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AMP/SUB question
Posted: Thu Aug 04, 2005 4:15 am
by Bwcad1
Hey guys Im new first off my name is bill and Im a tooling engineer Im nineteen years old and I’ve been an audiophile for a lot of years. I'm running all pioneer. Pioneer components pioneer gm-4000f amp for the components a single ts-w2000spl sub run of two gm-f5100 760watt amps bridged. I hit 138.1 with the single sub. But lately Im having trouble with the sub cutting out. But I don’t think its going into protection because the sub isn’t hitting some of the time and even when It does its not hitting very hard? Now I have the component amp run with speaker level in and then the rca output is split in a y for the two sub amps? Any idea what this could be? It seems like I loose the sub when the components need a lot. Could my 4 channel be dying? Thanks ahead of time. O and I have a comp. in a week so I need to get this fixed ASAP
Posted: Thu Aug 04, 2005 8:57 am
by William from NOLA
You need more power basically. I would first buy a new battery (a good battery) such as an Optima Red Top, Stinger Red Top, or greater. Your next best upgrade would be a new high output alternator, but judging by the way a new battery handles it first, that will decide how soon you sould need one.
Posted: Thu Aug 04, 2005 9:27 am
by Bwcad1
ok thanks I have a high output alternator its putting out about 150 from my stock 105 also the tweeters get incredibly loud when the sub cuts out I also have a 1 farad cap from Pg and I guess that’s not helping much is it? I guess ill have to get another battery or bump up the alternator. Thanks again.
Posted: Thu Aug 04, 2005 10:12 pm
by William from NOLA
Ah, I was assuming you didn't have a new alternator. Your best bet would be to unhook the cap and put in a good battery. A cap will really just be hurting you at this stage. You might want to just unhook the cap and see how that affects it.
Posted: Fri Aug 05, 2005 6:45 am
by Bwcad1
ok i just checked my voltages/ohms and all that crap everything looked good i was at 14.2 volts and 3.45ohms at the amps. now i check the alternator and im not getting 160 amps im getting about 65-70 at idle. but how sure are you that this is it? i really dont want to spend 500 for an alternator if its not that?
Posted: Fri Aug 05, 2005 7:10 am
by William from NOLA
You have an ammeter??? Give me one! lol
That is typical of alternators. They don't start putting out their power unless you are above idle.
Before thinking about getting a new alternator, get a good battery and unhook that capacitor. That will tell you there if you will need a new alternator.
Posted: Fri Aug 05, 2005 7:15 am
by JeremyC
Yeah don't worry to much about the amps your alts putting out at idle. The main thing to check is your voltage. if it is peaking 13.5 to 15 back to 13.5 or so your diode assemble is going out. If its just plane low 12 to 13 volts its the brushes. Either way yours doesn't seem to be suffering from those problems. So I wouldn't worry about the alt just yet.
Posted: Fri Aug 05, 2005 7:24 am
by Bwcad1
yea i do as i mentioned above i work for mtd products in valley city ohio we engineer outdoor power equipment like riding lawn mowers push mowers chain saws all that crap and i borrowed the ammeter from an electricle engineer. ok well ill try this out any ideas for my comp in two weeks?
Posted: Fri Aug 05, 2005 8:24 am
by Ryan from Ohio
Big 3 upgrade?
If not start there. Also your grounding spot for the amps. 1 spot, bare metal and close to where a unibody member joins that area of sheetmetal. THis provides for less resistance and more potential current flow.
Short of that I would say loose connection somwhere. The round AGU fuses have been know to be culprits sometimes. But since it fades in and out I dunno.
Usually when I trouble shot its by the seat of my pants. Just a lot of unhooking and rewiring and it usually magicaly work right then...

Posted: Fri Aug 05, 2005 8:45 am
by sinister audio
it really sounds like you have a bad ground and if you have separte grounds for each amp than that would make it have differnt volume levels when the other cuts out. it also sounds like its getting underpowered and then when teh sub abp kicks out the high amp kicks the kick of juice and jumps the volume. the big three and a yellow/red top would be what i would try. and also regrounding everything.