Reply to DJ in a restaurant

Dear DJ Techtools,

I'm currently employed as manager in a restaurant and we want to have a DJ play after dinner every friday evening . The restaurant has 2 levels (like a loft) so it's still one open room. We have 2 bigger speakers, in the corners of the ceiling, above the "1st" floor. These 2 speakers are connected to channel 1 on a Numark CM100 19"mixer. The speakers on the 2nd floor are mounted inside the ceiling. These are connected to channel 2. The music input is from a Xenox music computer (dutch brand, specially for the hospitality industry).

Now we want to be able to have a DJ play on the first floor, while keeping the "dinner" music going for the people on the second floor. Now we are not quite sure if the 2 bigger speakers on the first floor would clash with the music on the second floor, since these 2 bigger speakers do provide some volume along with the smaller ones on the first floor. Would there be a way to split the sound from the computer to the 2nd floor, and the DJs music to just the 2 bigger speakers for the first floor? If this is possible we could test if the different kinds of music will clash and if we should look for some smaller speakers for the DJ downstairs. We're looking to spend as little money as possible. Completely switching the music from the music computer to the DJ on both floors might be an option. But we're not sure yet if people appreciate the change during dinner. It's not going to be full on techno music, just some nice low profile deep-house/tech-house.

Thanks in regard,

Stan