Subwoofer Wiring Configurations

Chris,

Hey dyalden

You said that when bridging an amp the load the amp terminals see is half the rated load of the speaker.  Now I am confused.

I am installing a Rockford Fosgate P312D4 12" sub. It has two 4ohm voice coils and is rated at 500Watts RMS.  My plan is to wire the VC's in parallel to produce a 2ohm load.

My plan is to use a Hifonics Neptune amp rated at 500watts X 1 RMS into 2 ohms.  The picture of the amp has 4 speaker terminals (as far as I can tell see picture

Is this amp going to see 1ohm or 2?  Are D-class amps bridgable?  I am confused.

I don't know about having 2 sets of speaker terminals on that amp, I've never worked with it.  What Dyalden meant was that if an amp is 1 ohm stable in stereo it will be 2 ohm stable when bridged.  And a 4 ohm bridged load is the same as a 2 ohm load in stereo as far as the amp's concerned.  Make sense?  If your amp can do 500w x1 into 2 ohms, it should be fine running your sub wired parallel as a 2 ohm driver.

Chris Sr, if you haven't already left the building....use the parallel and series wiring calculators on the left column of this page to figure quad coil wiring.  If you were to use series/parallel wiring, the total load would be 1.5 ohms onto one amp (each sub's coils in series to 6 ohms and then four subs in parallel to make 1.5 ohms). 

This would be what it would look like:

Most mono amps have two sets of terminals, so you can wire two subs to one set and the other two subs to the other set.  The amp will parallel the pairs of subs for the same final result (see DYohn's response above).

If you intend to use two amps, use the calculators to find that you can make a 3 ohm load onto each amp.  You will still need to use mono amps because of the low impedance, and this choice might be more suitable if your single amp isn't able to handle such a low impedance as the 1.5 ohm shown above.  The power would be the same in either case, because 3 ohms is double the impedance of 1.5 and each amp would put out half the power that the single amp would into the 1.5 ohm load.  This solution, however, depending on the amp quality and the integrity of the MA coil measurements, will be easier on your system...sound better...and last longer.

The problem with this posted question is that it doesn't provide adequate info on exactly how many / what type of amplifier is going to be used.