Razer kraken Tournament Edition - bass control

I have had a lot of frustration with these headphones with regards to the sound, volume and sometimes not working at all. I have decided to not use synapse or the thx spatial as it caused more problems than it solved for me. My question however has to do with the bass control. I do agree having this adjustment is nice to have but not knowing how much or little you boosted seems like a bit of waste. Does clicking it all the way to left put it to flat (0 db) or does it cut from the bass frequencies (-). My question is where is flat? (all the way to the left or in the middle?). Also how many adjustments are there (i believe i saw 17) I know its a bit confusing but any help would be appreciated. thanks