Hey guys,
I have a 15" Memphis M3 which is 400/500RMS Dual 4 ohm voice coils and an Alpine M850 which is 500RMS @ 4 ohms and 800RMS @ 2 ohms What is the best way to wire these together to get the best and efficient performance out of the 2? Thanks!

 

Is that power rating per coil? If it is, wire the coils in parallel, which will make a 2 ohm load.

 

+1 .some speakers are funny on the dvc side . some times to drop the ohm you have to cross the dvc on the back of the speaker . + to - and - to + from one vc to the other just on the back of the speaker .it basically makes a big x diagram from one coil to the other . u need to get a volt/ohm meter and see what way will drop it . but it is either or . i had to cross them on my kicker l5 for it to drop ohms.

 

OK, this is really easy, and there isn't anything magic about it. If you connect both voice coil + terminals together, and both - terminals together (and then wire to the appropriate amp terminals), you have just wired the voice coils in parallel. Power from the amp goes through both coils at once, because both + are connected together, and both - terminals are connected together. That means the impedance will be cut in half. Think of it as two water hoses with a 'Y' on each end; two hoses means twice the flow. You will now have a 2 ohm load.

If you wire the - of one voice coil to the + of the other, and then connect the remaining two terminals to the amp, the voice coils are in series, and the impedance will double. You will now have an 8 ohm load. The amp power goes through one coil and then the other. Think of this as two water hoses connected end to end..

You don't need a voltmeter at all, you just need to understand what you're trying to do. Dual voice coil subs can only be wired two ways (correctly) and the only confusing thing is how different brands place the terminals on the sub itself. How they're wired has absolutely no bearing on where the terminals are placed, the wiring might appear different when you're done though.

 

is that 800 wrms @ 2ohm stereo or 2ohm mono. if its 2ohm stereo that amp wont work. it will go into protection on the first big bass note.

these are the only 2 ways you can hook up that sub

 

It's a single channel amp I think, that's what the 'M' in the model number denotes.

 

OK I failed to see that

 

Thanks guys!

After reading your posts and researching a bit more I see I can wire em at 2 ohms (800rms which is way too much) or 8 ohms(250rms which is underpowering it) So I think I'm going to sell the amp and downgrade a little to where the 2ohm rating is at ~500rms.

Thanks for all your help guys

 

that amp is enough for one sub at two ohms, just get a second amp (the exact same one) and get the full potential out of it!