How early before a performance do bands perform soundchecks?
I am the founder of a gig planning software (gixtra.com), so I have some data on when bands plan their soundchecks.
Let me just say that it varies — depending on the band and the size of the event.
On some occasions bands have no time for a decent soundcheck. This often happens at festivals, where many artists play throughout the day. In this case, bands perform a so called “line check”, which is kind of a 10–30min stripped down soundcheck. This is usually followed by a few signs from the musicians towards the monitor technician during the first song of the set.
Most common are probably sound checks a few hours before the show. If a show starts at 8pm, doors might open at 7pm. The soundcheck in these cases ends right before doors open. So to have enough time, a band would begin soundchecking somewhere between 5 and 6pm.
If more than one band is playing, soundchecks happen in reverse order of the show. So the band opening the evening checks last, while the headliner (the band later in the main spot of the show) checks first (the curse of the headliner ;)).
In same cases, soundchecks have to happen much earlier. A typical reason for that are be TV interviews or other press events before the show. Also if a band plays at an event (like a city fair), the soundcheck might have to happen before the event opens (usually before noon) to spare visitors the soundcheck.
The data I see from bands and booking agents in Gixtra suggests, that 2–4 hours before the show is a common time to soundcheck.
