Axiom Home Page Forums General Discussion Technical Questions M80v2 with NAD bridged amps

John,

Thanks for your detailed input. Maybe you can help me understand where my thinking is off; my understanding is:

A bridge tied load (BTL) amplifier applies a normal signal to one terminal of the speaker, and an inverted signal to the other. If a single channel of the amp is capable of producing 20V RMS across the terminals of the M80, this equates to P = V2 / R, so in this case, 20^2 / 4 = 100W.

When connected in BTL, the M80 "sees" 20V at one terminal, and an inverted 20V signal on the other - a total of 40V RMS Using the same formula, 40^2 / 4 = 400W - four times the power. But, each channel of the amp now sees only half the load impedance (think of an imaginary center tap in the voice coil, connected to ground). The amplifier must be stable into 2 ohms, or bad things happen..

regards,
clay