Question about my setup

[fly_marlin]

You're 100% sure the woofers are single voice coil and you wired the subs in SERIES?

 

[Justinbebustin]

Yes. And yes. Positive to left, negative to right, connecting the remaining positive and negative terminals together, just as the diagram suggests. I'm thinking bad amp, it IS pretty old.

Edit: I was driving my car tonight and it sounded as if it were getting weaker and weaker until I turned it up a bit and it turned off. Could this be a bad battery? Alternator and belt and everything are good...

 

[fly_marlin]

Amp could be getting bad. I've never encountered this kind of thing, nor tested it. If anyone has suggestions as to how to test whether something's wrong with the amp, please let him know. My next suggestion would be to get a new amp lol

 

[Justinbebustin]

Well it's been working, I have my thresholds down, meaning I know at which volume/bass level my amp shuts off at. I was wondering tho, I got my cap installed at a professional shop, and they used the same ground my amp uses. Is this a problem? I've heard it stated before elsewhere that you should always use a new ground for caps. Any truth in this? I was wondering if this could also contribute to my amp cutting out at high volumes.

 

[fly_marlin]

Well it's been working, I have my thresholds down, meaning I know at which volume/bass level my amp shuts off at. I was wondering tho, I got my cap installed at a professional shop, and they used the same ground my amp uses. Is this a problem? I've heard it stated before elsewhere that you should always use a new ground for caps. Any truth in this? I was wondering if this could also contribute to my amp cutting out at high volumes.

You should get rid of the cap, you don't need it. I used to have a cap back in the day and I think it went bad, my battery kept dying. Once I got rid of it, everything went back to normal.

 

[djnsmith7]

There are several tools available online to help minimize Ohm (Ω) confusion. Here are a few:

The Rockford Fosgate Wiring Wizard is a great tool to figure out the ideal Ohm (1, 2 & 4Ω) configuration for your subs (up to 4 subs).

JL Audio DVC Tutorial

JL Audio SVC Tutorial

 

[Justinbebustin]

You should get rid of the cap, you don't need it.

It keeps my headlights from dimming, so I'm good with that. My system still hits hard enough at acceptable thresholds to where it will dim the lights.

 

[fly_marlin]

It keeps my headlights from dimming, so I'm good with that. My system still hits hard enough at acceptable thresholds to where it will dim the lights.

You have it wired at 4 ohms now, right? With a 500W amp and wired at 4 ohms, lights shouldn't be dimming. If you take out the cap and your voltage is still getting too low, you have other problems.

 

[Justinbebustin]

It's only running 300W @ 4 ohms, and yet if I take the cap off the headlights dim considerably. It's an old battery I don't feel like replacing, this amp chews em up over the course of years, as I'm sure any amp does. When I got this battery brand new, it didn't dim at all, but the repeated bump sessions have taken their toll. It's a cheap fix to get the most out of my battery, the way I see it. I just spent a lot of money, and can't afford to replace the battery for a while, now that school's out and I gotta feed my kids! Free school lunch RULES! But anyway, I suppose I could do without the cap, but it seems to be serving it's purpose. Any truth in needing a separate ground for it? Does it even matter?

 

[els1989]

It's only running 300W @ 4 ohms, and yet if I take the cap off the headlights dim considerably. It's an old battery I don't feel like replacing, this amp chews em up over the course of years, as I'm sure any amp does. When I got this battery brand new, it didn't dim at all, but the repeated bump sessions have taken their toll. It's a cheap fix to get the most out of my battery, the way I see it. I just spent a lot of money, and can't afford to replace the battery for a while, now that school's out and I gotta feed my kids! Free school lunch RULES! But anyway, I suppose I could do without the cap, but it seems to be serving it's purpose. Any truth in needing a separate ground for it? Does it even matter?

That amp doesn't draw enough amperage to kill or dim a battery unless it's wired improperly...

Sent from my iPhone using Tapatalk

 

[fly_marlin]

That amp doesn't draw enough amperage to kill or dim a battery unless it's wired improperly...

Sent from my iPhone using Tapatalk

That's exactly right. I do not believe your problem would get any worse by removing the cap. In fact, it should improve. That amp isn't chewing up any batteries and if you're playing with engine on, it shouldn't even pull enough power to even touch the battery. Alternator should have enough juice to power it properly. You generally want separate grounds for your amps and such. Maybe you can sell the cap to one of your buddies and then buy a new battery. Better than waiting for your car not to start lol

 

[T3mpest 10+ year member]

I don't come to this forum much anymore, but stumbled on this so I'm going to try and help as much as I can.

First and foremost, the advice you've gotten up to this point is all pretty solid. Everyone has done a good job trying to help you and you listened to most of it. Many threads one of those 2 things dont' happen, so good so far.

Next major thing, if your talking about being broke shops are EXPENSIVE! In the long run you do save a lot doing things yourself and this hobby isnt' TOO complicated for the most part. Just getting good sound doesnt' take a PHD.

Now to try and help. As others have said, you shouldn't have any dimming on 300 watts at 4ohms. Can you take a picture of your amplifier settings? Gains, bass boost, etc what HU are you using also and is any bass boost on on it, what volume does the amp cut out? All those questions will give a better picture of your install for what could be wrong.

Now to quickly diagnose it online... You likely have a bad ground. Wiring too low was def an inital issue, but if it's overheating/protecting and drawing a lot of current it's very likely a bad ground..

Car audio basics, you should ground to the frame of the car when possible, using a short of a run as possible. This run should be the same wire size as the power wire (8 gauge in your case is acceptable, but I'd do 4 regardless) Most importantly, the ground the should be on bare metal, you need to sand it all the way down and secure it tightly.

Anyways pics of your current ground would be appreciated.

The other option is a bad battery/alt. If you have a bad battery or alt, a cap will NOT fix your issue. Caps aren't magic power generators. They still have to be charged by the same elecrtrical system the amp draws power from. Sure on a .5 second bass hit, they can discharge and stop dimming, but if your consistenly drawing too much power and have constant dimming, you can't fix that with a cap.. At the end of the day, they are bandaids and if the elecrical is the issue, you really do need a battery or alt.. I'd look into saving up and possibly even sell the cap to come up with the rest of the money if needed.

Anyways I know this was long, but hopefully it helps.

edit: Where you at in IL.. I may be local enough to just come look at it for you.. Doubt it though lol.

 

[Justinbebustin]

OK...well, I got an amp installed at Best buy back in '07, so that's how old the wiring is. It's all professionally done, and the ground is indeed secured to a sanded bare metal part of my frame, approximately 2 1/2 feet from my amp. I have the LPF, Bass, and Gain at about roughly 15 percent (on all 3) and my head unit is the factory cd player in my '06 Nissan Altima. I played around with the bass and gain to get it where it is now, any more bass or gain and the amp just ain't havin' it!! The volume goes up to 31, and if I turn the bass (which ranges from -5 to +5) to +2 I can get away with putting the volume up to 20 without worrying about it cutting out. If I turn the bass to -1 or lower, I can get away with a volume level of 25, which is very loud (the factory 6 x 9's are actually pretty decent.) and the bass hits good, just not as good as my 12's did with the same amp (and the amp NEVER cut out on my 12's, which I had wired parallel for about 3 years.) I can play rock music at louder volumes problem free, it's the hip hop basslines that cause the problems.

I had the shop install the cap (which I received as a birthday present) because I had heard you have to charge the cap before installing, which I wanted nothing to do with. It was only 35 to install it, so I didn't lose too much there. I'm not too good with posting pictures online and I don't have a smartphone, sorry I can't post pics, but I do appreciate all the advice I've gotten to try and diagnose my problem with the limited info I've provided.

I live in Danville, IL, about 2 hours south of Chicago near Indiana