Is it possible to connect an active subwoofer directly to a computer without a receiver or amplifier?

I have 2.0 active speakers and I want more bass so I found the Yamaha YST-SW012. The subwoofer has one input and it is a subwoofer cable input, which i think is a 1x RCA (correct me if I'm wrong). I plan to get a 3.5 mm adapter for this RCA and I would like to connect it directly to my computer in parellel with my 2.0 active speakers using a splitter. Will this set-up work or is it absolutely necessary that I have to get a reciever. If it is not possible what other ways can I add a subwoofer along with my 2.0 active speakers without having to get a receiver and without busting my wallet? (I don't want to spend more than 100 euros). My 2.0 speakers are 100w in total and I would like to get a 100w peak subwoofer at the least.