bro, this type of sub are consider old school technology / sub to me...they wont go low..for me, i tune my sub at 30-60Hz to make it really low...so this type of sub are more likely BASS-Mid to me...sorry to offence..but u cant get a "not so good" sub to go low...that;s why low sub are expensive....

btw, try to change to a box with small port...i tried b4 with my 10' sub long time ago..these sub cant pump too much air.if not it will not sound nice..so u must make the port smaller..i make my port like 20sen coin small using a pvc tube about 10" long...it really sound good for a 10" like yours...

btw, this is just my opinion...believe or not are depend on u