when you put tweeters and woofers in parallel through a crossover, they work as the same driver, because they are playing different frequencies. they work either/or, not together, if that makes sense. so 4ohm tweeter and 4ohm mb woofer in parallel should make a 2ohm load on paper, but it makes a 4ohm load in practice. 2 4ohm mb woofers in parallel will play the same frequencies, so that WILL make a 2ohm load. same with tweeters. figure out what your amp outputs need for a load. if it can take 2ohm (each pair of mids in the door parallel to one channel) then you can do that. if they cant take the halved load of running parallel, and need 4ohm, then you have to run them series (one driver runs through the other driver, instead of both connected to the same output..... amp to driver a, then out of driver a into driver b, out of driver b back to amp) when you series, you add the load together, instead of cutting in half. a pair of 4 ohm speakers: parallel makes 2 ohm load. series makes 8 ohm load. 2 ohm load is 2x the power of a 4 ohm load. 8ohm load is half the power of a 4 ohm load. i hope this helps you understand and draw your own diagram. theres a lot of ohm/resistance calculators if you google, to help you out. the biggest difference is when you wire 2 drivers with differnt frequencies. like i mentioned, if they arent playing the same frequencies at the same time, you count them as one driver. if you wired them in series, the frequency difference would kill most of the output from each other. i did it in the 90s to see what happens, and its just garbage...... kind of like a 90s internal computer tower speaker.