Bass is good as is. You can use kaisertone app or eq on spotify to add more bass. I like bright so no filter. I do use the filter with iOS app kaiser tone to get better sound from YouTube ripped audio. I like to rip you tube audio or video with iCabMobile (app) and export right to kaisertone...

On a mission today in Hong Kong looking for diy 6 armature and just yesterday found a fella doing some diy in Shenzhen china. Prices are way up there and I came across these and loved them. Did a search and brought me here. Got the K3 pro with one year warranty. To hell with all the diy, haha.