weird thump...

[jblayz1 10+ year member]

well, yesterday i decided to up my power wire from 8ga to 4ga. set the gains again. but now when i turn up the volume the sub makes a weird thump. it doesn't sound like it's humming on the low frequencies nicely like before. i had everything sounding really nice on wed. crap! frustration is starting to kick in so any suggestions would be appreciated.... //content.invisioncic.com/y282845/emoticons/furious.gif.fc81ca146dbff91fede3ed290dbc4f4c.gif :furious:

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[BJ The Man 10+ year member]

is the sub bottoming out?

 

[jblayz1 10+ year member]

honestly, i don't know what it sounds like when a sub bottoms out. it does sound like it is. it'll sound fine, then thump(kinda like when you have a bad connection somewhere and it thumps when you turn on the power).

when i was feeding the amp with 8ga power wire i had the subsonic filter off because it didn't sound right. should i tun it on now?

i had the amps gounded separate before too. should i keep it that way? i did ground them to the same bolt this time.

 

[jblayz1 10+ year member]

ok, so i separated the grounds and the weird thumping kind of went away. but now the lows sound crappy. i'm so frustrated because it was sounding perfect. //content.invisioncic.com/y282845/emoticons/verymad.gif.3f39c5c2fd57527b671fad3efdfac756.gif

 

[KidThump 10+ year member]

Maybe your RCAs went bad......

 

[Atimm693 10+ year member]

Nice ***. //content.invisioncic.com/y282845/emoticons/naughty.gif.94359f346c0f1259df8038d60b41863e.gif

 

[nismos14 5,000+ posts]

If you don't have a ported box, subsonic should be off. What amp? Sounds like the amp is either having issues, or there's a problem in the signal going to it. Rca's probably.

 

[jblayz1 10+ year member]

before i made the change the subsonifc was off. sounded better that way. it's an re12.1. why would going from 8ga to 4ga make it sound so awful? i mean i reset the gains to where they were. i had a feeling those would change and they did. i don't get it. i guess i'll try going back to how i had it powered before. 4ga to distro

 

[nismos14 5,000+ posts]

The power wire should have NO bearing on how it sounds, unless you're giving the amp alot less juice than it needs.

 

[jblayz1 10+ year member]

i know

 

[jblayz1 10+ year member]

well, i tried to switch it back to how i had it. the gains didn't change this time. weird thing is i can't set the gain on channels 3/4 of the S4 past 23.5v without the clipping light coming on....wtf? it should be fine at 28.3v(200*4).

am i missing something here?//content.invisioncic.com/y282845/emoticons/verymad.gif.3f39c5c2fd57527b671fad3efdfac756.gif

 

[jblayz1 10+ year member]

i think it's one of 3 things, RCA's, i'm grounding somewhere, or i messed the amps up in some way where they still pwer up and work....

anyone?

 

[jblayz1 10+ year member]

sub amp was grounding via the mounting screws //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif . i haven't figured out why the S4 keeps clipping past 23.5v i'm gonna try and set it again with a 50hz test tone instead of 1khz.

 

[nismos14 5,000+ posts]

What do you mean grounded to the moutning screws?? To the mounting screws of the amp??? Change that ASAP.

 

[jblayz1 10+ year member]

the screws i had the amp mounted with were touching metal.