so i was asked this question in a PM and i think the answer will benefit everyone so i am posting it here
QUESTION
hey
could u help me with some information on how to wire the following as i am a little confused and i dont want to blow anything up
a. 1 dual 4 ohm sub to a 2/4 channel amp
b. 2 dual 4 ohm subs to a 4 channel amp
ANSWER:
the voice coils of a dvc can be wired in two ways
1. parallel (both positive terminals are joined and connected to positive terminal of the amp, vice versa for negative terminal
2. series (connect negative of one voice coil to the positive of the other voice coil. you will have one free positive and one free negative terminals on voice coils. connect them to positive and negative terminal on amp)
in parallel, a 4 ohms dvc sub will give the impedance of 2 ohms, in series it will be 8 ohms.
coming to the amp, most 2 or 4 channel amps are only 4 ohms stable on bridge mode. this means you can wire a dvc whose total impedance is 4 ohms or above. with a 4 ohms dvc, it is not possible to have the voice coils hooked in parallel and use it on such a 2 or 4 channel amp. you can hook it in series at 8 ohms but the output of the amp at 8 ohms bridge will be very less.
some people will advise you to hook the voice coils separately on different channel of amp. while this is possible, it is not recommended. first of all yo will have to match the gains of both channels so that the voice coils are not working against each other. also you will have to check whether the amp outputs same on both channels.
coming to two dvc subs, an easy way to understand them is take each sub, wire it in parallel or series, you will get a resultant impedance, and then treat it as a single voice coil in another dvc sub. let me explain
take the above example of a single dvc sub wired in parallel to have a 2 ohms impedance. imagine there are two such subs with 2 ohms impedance each. imagine it as a 2 ohms dvc sub instead on two 4 ohms dvc subs. get my point? so now you can either hook these again in series or parallel to give you 4 or 1 ohms impedance respectively. again your 2 or 4 channel amp is only stable at 4 ohms bridge so u use that configuration. the only problem now is that whereas the subs will require around 600 rms plus power, your 2 or 4 channel amp might only be giving you around 200 watts rms output so thats around 100 watts per sub which is very less.
solution: use mono amps. they are designed to be stable at 2 or even 1 ohms and give you enough juice to power your subs.
so if you have a single dvc sub and you want to run it on a 4 or 2 channel amp, make sure u get the 2 ohms dvc sub (commonly known as D2) and wire it in series.
some branded mono amps are stable upto 2 ohms only. for them you use a D4 and wire em parallel. or you get a pair of D2 and wire them in a parallel-series combo (voice coils in parallel, subs in series or voice coils in series, subs in parallel. either way works)
