Kijanki, the lowest bass note is 44Hz on the electric bass only.
Acoustic bass / double bass / contrabass reaches 31 Hz and grand piano's lowest bass note is 27.5 Hz, clearly out of the frequency response of the OP's speakers.
http://en.wikipedia.org/wiki/Double_bass#Pitch
http://en.wikipedia.org/wiki/Piano_key_frequencies
Not to mention Oscar Peterson's favorite piano, the Bosendorfer...it does 16 Hz!
Personally, I would not mess with a subwoofer, they are difficult beasts to adjust and rarely if ever blend seamlessly with the main speakers. I would spend the money on a speaker upgrade.
Acoustic bass / double bass / contrabass reaches 31 Hz and grand piano's lowest bass note is 27.5 Hz, clearly out of the frequency response of the OP's speakers.
http://en.wikipedia.org/wiki/Double_bass#Pitch
http://en.wikipedia.org/wiki/Piano_key_frequencies
Not to mention Oscar Peterson's favorite piano, the Bosendorfer...it does 16 Hz!
Personally, I would not mess with a subwoofer, they are difficult beasts to adjust and rarely if ever blend seamlessly with the main speakers. I would spend the money on a speaker upgrade.