I don't understand "just for music" as opposed, I guess, to movie LFE's. For a lot of us "music" includes pipe organs, many of which are capable of musical notes - not noise! - a LOT lower in pitch than you'll find in movie sound tracks. Listen to the second movement of Saint-Saens's Third (Organ) Symphony - there are some soft organ pedal notes there that are below 20 cycles, at least in some recordings. Another place is in the "Saturn" part of Holst's The Planets. Maybe the LFM-1 can get that low - I don't know.
Does any music outside classical get down that far? Maybe someone else can tell us.
Anyway for that kind of music LFM1-size subwoofers woulod certainly not be "too much"; rather, anything smaller wouldn't be enough.