I was thinking of building my own speakers but had a question. If I build a center chanel with two 8ohm speakers, does that change the ohms all together? what about an 8ohm driver and 8ohm tweeter? Would I need two 4 ohms to make it 8 ohm?
The combination of all the drivers together, plus the crossover will give you the total impedance of the speaker. You can use how you wire the drivers together (series or parallel) to try to shoot for 6 or 8 Ohm nominal impedance. My recommendation is, if you have never designed your own speakers before and you don't have the instruments to test your design, to look into building an already designed kit. Check out Adire - click on systems -> and you will see the kits. Also check out www.gr-research.com