Amp wiring

Turn off the bold.  It's available to be used for emphasis, not for the whole post.  Now...... you were told correctly.  What you are missing is the fact that a two channel amp is, in reality, two amplifiers.  Each channel, or amplifier, sees a load.  When you bridge the three DVC 4 ohm subs' 2.67 ohms across two channels, each channel sees half that load, which is 1.33 ohms per.  The channels, or amplifiers, work independent of one another in that each one receives a load and reacts with the appropriate power output.  Or at least they try to....but with the load that low the amps will shut off or burn up.

Ratings are always per channel.  A mono amp is one channel, so there is no bridging involved and thus no splitting of the load.  But a two channel amp is rated as to what it does per channel....whether it be output, or minimum impedance load.  You'll always see that when a two channel amplifier is rated at a minimum load of 2 ohms per channel, that the minimum bridged load is 4 ohms.