Install filter onto appropriate wire.
B. No Noise: The dash harness is radiating noise. Locate and re-route harness and shield entire harness next to the head unit. Isolate head unit chassis from metal dashboard.
9.2 If noise still remains, determine which of the following noises is present and suppress the noise at the source using the following sections:
10. IGNITION NOISE II
11. ACCESSORY NOISE
12. ALTERNATOR WHINE

NOTE: The following checks will not be necessary in most cases, but if the previous checks are not effective, continue.



10. IGNITION NOISE II: Determine the source of the ignition noise.
10.1 ONE OR TWO CYLINDERS: Try the following fixes in order:

A. Check for loose or defective spark plug wire.
B. Check for cracked rubber boots at the distributor or ignition coil(s).
C. Re-route plug wires away from car wiring or sensor leads traveling into passenger compartment.
D. Check for bad plugs (excessive gap).
E. Replace cap and rotor.
Note: you can often mist the ignition system with water to help sparks from failed equipment show up. Do this at your own risk of course.

10.2 ALL CYLINDERS: Try the following fixes in order:
A. Check ground from engine to firewall. Upgrade if needed.
B. Install a ground strap from the engine block to the chassis, as well as the hood.
C. Check heater core ground.
D. Check A.C. accumulator ground.
E. Move all wiring away from high energy ignition (H.E.I.) and plug wires.
F. Inspect H.E.I. ignitions, modules, and coils for the following and replace if needed:
1. Distributor cap; cracked, loose, or carbon build-up.
2. A rotor with burned black spot on wiper or pits in the surface.
3. Defective coil.
4. Oily film on lead terminals or inside of cap.
5. Defective ignition module (can cause ignition noise on FM only).

11. ACCESSORY NOISE: May be identified as a turn-on "pop", relay "pop", or other motor type noise.
A. Turn-on "pop" is usually due to components turning on before transients have a chance to settle. Delay the turn-on signal to suspect unit.
B. Relay "pop" is due to a component ground being at the same connection point as, say, the brake lights. Move the ground location. This can also be caused by excessively high gain settings.
C. Filter the power line to noisy motors (blower, etc) (check motor current draw for correct filter.)


12. ALTERNATOR WHINE:
12.1 CHECK ALL GROUND CONNECTIONS. If an audio component has some type of internal ground switches or jumpers, try changing settings.
12.2 CHECK ALL GAIN SETTINGS. Some components have gain built into their circuitry (either fixed or variable) and will increase signal levels. Gain controls are for matching signal voltage levels. They are not volume controls.
12.3 Check continuity of all RCA shield connections. Look for open or cold soldered connections.
12.4 On products with Balanced Differential Inputs, make sure no metal barreled RCA plugs are touching each other. This will defeat the differential circuit and create noise.
12.5 Eliminate all ground loops. (Refer to section 8: GROUND LOOPS.)
12.6 Install a cable from alternator ground to battery negative terminal along side the alternator charge wire using same gauge wire as main system power wire.
12.7 Install a filter on alternator output lead.
12.8 Have mechanic check alternator '" repair or replace if necessary.

13. ANTENNA NOISE II: Fixed mast or power antennas go to section 13.2...
13.1 Windshield antennas: plug antenna back into radio and place aluminum foil over entire dash top and ground it with clip leads to door jamb switch.
A. NO NOISE: Use noise sniffer to locate which part of the dash the noise is generating from. After locating problem area, the following fixes are possible:
1. Line underside of dash with aluminum tape and run a ground lead to it.
2. If a noisy cable can be found, move it or shield it and ground the shield.
3. As a last resort, install a conventional antenna.
B. NOISE REMAINS: Measure resistance from antenna cable shield where it plugs into the head unit to a good ground using the lowest scale on DVM. Repair if necessary. Measure shield again. If ground is still bad, replace the antenna lead.
13.2 Fixed mast or power antennas: Measure antenna ground from shield at plug end to ground on back of head unit using the lowest scale on DVM.
A. POOR GROUND: Disconnect and clean all RF connections. Check for a good ground at the antenna trim ring and mounting bracket. If the ground is poor, run a braided strap from the base of the antenna to a good ground. If noise remains, please continue...
B. GOOD GROUND: Try using a test antenna. The base must be grounded. Hold the base, not the mast.
1. POWER ANTENNA TEST: Disconnect antenna connector. Measure the resistance from the mast to the center conductor pin of the lead-in.
a. If resistance is less than 2 Ohms using the lowest scale on the DVM, measure from the mast to ground. If open (infinite resistance), suppress at the source.
b. If resistance is more than 2 Ohms, replace the antenna.
2. FIXED MAST ANTENNA TEST: Replace antenna.

14. You're Done!