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ok, i have a rockford 250a2 running 2 rockford he's svc 4 ohm. i used to have 2 xtant a series 2 ohm wired in series so the amp was running 4 ohm mono. it ran that way for a year and a half at full boar and the amp never overheated and never shut down. i've had these he's for a week and the amp has shut down 3 times and last night the fuse in the power wire blew. they are bridged, giving the amp a 2 ohm load and that's within rockford reccomendations. the place that i got these said that it would be fine to run it that way. when i rewired the setup, i touched absolutely nothing in the power/ground. just the wiring to the subs. is there any reason why that fuse blew? can an amp run so hard, it blows a fuse??? i've never heard of it happening... help, please.
-------------------- ---------- you know who it is Posts: 599 | From: wentworth, south dakota | Registered: Oct 2001
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From what I know, RF doesn't recommend running their amps at 2 ohm mono, with a few exceptions. Most amps will survive it but if the protection is kicking in, it doesn't want to do it. You can easily run an amp hard enough to blow a fuse. The fuse supplied with the amp will allow it to run 4 ohm mono at full power without blowing. When you run 2 ohm mono the amp will try to make twice as much power, and draw twice as much current which will blow the fuse. After 1 week and a couple protection faults the fuse will have been weakened enough so that the next time it will just blow. Try just running one sub at 4 ohm mono and see if you still have the problem, if so the amp has a problem, if not it is the 2 ohm load.
Posts: 2575 | From: GA | Registered: May 1999
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so how should i wire these 4 ohm subs to get maximum performance from my amp? should i just beef up the fuse and let it ride? where i got the new subs, they said that i should have no problem running it like this, and if it blows, bring the amp in and they'll replace it because they said it should work. or am i just not thinking right and am totally not seeing the easy way to wire this??? it's funny. other people's systems are no problem. i change one little thing in my setup and all of a sudden i'm like a deer in the headlights...
-------------------- ---------- you know who it is Posts: 599 | From: wentworth, south dakota | Registered: Oct 2001
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With 2 4 ohm subs there is no way to get maximum performance out of you amp. You either do 8 ohm mono or 4 ohm stereo, both of which gives you half of the maximum power of the amp. But at two ohms the amp is trying to make twice its maximum current, which it obviously doesn't like. In some cases the subs actual in box impedance is high enough to get away with wiring them like you have them. But this doesn't seem to be the case here. If they truly will replace the amp every time it blows then you could go ahead and put a bigger fuse in it and run it until it blows up, and go get a new one. But after this happens a couple times they'll stop living up to what they said. And the protection circuitry may kick in, not allowing it to actually blow, just leaving you without bass each time it happens. On a more technical note. The amp I believe has one pair of output devices per channel, so there is no way it could support running two ohms mono wide open. But you may be able to run it two ohm mono if you turn the gain down from where it was when you had it a 4 ohm mono.
Posts: 2575 | From: GA | Registered: May 1999
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