Thanks for the response. I will be using these for an outdoor gig w/ 300 to 500 folks and possibly more.
I talked with
Crown Tech support about the 602 and bridge mode at 4 ohms. The comment was that though not advertised, the amp would do the work. He did say this was the most difficult load for the amp.
I should
wire my two speakers in parallel for 8 ohms in bridge mode for the most
power with available amp and least risk of equipment failure. Right?
The SP2 is a nominal 8
Ohm box when run full range, however the specified minimum
impedance is 6 Ohms, so while two in parallel would be a nominal 4 Ohms, the load would be as low as 3 Ohms at some frequencies. When running near the extremes of a device's operating parameters factors such as the difference between the nominal and minimum
impedance ratings can matter. I won't contradict
Crown but I personally would not try running two SP2s off a bridge
mono XLS602 unless I was taking it easy on the amp, which sort of defeats the purpose.
Maybe we look at this another way. Ideally you would define the levels desired and back into the output required from the
speaker and from that then determine the
power required to the
speaker. But we can run it the other direction to look at what you might get out in the audience based on the
amplifier you already have. When run full range the SP2 has a rated sensitivity of 98dB/1W/1m. Your amp is rated at 380W/
channel into 8 Ohms, but that is a 1kHz
rating so assume a little lower for full range operation, maybe 350-360W/
channel. Based on this data the
speaker would generate 123-124dB at 1m. Not knowing the actual audience area let's assume that the furthest person is maybe 75' away. Distance loss outdoors at 75' compared to 1m would be 27dB. That gives a
level of 96-97dB at 75'. But that is on axis and the audience off axis might see a lower
level, so let's assume 90-91dB there. However, that is also the peak
level, so assuming 10dB for dynamics/
headroom that would then be an average
level of 80-81dB. Is 80-81dBSPL loud enough? If so, then you're probably fine to run the XLS602 in stereo. And unless the difference between an average
level of 80-81dB and one of maybe 84dB really makes an important difference, it would seem difficult to justify running the amp in
mono bridge mode to
power both speakers.