splitting a pioneer ip bus cable

is it possible to split the the audio signal in a Pioneer IP-Bus cable? The line up is like this: There's a pioneer head unit with the typical IP-Bus input, an older model (but still working) Pioneer changer with a single IP-Bus connection (the output), and a DVD Player with an 1/8 inch audio output. The head unit does not have an AUX input. Im wondering if its possible to splice into the left and right audio signal running from the changer to the head unit and run a cable with an 1/8 inch lead to the audio out of the DVD player. I thought this could be done through diode-isolating the signal wires heading back to the changer and and DVD player. Are the signal leads directional (meaning that if I attempted this, would it matter which end went to the changer and which went to the head unit)?

can it be done without purchasing anything? thats what im hoping to do.