for what you're dealing with a 500
watt amp sounds like it can work, providing that you aren't going outdoors, and your sound techs aren't trying to push the highs to what you expect to hear out of a car blasting rap music without a sub.
The BR12's are 8
ohm so you can
daisy chain them and use the amp's
mono bridge mode if it is rated at 4 ohms for possibly a little more
headroom if needed.
depending on the budget you could go with a QSC RMX 1450 ($499?) which will offer the watts needed to safely
power the speakers, just make sure that while you're live, the peak lights on the amps don't light up, otherwise you're on the way to blowing the horns. they can handle a little but I would never push it to where they're on every time that a the
speaker gets a little rowdy and loud. just try and keep the
speaker cables short as possible, and if you choose to run stereo, then make sure they are the same length for equal performance. (longer lengths mean more floppy sounding speakers=not good)
A couple of common oversimplifications in this information. For one, you don't really need to worry about the cables being the same length unless you are talking about very long runs and dramatic differences in the run lengths. And longer cable length does not directly relate to 'floppy' sounding speakers. The real issue with the first is
line loss and the second is damping factor and both of these are dependent on not just the cable length but also on factors such as the load
impedance, the cable resistance and the
voltage and
current involved. In fact by halving the load
impedance, the idea presented of running two speakers on parallel off a bridge
mono amp could have more impact on reducing the damping factor than does the cable length.
Another sort of oversimplification, or perhaps more accurately a common misapplication, is the concept of needing a certain wattage to "safely"
power the speakers. For most installed or permanent systems the underlying issue here is simply having appropriate output for the application. If you only need 1W to the
speaker to get the necessary output then a 50W or 100W amp might be more than enough even if the
speaker is rated at 500W or 1,000W. The idea of basing the
amplifier on the
speaker rating comes from situations where instead of trying to achieve a specific result, which is more typical of installed systems, you are wanting to get all you potentially can from the
speaker in a relatively safe manner, which is more typical of rental and touring systems.
The RMX-1450 might be a good choice but I would run it stereo with one BR12 on each
channel. Both speakers in parallel off a bridge
mono RMX-1450 would be giving the speakers more than their peak rated
power and especially without any limiting, unless you were real careful you could be having to replace drivers on a regular basis.
Speaking of limiting, you might want to consider some signal processing, EQ might really help the
house system and the monitors if you don't use in-ears and some compression and limiting might help both.
