Purpose of a subwoofer

What is the main use of a subwoofer ?
I just got JBL Pro sbuwoofer and it sound sucks. Too much bass I think. Sound not as clear as my two Creative speakers.
It is a old subwoofer and has only volume control and line it though.

Can I mix this woofer with my Creative speakers.

the main purpose of a subwoofer is for bass. you can look at the frequency range, and see that its mostly lows. i dont know how to do this for non-home speakers, but if you can set the frequencies for each speaker correctly - you’d probably be much happier.

subwoofers are often in addition to regular mid/hi speakers. so yes, its fine to mix it, provided you can find a way to connect it.

Hi

is there a frequency cut-off button or switch? (or is just called volume )
Try to set it to an lower level.

The fucntion of a sub woofer is to add bass when you have for example small speakers. These small speakers are not able to produce low frequenzies. THis will be done with a sub woofer.

Best performance will be attained with a matched set of satellite speakers and subwoofer. The one you have could be meant for most any purpose, possibly even just for reproducing extreme lows, say under 100Hz. Unless you know what it is set up to do, it’s just a crap shoot.

The subwoofer has a volume control knob and a line in socket. If I lower down there volume, nothing can be heard. Where I try to raise the volume, the bass is extremely high and I think my whole house is shaking. In order to mix my speakers with the subwoofer, I need at least a four channel sound card. One for the speakers, the other one for the subwoofer.