For what it is worth I played 4 string bass through a 1970's Marshall Super Bass Valve Head into a quad box loaded with 4 x 12" Green Back 25 w Celestions. Never had a problem with bottom end reproduction, even when I played the Riccy 4001 in Stereo through both 'inputs'. The amp was ridiculously loud and rarely played past 1 as it didn't have a master volume control, and any higher just drowned out everyone's stage sound plus front of house. Fiver's weren't around back then so not able to comment on how that may have sounded, but seriously, if using a DI stage sound is only for your own benefit as signal would also be pumped back through foldback monitors for others to hear, including yourself.