sub vibration

jablonep

Just hooked up two tens in sealed boxes with appropriate amp/sub match but when they hit they have an empty vibration. I do not think it is the subs or box after trouble shooting. The amp is a fosgate 551s. Could the amp be bad or could the signal coming from my eclipse 8441 be off? I am worried that I messed up either the amp or deck because while hooking up the box the speaker wires from the amp touch and sparked a little bit. I know it should have been powered off, but its too late now. Any suggestions welcome

Thanks

mbdyer12

Empty vibration? Like no noise coming from them? If thats the case, you probably have them out of phase from each other, try swapping the + and - on just one of the subs and see if that does the trick... If thats not whats wrong, explain a little better please

PoweredByDodge

you may have too large of a box -- if you have WAY too big a box, then the subs may give u a hallow "empty" sound when they hit.

neomagus00

what do you mean by 'troubleshooting'? how did u go about that? and the amp should have kicked in protection circuitry when the wires sparked, so it should be fine.

mbdyer12

So many things that could be wrong, so little information Dont ya all wish we were rich enough to just go buy new crap when this stuff happens? sigh ...

jablonep

I went to a local place with lots of experience. We hooked up the amp to another box/sub and it sounded fine. Either the truck style box is a bad match for the subs or the subs are too underpowered, or they just suck.

neomagus00

well, the only way the box'd be a bad match is if it's the wrong volume, and if it's sealed that's probably not the source of an 'empty vibration'

um... since you haven't told us what subs you're using, the two remaining choices are likely. cept that you may be overdriving the subs and maxing them out (possibly) instead of underdriving them, which would just make them quiet. unless you're trying to push your amp too hard, in which case it could be distortion you're hearing, fixable by setting your gains properly.

jablonep

subs are infinity perfect 10.1s and the amp is a fosgate 550s. i have decided to send them back and go with a single 12. i know i am all over the board but i get a different answer every time i talk to someone. i think i am going to go with a single kicker L7 off the same amp. sorry for the lack of speaker info before. i am not sending them back till monday if you think i am making a mistake. thanks,

eric

neomagus00

thus is the nature of car audio; everyone has pet brands. how bout you consolidate all of the myriad opinions and post them, and then let us duel it out. i personally think that you'll be happy with the L7, and that you would with any of the others (leaving my personal preferences and prejudices aside).

exalted512

l7's get loud!
not much sound quality...but loud
maybe its that POS amp you have
or maybe im just the only one thats blown three Rockford Fosgates...
ill be sending my RF 550S back for warranty soon...
(not knocking you, just venting:D )
-Cody

mbdyer12

Well I have one kappa perfect 10.1d and I love it. It hits pretty hard. They only require 0.6 cubic ft per sub sealed, so compare that to what you have. Also, the subs handle 350watts rms. That 501S puts out 125x2wrms @ 4 ohms. That would be the only way to hook up 2 4ohm subs without hurting the amplifier. So you could very well be trying to push them too hard with not enough power and clipping the amp. But yeah, check the box volume too.

jablonep

The box was 0.65cu. It must be because they are underpowered as you suggested. I have decided to go with a single L7 12". It is a little underpowered, but I hooked up a demo at a local store and it sounded pretty damn good. I know it won't be as tight as the infinitys but good enough I think.

As for the comment on the fosgate amp being a pos, it's too late now, it's installed and I don't think I can return it. I'll cross my fingers it is ok, and doesn't go bad.

Thanks for the help

mbdyer12

I'd say that the L7 would much better match the amp but watch out.. I think they only come in DVC models. Dual 4 ohm voice coils wouldn't serve you any better than the two 12's you have now. If you get the 2ohm DVC sub, you could wire the coils in a series and bring it up to 4 ohms, then it would be ok. Amp at 500wrms and sub takes 750wrms, thats fine.

jablonep

Thats the plan. Using a 2 ohm L7 I should be able to get 550rms from the amp with the speakers rated at 750, I will be a little underpowered but not too bad, right?

mbdyer12

I'd say its plenty if not a decent amount in my opinion, as long as you dont push it really hard. "Underpowering" would be like 400wrms in my opinion.

exalted512

just make sure the gain is set so the amp will never clip, no matter how loud
if it does, then you can destroy both your speakers and amp
-Cody

jablonep

Thanks for the advice. I am new at this.....what is clipping and how do you set the gain so appropriately. Sorry fo the newbie question.

Eric

exalted512

clipping is when the speaker starts making these really nasty noises
as far as how to set the gain, neo just explained it in another thread...the title is something like "how do i set gains"
-Cody

jablonep

Thanks Cody

exalted512

no prob, glad to be of some usefulness
-Cody