Garfa I hope you don't take this the wrong way because I'm greatful for any help I can get, but are you certain that it will ony give 70-80Wrms bridged.
After reading 12Voltking's post on 'bridging amps' he calculated that a 50watt by 2 channel amp could put out 200watts if bridged. Attached some of his post below. Sorry if I'm wrong but I'm just confused how a 50watt amp can put out 200watts bridged, yet a 70 watt amp cannot??? After using the calculations below and substituting numbers I got 280watts......
""Imagine you have a two-channel amp that puts out 50 watts into each channel when driven into a load of 4 ohms per channel. Since we know P and Z, we can plug these numbers back into our power equation and find V. 50 = (V^2)/4 -> V = sqrt(200). So, we're seeing a voltage of 14.1 volts across each channel.
Now, imagine we bridge this amp, and use it to push just one of those 4 ohms loads. When the amp is bridged, the voltage is doubled. Since we know the voltage (2*14.1 volts), and the impedance (4 ohms), we can calculate power. Remember that P = V*V/Z. That means P = (28.2^2)/4, which is 198.1 watts. It should be clear by now that the new power is approximately 200 watts - quadruple the power of a single, unbridged channel!""
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