Wide 28, low 30 (without plug), high 11.1 should be correct

412 has no LAN/WLAN connection, streaming functions are only available on 612. It also has HEOS Multiroom technology.

According to the Quick Start Guide, only the connection of a TV is possible. In addition, music can be played with any app on the mobile device via Bluetooth.

According to our information, yes.

The Marantz Melody units are extremely compatible as far as speakers are concerned. Due to the amplifier power, according to the manufacturer, floorstanders and compact speakers (also 4 Ohm) can be operated with this system without any problems. With the Melody Media MCR-611, the predecessor model of the M-CR612, my old B & W CDM 7 SE floor-standing speakers deliver a wonderful sound, and you can also turn up the volume quite a bit if necessary. In this respect, I would trust the manufacturer's specifications, because the M-CR412 also delivers 2x 60 watts into 6 ohms.

Question 2: As you can see from the third product picture (view of the back), this unit is not equipped with a LAN connection. Question 1: This unit has enough power reserves to cope with a wide variety of speakers. I use the more expensive predecessor model (MARANTZ Melody Media M-CR611) with Bowers & Wilkins floorstanding speakers, and the amplifier power is the same with the M-CR412. At most, the question is whether the KEF and Marantz character positively support each other's acoustics. Let's say a receiver is warm in sound, plays treble clearly but still pleasantly, is strong in midrange reproduction, bass sounds a bit soft, lackadaisical. But because of the high musical quality, staging, stage, etc., you still want it. Then it makes sense to find a pair of speakers that can reproduce the strengths, but compensate - at least partially - for the weaknesses. Of course, other factors play a role, but what I want to say is this: even if the Marantz can easily handle the KEF's in terms of amplifier power, the sound result is not necessarily as convincing as test reports can suggest. However, since these are compact speakers that tend to be rather slim on bass anyway, I don't really see any problems with this combination. On the contrary: the two brands seem to harmonise so well that there was already an official set with Marantz receiver and KEF speakers (LS 50) for the predecessor model.