unfortunately, running two sounders as the same frequencies is not recommended.. there WILL be interference. Even if you set the display to 50k on one sounder and the other machine to 200k, the transducers are still transmitting at both frequencies with those models. Installations of dual sounders of course have been done with varied results (none of them good), and there are certain levels of interference rejection settings, but IR was designed to suppress OTHER boat's transmitting nearby, not two ducers on the same hull blasting away at at parallel angles. That said, there are ways to help tune the image between IR/PingRate/Gain, it just really depends on what you're targeting and making sure you don't filter it out or make it unrecognizable when dealing with the actual interference. right now I'm on VaCa but if you shoot me an email at email@example.com with a # to call, we can go thru specifics.