Amp All Of A Sudden Shutting Off At High Volume?

[Brandon X]

Looks like ive come across ANOTHER problem with my system. I swear next time I put a full system in a vehicle, im saving up like 3k and buying the BEST and getting it installed by the best. I'm so sick of this shit.

This all started a few days ago. Was on my way to my girl's house which is an hour away, with my stereo turned up to 25 for the majority of the way. I always do this, and that's the volume I usually keep it at since ive broken the subs in which was a month or so ago. Shit sometimes I even go to 28-30 for a couple songs. Well I was playing a song that usually bumps hard (F.L.Y. - Swag Surfin') like 5 minutes away from her house and the amp cuts out on the real hard bass parts in the song. This has NEVER done this before with these subs. I get there, turn it up to 25 like it's been, and look in the back and see the amp light shuts off every time the bass hits real hard.

I know it's not overheating, and im having a hard time believing the amp is over/under powering the subs. I just don't know why all of a sudden it's doing this. And I think it's getting worse, because I turned down the gain and the sub level on my head unit and it's STILL doing it, even on songs that don't even bump that hard!

The amp is a Kicker ZX750.1 and the subs are 2 Kicker 12" CVR's in a ported box. Everything was bought brand new. Could the subs or amp be going? If so why the hell? Those subs match up almost perfectly with that amp, and the gain hasn't been over 3/4th ever, so I don't see what the problem could be. If that's the case though im going to sell them while I still can and invest in 3 12" CVR's or 2 15's. Sorry for the super long post but after dropping around $1500 on this crap and problem after problem occurring, it starts to get a little frustrating.

[grnrpr68]

check the ohm of the subs at the amp and make sure you are not dropping below what the amp can handle

[Crispy]

Subs may be partially blown. The will play at a very low level, but once the music starts pumping through it will cause the amp to go into protect. As mentioned above, check the resistance of the subwoofers. Also, see of you can swap a friends box into the truck to test the amp.

[xX Mavr1ck Xx]

When I installd my friends, he went through the same thing, you might take a look at the power wire fuse. He had a shitty fuse holder and it had melted the fuse, the solution was buying an ANL fuse holder w/ ANL fuses.

[Brandon X]

Anyone else got any other ideas? It's gonna really suck if I end up blowing them.

[Mild]

get a DMM and check your voltage @ the amp.

then check your fuse up front.

[blueflamed03]

what is voltage, AT the amp when you are hammering it? are they two DVC 2's? have SSF on? what gauge is power wire?

[josetizapan]

Mine was doing the same and my amp connection to the battery was all corroded i will check there. An also check how meny volts your getting into the amp making sure you dont have a voltage drop and your getting full power.

[Brandon X]

what is voltage, AT the amp when you are hammering it? are they two DVC 2's? have SSF on? what gauge is power wire?

I'll have to check the voltage. Yes they are two DVC 2's, 0g power wire, and what is SSF?

[2drhoeon4s]

also do you have an eq/ linedriver? sometimes your input signal is too strong. more than likely your subs are wired at 2ohms which is prolly the lowest the amp can take. and when they play at high levels the impedance is dropping below 2ohms causing the amp to shut off... Does it turn back on after a few seconds?

---------- Post added at 10:11 PM ---------- Previous post was at 10:08 PM ----------

try wiring your subs up to 8 ohms and see if it stops the amp cutting off.... it wont be as loud but you will be able to run it full tilt without it shutting off if it is your problem....
if that fixes it, then you need to get a different amp that will run below 2 ohms so that if the imp drops it wont shut off.

[Brandon X]

also do you have an eq/ linedriver? sometimes your input signal is too strong. more than likely your subs are wired at 2ohms which is prolly the lowest the amp can take. and when they play at high levels the impedance is dropping below 2ohms causing the amp to shut off... Does it turn back on after a few seconds?

---------- Post added at 10:11 PM ---------- Previous post was at 10:08 PM ----------

try wiring your subs up to 8 ohms and see if it stops the amp cutting off.... it wont be as loud but you will be able to run it full tilt without it shutting off if it is your problem....
if that fixes it, then you need to get a different amp that will run below 2 ohms so that if the imp drops it wont shut off.

Nope no eq/linedriver. The amp doesn't really turn off, it's strange. The power light shuts off on the hard deep bass, and turns right back on as soon as its over. It's frustrating as hell.

[JKmotorsports]

When you check for voltage, check it at the connections at the amp, with the amp on roughly half power. Everyone keeps mentioning to check the power wire/fuse, but don't forget the ground. Just like on the power side, a loose gnd will cause resistance and a high voltage drop, especially under load.
If the power light is turning off under high loads then coming back on, then it could be a voltage drop issue rather than an impedance issue with the subs.

[gechidan]

I had that same problem with that same amp but I never found the problem......

[Brandon X]

Well im definitely going to have my voltage checked. Since I don't have the tool to do that im gonna have my audio guy who installed all this shit check it and fix the problem for me if he can.

[nimrodcs]

+1 on checking the ground connection. I put a crappy little system in an old cavalier I had years ago. About a week after installing it, it did the same thing yours did. When the bass would hit, the power LED would turn off then back on. I thought it was the crappy little amp I had, but my brother-in-law found out my ground came loose.

After fixing that, my crappy little system was pumping crappy little beats. All was fine.

[blueflamed03]

the amp will play under 2 ohm easily, but two dual 2's, playing will have an actual higher impedance rise.

SSF, is the box ported?

[2drhoeon4s]

not neccisarily.... If a coil is bad it will throw the reading off.... also we had mine hooked to an ohm mete while playing andjust like clockwork, it dropped below stable impedance on the heavy low notes and the amp shut off then turned right back on. EVerytime. I rewired my subs up to a higher ohm load and I havent had that problem since. full tilt on any note and it has never shut off since...

Get an ohm meter and check your nominal impedance.turn everything off including the truck. all windows up and all doors closed.unplug the speaker wires from your amp and hook up the ohm meter to them, whatever they rest at is your nominal impedance.

[Brandon X]

I'll have to also check the ohms, hopefully my dude has an ohm meter, he should.

Here is the specs of what amp I have and the subs if that helps anyone.

Amp:
# Amplifier Class : D
# Number of Channels : 1-CHANNEL
# Maximum Power : Not Known
# RMS Power Output @ 4 Ohms : 375 watts x 1
# RMS Power Output @ 2 Ohms : 750 watts x 1
# THD: <1%
# Signal-to-Noise Ratio (dB) : >95dB, a-weighted, re: rated power
# Frequency Response (Hz) : 25Hz - 200Hz
# Input Sensitivity (Low Input Level) : 125mV - 5V
# Input Sensitivity (High Input Level) : 250mV - 10V
# Built-in Crossover : Low-Pass
# High-Pass Crossover Frequency : N/A
# Low-Pass Crossover Frequency : 50Hz - 200Hz
# Bass Boost : 0 to 18dB
# Bass Remote : Yes
# Fan Cooled : N/A
# Fuse Rating : 40A x 2

2 of these in a ported box:
# Subwoofer : 12" (300mm)
# Power Handling Watts (PEAK) : 800 Watts
# Power Handling Watts (RMS) : 400 Watts
# Resonance Frequency : 26.1Hz
# Total Q-Factor (QTS) : .527
# Equivalent Volume (VAS) : 3.37cu.ft (95.37L)
# Frequency Response : 25~500Hz
# Outer Frame Diameter : 12-1/2" (31.7cm)
# Mounting Cutout : 11-1/8" (28.3cm)
# Mounting Depth : 6-5/16" (16.1cm)

[2drhoeon4s]

yes that is definately the problem... your subs are dual 2 ohms correct? that would mean each sub is wired series up to 4 ohms and then both are paralleled back down to 2 ohm. but they could be sitting at 1.9ohms or 1.8ohms which could cause the amp to shut off.

This is exactly what my problem was. I had 4 dual 4 ohm subs wired to 2 ohms on a 2 ohm stable amp. It worked fine until i played lower notes in which case the amp would cut off for a second or two then cut right back on....I had to rewire the subs to a higher ohm load until i can get a different amp than will handle lower than a 2 ohm load.

[Brandon X]

yes that is definately the problem... your subs are dual 2 ohms correct? that would mean each sub is wired series up to 4 ohms and then both are paralleled back down to 2 ohm. but they could be sitting at 1.9ohms or 1.8ohms which could cause the amp to shut off.

This is exactly what my problem was. I had 4 dual 4 ohm subs wired to 2 ohms on a 2 ohm stable amp. It worked fine until i played lower notes in which case the amp would cut off for a second or two then cut right back on....I had to rewire the subs to a higher ohm load until i can get a different amp than will handle lower than a 2 ohm load.

They are dual 4 ohm CVR's. So you're saying the guy who wired them up wired them wrong? It was a different guy who wired them up for me and I thought everything was fine. Everything worked great untill just a week ago, that's what I don't understand.

I went outside and took a picture of how the guy wired them up since I don't know jack shit about car audio so I don't wanna describe it wrong:

http://i43.tinypic.com/2wn4knk.jpg

The red & black wire is coming from the amp into that first sub. And the clearish redish wire is coming from that first sub to the second sub. Is that right?

I want it wired down to 1 ohm that way I can the most out of my amp as possible you know?

[josetizapan]

According to the specs you posted of the amp it can only handle a 2ohm load.

[nimrodcs]

The wires coming from the amp look a bit small. What gauge are they?

[Brandon X]

According to the specs you posted of the amp it can only handle a 2ohm load.

I think you may be right. But all of the diagrams ive been finding on the internet are for 1ohm or 4ohm loads. Is there a way to wire my two subs down to 2ohm?

And the wire is 12g if im not mistaken. I'll have to double check.

[2drhoeon4s]

12g is fine for wiring especially for only 750w.... if they are dual 4s then they can wire to 4ohms or 1 ohms. if they are wired at 1 ohm right now then the coils are prallel inside the box, then obviously they are also parallel on the outside....making a 1 ohm load. it could be too much for your amp to handle.take it and wire it up to 4 ohms to see if that fixes it.... take the positive of one terminal on the box and connect it to the negative of the other terminal. then wire the remaining two to the amp. this should give you a 4 ohm load.

+- +-

Connect the reds together and connect the blues to the amp

[Brandon X]

12g is fine for wiring especially for only 750w.... if they are dual 4s then they can wire to 4ohms or 1 ohms. if they are wired at 1 ohm right now then the coils are prallel inside the box, then obviously they are also parallel on the outside....making a 1 ohm load. it could be too much for your amp to handle.take it and wire it up to 4 ohms to see if that fixes it.... take the positive of one terminal on the box and connect it to the negative of the other terminal. then wire the remaining two to the amp. this should give you a 4 ohm load.

+- +-

Connect the reds together and connect the blues to the amp

Alright il give this a try. If this is the case and the amp isn't stable at 1ohm (which it probably isn't) I guess il have to get a different amp even though I really don't want to. I wanna keep it full kicker but at the same time I would need an amp stable at 1ohm and I don't think they make one.

[2drhoeon4s]

get a RF T10001bd they do a bit over 1K RMS. Might be a bit much for your subs but be easy on the gain and you should be good. matter of fact I have a friend selling 4 of them....

http://www.floridaspl.com/forums/showthread.php?t=9313

tell hime you were reffered by leamangriffin.. that is my name on that forum.

[josetizapan]

get a RF T10001bd they do a bit over 1K RMS. Might be a bit much for your subs but be easy on the gain and you should be good. matter of fact I have a friend selling 4 of them....

http://www.floridaspl.com/forums/showthread.php?t=9313

tell hime you were reffered by leamangriffin.. that is my name on that forum.

Do you know how much he is asking for just one?

[2drhoeon4s]

300 each plus shipping... Good guy... he has all the boxes and bass knobs and the birth sheets. all these amps birth at 1300w or more. sign up and ask for references. hes a good seller.

[718frankb]

+1 on the rf t10001bd - bullet proof amp

[blueflamed03]

yes that is definately the problem... your subs are dual 2 ohms correct? that would mean each sub is wired series up to 4 ohms and then both are paralleled back down to 2 ohm. but they could be sitting at 1.9ohms or 1.8ohms which could cause the amp to shut off.

trust me, that amp will not shut off evenm at 1.8 ohm

They are dual 4 ohm CVR's. So you're saying the guy who wired them up wired them wrong?

yes, that amp plays at 2 ohm, you have it wired to 1 ohm, it will 'play' but not long, you need to match the mnaufactures rating, to the proper impedance.

You need two dual 2s and your fine.

[2drhoeon4s]

wow, I never said it would shut off i said it could.

also, he didnt wire it wrong, he installed what the customer gave him to install. he just bought the wrong type of subs....

either subs or amp. Doesnt matter which you choose.

And you dont always have to match the manufacturers rating....

Ive seen 1 ohm stable amps play at .70 ohm all day no problem. just depends on the quality of the product....

[blueflamed03]

also depends on impedance rise, set readings of each manufactures coils, box, power, voltage, etc,etc.
It's always on the safer side daily, to follow what the manufacture recommends. If someone plays down to .5 ohm and wonders why they blow stuff up, they surely can't blame the manufacture.....

I just agreed, his INSTALLER wired it incorrectly. :D

[JKmotorsports]

I think something is being overlooked here. Brandon stated in his first post that his "amp light shuts off". If the amp loses power and turns off, then it's a power issue, not an impedance issue. An impedance issue will shut down the output of the amplifier (or fry transistors if the amp doesnt have a low impedance protection circuitry). Subs dropping below the ohm load of its rating can temporarily shut down the audio output circuit, but not the amp's power supply circuit. The power light turning off on the amp during high volume suggests that the issue is a voltage drop somewhere. Problems like these are usually either a grounding issue or a voltage drop at the fuse holder. 99% of the troubleshooting I do for this exact same case is due to some sort of bad connection somewhere, usually at the fuse holder or the grounding point.

[blueflamed03]

agree Jeff, the amp has a power light and a protection light, he may be mistaken which one is on. But agree 100%, could be voltage, but wired to 1 ohm, for sure will shut it down at higher volumes.

[JKmotorsports]

Oh yea, I definitely agree the amp should be going into protect if the amp is seeing 1ohm.
But are we sure the amp is seeing a 1ohm load? If the subs are DVC 4, then the coils on each sub can be wired in series, bringing it to 8 ohms. With both subs at 8 ohms and wired parallel to each other, that would present a 4 ohm load at the amp. If he's been playing his system as hard as he claims for a long while now, then normally the amp should have been going into protect a while back if it was seeing a 1 ohm load. That leads me to believe he may have the coils wired in series and the subs parallel. That would bring us back to the voltage drop issue:) Did I make sense?

[Brandon X]

I should have mentioned that the amp light shuts off and the protection light comes in. Sorry about leaving that out.

I think I probably should sell these subs and buy 2 CVR 2 ohms. I think that would fix the problem because it's not wired correctly and I don't want to mess up my amp or subs in the long run.

Thanks for all the help guys I really appreciate it. Just to make sure though im gonna have him check everything out and if the voltage and everything is alright then im going with the new CVR's.

[blueflamed03]

makes total sense, if he had another guy wire it up, no offense at Brandon at all, is some installers feel "if 2 ohm is good, 1 ohm is perfect" when in all reality it may not work. May work for a quick burp on a competition vehicle, but not on a daily user. there's a couple ways he could have wired the coils in the box, no telling.
But Brandon, if you make sure you have good voltage at the amp, a good solid ground and run it at 2 ohm daily, you'll be fine.
Some of the ZX's are picky, I've seen some ZX2500.1's run below 1 ohm daily, but really good voltage,etc. So some are more picky than others :D

[JKmotorsports]

I should have mentioned that the amp light shuts off and the protection light comes in. Sorry about leaving that out.

.

Ahhh, well, *(*^! That makes a difference!:D

[2drhoeon4s]

yeah could be voltage issue also. If it is wired at 1ohm you have been lucky the amp has held up this long....get a multimeter and test the voltage full listening volume AT THE AMP....

[blueflamed03]

the amp will shut down if it see's an impedance it doesn't like.

[xX Mavr1ck Xx]

Maybe, have you let the guy who installed it take a look at it? I think since he installed it, he might have a better idea of whats going. IMO

[2drhoeon4s]

eh i dont think that will matter much.... simple setup 2 12s and an amp. I think we pretty much covered anything it could be. Now he just has to decide whethr he wants different subs or a diff amp... or both.. I say wall it off. big boy style.