From one of my valued customers about my double piezo pickup. I always use double sided tape to stick the discs but this customer used the pickup on a very old upright bass and came up with a better idea
I purchased one of your dual pick up piezo's for my upright bass. It is the one with a small and large pick up. I just thought I would let you know how it is working. I mounted both pickups on the bridge. The small one on the bass side leg and the large one right in the middle under the heart. I had to put a piece of tape on the small one and a piece of 1/16 cork on the large one. This gave it the best and most natural sound and reduced finger noise. I tried different spots on the body but it is hard to find a truly flat spot on a 70 yr old instrument and the vibration of the body was a bit too much for the pickup. I also found tape would pull the varnish off the body. I actually attached the pickups with zip ties which makes them movable and leaves no marks on the instrument. The cords could have been a about 6" longer to provide more mounting options. I am getting very good compliments on my sound and I would say your pick up is as good as the ones that cost 10 times more.