overexcursion symptoms

[vario 10+ year member]

I'm feeding my beater audiobahn 500 watts rms, its rated for around that much and its a high end older model so its not like the modern crappy audiobahn, but its still my beater. Its in a 1.2 cube sealed box.

I played around with the gains since I bought a new head unit with more voltage and it seems to make a whacking noise when I run a bass test. The excursion is rather ridiculous.

Another question is how do I know the polarity of the sub's terminals? Prior to resetting the gains this afternoon I set the head unit's subwoofer option to REV, meaning it reverses the signal and it seemed to be in better phase with the music. Just to clarify, I set the gains as described above with it on NORM. Is it possible that the terminal's are incorrect on the sub? Is there a way to check this?

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[hrtbrk1 5,000+ posts]

turn the side upside down...all audiobahn - terminals are on the left if i am not mistaken...

 

[vario 10+ year member]

turn the side upside down...all audiobahn - terminals are on the left if i am not mistaken...

Its DVC, 2x4ohm. Ill open it up at some point and check.

In retrospect, I think the sub is bottoming out //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[dragnix 5,000+ posts]

yea, sounds like it is bottoming out, the sound you hear is the voice coil smacking the backplate. Fun

 

[vario 10+ year member]

Turn the power down I guess? I kinda like the sub even if it is a beater. Its got a big *** magnet. Or maybe its just the test music, I havent tried anything besides Tojo bass test and 50 hz tune. Im gonna try and seal the box up a bit more and maybe try some rap music, see if it still does it.

 

[miker 5,000+ posts]

Is it a 12"..

That box isn't even very big, and thats not much power..

 

[hrtbrk1 5,000+ posts]

and try porting the box...give the sub some air

 

[vario 10+ year member]

Its a 10 in a prefab box. Im not going to port the box, this is just my beater set up b/c I need more trunk space. Its a big box for a 10. I got both box and sub for dirt cheap so I'm not complaining.

 

[dragnix 5,000+ posts]

Turn the power down I guess? I kinda like the sub even if it is a beater. Its got a big *** magnet. Or maybe its just the test music, I havent tried anything besides Tojo bass test and 50 hz tune. Im gonna try and seal the box up a bit more and maybe try some rap music, see if it still does it.

nvm, i read it wrong. If it's a sealed box i don't understand why it's bottoming out.

 

[hrtbrk1 5,000+ posts]

phase shift on amp?

 

[dragnix 5,000+ posts]

phasing doesn't cause that kind of problem. Only when the sub it's in a ported box and playing below tuning does it cause bottoming out. Unless it's something else that makes the OP thinks it's bottoming out.

 

[vario 10+ year member]

its a deathrattle noise, sounds like all the bottoming out subs on youtube.

Sounds like something is hitting something else.

Settings are:

Flat Eq.

Sub is crossed at 80 hz with a electronic crossover (not the headunit) and a line amplification of +6 on the head unit on the sub channel (not bass boost).

Amp gain is set to proper amount of voltage and there is no bass boost. Filter is set wide open because of the external electronic crossover unit.

 

[dragnix 5,000+ posts]

I figured out what the problem is, it's an Audiobahn

 

[vario 10+ year member]

yeah probably but its also a aw1000 which isnt a bad one, it was mfgd maybe 8 years ago. Ill just use it till it blows and then Ill probably have my two infinities installed again.

 

[dragnix 5,000+ posts]

I want your car //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif