Re: bridging amplifiers for dual 18 passive subs
The link to the B52 in question states that it's 2 single 18" drivers, each with their own separate connection. If you parallel the connections, it's going to be a 4 ohm load.
The P3000 run in dual channel mode would deliver about 850 watts per speaker. That's a very safe amount of power, and would be difficult to blow speakers unless you rode into hard clipping. Note, I said difficult, not impossible. If driven into hard clipping, the signal from the amp could square off, resulting in a higher average power than the rated output. You also run the risk of mechanical damage to the sub. This can potentially happen at lower power than the rated power of the driver.
If you bridge the amp and parallel the 2 channels, the amp can deliver 3600 Watts, or roughly 1800 watts per speaker. This would net you about a 3db increase in output. However, if you drive the speakers for a significant amount of time at that levee, your average power could easily exceed the 1000 watts that they are rated for, and burn up the speaker. This will happen with bass heavy music, especially that with sustained LF notes. With a lot of current 'DJ' music, I recommend matching RMS of the amp with the speaker, as the dynamic range of the bass is typically fairly small, leaving not much room for error with an oversized amp.
Having heaps of headroom should mean that all pieces of gear in your chain have room to spare. Heaps of headroom on an amp without a speaker that is ready for that power is a recipe for disaster. When you are dealing with unknown operators, match RMS of the amp with the speaker, and you'll be reconing far less often. If you need more output, get more cabinets, or adjust placement of what you've got. Sometimes a reposition of the sub can give you just as much as doubling the power delivered to them.
