Recording Audio Post RMX1000 - DJM450.

I'm currently running a DJM450 Master out into an RMX1000 Station then into a Speaker System.

The Speaker System is from the RMX 1/4 Jack output on the RMX1000, When I plug RCA cables into the other Output and into my USB Soundcard to record the Speaker System audio Drops drastically.

Is there anyway to Rectify this without resorting to Splitting either the 1/4 Jack or RCA cables into a Y connector?


Many thanks in Advance.