Posted May 28, 201213 yr Ok, so yesterday I was warming the car up for an oil change and started beating on the system a bit. I noticed one woofer not moving quite as much as the other. So today I took all the speaker wire out of the amps (2 bc3500's strapped) and each woofer is reading 4 ohms??? It's supposed to be wired to 1 ohm per woofer 2 ohm strapped. I don't know what I did wrong. I'm not sure if there is a different way to check impedence if the amps are strapped.? I notices the master amp gets slightly warm and the slave is cold. I need some advice as I'm gettign frazzled. The woofers are 2 fi btl 15's Dual 2'sI put a camera inside the box to make sure no wires came loose but everything seemed ok.Also, when I checked the wires still in the amps they gave me 1.4ish ohms on one woofer and 2.6 on the other... now out of the amps they are giving me 4 ohms each...so idkHeres how they are wired:pos from one coil to a negative of the other coil. Do that for both subs.Wire the two remaining positives to the positive of the master amp.Wire the two remaining negatives to the positive of the slave amp.Connect the two ground terminals of the master amp to the two ground terminals of the slave amp.
May 28, 201213 yr Author you need to wire it like this,you probably have a bad coil on one side.Uggg I hope not.. they arent even broken in yet.... Also how do I wire them paralell if the amps are strapped? To many people telling me too many things sometimes. I still don;t get why they are both reading 4 ohms when not in the amp.
May 28, 201213 yr just wire it like the picture, that's the way you need it itll be extra wire but itll save you some time
May 28, 201213 yr I still don;t get why they are both reading 4 ohms when not in the amp.Because each individual subwoofer's coils are wired in series.So each subwoofer will be wired in series for 4ohm per subwoofer.The subwoofers are then wired in parallel to the amplifier resulting in 2ohm final load.This is actually the preferred method as opposed to wiring the subwoofers coils in parallel (1ohm per sub) and then wired in series to the amp for a 2ohm final load.
May 28, 201213 yr Author just wire it like the picture, that's the way you need it itll be extra wire but itll save you some timeSo instead of 2 positives to master ans 2 negitives to slaves positive. I will only have one positive to master and one negitive to slave;s positive? I still leave the negitives of both amps connected right?
May 28, 201213 yr Author I still don;t get why they are both reading 4 ohms when not in the amp.Because each individual subwoofer's coils are wired in series.So each subwoofer will be wired in series for 4ohm per subwoofer.The subwoofers are then wired in parallel to the amplifier resulting in 2ohm final load.This is actually the preferred method as opposed to wiring the subwoofers coils in parallel (1ohm per sub) and then wired in series to the amp for a 2ohm final load.holy crap.. So they way I have it is correct? 4 ohms each works out to 2 ohm final load. So each sub will see 1 ohm? so 2 subs will give me the 2 ohm load for strapping
May 28, 201213 yr I still don;t get why they are both reading 4 ohms when not in the amp.Because each individual subwoofer's coils are wired in series.So each subwoofer will be wired in series for 4ohm per subwoofer.The subwoofers are then wired in parallel to the amplifier resulting in 2ohm final load.This is actually the preferred method as opposed to wiring the subwoofers coils in parallel (1ohm per sub) and then wired in series to the amp for a 2ohm final load.holy crap.. So they way I have it is correct? 4 ohms each works out to 2 ohm final load. So each sub will see 1 ohm? so 2 subs will give me the 2 ohm load for strappingFrom your description it sounds like you have them wired properly.The subs don't "see" anything. They present the load to the amplifier. And yes, wiring the subwoofers in series-parallel results in a final 2ohm load at the amplifier(s). Series-parallel wiring is what is shown in the picture posted earlier. Generally speaking if you can avoid wiring two or more speakers/subwoofers in series with each other, you want to. Coils on the same subwoofer wiring in series is not an issue. But two different speakers should be avoided when possible.If strapping is causing part of your issues (confusion on how to wire them), you could always just NOT strap the amplifiers and wire one subwoofer per amplifier. In your situation there's no benefit to strapping other than having a "master" control, but it's a simple matter to match the amplifiers with a basic DMM and test tones and it makes the wiring less confusing.
May 28, 201213 yr Author I still don;t get why they are both reading 4 ohms when not in the amp.Because each individual subwoofer's coils are wired in series.So each subwoofer will be wired in series for 4ohm per subwoofer.The subwoofers are then wired in parallel to the amplifier resulting in 2ohm final load.This is actually the preferred method as opposed to wiring the subwoofers coils in parallel (1ohm per sub) and then wired in series to the amp for a 2ohm final load.holy crap.. So they way I have it is correct? 4 ohms each works out to 2 ohm final load. So each sub will see 1 ohm? so 2 subs will give me the 2 ohm load for strappingFrom your description it sounds like you have them wired properly.The subs don't "see" anything. They present the load to the amplifier. And yes, wiring the subwoofers in series-parallel results in a final 2ohm load at the amplifier(s). Series-parallel wiring is what is shown in the picture posted earlier. Generally speaking if you can avoid wiring two or more speakers/subwoofers in series with each other, you want to. Coils on the same subwoofer wiring in series is not an issue. But two different speakers should be avoided when possible.If strapping is causing part of your issues (confusion on how to wire them), you could always just NOT strap the amplifiers and wire one subwoofer per amplifier. In your situation there's no benefit to strapping other than having a "master" control, but it's a simple matter to match the amplifiers with a basic DMM and test tones and it makes the wiring less confusing.Thanks. I just don;t know why at the amp, one sub is reading 2.6 ohms and one is reading 1.4 ohms. Unless there is a different way I should be checking their impendence while strapped? Other than that obviously the woofer are fine as they both read 4 ohms. Its just the 2.6 ohm on one that i don't get. my woofers are such a pain in the A** to take out you wouldn't believe.
May 28, 201213 yr Author Ok, I just went out and wired everthing back up step by step and now both subs read 2 ohms at the amp so they are both the same now but isn;t 2 ohm and 2 ohm 4 ohm ? I think I know something but this makes me feel supid lol
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