Hi guys, Im not sure if this is an amp problem or a power problem or what it is for that matter so i figured this was the best place to post my much needed help topic. First off my set-up is one alpine type r 15, ported box @30Hz, alpine MRP M1000 amp (bought brand new and has been installed for a month). Well i recently installed alpine type r 5.25 component set in the front doors and alpine MRP F300 to power them(also bought brand new and has been installed for 2 weeks). (i dont know if this had any effect on my sub problem but dont wanna leave out any details). Anyhow for no apparent reason the sub just stoped (no sound). So i did my usual checks, i realized that the amp light was still on so i powered down the HU and turned it back on and it worked again. But now every time i start my car the sub will work but only for about 5 minutes until it stops again. I cannot figure out what it is. My electrical system is completely factory. Gain on the sub amp is just a hair past half way and bass eq is turned off. Gains on my door speakers amp are the same. This equipment is not even a month old, although ive had the sub and amp in a few weeks longer the the door speakers and their amp. Any help would be greatly appreciated and if you may need more details about the setup let me know, i did everything myself so I know everything about it. Thanks so much in advance.
okay, lets start with the way you wired the amps. 1. Are you fused under the hood and does that fuse equal the amounts of fuses in both amps? 2. are you using a distribution block? how do you have the two amps wired? 3. How are your grounds? where did you ground the amps to?
thanks for the reply. 1. yes and yes (each amp power wire has their own dedicated fuse) (also just FYI, the MRP-M1000 is using 4-guage and the MRP-F300 is using 8-guage) 2. No, I use a specific after market battery terminal that accepts the power wires i am using. 3.Grounds are fine, i have them attached to bolts under the back seats. (each amp has its own dedicated grounding point). Further more, i have eliminated the grounds as being a problem because like i said, the amp light does not go off or go into protect mode (the sub just stops functioning), thus also eliminating an overheating problem. This is such a tricky problem and i really appreciate your concern and help so far. Personally, I've started to entertain the thought that it may have something to do with the RCA wires. I've also removed the sub from the box and inspected all the connection points for the speaker wire, everything is secure and looks good. Any other thoughts? Thanks again man, I do really appreciate it.
that's the next thing i was going to mention. The RCA's may be a problem. You can try to switch them out to see if that will fix the problem. If it still doesn't then you may want to try them on another set of pre-outs on your deck. I may also be a problem with the sub pre-out but i seriously doubt it. We're going to have to do a trial and error kind of thing with this problem. Just to make sure, your sub is a DVC 4ohm sub, right? your running it at a 2ohm load?
Yea I may swap out those RCA's. Do you think that electrical system in my vehicle could play a part? like I said, its all completely factory. And yes, its dual 4 ohm wired in parallel, so the amp sees a 2 ohm mono load.
Unfortunately I have not been lucky enough to have My volt meter across the amp the moment it stopped working. I did check it after it stopped working and it read 14.1 volts and still there was no sound coming from the sub.
ok, so i did some more research. I swapped out the RCA's and still had the problem. then swapped out preouts and tryed the preouts on my F-300 amp, still the problem persists. So I turned the vehicle on and waited until it cut out and put my volt meter across the speaker wire leads at the amp and got nothing. So I believe its the amp thats malfunctioning because if it was the sub malfunctioning i should still get a reading at the amp leads, correct? Let me know what you guys think. Thanks so much.
set it for voltage and play the system. dont check it after, check it during. check the power not the speakers.
I have checked it during and the voltage has not dropped under 14.1 volts its just that i have'nt happened to have the volt meter across the power when it cuts out but i have sat there and checked while it was playing for about five minutes straight. Its just tricky because sometime it will cut out almost instantly and sometimes it will happen after about an hour. Besides, It has to be the amp, why else would there not be voltage at the speaker leads after it cuts out while it still maintains a good voltage at the power an ground leads? To me, if it reads 14.1 volts (at the power and ground leads) and it reads a voltage at the speaker wire leads while its working of course, this tells me that the amp is getting good power and sending good power to the sub. However if after it cuts out, and still maintains a good voltage at the power and ground leads but has no reading at the speaker wire leads, it is getting good power but obviously not sending good power. Somewhere in the amp it is not working and it will receive the power but not send it. (remember during all this, the amp light never ever has gone off so i know that im reading the power thats getting to the amp and not just the power that im getting from the battery). Let me know what you think. Thanks.
In the event of a thermal shut down, will the amp power light go out? I highly doubt its a thermal shutdown though because like i said, sometimes it will shut down instantly. For example: I could go start my vehicle in the morning and the music will play for maybe 2 minutes and it will shutdown ( i dont think it could possibly overheat that quick). Other times i can start it in the morning and it will work fine for maybe an hour or two, or the whole day for that matter, but again it will end up shutting down. There is no telling when it will stop, it just does when it wants to. When it does, the amp light will be on still, there will be no voltage at the speaker wire terminals and the amp never really gets that hot anyhow, (never too hot to touch) just a little warm.
