I have cut speaker cable or 12 guage zip and used it for jumpers also solid copper available in hardware stores. Have to say I don’t hear much difference. Also tried 1.5, and 2 ohm resistors and found they dulled the sound to much.
Magnepan 3.7R's Jumpers and Resistors
I'd like recommendations on mid-range and tweeter jumpers for the 3.7's, and also on use of attenuators for the ribbon tweeters. I'm currently using the stock jumpers on the midrange, and the supplied 1 ohm resistor on the ribbon, since Magnepan only supplies one set of jumpers. I currently do not experience excessive brightness, and will consider replacing the 1 ohm resistor with a jumper or a lower value higher quality resistor. Thanks in advance for sharing your experience and opinions.