CAV Audio speaker set-up

[PsyTrix]

Back in 2008, I purchased a speaker package made by a Chinese company called CAV Audio (http://www.cav-audio.com/) - I'm not one to generally buy products from a relatively unknown company, however the build quality was top notch and for the price I paid, I'm pretty happy with it.

However when it comes to the two large front speakers, I'm a bit confused. They have the main speakers at the top followed by a large sub looking speaker at the bottom. Please refer to this image: http://auctions.c.yimg.jp/images.auc...4081800004.jpg

I notice there is also 4 banana plug ports on each speaker - how would I set this up? I only got one banana plug cable for each speaker. Would I need to modify them to have 4 banana plugs where there was originally only two on one end?

I've only ever been able to hear audio from the top half of the front speakers and it would be great to finally utilize the bottom one's as well.

Anyone who could shed some light on this matter would be extremely helpful - Thanks!