Blown sub?!

[Rowdy S13]

OK this isnt a home theater question, but it is a sub question I have a 10" Infinity Perfect in my car and its been awesome so far. Well I took the car to the dealer last week and decided to leave the face on my headunit, big mistake. When I was driving home my stereo sounded... well not so good. Most of the way home I was trying to decided if they hooked the amp back up or not (I know they had the battery disconnected because it needed a sensor replaced) It sounded like more bass than my speakers should have, but not enough to be the sub. Long story short, amp is on and working, sub is working, some settings may have been off in the head unit. The worst is one of my front speakers is 100% blown, the back speakers are rattling but Im not sure why, and the sub is VERY quiet. The question for you guys is why would the sub be about half (or less) as loud as it was before? If one voice coil is shot would that do it? Is there any way for me to test if something is damaged with the speaker, or the amp? This is NOT a big huge waking the dead system, it WAS a well balanced great sounding one. I want it back the way it was


Thanks,
Sean

 

[Exit]

It sounds to me that when power was disconnected, your crossover was altered and bass that used to be routed to the sub is now going to your rear speakers and making them rattle. On my car the crossover was mechanical and was part of the amplifier. If your crossover is electronic (in the head unit for example) than you want to start checking setup there. The front speakers may have received bass signals which they couldn't handle too, which again might be a crossover setting in the head unit. Also, there is a chance that someone at the dealership cranked it up to see what if could do and blew the speaker and/or something else. It might be worth it to take it to a professional installation shop and let them have a crack at it. It might only be $30 to $50 if it is simply adjustments that are required.

 

[Rowdy S13]

I dont have a crossover, and the head unit settings look ok. I did adjust a little but it didnt do much for fixing anything. It would have been impossible to adjust anything on the sub amp so thats not the problem either.

Sean

 

[croseiv]

Can't really help you, but man does that really bite!

 

[Alex2507]

When you installed everything there should have been some set up procedure that you followed to set your fade and gains on your head unit and amp/amps. I think you need to go through all that again to reset everything. There is always hope that disconnecting the battery set everything to a factory default which doesn't sound good.

 

[lsiberian]

I doubt you blew the sub. Those subs can take a lot. It's probably just a hook up thing.

 

[Rowdy S13]

I doubt you blew the sub. Those subs can take a lot. It's probably just a hook up thing.

I dont doubt that, but what to look at? Its obviously working to some extent so the amp has to be connected to it. What happens if only one voice coil is hooked up/working? Im not sure where to start trouble shooting the sub, besides the headunit which I have gone through already. Id rather not buy a third sub for this car, but I miss it so much

Sean

 

[lsiberian]

I dont doubt that, but what to look at? Its obviously working to some extent so the amp has to be connected to it. What happens if only one voice coil is hooked up/working? Im not sure where to start trouble shooting the sub, besides the headunit which I have gone through already. Id rather not buy a third sub for this car, but I miss it so much

Sean

The voice coil might be messed up, but I would make sure your amps and other things are working first.

If you've blown one already the setup is not right. Those Kappas don't take a lot of power to generate lots of volume. Maybe your overpowering the voice coil.

How many watts are you feeding each channel?

 

[adwilk]

What kind of amp is it? If the sub is working, simply put, its not blown. A blown sub "typically" wont make any sound at all. I'm curious to know what amp and how its hooked up. Is it hooked up using low level signal inputs or high level? (patch cable in or speaker wire in?) If its speaker wire in, its very possible that a crossover setting in the head unit is not sending signal below a specific frequency point. That'll keep that sub from doing what its supposed to do. As far as a VC being blown... its my understanding that the dual voice coil is simply provided as a means for more wiring options and additional power handling. One operational VC will allow the sub to perform... those VC's need to be tested individually. How are the VC's wired, series or parallel?

If you can answer these questions, there might be some more insight we can provide...

 

[adwilk]

If it is a blown VC, your amp might be seeing an 8ohm load or something, you'd notice a huge drop in volume.. Thats my guess. The resistance is probably much different than it was. If only one VC is working, bridge your amp to that one voice coil.

 

[Rowdy S13]

The amp is a Alpine MRP-M500, 500 watts at 2 ohm. The sub is a dual 4ohm wired in parallel so it is a 2ohm load. The amp is getting its signal via a RCA cable from the headunits sub out port. The head unit is a Alpine CDA-9857 that is a couple years old. It was never a very loud set up to begin with, but now it sucks.

Sean

 

[adwilk]

The amp is a Alpine MRP-M500, 500 watts at 2 ohm. The sub is a dual 4ohm wired in parallel so it is a 2ohm load. The amp is getting its signal via a RCA cable from the headunits sub out port. The head unit is a Alpine CDA-9857 that is a couple years old. It was never a very loud set up to begin with, but now it sucks.

Sean

That amplifier does have some eq settings... Is it possible they got jacked with? Also, if the resistance the amp sees had changed, you'd hear a difference in that scenario... Bridge the amp to each vc, one at a time and see if both are working?

 

[Rowdy S13]

I will try each VC individually this weekend, I was planning on that anyway. For the amp to get messed with you would have to take out my passenger seat, then take the amp off of the floor (and disconnect the ground) and then put a screwdriver in there to turn the adjusters. So I think its safe to say they didnt do that

Sean

 

[adwilk]

So I think its safe to say they didnt do that

Yeah, sounds like a pretty safe assumption. I think it has to be a VC thing.

 

[brendy]

Should have turned right around and went back to the dealer.Sound like the mechanic was playing with the volume control. How else would the front speaker get blown ?

 

[Rowdy S13]

You are right, but how would I ever prove it wasn't like that when I brought it in? Also it isn't factory, so what would they even do? It kinda crappy that someone wont man up and take responsibility for messing up my stereo, but that's the reality. Oh well, it will give me a chance to try different interiors/upgrade. The annoying part is this will be my third sub if I have to replace this one. I dropped the first on and broke the basket

Sean

 

[Rowdy S13]

Well the sub problem turned out to a simple one. I was really scratching my head, check the resitance on both VC's they were good, hooked them up one at a time and the sub was "working" but limited output, checked the voltage at the amp which was good. I was about to give up and then I noticed that one of the RCA's was loose on the amp, plugged it back in and shazam it worked. I put on something with good bass, and turned it up and tried it unpluged and then pluged in and that was the problem. Now though, the front speaker is shot though. Somehow water is getting in the door so I will have to take it in to have that looked at. I am not sure if it was the water was the problem or if something actually happened to it, either way it needs to be replaced.

Sean

 

[adwilk]

Glad you got the sub scenario figured out, Sean... Hopefully you can get that water problem fixed as well. Water will definitely ruin a speaker. Probably what the issue was...