Advance apologies, this is really a hifi question, but I'm sure you good folks that understand amplifiers and speakers can help.
I have a set of passive bookshelf speakers B&O CX100 and a matching passive sub the B&O Beovox Cona.
To connect these up, the Sub has a crossover in it and you send both L & R to the Cona 'IN', then the L and R to the respective CX100 bookshelf speakers come out of the Cona 'OUT'. Having said that I have no objection to a 2.1 setup where the sub has a dedicated output from the amp, rather than just being in series with the shelf speakers.
The exam question is what power amp do I need? I would have simply matched the power to the speakers power, but wasn't sure of the impact of them being in series, and then the impedences are 6ohms not 8 etc
I am looking for a bluetooth amp and was thinking about one of those mini D class amps you find on Ebay, often 50WPC or 100WPC some are 2.1 50Wx2+100Wsub and so on.
The specs are:
For the CX100 Speakers:

And for the Beovox Cona sub:

I am open to suggestions for an amplifier, requirements are: that it can receive Bluetooth and be of the correct oomph to drive the speakers in what ever configuration.
Thanks in advance for your advice!
Stu.