Thanks so much. I did build a sound box for the pump. In tests inside, it lowered sound 30 db. When I used it outside at the lake, it lowered it quite a bit, but was still very loud for my tastes. I’m not sure how to post a picture of my box, but I have: an exterior of 5/8″ particle board, with caulked joints; then a layer of 1/2″ closed cell foam (like that which came in the Puffer Pro case; then a layer of self-stick, mass loaded vinyl (1/2lb? or 1lb?) with foil backing, and then a thin layer (1/16″) self stick foam. The lid is a removed wall, with foam gasketing. I need to study how sound must be leaking out of the instake/exhaust holes of the box first. I’m thinking, some insulated “sleeves” (like interior sound insulated air ducting) might be next step. Solving acoustic transmission problems is as difficult as trying to dam water, but it’s a fun problem. Now I’ve got “error 4” (EE4). I’ve written to manufacturer, but I’ll try draining the battery also.