Using a Mixer with Eclipse Version 7

[Barbara Memory]

Hi, ya'll.  I need to add a mixer to add microphones at multiple locations in a courtroom.  I purchased the Nady mixer and have all the appropriate connectors.  When I use it in the diamante, it is great.  With the puter, it sounds not usable.  So many issues I cannot even describe them. Not even sure if it is picking up through the internal microphone or the mixer.  Is anyone else using a mixer? If so, can you help me?

Thanks,

Barbara