Noob here, but my opinion from extensive reading.
HDMI sucks for audio, extract it ASAP and use well established standard transports.
I2S is only suitable between boards within a single enclosure over short distances, as in a few cm.
For cost effectiveness, ADAT at 8ch can't be beat, but AES3 over CAT LAN cabling is good also
skip XLR, use DB-25 to RJ45 / AES-72 for patch blocks, snakes
breakout cable matching RJ45-to-XLR or RJ45-to-DB25 adapter at the other end.
Proprietary AoIP gets expensive fast, with IT skillz stick to AES67, but IMO for recreational home systems above is just as good but MUCH easier.
A low powered PC or evenbRPi for routing and DSP. Besides RPi doing AES67, also have a look at the DSPi project here for ADAT and AES3.
USB for output from hosts, either a primary interface with the I/O format you want, or e.g. RME Digiface USB gives 4x inputs & outputs so 32ch total via ADAT connections to format converters in 8ch blocks.
Anything doing DA or AD should be BNC WC clocked, all DDC interfaces ideally as well.
Legacy secondhand gear can get down to $15-25 per channel.
These 8ch AD/DA converter boxen and primary interfaces are much more practical than one-way 2ch DACs, not least wrt clock sync'ing, phase drift smearing is a real issue especially full range, less so for subs LF
HDMI sucks for audio, extract it ASAP and use well established standard transports.
I2S is only suitable between boards within a single enclosure over short distances, as in a few cm.
For cost effectiveness, ADAT at 8ch can't be beat, but AES3 over CAT LAN cabling is good also
skip XLR, use DB-25 to RJ45 / AES-72 for patch blocks, snakes
breakout cable matching RJ45-to-XLR or RJ45-to-DB25 adapter at the other end.
Proprietary AoIP gets expensive fast, with IT skillz stick to AES67, but IMO for recreational home systems above is just as good but MUCH easier.
A low powered PC or evenbRPi for routing and DSP. Besides RPi doing AES67, also have a look at the DSPi project here for ADAT and AES3.
USB for output from hosts, either a primary interface with the I/O format you want, or e.g. RME Digiface USB gives 4x inputs & outputs so 32ch total via ADAT connections to format converters in 8ch blocks.
Anything doing DA or AD should be BNC WC clocked, all DDC interfaces ideally as well.
Legacy secondhand gear can get down to $15-25 per channel.
These 8ch AD/DA converter boxen and primary interfaces are much more practical than one-way 2ch DACs, not least wrt clock sync'ing, phase drift smearing is a real issue especially full range, less so for subs LF
