If you just powered up one of the voice coils you should be ok. Do a quick check with a MM and see if the impedance on the suspect coil is still good.

 

i actually ran all 4 subs like that for about 2 weeks, as for the mm, that will be the next step.

are the notes below the tuning frequency considerably? are they subsonic?

i havea subsonic setting on the amp, if thats what your asking, and im pretty sure i have it on.

 

are the notes below the tuning frequency considerably? are they subsonic?

 

Phase issues?

 

??

Wire the DVC sub [ each one in series ], make the port shorter

turn subsonic up or on !

JL Audio has tutorials on wiring subs and making ports [ vents ]

i have them wired the only way that i can wire them to get full potential out of that US, 2 ohms a channel

It initially sounds like the subs are unloading by playing too far below the tuning of the enclosure.

What is the size and tuning frequency of your enclosure? What "notes" does this occur on?

You're subs should not have been damaged by only having one coil connected....unless you were overpowering that coil.

this is a good possibilty here. i built the box at 3.5 cubes a sub tuned at 34 hz. it mainly occurs on the lows and how could i change this?

Had the same problem with my W7, my box was wrong,too big of a box. Did you build the box? Is the cubic volume and port lenght right?

i had a dude over at CA.com design the box for me. i made sure it just wasnt a typical "i know everything" kind of guy, he had plenty of box designing refs.

also, i changed the ground and also my rcas going from my inline driver to my amp and still the same thing. could it possibly be my rcas from my head unit?? i ask this because i dont remember having this problem at first,i sold that head unit and replaced it with a used temporary one til my main one comes in, and im thinkin it could be the unit. thanks very much for everyones input------Rob

 

Wire the DVC sub [ each one in series ], make the port shorter

turn subsonic up or on !

JL Audio has tutorials on wiring subs and making ports [ vents ]

 

It initially sounds like the subs are unloading by playing too far below the tuning of the enclosure.

What is the size and tuning frequency of your enclosure? What "notes" does this occur on?

You're subs should not have been damaged by only having one coil connected....unless you were overpowering that coil.

 

Had the same problem with my W7, my box was wrong,too big of a box. Did you build the box? Is the cubic volume and port lenght right?

 

that but once i get the volume up real loud, the subs will hit certain notes that make my subs basically flex out FULLY, but do NOT give out the bass, and even if it did give out the bass, there definately flexing way too much, so can a blown sub result in this? {hell NO }

The amp is being overdriven [clipped like a MOFO ]. {start saving money for a real amp }
and some new subs [ sad face ], school of hard knocks is an excellent teacher !!

Average people hear to 20 Hz.

I have put 14 Hz to some subs ~ moved in and out 14 times a second [ saw it, but I couldn't hear it ]

 

say what? a REAL AMP? i do appreciate your help, but youve got to be kidding me! i dont care if you had 50,000 posts, do u know about the old school US amps? ive never heard anyone ever say to save up and buy a REAL amp while running this, and new subs. boy, thanks, you only have me spending a couple g's now, which im not gonna do, so is there any way to cure my current problem, without taken the advise of redoing my whole shiit?

 

play 1 sub at a time in a sealed box, if they both perform good its your

1.wiring
2.box
3.ssf.

or all 3.

 

My bad , { very nice amp ]!

Personally, I would tune the box with a shorter port [ higher frequency ], but you do whatever you want to do

 

kewl dude, i wasnt tryin to sound like a dick, even though your obviously an ******* but i just havent had a person yet to say anything bad about the old school amps, but when it comes to shortening the port, thats something I may try. i guess I just didnt realize how important the specs are on a box, when i comes to making the subs perform oddly. thanks all-----Rob

any other inputs are more then welcome still

 

You've heard them loaded = nice, you've seen them unloaded = scary {jumping up and down w/no sound.

The box is unloading ie. pretend you are lifting weights, suddenly the weights slip off no collars to hold them on.

bar shoots skyward with a force designed to lift 1,000 pounds on a 10 pound barbell

 

And tuning higher will NOT help, only tuning lower.
Try tuning the box to 30hz, that will get you more low end, while sacrificing a bit of "punchiness".

With that US2000X and the 4x 15L7's in those boxes you should get a LOT of bass... right?

 

I agree with the following:

1) Subs could be wired out of phase.
2) Subs are unloading below port frequency.

The first is easy to verify with your wiring. Unhook the amp from the subs and take a 9v battery. hook it up and verify that all the speakers move the same direction, if 1 or more move the opposite direction reverse the connections on that sub so they all match.

For the second, burn or buy a disk with different low frequency tones. Verify which frequency you are noticing the sub *flexing* out of control. Now verify what the tuning frequency of your box is. If the speaker is unloading at a lower frequency, you need to retune the box lower by making the port longer. Not knowing what specs the box was built to is a big issue. For all we know the guy you had build your box built it for high spl and tuned it at 45hz or more. This would give a large peak around that frequency but something lower such as 25-35hz would be unloading causing a large loss of output with a speaker cone that would have little control. Try these and let us know what you come up with.

Josh F

 

The pic in my avatar is my old setup with ONE L7 12 and a 2000X running >2000rms into it. It liked the sealed ~1.1 cu ft box I had it in. TONS of headroom, with the ability to stop your breathing.

The first sub I ever blew up was an Orion SXTR DVC 12 that I had in too small of an enclosure, tuned way too high, and it was dead in a week.

I fried the Kicker eventually as well, but it took a lot more abuse that the mistuned vented sub. Below tuning frequency, I have learned, you lose most of your power handling.