mono subs, dual speaker posts, drop ohms?

it wont matter which posts you use as long as the are single voice coil subs, if in fact they are dual voice coil subs then you will have to use both sets of posts. The old school Kicker Comps always had two sets of posts and i am sure those are the not the only subs that did, it has been so long since i have used an SVC subwoofer.

Jazzy

Yes, just like parallel-wiring voice coils or two subwoofers.  The load that is wired to one set of terminals is paralleled within the amp to the load on the second set.  Take my little diagram below:  say the subs are DVC 4 ohm.  You would get the same results from each way of wiring shown.  The top sub has coils individually connected to the amp terminals, so the coils are paralleled down to 2 ohms at the amp.

The bottom sub has the coils wired on the sub in parallel.  Then one set of wires goes to the amp.  They can attach to either red and either black.  Normally, an amp should have a diagram showing to use a red on one side and a black on the other side...so later you don't forget and wire another sub to it. 

Likewise, two subs can be connected to the amp using the two sets of terminals, and the amp will parallel the subs.  e.g. two 4 ohm subs will become a 2 ohm load. 

I'm trying to picture that.  A total of 4 voice coils all wired to the same two terminals?  That would be parallel/parallel.  If the subs are 4 ohm DVC, then each sub becomes 2 ohm, then the two subs are paralleled together for 1 ohm.  One set of terminals on a mono amp is all that is required for hookup.  Just know that everything connected to the terminals is paralleled.

Now if you're saying he is using only one coil on each sub, then yes the subs will be destroyed.  He must have been trying to avoid too low of a load on the amp.  He would have gotten the same output by using only one sub and wiring it correctly.

I didn't say that.  Your wiring to the amp is just one + and one -, so the amp is not paralleling anything.  That's a 2 ohm load you show.  Now, if another sub just like that one were connected to the amp's two free terminals, it would get connected with the first one at the amp...and then the amp would have a 1 ohm load.

Same diagram as my first one but with added labelling:

Actually running only one set of voice coils in a dual voice coil sub will not damage it.  It will reduce your power handling, so you will want to be careful.  What changes is the Qts of the speaker.  Here's a link to a tech paper on this topic: http://www.adireaudio.com/Files/TechPapers/DualVoiceCoilDrivers.pdf

Steven Kephart

Adire Audio