I lower all channels to cut Audio and Music was still coming out of Master Out.

Your buffer size may be too low for your system.

@Luis > I noticed that you have posted a few questions, some of which are answered in the rekordbox DJ user manual, others are a matter of configuration. Rather than suggesting that it's unacceptable and asking for a refund (which you are certainly entitled to), perhaps trying to resolve the issues first may be of interest?

Too many bugs for the price guys.. Manuals ? the latest Manuals you have on your site is for 3.3..

The manual I linked is directly to the 4.0 manual.

There is also a 30 day free trial of the software.

Might have been some effect being on??