HELP, amps keep cutting out

[ItsOnlyMe_vRS]

OK people I'm at the end of my tether.

I have a alpine d310R sterio, 1 JL Audio 250/1 (sub) and 1 JL Audio 350/2 (front speakers) amps.

THey keep cutting out, sterio works fine and when the cutout happens i can change the setup to the rears and i have sound.

After a random period of time, sometimes minutes and sometimes 10's of minutes the amps cut back in.

NOW, when the sound cutts i have noticed that there is no power lights on the amps, and the Volts to the amps are only 7.5. Now when there working the Volts are 14.

Phoned up a skoda dealer and he said that the alternator charges constant, but changes below and above 1500 RPM and from a healthy battery he would expect 14 volts.

Spoke to the people who fit my car sterio and amps and they think it may be the fuse, as the alternator isnt a smart altinator.

Has anyone else experianced this, is it just a case that the battery isnt beef enough for the sterio equipment.

Going to check the amps and earth with a mulitmeter this weekend to gain more info. Its seriously anoying.....

Car is a 55 plate fabia vrs, 2 months old

ItsOnlyMe_vRS

[faboka vrs]

First thing I thought of was to check how good your earth point is. I surgest you earth them to the seat belt mount under the seat. Undo the bolt. Take of the paint and bolt the seat belt mount on top of the earth cable.

Also check the connections of the power leads on the amps.

[faboka vrs]

As both are cutting out at the same time I doubt theirs anything wrong with the amps.

[devonutopia]

I vote for an earthing issue as well. Had something similar myself. Does it seem to work ok at low volumes, but cuts out when cranked up? :speaker:

[badgerbrain]

I have a similair system running in my octy... Earth would be the first thing to check... check also the power cable is capable of supplying enough power to the amps. check your trigger wire from the back of your radio to the amps as well.

[ItsOnlyMe_vRS]

I vote for an earthing issue as well. Had something similar myself. Does it seem to work ok at low volumes, but cuts out when cranked up? :speaker:

first time i noticed it it was at high volume, clicked off thought it was some sort of cut out to protect the speakers. Earthing is my fist choice to check this weekend

I have a similair system running in my octy... Earth would be the first thing to check... check also the power cable is capable of supplying enough power to the amps. check your trigger wire from the back of your radio to the amps as well.

Trigger is outputting 12volts, as it should. I hope the issu is with the earth.

Well thanks guys and i'll let you know monday

[Sallyann]

If it still cuts out after checking all the connections, buy or borrow a testmeter. Connect it across the 12v input at the amplifier's supply terminals and turn up the volume. The voltage shouldn't drop noticeably with heavy bass. If it does then you'll need thicker power cables, and perhaps one of these as well:

http://www.maplin.co.uk/Free_UK_Delivery/1_Farad_Capacitor_with__Display_25446/1_Farad_Capacitor_with__Display_25446.htm

Sal

[bengie]

If it still cuts out after checking all the connections' date=' buy or borrow a testmeter. Connect it across the 12v input at the amplifier's supply terminals and turn up the volume. The voltage shouldn't drop noticeably with heavy bass. If it does then you'll need thicker power cables, and perhaps one of these as well:

[url']http://www.maplin.co.uk/Free_UK_Delivery/1_Farad_Capacitor_with__Display_25446/1_Farad_Capacitor_with__Display_25446.htm[/url]

Sal

not really true about the cable size causing them to cut out, with smaller cable all it will really do is over heat and eventually burn out the cable if its way under sized.

my system is wired in zero gauge and when sat on tick over i get about a 3v dip when heavy bass kicks in

i need a bigger/more power caps

if the earth isn't the cause(but it probably is) then just check all conections

[Sallyann]

not really true about the cable size causing them to cut out, with smaller cable all it will really do is over heat and eventually burn out the cable if its way under sized.

You are wrong. The total resistance of cables + connections + fuses causes a voltage drop (as you have measured on yours). Depending upon the amount of voltage drop and the design of the power amplifier, this could cause any or all of the following:

- loss of volume

- distortion

- instability (strange noises)

- intermittent drop-outs

We don't know what size cables ItsOnlyMe_vRS has fitted, but if they are not sufficiently low resistance they will need to be changed. However the first step is certainly to check all the connections.

Of course it is possible that the power supply is OK and he's just driving the amps too hard, in which case they may cut out due to overheating.

Sal (BSc electronics)

[Whelan_vrs]

is the amp inclosed in anything? i had the problem with mine, turned out to be over heating. when it gets a certain temp it will turn off until it cools enough and will then randomly turn back on.

[faboka vrs]

If it does then you'll need thicker power cables' date=' and perhaps one of these as well:

[url']http://www.maplin.co.uk/Free_UK_Delivery/1_Farad_Capacitor_with__Display_25446/1_Farad_Capacitor_with__Display_25446.htm[/url]

Sal

Powercaps are pointless. Better spending the money on a better battery.

[bengie]

i do know about volt drop mate.

the smallest cable you will have feeding an amp really is 8awg(8mm in sparky terms) and seeing as his amps are a total of 600W(50A) then the volt drop on 8awg will be about 0.45v and the drop on my install with 0awg(50mm) on full load would be about 0.15v

don't really think volt drop is going to be a big issue here really

the real cause is either bad connection(usually earth) or the supply not being strong enough so needs either a bigger battery or power caps.

Ben(bothered?)

[150HP&counting]

Optima Yellow top battery would be my preferance over Capacitors any day - ask the guys on Car audio direct forum(who compete with their audio setups)

[Sallyann]

Optima Yellow top battery would be my preferance over Capacitors any day - ask the guys on Car audio direct forum(who compete with their audio setups)

That's a good battery, and if you need a new one it's the one to go for. But first check the voltage drop in the cables because if the fitter used thin wires no battery can ever make up for the voltage drop.

Here's how to check:

Measure the 12v on peak bass, across the battery terminals and again across the amplifier terminals:

Battery = 12v, Amp = 9v means new cables needed.

Battery = 9v, Amp = 9v means new battery needed.

But it's still not certain that either the cable/connections or battery are at fault. I've just re-read the original post and it's not clear from that whether there is a time delay before the amps cut out.

If the volume gradually fades, that suggests a battery losing charge.

If the volume suddenly cuts out after a few minutes, that suggests overheating and a thermal trip operating to protect the amps.

Sal

[chris_newell41]

your amp keeps cutting out because..... god can hear your music and he wants you to turn it down!!!

[bengie]

If the volume gradually fades' date=' that suggests a battery losing charge.

If the volume suddenly cuts out after a few minutes, that suggests overheating and a thermal trip operating to protect the amps.

Sal[/quote']

doubt that very much, all modern amps i have seen have low voltage cut outs built in so if the voltage drops too low then they just cut out.

my front amp is a bit over sensitve and when a heavy bass comes in with my system loud the fronts cut out due to the momentary drop in voltage.

i had a nightmare with my previous amp cutting out all the time and it was due to a bad earth where it had come loose.

did you not reaad my previous reply, the one with actual calculations involved rather than just theory? i sat there and worked out the voltdrop on what is more than likely the size cable he has and it's nominal, quit pushing the voltdrop issue as it's sod all over the 10ft or whatever that the cable is. if he is pushing his amps to the limit then he is losing a maximum of about 0.5v which is going to make absolutely no difference at all.

[Sallyann]

did you not reaad my previous reply' date=' the one with actual calculations involved rather than just theory?[/quote']

Yes I did. Since we don't know what cable they used it's difficult to justify any calculation.

There are several possibilities and we've explored them all. I don't see any point in speculating further until he's done the tests.

Sal

[bengie]

8awg is the smallest he will have, so the chances of voltdrop being an issue greatly reduce.

[chris_newell41]

why not use the normal stereo unit? how loud do you need it ??? are you deaf?

[macatac]

why not use the normal stereo unit? how loud do you need it ??? are you deaf?

The standard HU is pants,it's not all about excess volume, a good HU and amp and some decent speakers can do wonders to the clarity of the music .

[walkie]

why not use the normal stereo unit? how loud do you need it ??? are you deaf?

Oh dear.....

[bengie]

chris what car do you drive? is it a base spec 850 mini?? they can reach the speed limits and carry 4 people

[ItsOnlyMe_vRS]

why not use the normal stereo unit? how loud do you need it ??? are you deaf?

THats a shame!!!!!!!!

JUst cos i have upgraded my audio equipment doesnt mean i have to have it at earth shattering volume. I take it that this means that you drive your car to the max everytime you get into it!!!!!!!!

I have an IPOD, doesnt fit into the standard Unit

Yes I did. Since we don't know what cable they used it's difficult to justify any calculation.

There are several possibilities and we've explored them all. I don't see any point in speculating further until he's done the tests.

Sal

The wire from the baterry is 0/4 gauge with a Directed Electronics fuse box.

After investigating DEEPLY into the install of the system, which was done by a company not myself. I found that a screw had come loose causing a loose power connectin inside the fuse holder.

Screwed it down tight and (touch wood) all seems OK.

Thanks for you help on this matter guys and gals:thumbup: