Blue Collar Audiophile
The d4 needs a bigger box than the s4. No clue why but it just does. I will tell you this...my ho10d4 was the perfect sq sub until the truck started moving. Always thought going ported with this sub would do the trick by lowering the f3. As you probably know well getting LOW bass in a single cab truck can be a challenge which is why I'm going to switch to a smaller box sub and give it the ported box it needs. Actually Nasty, ygpm!