Hi.
It all depends on how far down your speakers go.
Yes, "how far down" & how much
acoustical bass power the loudspeakers can deliver. It means to get the right bass SPL, the driving amp will NEED to have adequate 'muscle' to drive LF (assuming low enough for the loudspeakers) to the right SPLs.
Like my 2-way KEF bookshelvers, already got a large 13.5" x10" woofer. But so what! My 35W+35W tube power amp fails to deliver the realistic low bass acoustical power out of my loudspeakers. I did not know until I added my brandname 100W 10" active sub which gives me back the long time missed LF music already recorded in the music! For a few digitally mastered
vinly recordings, I have to find my dropped jaw when the bass notes pumped out so clean, fast & powerful.
Never before without an active sub, properly interfaced with my stereo tube phonostages & properly positioned.
Pipe organ music & the like LLF instruments can go down to sub subsonic frequencies which can be produced by an active sub (after
proper placement) withOUT sweats & withOUT overdriving the power amps.
By hook & by crook, I can now enjoy really FULL range music comfortably at not too high SPL with
LF bass pumped out realistically withOUT affecting the finest details of the HF & MidF of the music.
c-J