Editors said the departure of guitarist Chris Urbanowicz was a "traumatic, heartbreaking time" for the band but a new line-up has left them revived.
Speaking at Leeds festival, where the band will perform on the main stage, frontman Tom Smith and Russell Leetch, bassist, said adapting to the formation had breathed new life into the musical outfit.
Tom said: "It was a bit weird. It happened at a time that was a bit weird anyway.
"When Chris left the band, it was a traumatic, heartbreaking time for us.
"It was the culmination of a year-and-a-half's worth of things getting worse and worse.
"We got two new guys in to replace Chris; when they came in they had new ideas and everyone was talking and it revived the whole thing."
Their set at the festival, which also sees them playing at sister site Reading, is shorter than they would usually like but the band were still excited about playing, they said.
"Today it's 45 minutes, which is as short as we've played for a long time," Tom said.
"Play a few singles, play a few new songs, get off. That's kind of it. You have to be quite intense and throw yourself at it."
The band have a new album, The Weight Of Your Love, which has seen them return to a more stripped-down style.
Russell said: "It's gone back to original songwriting with just core instruments."