Irek

That is a very very good system and sopras are extremely honest. The side effect is you can sometimes experience imperfections in some recordings as sopras were design for good or high quality only. You can try to use something like Primaluna to smooth the tweeter or get another set of speakers like aria or chorus for average or low quality recordings. At this level/price I would definitely try to audition at home for at lest 2 days before buying anything. It might cost few hundreds but can safe thousands.

Room acoustic is unpredictable. Only home audition can help with that which is complicated to organize but not impossible.

Very cool looking speakers + great speaker stands. Splitter should work well but 2 subs will receive the same signal, not L and R me think.

Well, first of all Focal sounds really good in comparison at the same price range. The second thing Focal pay extra attention to design. There speakers look very cool, different shapes and colors to choose from. I have a feeling the new flax drivers primarily were developed because of the eye catching look.

What system do you have?

Hi, does the Denon have pre outs ? Did you get preamplifier + power amp + RCA cables? If you are not sure feel free to post photo of the front and back of Denon and Luxman.

Hi, for movies center is very important, preferably the same brand as mains. Subwoofer for movies can be whatever brand. Set up for music is more complicated.

Rega brio or Exposure integrated or pre + mono blocks.

I think it depends of the sub, if the sub has 2 RCA inputs L&R than 2 cables from preouts but if the sub has 1 than only 1 cable RCA from L or R preout. For music it is recommended to use speaker level outputs so if you are planning to get a sub make sure it comes with those inputs.

Hi, you can connect subwoofer to integrated amp if the Yamaha is used as a steamer only. Have a look as Rel or Svs subs connections.

At this very high level I would go with 2 the same subwoofers.

Last week.

Sennheiser Ambeo Soundbar Focal Dimension Focal flax + Marantz NR1609 7.2 Channel Slimline AVR

I would consider AVR with pre outs - just in case.