[G Georgopoulos]

To op poster,have you considered using the parallel mode it produces p=x2 as well but you need to have Zspk/2 at the current taps of the transformer,this means your current spks won't produce p=x2,please note bridging produces p=x4 when v=x2 into your current spk which means the amp power specs are exceeded the max is p=x2 (1 amp max p + 1 amp max p = px2)

try parrallel but use spk with half the impendance of you current ones for p=x2,also the wiring is simpler with xlr

cheers

[Speedskater]

The DEQX does not float pins 2/3 of the XLR outputs.....they are properly referenced to ground.
Dave.

They well may be referenced to circuit ground, as many components do so. But there is nothing proper or improper about it. There is no requirement that the balanced output be referenced to circuit ground. A modern transformer output won't be referenced to circuit ground.
Remember that XLR pin1 is not ground, it's the shield.

[JohnR]

Purpose get more gain?

Oh. In all the flurry, the fact that the DEQX has a set of jumpers to set the analog output gain has been missed. If those are not already set at the highest settings, that would probably be the first thing to do.

[Davey]

They well may be referenced to circuit ground, as many components do so. But there is nothing proper or improper about it. There is no requirement that the balanced output be referenced to circuit ground. A modern transformer output won't be referenced to circuit ground.
Remember that XLR pin1 is not ground, it's the shield.

As you mentioned, there are certainly exceptions, but I think you'll find very few non-transformer outputs that are floating. 
Whether it's "proper" or proper is just semantics.  But, it was a poor choice of words on my part.

Dave.