iv got a 15 memphis in my std cab ranger and it hits pretty hard- its in a sealed box and i was wondering if i made a box with more air space would the sub drop more? mayby hit deeper notes? iv always believed more air space= better is this right? i cant get to crazy cuz its only a stnd cab-

 

do an online search according to model number of sub use the maximum sealed air space ie: 1.25 etc to calculate the the box air space you multiply length times width times height divided by 1728 also if you use 3/4 mdf you must subtract 1.5 from the length/width/height for example you have a box that measures externally 18 L X 15 Wx 14 H so you true measurements for the air space would be 16.5 L x 13.5 W x 12.5 H keep in mind speakers have displacements meaning the size of the airspace the speaker it self occupies let's say as an example .10 so this box's air space is 1.611- .10 gives you 1.50 cu hope this helps

 

^ +1 to above but you can also exceed the manufacturers specs but you willhave to decrease power handling to comphensate for it.

A better aproach would be to build a bandpass box tuned to a lower frequency, remember to use(or enable) a subsonicfilter though or you will more than likely blow your sub(most class D amps have hte subwonic enabled by default - if you dont see it on the outside, open the case look for a switch of a button labled subsonic or check the manual. My polk 300.2 has no lable for it but inside the. Bandpass boxes sound better in open cab environments than sealed boxes.

Then more to think about, your 15" may just be at its limit. Theres only so much bass you can sueeze out of it. Two 12"s will give you more surace area than one 15.

 

good point NOTLADSTYLE