Speakon connectors are used for amplifier output, not input.
Don't know what you mean by "as REL or BK".
Don't know what you mean by "as REL or BK".
That is a non standard design and will cause problems. The Speakon is designed purely as a loudspeaker coupling connector.
In a standard 4 way connector pins 1+ & 1- are full range, pins 2+ & 2- are treble in mixed bi powered speaker systems.
In the 8way Speakon, pins 1+ & 1- are sub, 2+ & 2- are bass, 3+ & 3- are mid range and 4+ & 4- are used as treble.
See Neutrik's link for the correct wiring; https://www.neutrik.com/en/neutrik/products/speakon-loudspeaker-connectors/speakon-cable-connectors
REL subwoofers are designed so that you can integrate them with a conventional HiFi system - they use an NL4 speaker-level input which is then attenuated and summed to mono to feed signal to the internal amplifier.
A rather good idea, if you ask me.
Chris
Beware if the source is bridged amplifier, because the BK speakon input is unbalanced (must check about REL).
