After doing the SPL tests with the four Digital Designs DD-512-D4′s it was brought to my attention by Ashley ‘MAD BASS’ Burrell that we have not yet tested two of them for a comparison. This got the brain ticking over and after a long conversation (Ask anyone that knows us, Ashley and I can talk!) with Ashley the decision was made to run with the same design that was netting us results with the four DD-512-D4′s, but this time with only half the box.

As I do I setup the car the way I always do before testing, checking and double checking all my settings just in case I changed something during daily driving which I do when I’m running different setups. Once that was done we positioned the Sub-Woofer Box in the boot/Hatch of ABTEC3 and gave it moderately powered sweep. Just like the four Sub-Woofer Box the sweep showed the optimum frequency @ 58Hz, so now it was time to test them.

On the first ‘Burp’ we netted a mid 150dB so I tried out a couple of frequencies above and below 58Hz, funny enough the sweet spot was 56Hz and not 58Hz as the sweep showed. At 56Hz the gain was almost 0.5dB which doesn’t sound like much but can make a world of a difference when you are competing, we also tried changing the box position and this even made a slight difference too!

On our final run we managed a 151dB out of the entry level DD-512-D4′s, so I had to know if it was a one off so tried a few more times getting 151dB every time! This result has surprised me quite a bit and to be honest I was really happy with this result. At the same time it tells me there is still more to be squeezed out of all four DD-512-D4′s, so now its time to brainstorm and test until we get that 1 or 2 dB more we are looking for but only time will tell!