I am pretty new to car audio, but am looking to get a Q 15 and run it with a sundown 1500. Fi suggests 2-2.6 cuft. My main point is understanding how I should tune and set it for 28hz, but have also seen threads saying it should be over 35. Does this depend on the cuft in the box? I think at this point I am reading too much into all this and confusing myself.

If it's sealed you can't tune it. If it's ported you can tune it.

So does it really matter on the cuft as long as its between the recommended? Will one have a better sound then another?

If you are planning running 1500wrms I would use the smallest recommend size

Which brings up a nother confusing subject on my part. The Fi site now says the 15 is 1500watt rms. So if the sub is dual 1 ohm, amp can be ran at 1ohm for the 1500 watt? But is the 15 actually 1500watt now or did they misstype?

Which brings up a nother confusing subject on my part. The Fi site now says the 15 is 1500watt rms. So if the sub is dual 1 ohm, amp can be ran at 1ohm for the 1500 watt? But is the 15 actually 1500watt now or did they misstype?

Dual one ohm is .5 or 2 ohm. Depending on the way you wire it. You want dual 2 ohm to run an amp at 1 ohm. Do a search for wiring dual vc subs.

Duane

If it's sealed you can't tune it. If it's ported you can tune it.

You can tune a sealed system by using different enclosure volumes. Using the same sub each volume will have a different Fc and F3.

If you have that much power I would keep it smaller, or just use the cut sheets on the tech forum section. My Q shined in a smaller sealed enclosure than the box I made via the cut sheets on the forum.