Complex sentence: Including a second connector adds two additional 28-bit channels (2 cables yields 3 separate 28 bit channels), but it is important to note that only "24 bits per channel" actually transfer data.
Split into simpler sentences: Including a second connector adds two additional 28-bit channels (2 cables yields 3 separate 28 bit channels). It is important to note that only "24 bits per channel" actually transfer data.