hei, here is the pic u asked - View image: WP 20131223 001
i have decided to connect amp and sub in another car with grounding and everything. So i will know where is the problem, supply? or RCA? HU? Just it will take time finding cables and wires. I would throw away this junk model amp if i didnt know it working well 🙂
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well on the simple fact that the system works when the car isn't running is what leads me to think the problem is with the car.
when you say "everything" i hope you mean the head unit too because if you think leaving it in the audi and just extending the rca's and the remote line think again!
when you say "everything" i hope you mean the head unit too because if you think leaving it in the audi and just extending the rca's and the remote line think again!
Just curious...
Has anyone done a proper "input sensitivity" adjustment on either of these amps? The amp in question may just be tripping it's input stage overload sensors or operating above it's output device's (SOA), which may be suffering just when 13 V is reached. Seems like a simple thing to consider, but you'd be suprized how many have never done a proper system start-up.
Rigtec, cheers
Has anyone done a proper "input sensitivity" adjustment on either of these amps? The amp in question may just be tripping it's input stage overload sensors or operating above it's output device's (SOA), which may be suffering just when 13 V is reached. Seems like a simple thing to consider, but you'd be suprized how many have never done a proper system start-up.
Rigtec, cheers
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Good point there..I doubt that anyone has done any actual adjustments (beside just luck) on this one. The fact that 50Hz sine doesn´t come thrue does support that assuming.
Also I doubt that 31VAC from alternator.......everything else in car would be in a large danger to break up. Probably multimeter used has automatic range selection, so I think 31mVAC could be closer.
If groundings do loss 5V so there are no groundings at that point..so there is one place to fix.
I asked the post starter to measure those voltage losses, but nothing seemed to go through......if Nikila could repair those groundings and measure the voltage losses as explained.
I´ll post gain and crossover set up info soon.....no we have to take kids to bed 😀
Hei, how could i measure those voltage looses? Also i have been at service where my friends works, they were surprised when i told them i measured VAC over battery. I v been told its doesnt say anythign about bad alternator, cuz nobody measures VAC over there. That i was wondering too but anyway.
Hei, what do u done a proper input sensitivity adjustment? I really dont know what it can mean. Would be interesting to know what is this for and how i can do it?
Strange servicemans 🙂 If your alternators rectifier is gone bad (in short circuit for some reason) it´s going to give you AC voltage to your system. That´s why I asked you to measure AC because in that case you won´t do the VDC measuring anything.
I do understand the concerns about wire size & proper grounding, but let's not turn this into a "science project nightmare". These amps are only dependant upon a few things:
12 to 14.8 VDC, (vac has nothing to do with it), properly sized cableing, and a nice cool spot to live in (correct wiring goes w/o statement). Chances are that if the op isn't familiar with system installation, he would likely overlook the "input sens" step before start-up, so good chance that amp is being ..."overdriven".
Rig
12 to 14.8 VDC, (vac has nothing to do with it), properly sized cableing, and a nice cool spot to live in (correct wiring goes w/o statement). Chances are that if the op isn't familiar with system installation, he would likely overlook the "input sens" step before start-up, so good chance that amp is being ..."overdriven".
Rig
^^^this is true. If the gain is cranked all the way up then it is being overdriven. Try setting the gain at halfway and see if it cuts out.
I would set gain more down if it would be possible... I mean it cuts already on 10% gain
Hi,
Some members recommended you to read the battery voltage with the meter in AC. You mentioned that read 32 volts AC. To double check do the same check in another car and see if it read same as your are. Remembered that the alternator put out AC and then the rectifiers change it to AC pulsating. The battery then it is used as a capacitor and smooth it to DC. Right here when the car it is running the amplifier cuts out. When the engine it is off it ran OKAY. I think checking another car battery in AC will definitely eliminate the alternator. Do the test and see if they compare.
Some members recommended you to read the battery voltage with the meter in AC. You mentioned that read 32 volts AC. To double check do the same check in another car and see if it read same as your are. Remembered that the alternator put out AC and then the rectifiers change it to AC pulsating. The battery then it is used as a capacitor and smooth it to DC. Right here when the car it is running the amplifier cuts out. When the engine it is off it ran OKAY. I think checking another car battery in AC will definitely eliminate the alternator. Do the test and see if they compare.
Hi Nikila,
The "input sensitivity" adjustment is a means of matching the "output voltage" of the HU with the relative, predetermined "input voltage" of the receiving amplifier. The industry line voltage standard is: 2mV-9mV or 2V-8V; there's usually a switch on the amp to set the voltage range, for instance. If you are going from a L & R RCA on your HU, then you would set the amp's input range to "200mV-800mV", because 800mV is usually the highest "Line-side voltage" found in "car audio" (RCA) equipment. But if you use your HU's speaker outputs to feed your amp the signal, then you'll need to adjust the amp's input for a much higher operating range of 2V to 8V; a huge difference in range.
rigtec
Khaos in my head, i mean its everything can be possible and i really out of ideas. I just dont believe amp is broken cuz it worked okay on another car. Tomorrow i will play it with different HU maybe somehow this can be a reason, because it goes to prot. mode when rca cables are inside.
Marry Christmas btw! 😀
Marry Christmas btw! 😀
If the op were having some serious automobile electrical system issues; like 31VAC, then wouldn't he also be having trouble w/ burned lights, HU, blower motor, wipers etc... "let's just keep it logical". 
I saw your control panel. The L & R RCA's are for "low sensitivity" and are fed directly from the RCA outputs on the back of the HU. If you don't have rca outs on your hu, then you can use the rectangle plugs labled "High input" on the amp; they're meant to be fed higher input voltages from the speaker outputs. Use the "gain knob" to adjust/buffer the sound volume with the HU @ 3/4 of the way up. Here's a "How to" link below:
JL Audio header Support Tutorials Tutorial: Input Sensitivity (Gain) Setting
This is incorrect. The diodes in the alternator convert AC to DC. It does not put out AC and DC and smoothed out by the battery. The battery actually does nothing when the alternator is powering the car. If the battery is compensating for the load then the alternator is not big enough.
rigtec: Should you at first read the whole topic?
The HU is Kenwood 357sd so it has one RCA pre-out connection. Pre-Out output level is 2,5V. -> JVCKENWOOD Nederland B.V. | All Receivers > KMM-357SD (details)
Op has tried to set gain to some level, but he/she cannot open GAIN more than 10% when vehicle motor running and amp starts to blink prot light. When only with battery power -> gain can be increased a lot more and no prot light.
Battery to chassis ground wire had 5V voltage loss if I remember right.
This topic sure starts to sound like trolly 😀
E: Yes..and according to op, alternator gave 31VAC when motor running but I assume that 31mV is correct. There is a rectifier bridge in alternator, so if the alternator is good - > it produces only DC -voltage.
http://en.wikipedia.org/wiki/Rectifier
The HU is Kenwood 357sd so it has one RCA pre-out connection. Pre-Out output level is 2,5V. -> JVCKENWOOD Nederland B.V. | All Receivers > KMM-357SD (details)
Op has tried to set gain to some level, but he/she cannot open GAIN more than 10% when vehicle motor running and amp starts to blink prot light. When only with battery power -> gain can be increased a lot more and no prot light.
Battery to chassis ground wire had 5V voltage loss if I remember right.
This topic sure starts to sound like trolly 😀
E: Yes..and according to op, alternator gave 31VAC when motor running but I assume that 31mV is correct. There is a rectifier bridge in alternator, so if the alternator is good - > it produces only DC -voltage.
http://en.wikipedia.org/wiki/Rectifier
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haha thx mika, well i didnt say its 5V loss, i said its 5ohm from chassis to negative terminal on battery. And it wasnt 31mV, voltmeter is manual, i had on 200 VAC and measured 31,1 V. 🙂
I'm lost too, its really weird thing. Like there is no logic at all. well tomorrow christmas so i wont do much, but after i will install this stereo system to another car... Because i really dont understand where could be a problem, car or bad stuff... Just hope not all together 😀
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