While the amp sees the same load, the first few inches of wiring in diagram2 are going to see a lot of current. Better to stick with diagram1. What's the impedance rating on those? If those are standard 8 ohm woofers, all of them in parallel is driving down to 2 ohms which is a tough load. Alternatively you can try an in-between by wiring pairs in series and then put those pairs in parallel. It will keep your load the same as a single driver.