Wiring issues inside the bass boost controller

So, I've had these headphones for 10 or so years and I have re-wired the audio jack side of the bass boost controller a couple times, but most recently I have been having trouble with the bass side of the controller. I have audio out of both sides of the headphones but I do not have any bass. While tinkering with the board I noticed the bridge the positive and negative wires of the left sub-woofer the bass works on the left side of the headphones. If I try to bridge the same way on the right side the headphones cut out all together. I am fairly confident that my wiring is correct due to the fact that I used a diagram i found on this website, they also labelled the board well. Any ideas or suggestions for resolving this issue?