Subwoofer for a shelf stereo system?

Question

I have a Sharp Micro Component System (Model XL-MP131) and am wanting to add a subwoofer to it. On the back of the system there is an RCA jack labeled "Subwoofer pre-out" and in the manual it says "When a commercially available speaker with a built-in amplifier is connected to this unit, you can enjoy sound with emphasized bass. Connect an RCA cord from a commercially available speaker with a built-in amplifier to the SUBWOOFER PRE-OUT jack"

Is a speaker with a built-in amp the same as a subwoofer? If not, could you plug either a subwoofer or a speaker with a built in amp into this jack and still get the same effect? Are speakers with built-in amps specifically labeled as having the built in amp?

If you could suggest any specific subwoofers/speakers with built-in amps that would be wonderful. I'm not looking for anything too crazy, just something to give my sound a more defined bass.

Answer 1

A powered subwoofer is really just a single, larger, speaker with a crossover to limit it to low frequencies and a built in mono amp.  The output from the jack on your speaker system provides a low level signal that requires an external amplifier.

Given the speakers on your system are not top of the line there is little point adding an expensive subwoofer (you can spend $thousands on top end models) ... maybe Sharp sells a suitable accessory model,

or

see the one at the link (it's about as inexpensive as dedicated powered subs come)

or

for less money you can use a computer subwoofer.  Look for a stereo computer speaker setup with a powered subwoofer and simply don't connect the satellite speakers (i.e. just connect the sub).

Answer 2

They are called powered sub woofers. Check Sharp online for one to match your system. They are not very expensive.