Stereo amplifier for a pair of passive subwoofers.

A lot depends on the subs used as far as how much power your going to need. My power meters on the front of my Onkyo M-504 very rarly hit peaks of over 100 watts driving two vmps subs.

Most of the time the Onkyo is coasting along at well under 100 watts...more power would be nothing but a waste of good money.

I should mention also that this is in a large room.

Dave

Sogood51, transient power peaks is also a very important parameter.

Yes, most of the time amplifiers just coast along around 5-10 watts. But even within that period, there are transient signals (in milliseconds, too fast to register on power meters) which can consume huge amount of power in short bursts. That's what the extra dBs of headroom is for.

Typically, most good power subwoofers use amplifiers in the 250-500 watts range. Some, like the new Velodynes DD use around 1,300 watts (Class D amps). If space, weight, heat dissipation (for class A/AB amps) and cost weren't a problem, subwoofer manufacturers would probably use even higher power amps.

Justin_time

Well shure, and my Onkyo has over 300 watts a side for my 90-91db VMPS's. As I mentioned, the subs design along with the size of the room they will be used in play an important factor in the amount of power that will be required. Also, I use two subs for stereo and three for hometheater.

A single sealed sub in a large room may indeed need huge amounts of power to reach high spl's.

Dave