I wasn't 100% sure where to post so I figured the General forum was safe (gotta hate that first post on a new board)
I thought this was pretty basic but apparently I'm missing something since a salesman at local 'high-end' audio shop stopped short of calling me an idiot today. I always thought that wiring a single DVC sub to an amp would result in the amp seeing a load of either half or twice the impedence of the sub depending if it is wired in series or parallel. So when I was in shopping for an 8" 4Ohm DVC sub I understood that my amp would either see a 2Ohm load (too low for my amp) or 8Ohm load (too high for my liking given my amp). This salesman persisted in saying that my amp (when bridged) would only 'see' half the load and would run like it had a 4Ohm load. Last I checked this doesn't fit with Ohm's law unless I'm missing something here.... is there any way for a single DVC sub to be wired so that the amp sees the load as the rated impedence of the voice coils (ie a 4Ohm DVC gives a load of 4Ohms to the amp)??
Related to #1 of course, can a DVC sub be wired from 2 seperate bridged channels or two seperate amps (1 to each voice coil)? I've found 3 sites online that clearly state it can (eg. Crutchfield and Audiobahn). The aforementioned salesman, when asked, said no this wasn't possible because the movement due to one voicecoil would induce an electrical current in the other (and vice versa) which would be fed back into the amp causing a failure. This struck me as odd but I don't know enough on this topic and it concerns me that most manfacturers sites do not show this as a wiring option (with the exception of Audiobahn).
Basically what I'm looking to do is pick up a single 8" sub and run it off of my existing system. I have two 4 channel amps (Crossfire cfa404 and a cfa404s), 4 channels are of course spoken for with the existing speakers. So I have another 4 channels (50rms each) which can be bridged (100rms each @ 4Ohms). If it is possible to wire up the voice coils of a DVC sub to the two seperate bridged channels then I wouldn't mind doing this.
Any thoughts, comments, etc. would be greatly appreciated!