DVC Sub Wiring..i think i got it wrong?

[Grip72]

and this is the way they connected them on Alpines website to one amplifier. It basically says that from the + terminal on the amp, you connect it to ONE + post from EACH sub and from the - post you connect it to ONE - from EACH sub and then ua re left over with one - and one + post on each sub. So it shows to connect the left over - and + posts on each separate sub together. I hope you followed..here is a diagram to help explain it..anyways, i need to know if they did somethign wrong of if i did?!?! I have been using MY setup (first one) for over 6 months now. Please tell me the difference. thanks!