Subwoofers turn on and off randomly

[Paralystic]

So the system is 2 10 inch alpine type s subs with a 1800 watt hifonics mono amp (wired at 1 ohm 1000 rms), the problem is that the subs will randomly go from working with full power to barely thumping (just moving enough so i know they are recieving some kind of power and also worth mentioning the letters that light up on the amp stay on and just as bright as normal.) and it seems to happen completely randomly. Sometimes they stay on for 5 minutes before cutting off sometimes they stay on for 30 seconds, and it happens when driving around or with the key back, all the wiring is clean and tight too. The system itself should be fine because I had it working perfectly fine in my minivan before installing it in my 2002 toyota corolla, when the problem immediately started. The only problem I can think of is the ground might not be in a good spot (top of the trunk) but ive cleaned all the paint off of it and the signs dont seem to be that of a bad ground, any ideas?

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[loudenuff]

So the system is 2 10 inch alpine type s subs with a 1800 watt hifonics mono amp (wired at 1 ohm 1000 rms), the problem is that the subs will randomly go from working with full power to barely thumping (just moving enough so i know they are recieving some kind of power and also worth mentioning the letters that light up on the amp stay on and just as bright as normal.) and it seems to happen completely randomly. Sometimes they stay on for 5 minutes before cutting off sometimes they stay on for 30 seconds, and it happens when driving around or with the key back, all the wiring is clean and tight too. The system itself should be fine because I had it working perfectly fine in my minivan before installing it in my 2002 toyota corolla, when the problem immediately started. The only problem I can think of is the ground might not be in a good spot (top of the trunk) but ive cleaned all the paint off of it and the signs dont seem to be that of a bad ground, any ideas?

Well for one that's generally a lot of power on a stock electrical system, especially on an older commuter like that. Could be overheated or low voltage, they could be cutting back on power to prevent damage to the amp/woofers. Trunk lid isn't that great of grounding. Try cleaning off the paint around your strut towers (the things in the back corners of your trunk with large lock nuts on them). 2 you should have a local autozone or shop of that nature test your battery output under load (when you have your speakers playing at listening volume with a bassy song. Or you can do it yourself with a DNM if you know how to. Try having a load test first since most shops do it free. If it's low voltage you might want to do a big 3 upgrade or even replacing your battery with an agm. Stock alt might be too low amp to support the power draw. Also make sure your amp wiring is sufficient to support that much power, gauge and fuse. Give that grounding location a try as well, I use to ground to thin metal on my car and had problems when using bigger amps. Good luck to you

 

[Paralystic]

Ive done a load test myself and found that the voltage never drops below 12 when the bass is hitting at its hardest and normally doesnt go under 13.5 with the full load, while i understand this is not good it should be good enough for the system to work properly (ive seen other people use small alternators on big sytems and nothing like this happened but i thought the same thing you did), you mentioned overheating but i know the amp that isnt the problem because it sometimes doesnt work when i first start my vehicle but will kick on maybe 5 minutes or so later and play. my alternator is only rated at 50a so i know I need to upgrade it soon and when i do that ill get the big 3 upgrade and probably an xs battery too, i was also thinking about using self tapping screws to making a new ground just straight into the chassis of the vehichle, but ill probably try you're idea first, also the wiring is knukoncepts kollosal 4ga rated at 120a and the amp itself is rated at 120a so I should be good in that case

 

[loudenuff]

Ive done a load test myself and found that the voltage never drops below 12 when the bass is hitting at its hardest and normally doesnt go under 13.5 with the full load, while i understand this is not good it should be good enough for the system to work properly (ive seen other people use small alternators on big sytems and nothing like this happened but i thought the same thing you did), you mentioned overheating but i know the amp that isnt the problem because it sometimes doesnt work when i first start my vehicle but will kick on maybe 5 minutes or so later and play. my alternator is only rated at 50a so i know I need to upgrade it soon and when i do that ill get the big 3 upgrade and probably an xs battery too, i was also thinking about using self tapping screws to making a new ground just straight into the chassis of the vehichle, but ill probably try you're idea first, also the wiring is knukoncepts kollosal 4ga rated at 120a and the amp itself is rated at 120a so I should be good in that case

That wire should be fine then. A new battery won't do you too much with a 50a alternator but you'll easily spend 500 getting an HO alternator. Find out if you have any alternator/car electrical specialists in your area. You might be able to get that 50a beefed up a little bit. Unless you're planning on doing serious upgrades in the future, or just have the money to spend, a quality ho alt wouldn't be in the best of interests. If you have any smaller amps try hooking them up and see if that's a problem. I have my voltage as low as 12.9 now that I have my ho getting repaired (stock with a batt Under hood and agm in trunk). But another idea might be your remote wire. Give it a wiggle while the radio is powered on, one tug from where it's wired to the amp, and one from your radio harness. You might just have a loose connection or possibly a sliced wire. Matter of fact you should check your rcas as well..

Slipped my mind but you also should realize that amp is going to pull that full 120a you have it fused at. Hifonics aren't too efficient and Yoj may just be taking too much from your electrical system. Big 3 + battery would make a difference but your battery will not be charging as fast as it is depleting. And you are pulling close to triple the amps your alternator supplies in the first place.

Just a little background info for you if you don't already know, your average lead battery isn't designed for quick energy release. Your alternator is designed to handle all your electronics while the engine is running. So when your sub hits a note it's pulling a majority of that amperage and it probably needs much more than you're feeding it, which in turn could cause your problems

 

[Paralystic]

Yeah I plan on investing into a 165 amp alternator or something around there and an xs power battery and do the big 3 with i do both of those upgrades, The wiring behind the radio is fine, I'm thinking I should take it in to a car audio shop and see about getting my amp tested but I'm not sure how that might work (they either test it when the subs are working full power or when they aren't), I think at this point I'm going to have to see if getting a new electrical system will do the trick and if not I might just have to pay someone to figure out the problem because it's beyond my skills, I appreciate the help and information and I'll keep you updated