We are considering one. We have a pair of the older turbosounds m15s and are considering an alto 15 inch sub to add permanently, we often use/borrow one as an add on at bigger gigs.
About 4 times a year..... but we are out every week and sometimes throw in a new song or 2 to see if they work.
i was once in band where the band leader (of sorts) wanted weekly rehearsals... it’s too much in my opinion.
I have a whole album of Prince - One Night Alone. A live album (his 21 nights in London tour) - specifically, strange relationship and other side of the pillow. Rhonda smith on bass. Maceo Parker on it too. Always in my car!! 💜