To add to Auxinput’s comment, in stereo mode your amp is capable of supplying about 400 watts into 6 ohms, while the recommended range of amplifier power for the Wharfedale Diamond 250 speaker is 25 to 200 watts. So the speaker almost certainly wouldn’t be able to handle the additional power capability that would be provided by using two of these amps in bridged mode, even if the amps could handle the 6 ohm load (spec’d as reaching a minimum of 3.1 ohms) in that mode.
Regards,
-- Al
Regards,
-- Al