Dale Stewart

It's his signature bass

At Uproar Festival 2011 in New Jersey. About 0:36 you can see the front of the amp, though the oversized version, specifically made for Dale on tour.

At around the 6:10 mark in this video, you can see an Ampeg SVT 4 Pro head behind Dale

At around the 6:10 mark, Dale can be seen in fron of an Ampeg 8x10 bass cab

At around 14:42 or 14:43 in this video, Dale mentions running Hartke 8x10 cabs, one on either side of the stage

Picture was taken by me at Seether's Cleveland show at the House of Blues on May 12th, 2015. Though the picture may be slightly blurry, it's clear that is what the pedal is. I got a better look in-person.

At the 13:02 mark in this video, Dale's pedalboard is shown, and you can see a Boss ODB-3 bass overdrive pedal

At the 13:02 mark in this video, Dale's pedalboard is shown, and a Boss TU-2 tuner pedal can be seen

At the 13:02 mark in this video, Dale's pedalboard is shown, and a Dunlop Cry Baby bass wah can be seen

When Dale's pedalboard is shown at around 13:12, you can see a Lehle P-Split, which his used to split his singal into two bass amps

As seen in Ernie Ball's Instagram account.