To be honest the XT4000D is not going to cut it. You'll get between 1200-1500wrms at 1 ohm, the problem is that the rated power drops to 450rms at 2 ohms, so as soon as you get impedance rise in your box your sub is going to be getting buggerr all power. I have one in my car at the moment and it's noticeable when compared to a 1200wrms amp that only drops to 900 at 2 ohms. I was selling US Amps and while they are pretty solid, that was one big let down in those amps.

If you had a sub that was rated for say 600wrms then the amp would be fine, but you need to feed the monster. I had an MT12 built for around 4k daily the new BTL are even badder

what is your port area, and pics of said box.

This Doesn't Make Any Sense. I've Seen SSD's Kill L7's With The Utmost Of Ease.

A Rule For Me Is If You Have To Take It To A Shop, You Shouldn't Have It At All.

Quantum Is Childs Play To Me, Never Liked Them. And I'm Sure A Sundown Can Cure Your Problems If You Set It Up Right, And Not Let A Shop Do It. Most Shops Are Filled With Mainstream Brand-Loyal Noobs Anyway.

I never said that I was at a shop. I dont need a shop to handle my stuff. I was testin it usin my friends amp and I said before i actually buy the amp from a shop, not that i was at a shop. I know the quantum is a POS I was looking at it because i didnt have money for somethin else.

Clearly you DO need a shop. If you can't handle getting a sub to go bump.

Please post pics of the enclosure with the specs. We definitely want to get this sorted and working properly for you.

Thanks,

Scott

you cant compare two 15's to one 12 cone area will win with a decent sub

depending on box and a fixed power going to them then sure cone area will win.

Your comparing 2 speakers agaisnt the one which doesnt have enough cone area to beat as hard as those L7's. Maybe the BTL gave you impressions that it was going to knock very hard before you even bought it. Which it will knock hard but your comparing it to something that cant be beat with normal setups.

depending on box and a fixed power going to them then sure cone area will win.

Exactly right! He's expecting to much out of 1 12"

install dependent...amp, box, electrical...but you may want to listen to these guys about cone area! 2 10's will push more air than 1 12".. however the 12 will pick up the lower frequencies better..but at the same time as i have mentioned it will be install dependent!

yo guys its been solved i bought a better amp. been solved 4 a while my bad

What do you think of it now?