2 amps to 1 sub?

This is a false statement.  The only damage would be if the amplifier is producing more power than the voice coil (or the mechanical suspension) can handle.

I know I've been out of this for a while, but it use to be that bridging and  dropping the load to the amp increased the power of the amp.  If that's true and you give the amp 4 ohms bridged, it won't produce the 1000W  that it's suppose to.  correct?

DYon, you are wrong, in stating that if both coils receive different power, that no damage will occor. You are correct in the fact that it all must be in phase. Here is a lengthy, & correct way to Gain Match (Voltage match is the wrong term) two amplifiers.

You will need a sub that can handle the amp wide open. A Test CD with multiple frequencies, & a DMM on the AC voltage setting.

1. Hook up 1 amp, gain at full, x-oxer at full, bass boost at full. Hook the sub up so it reads closest to the ohm load that you will be using in the end. Play test tones starting at 25Hz  up to 120Hz(assuming there is no sub sonic filter on the amp), rolling on the volumne knob on the deck, untill the amp is at full saturation (where the volt meter no longer increases in #'s). Do this to find the frequency of max output from the amp. Now do the same with amp #2. Make shure your charging system can keep the voltage to the amp constant, to ensure accurate results.

2. Hook up the WEAKER of the 2 amps, & set the gain, X-over point, & bass boost as you normally would. Hook up the STRONGER of the 2 amps (this time 1 amp to each voice coil), & at low volumne, set the output at all the frequencies the same (or within .3 of a volt). Start with the settings on the stronger amp all the way down, set gain approx, tune in bass boost frex. & level, & x-over point...then fine tune it in. This will ensure that, gain, bass boost frequency, & x-over point are all set the same (no matter what the knobs on the amps say).

3. Turn the volumne up, to max output of the weaker amp, & check the output of the stonger amp, to make shure it is still within .3 of a volt.

I learned this from a post Jeff Sanford did on the USACi forums a long time ago....in 04 I think, & have used it multiple times, & it works perfectly......it does seem that any more than a .3 variance in the out put, gives that burning VC smell....so make shure the DMM you use is accurate.

Just a side note, the ZAPCO DC amps WILL NOT work well this way, as the adjustment increments are too large, & (with the 1100.1) max output voltages can't be matced, even with adjsting the rail voltage, not just the gain structure) 

IF power is different to each voice coil, one with more power will try to move farter than the other, & WILL destroy the sub, as it will "push" the other VC, & generate exessive heat. You can easily prove this by hooking up matching subs, in the same sealed box, hook a 1000W amp to one sub, & a 500W amp to the other, & count how many seconds it takes for you to smell VC burning. do the same with 2-1000W amps, & count the time. The sub getting the LESSER power will get destoryed first, because it is being FORCED to move. Same goes for our DVC with different power to each VC, the one with lesser power with be forced to move.

That is utter BS.

I skimmed all 14 pages (sorry, but most of it was just banterings, or simple questions that have been asked & answered many time), & did not see one post about running 2 different amps to 1 speaker...although page 11 had some very good info (in wich I read in full). I AM correct on how to match 2 amps to one sub, in wich that thread has no mention of what so ever. So go ahead, test away, or we can stop this wizing match, & ensure the proper way of matching 2 amps to one sub is posted. It is not how much you or I know, it is getting that knowledge to those that need it.

Perhaps it would be better for you to just call me, as somehow I must be reading things incorrectly. My Phone # is (408) 406-8773 Tony Sorritelli, Just because he is a moderator, does not mean he is infallible....& I was not trying to be a jerk about it, & if it came off that way I apologise.

(I intend no animosity what so ever...so please do not read it that way)

IF you beleive it is BS, please do the test I posted. You will find out that it is true & correct. Perhaps not in theory, but in reality. I can save you the time, as I have done it, & the one with LESS power got destroyed. I did not type that because it is somehting I am guessing. I have done it, that is what happened, period.

Flame away if y'all want, I gotta get back to work. I stand by the post, as it is a very solid way to match 2 amps to one DVC sub.

I've done it many times with no issue UNLESS (as I said in the initial post) the voice coil is overpowered.  But there is no (repeat NONE) problem using different power levels from different amps on a DVC speaker (indeed, even completely different signals can be used with no damage what so ever.)

I agree, there is nothing wrong with your instructions on how to match the output levels of two amps.  That is not the issue.  The issue is that you do NOT have to do that if your intention is simply to avoid speaker damage.  The only thing that will damage a loudspeaker voice coil is over power.  Period.