I purchased an NM200 retro fit system and I don't see any other way that is provided in the instructions
Thank you for your question on the model NA300MCWH. The NA300MCWH is the proper volume control, for use with "music only" speakers on our NM series of radio intercoms. Please remember that when updating the IM4006 with the NM200 system, you will also need to change out the ceiling speakers from the current 25 ohm to new 45 ohm speakers. Please contact our Technical Support department for further assistance at 888-336-6151.
Date published: 2013-10-23