I'd like to try my electret with a different box, but I'm not too familiar with electret transformer boxes. (I'd like to hear whether the box is what limits the bass output.)

Is this thre-pin connector common?

Is this thre-pin connector common?

Never seen it before in my life. What's the low/high switch for?

That's bad. I was hoping to find some other box to try.

The high/low switch toggles between 8 ohm and 600 ohm impedance (supposedly, I have not measured it myself). The "low" setting sounds bad with my gear. I have seen no obvious way of opening the small box, so I don't know what else it does / what's inside.

The only other box like this is on the Phillips N6326 (or what ever it was called) or any of it's oem versions. There are two small transformers inside but the cable is fixed in place.

Could a bigger transfomer or a different amplifier than the XCANv3 increase the amount of bass? (When I turn it up really loud, then there is deep bass. I'd like it also with lower volume.)

First step is to use them on a speaker amp with the headphone output taken from the power amps or build a M3/B22/Dynahi. These things need a lot of current which the Xcan was not designed to do.