To achieve maximum power transfer, the output impedance of the supply device (ie Amp) should match the input impedance of the receiving device (ie Speaker) So if the o/p impedance of your amp is 2 ohms then the device you match to it should also be 2 ohms to get max power. Same for 4 ohms or 8 ohms etc etc... ONC electronics! In the old days, if you put too low an impedance speaker on your amp you ended up blowing the output/driver transistors of your amp. Nowadays, modern amps have built in safety circuits to help stop that happening. If you put 2 speakers in series then you double the resistance. So 2 x 2 ohm speakers = 4 ohms. If you connect them in parallel then the resistance is worked out as follows. Remember, parallel resistance is NOT the same as averaging. It uses the formula Resistance Total = 1 / ((1 / R1) + (1 / R2) + (1 / R3)) etc. So Total resistance for 2 x 2 ohm speakers connected in parallel = 1/ (1/2 + 1/2), therefore 1 ohm!

(Just to confuse things even more…in electronics, resistance is NOT exactly the same thing as impedance…but don’t worry too much about that!)

Hope this all helps?

Here's a good link to help work out parallel resistances:

http://www.raltron.com/cust/tools/parallel_resistance.asp

Pal ;)

well its not that hard gets a bit more complicated when u start calculating the impedence of capacitors etc. u dont really need to know everything anyway just which way to connect them up

didnt do physics a level, i understand it. :P

impedence is the oposition offered to current by components. in this case the components are the amps and speakers. When u connent the components, u can either connect them im series or parallel. depedning on which way u connect them ,depend on the impedence u end up withe. thats why some subs come with dual voice coil so that u can connect them in parallel and get a lower impedence and therefor more power.
its a little complicated to understand unless u do physics a level (like me), but i still find it complicated lol
hope this makes some sence

Some amps allow you to use two channels for your 6x9 AND bridge a sub on these two channels. obviously you'll need some inline filters.

you lower the impedence when you bridge channes on your amp

U NEED EITHER 1 4 CHANEL AMP OR IF U WANT MORE POWER USE 2

How many channels?

im lost someone explain! which is best then to run a 12" vibe sub, its 700 max, 300 RMS but need to run some 6x9's off as well

2 OHM AND 4 OHM is the impedence.
the lower the impedence the less resistance to current flow and hence more power

whats the difference between running an amp in 2ohm or 4ohm?

Difference as in what??

very funny! but really what is the difference?

haha

quality reply. I cant believe I didnt think of that. ha ha

2 ohms

AS ABOVE?

ANYONE KNOW?