Electrical

General

• Wire gauge: 18-15 for speaker cables and 15-13 for power cables. (Saturnus)
• Water proofing: I'd strongly advice you put your amplifier in a closed aluminum case with at least some effort made to make it water proof, such as Hammond 1590N1. if you're playing a late night/early morning during the summer the dew can visibly condense on the amp and drip off if not in a case. You'll want to avoid that.
• Choosing only from Parts Express parts the Goldwood GW1058 as used in the North American version of the Boominator (because the p.audio HP10W is unavailable in North America) is an excellent low cost driver that pairs well with a superpiezo, for example the new GRS PZ1005 available from Parts Express. Use a 47ohm carbon composite resistor of 2-3W rating in series with the piezo. Must be carbon composite or metal film, even so-called "non-inductive" wire-wound power resistors have far too high inductance. (Saturnus)

VU Meter LEDs

• Danish builders have found that with music control the LEDs will consume about 1.5-2W. It will naturally depend on the setting, the controller and the LEDs themselves but about 1/6th of maximum seems to be the consensus. (Saturnus)