150hz lpf too high for a 8" sub?
 

I've got a 8" sub in a dual reflex bandpass box, it plays low but I am missing some tighter bass. I have my amp's lpf set at 80hz but I'm thinking perhaps an 8" could take higher frequencies, 100hz or 150hz? I am not sure if I am missing the low-end MID bass because of the lpf setting or if the box is just tuned for lower frequencies. Basically is 150hz too high for any sub? My fronts are not powered by an amp so the hpf does not apply. Thanks in advance.

You could always try it to see what happens. You could also try moving the box into different positions in the car to see which reflection works best for it. If you load it into a corner (the ports) then you'll get louder, but more droan. If you aim it forward into the cavity, you'll have punchier bass. I would have someone move it for you with your favorite song playing until you find the perfect spot for you, then bolt it in.