I just posted this on the LZ owners thread but have seen recent posts here regarding adding a Subwoofer to your system so I thought I would post it here even though I don’t have a GZ.
I recently added a Polk PSW10 subwoofer to my LZ Pro. I already had the PinWoofer set up with the GT amplifier (highly recommended!) so I reached out to them for advice on the cleanest, most efficient way to incorporate the additional subwoofer into my existing system. Dan PinWoofer quickly responded, recommending the BBU (Bass Boost Unit). Though it cost a little more than alternatives it looked to be the cleanest, most controllable, way to integrate the subwoofer into my system.
Install is simple and the performance is excellent.
Dan has gone above and beyond with the quickest response time in the industry to my noob questions. (Including responding instantly, on a Sunday, to a question that I later realized was already answered in the documentation he had previously provided me with). I can’t say enough positive things about Dan, Pinwoofer, and their products. From the moment I ordered the BBU, through quick shipment, good packaging, installation assistance and guidance, settings advice, and finally, outstanding performance, this is a great way to improve the sound on your Pin! I highly recommend it!
https://pinwoofer.com/pinwoofer-jjp-bass-boost-unit/