jellymonster

When I'm driving, at random my music will just stop. I pull over look at the amp, and the red protect light is on instead of the green power light.

At the moment I have my carputer outputting into the 2 RCA inputs. The computer and amp are both grounded to the same place.

I only started happening when I replaced the stock HU with the computer.

What is the cause. Is it yet another dodgy grounding or something else?

I also have a sub, 2 6x9's and 2 5.25" speakers powered from it.

Thanks
JM

MP3Car.com

 

thekl0wn

Is it a 5/6-channel amp? If not, you've probably got some serious issues going on with that end of the wiring!

A bad ground can cause this. Overheating can cause this. Something broke in the amp can cause this. Clipping can cause this. etc.

__________________

jellymonster

it's a 4 channel 1000W amp. When I felt it, it did feel quite hot :S.

Are there any troubleshooting methods u guys have?

thekl0wn

How in the heck is that thing wired?

And what kind of amp is it? Almost any amp is going to get hot. It's just a matter of how hot.

__________________

jellymonster

I have a blaster bl-1000 amp.

I have the amp plugged into battery through 30A fuse. Sub bridged with 2X250W ports. The 6X9's and 5.25"s are plugged into remaining 2 250W ports.
PC is plugged into battery and ground is in amp ground port (also grounded to chasis).
The amp turns on via PC remote (m4-atx).

Anymore info needed please state

Thanks
JM

soundman98

are the 6x9's and 5-1/4's wired in series or parallel, and what is the end load on the amp(measured across the output terminals of the amp)?

also, what type of subwoofer(brand, model #) and how is it wired if it has more than one voice coil? and again, what is the end load on the amp?

how hot did the amp get? most amps, when they get hot enough to go into protect will be hot enough to burn you.

I did a very brief search(very brief) and did not see anything about the amp being 2 ohm stable, so i have a hunch that you will find that either the end load is 2 ohms(for either the sub or speakers) or that you have a grounding issue.

jellymonster

The 6x9's and 5.25" speakers are in parallel.
Amp speaker ports (250W) each.
1) One Kenwood KFC-M6942A speaker and Kenwood KFC-1350S speaker both in parallel.
2) One Kenwood KFC-M6942A speaker and Kenwood KFC-1350S speaker both in parallel.
3 + 4) Bridged kfc-w3011

The amp was definately not hot enough to burn me, so I guess that's out of the picture.

How do I measure the end load?

Thanks
JM

jellymonster

o and before I replaced the HU for the computer, I had all speakers except the 2 - 5.25" speakers plugged into the amp all running fine.

MP3Car.com

 

soundman98

to measure the end load, unplug the speakers from the amp, and put a ohm meter across the 2 connections.


I think that this is where the problem is-- having 2 speakers parallel for each channel will produce a 2 ohm load. try hooking the speakers up in series. this should produce a 8 ohm load, but will be alot quieter, and will not send the amp into protect.

jellymonster

ok, I will give that a go. At the moment I'm sorting out yet another problem, hopefully I will get a chance to test it tonight .

Thanks for your help.

roflcopter

i'm no expert, i dont even have an answer to my speculation, but when you bridge your sub, that changes the load. when the 1/2 channel impedance doesn't match the 3/4 impedance, doesnt that cause a problem?

also, some amps are not bridgeable which maybe an issue. make sure your amp exclusively states that its bridgeable.

__________________
2007 Saab 9-3ss 2.0T
Jetway J7F5M1g5d-VHE-LF, 32gb patriot SSD, 160gb WD hdd, nLite XP sp3, EWF/Horm, RideRunner

Current Progress:
PC
HARDWARE [100%] SOFTWARE [95%] FABRICATION [100%] INSTALL [75%]

Workblog

WuNgUn

Remember, bridging and parallel are two seperate things...

Bridging is when you combine the amps load over 2 channels...
i.e. a typical, single sub bridged would look like sub + to LEFT + amp connector, sub - to RIGHT - amp connector...
Bridged over 2 channels...

Paralleling is combining more than one speaker to a channel...speaker A and speaker B both connected together to the amps left channel for example...
This HEAVILY loads the amp (making the output louder) but also raising thermal issues with the amp, which could lead to load protecting.

SoundMan is right...you should run then in series to spare your amp any harm. Of course doing so, you'll also decrease the output.

Your best solution is another amp for your extra speakers...

jellymonster

ok, my amp is bridgable and my sub seems to be working fine. Has done even with old HU.

I will put the others speakers in serial and see what volume difference it makes. I can always increase the gain for them. If it is too much of a decrease, I will think of another amp, but I don't know how much more power my alternator can handle :S.

Thanks for your help guys, I will post back with the results.

WuNgUn

A 'Blaster' amp? Never heard of 'em...

So your running a sub AND 4 sets of drivers off this one amp?? And it's fused at 30A? I must of missed that reply...

Each pair of CHANNELS on my TRU amps are fused at 30A (4 channels) and they are rated for 'just' 65 watts output. The power line from the battery (4awg) to these amps is fused at 80A.
I have a very hard time believing this Blaster is a 1000 watt amp...it would likely melt at 30A fuse if it were!

I would buy another amp just for the sub, then seperate your drivers into their own channel on the Blaster, and all should be fine.

Crinos

The amp can be 450watt at max with a 30A fuse, based on 15v current.
This would be true if you had a class-d amp... well.. kinda true.. the best amps can give you as much as 98% effect.

For a normal class-b amp, you would have something like 300watt

the "blaster" is probably 1000w PEAK...

But, to answer your question...
It looks like your overpowering the amp, so that it goes hot, and shutsdown. Even thought the casing of the amp is not hot enough to burn you, the components can be to hot... especially if they are of the cheaper type.

Whey buying an amp, "getting what you pay for" is a true statement..

MP3Car.com