I borrowed my guitar player's used Spector bass to do some setup work on it. When I plugged it in, I noticed something weird with the volume/tone controls. First, it appears to be something along the performance series bass line, 4-string. Has 2 EMG-SSD passive soapbars, 2 volume, 2 tone (or I think it should be?)..haha. Here's what's weird. Each volume and tone seems to work properly as long as the other pickup's volume is turned completely off. When I try to bring up the other pup's volume, there are spots where the sound completely dies off. This works both ways with both volumes. I actually had to get online to find out just what the controls did, because I could not figure it out. So I opened the electronics cover, and the first thing that caught my eye were two of the pup wires (red-to-red/white-to-white), connected together with the other pup's wiring, with electrical tape wrapped sloppily around them. I didn't think this could be factory work, so I removed the electrical tape and found very shabby solder joints, one of which was a cold solder joint. It appears to me that someone rewired this thing, and didn't do a very good job of it. In the attached photo, the red pointers show the connected wiring. I can draw a complete diagram if needed. I know SOMETHING is wrong with the electronics, and all 4 of the pots are working ok. Only when they are used together does the problems start. I'm hoping someone can advise me on this, or if a schematic/wiring diagram is known of, it would be a great help... Mag... Problem solved. Bass was miswired. Spector tech helped me sort it out..