In reply toI may be wrong but I always thought that making your bass mono, was mainly for tunes going to vinyl as it made cutting them easier?
yes and no...yes it was the case as i had a record Vinyl cutting machine and had to multiband compress and mono below a certain frequency.
Some clubs were mono too so a mono bass had more power..... I tried this and it works, mixed stereo and mono works too when layering depending on the bass, i usually mono'd the lower sub and kick.
try it and see...there might not be much in it these days with powerful VST FX, but when we used to have just a basic compressor and the sound from a desk it worked.

My recent tracks i DIDNT mono the bass and loss some of the impact...so had to mess with them a lot to get the required sound...all a good learning curve in the new days of engineering



So, no, it isnt a must do to mono, its just a tip that worked but you might have your own methods.
