Help a newb with amp hitting low voltage cutoff

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Not to throw a monkey wrench in the discussion.... And not to doubt Kicker's crack tech support.... But are you sure the amp is shitting off due to low voltage.. I have a KXM1200.1 and those amps were only rated to go down 2 ohms... The KXMA series I know says it can do 1 ohms... but it might not be 1 ohm stable at 12V cranked up... Also how was the gain set on the amp?

The shop set the gain but I can open it up and take a look. I was seeing 11.2 at about the lowest on my cheap multimeter and they said shutoff is 10.8. That’s all I’ve got to go off, but it **** sure acts like low voltage cutoff.

Not that easy on a boat my friend, a lot of boats don't even have a Alternator, mine has a generator. Many marine amps are meant to be ran on battery power only....

I do have a alternator, but it’s not necessarily “legal” to have it modified due to coast guard certification.

 

[hispls 5,000+ posts]

yeah if it's good ofc wire 4g is good that short if it's cca wire i guess that could be it.

Probably not making the amp power down, but I too would be a little skeptical about running aluminum wire to those Kicker amps.

The alternator is a 70 amp.

And you are running 300A worth of fuses. Granted you should never be drawing more than 180A between the pair real world, but still. Assuming your boat can potentially draw most of the 70 (since that's why they use that size alt) it may well be that even at modest power you simply are draining those batteries faster than you can charge them.

That said, I'm suspicious about the whole 11V thing. Most amps shouldn't power off until below 10V so either your meter isn't terribly accurate or there's some other issue. I'd also advise you to triple check your amp is seeing 1 ohm load or higher. The symptoms (assuming alt and both batteries are functioning properly) are more in line with the amp being run at .5 ohm and going into protect from that as you push it hard as opposed to a low input voltage protect.

In short, I'm leaning towards some other issue besides low voltage at the amp.

 

[hispls 5,000+ posts]

Not to throw a monkey wrench in the discussion.... And not to doubt Kicker's crack tech support.... But are you sure the amp is shitting off due to low voltage.. I have a KXM1200.1 and those amps were only rated to go down 2 ohms... The KXMA series I know says it can do 1 ohms... but it might not be 1 ohm stable at 12V cranked up... Also how was the gain set on the amp?

I was thinking this as well. I also believe that fully charged 110AH batteries should run his amps plenty engine off and those amps shouldn't shut off until below 10V.

 

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Probably not making the amp power down, but I too would be a little skeptical about running aluminum wire to those Kicker amps.



And you are running 300A worth of fuses. Granted you should never be drawing more than 180A between the pair real world, but still. Assuming your boat can potentially draw most of the 70 (since that's why they use that size alt) it may well be that even at modest power you simply are draining those batteries faster than you can charge them.

That said, I'm suspicious about the whole 11V thing. Most amps shouldn't power off until below 10V so either your meter isn't terribly accurate or there's some other issue. I'd also advise you to triple check your amp is seeing 1 ohm load or higher. The symptoms (assuming alt and both batteries are functioning properly) are more in line with the amp being run at .5 ohm and going into protect from that as you push it hard as opposed to a low input voltage protect.

In short, I'm leaning towards some other issue besides low voltage at the amp.

I’ll do my best to answer this. The 1200.1 has a 150A fuse, as recommended by kicker, and the 800.8 has a 100A. I’ll pull out my paperwork for the subs and should be able to figure out the ohm load that way? Kicker tech told me that low voltage cutoff is 10.8V, and yes, I do have a crappy multimeter.

 

[BOOMINGRANDPA 5,000+ posts]

Your boats alternator isnt strong enough for the current draw of the amplifiers. The batteries are discharging faster than the alt can charge them back up.
Is it outboard powered or an i/o?

And btw ignore what gramps says cuz its usually wrong and misguiding.

lol i was the one smart enough to call the guy with a boat but whatever..

 

[Rotate]

I was thinking this as well. I also believe that fully charged 110AH batteries should run his amps plenty engine off and those amps shouldn't shut off until below 10V.

And these are 120AH. The batteries should run the system, according to the battery manufacturer, and Kicker. I consulted both before buying. They told me to buy the XP1500 so I bought the 3000s. Lol

 

[tymoto21 10+ year member]

Any chance the amp is hot?

Does the amp protect right away at times or is it always after hours of playing?

I do know my kicker low voltage protected WAY before my RD amp. But I was down in low 10’s and the kicker did cut out right around 10.8v

You could try to add a ground wire temporarily to see if maybe the wire was damaged at all. It really does sound like a bad ground.

 

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Any chance the amp is hot?Does the amp protect right away at times or is it always after hours of playing?

I do know my kicker low voltage protected WAY before my RD amp. But I was down in low 10’s and the kicker did cut out right around 10.8v

You could try to add a ground wire temporarily to see if maybe the wire was damaged at all. It really does sound like a bad ground.

I do not believe it’s hot. I can walk outside right now and at a specific volume, it’ll shut off. If I ran another ground, would it need to be another 4 gauge back to the battery? There’s really not much to ground to in a fiberglass bathtub.

 

[hispls 5,000+ posts]

I’ll do my best to answer this. The 1200.1 has a 150A fuse, as recommended by kicker, and the 800.8 has a 100A. I’ll pull out my paperwork for the subs and should be able to figure out the ohm load that way? Kicker tech told me that low voltage cutoff is 10.8V, and yes, I do have a crappy multimeter.

My point being two fold. First just going by the fuse rating and the alternator rating you should expect a deficit there somewhere, and second those amps are both over-fused. It is likely you wouldn't open an 80A fuse on the 1200.1 or a 60A fuse on the 4 channel. In fact I'd say you'd have to be pushing things pretty crazy to open and 60 and 40 respectively.

Don't get so defensive with this stuff. None of us are there to see what you've done and few of us own boats or those exact amps. You'll get a lot of ideas for troubleshooting or common fixes for similar problems. This is going to come down to trial and error and don't think you're too clever to double or triple check something particularly as other things are eliminated from the list of possible culprits. The best of us have overlooked obvious stuff now and again.

 

[Rotate]

My point being two fold. First just going by the fuse rating and the alternator rating you should expect a deficit there somewhere, and second those amps are both over-fused. It is likely you wouldn't open an 80A fuse on the 1200.1 or a 60A fuse on the 4 channel. In fact I'd say you'd have to be pushing things pretty crazy to open and 60 and 40 respectively.
Don't get so defensive with this stuff. None of us are there to see what you've done and few of us own boats or those exact amps. You'll get a lot of ideas for troubleshooting or common fixes for similar problems. This is going to come down to trial and error and don't think you're too clever to double or triple check something particularly as other things are eliminated from the list of possible culprits. The best of us have overlooked obvious stuff now and again.

I understand.

But it did indeed pop a 100A fuse. Coincidentally, that happened about 5 minutes into the first trip after switching from standard marine deep cycle batteries, to the XS batteries.

View attachment 26557610

 

[hispls 5,000+ posts]

I understand.

But it did indeed pop a 100A fuse. Coincidentally, that happened about 5 minutes into the first trip after switching from standard marine deep cycle batteries, to the XS batteries.

View attachment 26557610

You really should not be opening 100A fuses on a 1200W rated amp. This is a red flag for me.

Look at the Kicker power ratings:

@ 14.4V, 4Ω mono, ≤ 1% THD+N : 600 x 1

@ 14.4V, 2Ω mono, ≤ 1% THD+N : 1200 x 1

@ 14.4V, 1Ω mono, ≤ 1% THD+N : +/- 10%

WTF is +/- 10%? Whatever it is, that's not a proper 1 ohm rating and if it'll make its rated power at 2 ohm there's probably where you want to operate to be safe. As you drop impedance efficiency goes out the window (opening 100A fuses) and it is very rough on electronics particularly if the amp isn't purpose built for competition tier abuse. Sounds to me like an amp that's meant to drive 2 ohm.

I used to run Kicker ZR and the very early KX series I drove at low impedance and they did get protect happy when you pushed things. Depending on the subs/box they'd even stay out of protect most of the time, but they did protect here and there. I'd audition some subs that you can wire to a 2 ohm load and see what happens.

More worrying is if you're pushing this thing into protect and drop into 2 ohm sub load you may or may not be satisfied with the output which puts you in a real bind because adding power seems impractical for you and who knows how much volume you have for a big sub box or bigger subs?

 

[Rotate]

You really should not be opening 100A fuses on a 1200W rated amp. This is a red flag for me.
Look at the Kicker power ratings:

@ 14.4V, 4Ω mono, ≤ 1% THD+N : 600 x 1

@ 14.4V, 2Ω mono, ≤ 1% THD+N : 1200 x 1

@ 14.4V, 1Ω mono, ≤ 1% THD+N : +/- 10%

WTF is +/- 10%? Whatever it is, that's not a proper 1 ohm rating and if it'll make its rated power at 2 ohm there's probably where you want to operate to be safe. As you drop impedance efficiency goes out the window (opening 100A fuses) and it is very rough on electronics particularly if the amp isn't purpose built for competition tier abuse. Sounds to me like an amp that's meant to drive 2 ohm.

I used to run Kicker ZR and the very early KX series I drove at low impedance and they did get protect happy when you pushed things. Depending on the subs/box they'd even stay out of protect most of the time, but they did protect here and there. I'd audition some subs that you can wire to a 2 ohm load and see what happens.

More worrying is if you're pushing this thing into protect and drop into 2 ohm sub load you may or may not be satisfied with the output which puts you in a real bind because adding power seems impractical for you and who knows how much volume you have for a big sub box or bigger subs?

This is inline with what the installer was hinting at. He didn’t come right out and say it, but he kind of danced around that this amp would not meet the demands of the subs. So, how I ended up with the amps, is a friend of mine has worked at Kicker for a long time as a salesman, and I got them at a very good cost with the intent to run some other junk stuff that was already in the boat. This year I decided I wanted to upgrade the subs, and I wanted the previous wiring job cleaned up, and a proper enclosure built. The shop recommended the W6s over L7s, and since they were building the enclosure, and doing the work, I took their recommendation. They went through the whole system and rewired everything and looks to have done a great job. I feel like he didn’t want to come right out and trash the amps, because my friend works at Kicker.

As I was on the boat today, I was thinking about my post here and I feel I should clarify this voltage drop. To be more clear, at a normal listening volume, or for a better way of putting it, time of less than “max draw” on the amp, I’m seeing 12.3-12.4V at the amplifier. The only time I see it drop into the low 11s are on a low note, at high volume (high amp draw), so the low 11 volts are just brief moments of high draw. All other times, it’s 12.3-12.4V. I never see the battery drop below 12.3.....ever. Even on a high volume, low note, max draw situation. The battery never drops. So going into the amp is he same 12.4V at any volume, except for when it hits a real low note, and then it drops to low 11s at the amp, and not the battery.

As far as opening the 100A fuse, Kicker flat out told me it would, and that amp needs a 150A. That’s all I know. I don’t claim to know if that’s right or wrong, but that’s what they said.

 

[hispls 5,000+ posts]

As far as opening the 100A fuse, Kicker flat out told me it would, and that amp needs a 150A. That’s all I know. I don’t claim to know if that’s right or wrong, but that’s what they said.

That is wrong and you should not be opening those fuses for normal or even hard music listening. Whatever Kicker says, that amp is obviously meant to drive a 2 ohm load and I wouldn't suggest to run it any lower outside of SPL burst for competition. I was running 1200W amps in my Jeep for a few years and rarely opened 60A fuses. I only opened a couple 80A fuses competing.

Do you have a way to test that amp to a 2 ohm load? I'm betting it doesn't protect and you won't open a 100A fuse.

 

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Not really. With the speakers being DVC 4 ohm subs, I get 1 ohm. I don’t have much else laying around.

 

[poolman966554]

thinking outside the box here, maybe 4 ohm setup is the way to go? Follow me here.. You can get a decent 5k amp for $600 (wolfram 4500.1) that does more power at 4 ohms than you current amp at 1 ohm. But what im thinking here is Efficiency. Amps are terribly inefficient at 1 ohm vs 4. typical 1 ohm is around 60%? and 4 ohm load s can get in the 80% range from most dyno tests ive seen. Less hard on everything, and you can still be loud. that will give you extended play time aswell. Just a suggestion.