Adding an active subwoofer to Edifier 1600T 2.0 setup?

[SouthEastBlue]

I have a Xonar DGX and some Edifier 2.0 1600T speakers (few years old tbh), but they're still pretty decent but they really lack low end punch.

I got £100 max to spare on a subwoofer, anyone know what I should be looking for and how I can link it so the volume is controlled through one place rather than by the speaker and the sub separately? I was looking at car subwoofers but I think a home audio subwoofer is probably an easier option albeit they seem more expensive.

Any ideas or anyone else done something similar? Only other option is buy a new 2.1 speaker system, but seems a waste on the current speakers I already have.

 

[SouthEastBlue]

It's literally for my PC in the dining room which I also listen to music on. Just noticing how even the cheapo £30 2.1 system on my wife's PC puts out better bass than my Edifier speaker, and it made me look into adding a sub to get some low notes!

I know adding a car sub would require a 12v power source - I have an old Corsair PSU I planned to use if I went with this option but it's not the neatest way to add some bass. This got me looking at home subs, but it seems I can't get a great deal for my money. I'm not a mega audiophile I just fancied making my 'sound system' better.

I also had a look at new 2.1 system and the Logitech Z533 was the best I could find under £100.

As for my soundcard it has outputs for 5.1 surround so front rear and subwoofer.