RJ45 Pin 1 -> RJ45 Pin 1
RJ45 Pin 2 -> RJ45 Pin 2
RJ45 Pin 3 -> RJ45 Pin 3
RJ45 Pin 4 -> RJ45 Pin 4
RJ45 Pin 5 -> RJ45 Pin 5
RJ45 Pin 6 -> RJ45 Pin 6
RJ45 Pin 7 -> RJ45 Pin 7
RJ45 Pin 8 -> RJ45 Pin 8

Straight through cable.

Of course the cable would work - even if you rearrange the pairing (for short distances / low frequencies / etc...)

Trying to justify the use of a device on the basis of 'you can use the same cable' is not a good idea - see the other things I listed with RJ45 - all of which I can use the same cable for, but you do NOT want to mix them.

The isolation transformer(s) should not be considered as a passive device.

The posts I made were not about a straight through cable - the posts were made about an isolation transformer - and trying to shove 5 pairs of signals through 4 transformers.

Isolating RS232 (within the speakerlink wiring) should be done with an Opto-isolator - not a transformer (or does the Manufacturer claim it will work with RS232 (doesn't EBA control need this?) and I'm not sure about Meridian Comms?)

Once you start throwing transformers in, you no longer have a straight through cable. My posts were NOT about cabling but the signals going though it and only 1 of the 5 is the digital 'AES/EBU-ish'

Personally I can't afford to risk my Audio equipment on this sort of experimentation and I was concerned about leaving it unchallenged in case something expensive happened to someone - you are trying to isolate digital audio (that the isolator is compatible with) AND Meridian Comms AND RS232.

This is no longer at the swapping interconnects level but modifying the signal going through the interconnects (which would require detailed knowledge of the endpoints to evaluate - although the RS232 issue disqualifies the device from the start).

When I say 5 pairs of signals - don't immediately jump on that and say that a 4 pair cable works - the signals are SHARING the grounds for comms (M+RS232) - as soon as you throw a transformer in you loose the shared ground because of ISOLATION.

Somewhat frustrated at this point... Do you know what RS232 is?
This is NOT about cabling - this is about the suggestion to use an isolator designed for something else and why this is not a good idea.

Remember - only 1 / 5 of the signals is AES/EBU-ish.

Is there anyone else that can chip into this?

I'd want assurance from someone that the device:
Is compatible with Meridian Comms?
Is somehow capable of taking RS232 through a single transformer and ending up with separate Receive + Transmit at the correct DC levels (i.e. not actually working as a transformer)?
The DC resistance (NOT AC impedance) of a coil will either be high enough not to matter or not end up across the SpeakerLink power connection.

Is there anyone else that can chip into this? (could save someones system at some point).

Matt.