strange knocking noise?

I have two 12" CVXs wired at 1 OHM impedance to a JL Audio 1000v1 amp and every time I turn the bass up really loud and with low bass I get this weird knocking/popping sound like the speaker is hitting something. I was wondering if anyone knew how to solve this problem and if I should lower my impedance down to 2 or 4 ohms load...keep in mind this happens when my gain is a little less than mid level and I just turn up the bass on my radio really high. Thanks!

Forgot to add these are the Dual4 Voicecoils

Sounds like you are overpowering your speakers.  That amp is not stable at 1 ohm.  Wire them at 4 ohms and see what that sounds like.

Would 4 Ohms be a better option rather than 4 Ohms? The speakers are rated to run at 750rms a piece so 2 of them at 2 ohms would even be a bit under powered.

I meant would 2 ohms be a better option rather than 4 ohms...

Are you getting different speakers?

claytonb57 wrote: ...and every time I turn the bass up really loud and with low bass I get this weird knocking/popping sound like the speaker is hitting something.

It IS hitting something... THE STOPS!!! You are gonna destroy those woofers, in very short order. STOP it. NOW! Dual 4-ohm voice coils, with two woofers offers you 1-ohm load, 4-ohm load, and 16-ohm load. You can't GET a 2-ohm load. Where is your cabinet vented, meaning what's the frequency? If it's too high, then you're gonna flap at the lowest frequencies. Have you implemented a subsonic filter? Probably should, anyway. Sounds to me like the system is installed wrong, all the way around. Fix it, soon, or you're gonna literally beat those woofers to an early death.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Couple more things about your posts, and these are informational only... I am truly not picking on you, but these are things you should know. If you simply made typos, please just forgive my attempt to correct you constructively.

claytonb57 wrote: I was wondering if anyone knew how to solve this problem and if I should lower my impedance down to 2 or 4 ohms load

That's RAISING the impedance, not lowering it... Less LOAD, yes, but higher impedance.

claytonb57 wrote: Would 4 Ohms be a better option rather than 4 Ohms? The speakers are rated to run at 750rms a piece so 2 of them at 2 ohms would even be a bit under powered.

Who told you there was EVER such a thing as "underpowering" a speaker? Please read this thread: "Too Little Power" thread...It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

2 kicker cvx's should eat a 1000/1 without a problem. and yea i know it could still be a faulty box design causing the subs to unload at low frequencies but actually, it sounds more like the box blew a seal and two wood panels are slapping against each other at high volumes or low frequencies . it only makes the noise when you have it turned up or when it hits a low note. turn your system up and try to push on individual panels of the box and see if the noise doesnt go away.