help with RF amp
Thread Starter
Le Mans Master
Joined: Oct 2002
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From: dudley MA
help with RF amp
i have a rockford fosgate 1500db amp for my sub. i have 200 amp alt and 0gauge wire runing to that amp and another rf amp for my front cdt components. every time i turn the volume up the sub amp clips and goes into protect mod. so i have to shut the car off and turn it back on for the amp to work again.the other amp works fine. any thoughts?
Le Mans Master
Joined: Jun 2004
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From: Los Angeles Ca
i may be too tired but how is it possible to have sub that is either 2 or 4 ohm?
if you have dual 4 ohm voice coils you can have 2 or 8 ohms final impedance, if you have dual 2 ohm voice coils then you can configure it to be either 1 or 4 ohms. i think i am missing some information.
if you have dual 4 ohm voice coils you can have 2 or 8 ohms final impedance, if you have dual 2 ohm voice coils then you can configure it to be either 1 or 4 ohms. i think i am missing some information.
Thread Starter
Le Mans Master
Joined: Oct 2002
Posts: 6,799
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From: dudley MA
each voice coil of a DVC speaker carries its own impendance, altering the wiring configurations gives a range of options for impendence loads.
4 ohm dvc speaker=2ohm load
2 ohm dvc speaker=4ohm load
out of my owners manuel
4 ohm dvc speaker=2ohm load
2 ohm dvc speaker=4ohm load
out of my owners manuel
Le Mans Master
Joined: Jun 2004
Posts: 5,572
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From: Los Angeles Ca
correct...so which sub do you have? a sub with two 4-ohm voice coils or one with two 2-ohm voice coils?
4 ohm dvc speaker wired in series = 8ohm load
4 ohm dvc speaker wired parallel = 2ohm load
or
2 ohm dvc speaker wired in series = 4ohm load
2 ohm dvc speaker wired parallel = 1ohm load
(for more info see: http://www.bcae1.com/spkrmlti.htm )
4 ohm dvc speaker wired in series = 8ohm load
4 ohm dvc speaker wired parallel = 2ohm load
or
2 ohm dvc speaker wired in series = 4ohm load
2 ohm dvc speaker wired parallel = 1ohm load
(for more info see: http://www.bcae1.com/spkrmlti.htm )
Thread Starter
Le Mans Master
Joined: Oct 2002
Posts: 6,799
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From: dudley MA
4 ohm dvc speaker wired in series = 8ohm load
4 ohm dvc speaker wired parallel = 2ohm load
i dont see in the manuel if its a 4ohm or 2ohn dual voice coils but i do have it wired in parallel and the manuel says thats a 2ohm load so im guessing there 4ohm dual voice coils
4 ohm dvc speaker wired parallel = 2ohm load
i dont see in the manuel if its a 4ohm or 2ohn dual voice coils but i do have it wired in parallel and the manuel says thats a 2ohm load so im guessing there 4ohm dual voice coils
Racer
Joined: Apr 2005
Posts: 264
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From: Phoenix AZ
If the amp is in fact clipping, the gain is set too far causing it to go into protect. The amp is stable at 2 ohm. It goes into protect due to heat or clipping to save destruction of the amp. Many people make the mistake that the gain is a volume ****.
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Thread Starter
Le Mans Master
Joined: Oct 2002
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From: dudley MA
Originally Posted by BlakMajik
If the amp is in fact clipping, the gain is set too far causing it to go into protect. The amp is stable at 2 ohm. It goes into protect due to heat or clipping to save destruction of the amp. Many people make the mistake that the gain is a volume ****.
Race Director
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From: Canton GA
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If you have a dual 2ohm voice coil sub and they are in parallel, the amp is seeing 1 ohm. Now, if that amp is bridged, it is actually seeing 1/2 ohm! That's usually VERY bad for an amp in bridged mode.
Re-wire the sub to a series configuration and test.
Re-wire the sub to a series configuration and test.
Thread Starter
Le Mans Master
Joined: Oct 2002
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From: dudley MA
i been blasting the tunes for 10 min straight and the bass didnt shut off once, but the car wasn't running. it seems like the bass only shuts off when the car is running. any ideas? ya i tried both series and parellel and still the same thing. the amp is not bridged. i wired it according to the owners manuel. in series its 4ohm. in parellel its 2ohm. the amp is rated for both 2ohm and 4 ohm
Last edited by pdd000; May 18, 2005 at 03:37 PM.
Thread Starter
Le Mans Master
Joined: Oct 2002
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From: dudley MA
ok. went for a ride and the sub works great till i turn it up past 5/8' sthen it shuts off. this blows. i cant turn up my favorite songs and have to fight wind noise in the vert and that lumpy cam 
Le Mans Master
Joined: Jun 2004
Posts: 5,572
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From: Los Angeles Ca
can you turn it up past 5/8's while the car isn't running?
did you try to turn down the gain?
(it's still impossible to have a single dvc sub to be wired so that it can be 4 ohm or 2 ohm, those two impedances can't be achieved from the same speaker unless you are just wired each voice coil to the amp.)
did you try to turn down the gain?
(it's still impossible to have a single dvc sub to be wired so that it can be 4 ohm or 2 ohm, those two impedances can't be achieved from the same speaker unless you are just wired each voice coil to the amp.)
Race Director
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From: Canton GA
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Originally Posted by pdd000
i been blasting the tunes for 10 min straight and the bass didnt shut off once, but the car wasn't running. it seems like the bass only shuts off when the car is running. any ideas? ya i tried both series and parellel and still the same thing. the amp is not bridged. i wired it according to the owners manuel. in series its 4ohm. in parellel its 2ohm. the amp is rated for both 2ohm and 4 ohm
Could you have a sub going bad? As in, it will take up to XX Watts but past that, it shorts out? I've seen some bizzar failure modes in speakers before!
Have you tried the subs on a different amp? Try running one channel/one coil at a time (for a short time).