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i have a pioneer cd player in my car. i also have to 12s. i could push on the face of the cd player and it would get quite a bit louder. i figured this was due to a wiring problem. i rewired everything. when i put everything back togather and turned the car on i could hear a steady humming in the subs. i figured this was a bad ground. it wasnt. i replaced the rca jacks and still had the noise. i have an extra rca jack spot on the back of my cd player that says (front output). i dont think this is going to give me the same sound. do you think that my jacks are bad on my cd player or what. the extra spot i have them hooked up in doesnt make thta sound but doesnt seem to have the bass response. what should i do.
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Hmmm... This could be any number of things
1) a bad transformer in the power supply of the head unit
2) current induction from the power cables running from a dirty altenator to the subs and/or head unit
3) Bad contacts internal to the head unit
4) Bad contacts/circuitry in the sub
Are all your speakers on outboard amps or are you powering the L&R mains with the Head Unit?
Is it in ALL speakers or just the Subs? If it's in all the speakers it might be the Head Unit (Problem 1 or 3), if it's in any speakers run off an out-board amp it's probably something elese (Pblms 2 & 4, or bad amps).
Does the humming increase in frequency when the car accelerates or is at higher speeds (Pblm 1/2)? Do you only hear it a low speeds (Pblm 1/2)? Is it always present or at least not seem to correlate with enine rev's at all? Is it more likely to happen when you've got allot of other things like lights and wipers on (Pblm 1/4).
The best way to figure this out would be to do a bench-test - get yourself a 12V power supply for a computer (or a really good lead/acid battery inside a safe container) and mock-up your stereo system at home and see if the problem is still there. If so, you should start thinking about a new Head Unit. If not you might want to re-check your car circuitry - seperate the amp power cabling from the audio cabling. -Check the grounding for everything else on the same circuit in the car, even clocks and GPS units can mess with stuff. -When it happens, turn off anything "wireless" like cellphones and GPS units. Does it go away?
If you determine that the problem starts with the head-unit I might also be worried about the gold contacts on the detachable face of your pioneer unit - get some contact cleaner and Q-tips and go to town on both sides.
If you have exhausted every possibility you may have just found that the signal distribution op amp on your circuit board has a bad output, and that it snuck by quality control because it was on the pre-outs (something that isn't prioritized in alot of consumer electronics). At that point it may be time to try and return it or buy a new unit but if that was the case (and you bought anything but the cheapest Pioneer unit) it should have popped up an Error code on the display already.
I hope this helps. Please feel free to get back to me with your questions or contact one of our other experts whose expertise is more focused on car installation (such as Garry or Mark Lampi).
Good luck, sorry about your frustrations!
thanks a million for answering my question. when i have the amp jacks hooked to the jacks on the cd player it will just surge and not even beat to the music. the subs and my mains are doing two differnt things. when i hook it to the jacks that say (front output) it does fine. i havent had any other problems out of it since i swithched it over. the only thing i can figure is that that one set of outputs on the cd player went out, because other than that there are no problems. thanks again
Answer -
Yeah, it sounds like the sub output is fried. Hopefully you can get this replaced under warranty, but I would bet money that your Pioneer is 3-6 years old and past coverage. The durability of head-units has seriously degraded since the 90's and it really breaks my heart.
The subs should have their own crossover. If not, you should absolutely put one in - especially if you are feeding it the "fronts" pre (which is full bandwisth audio). That should get you more or less the same results as the "Sub" out, except of course you won't have the same controls over sub crossover topology at your fingertips (from the head-unit). If you fill me in on your speakers I can recommend a crossover slope and frequency.
I'm really sorry to hear about this problem, it sounds like you're a pretty knowledgable person who's done everything right.
thanks again man. i have two HE2 rockford fosgate 800w max 400rms, dual voice coil subs, that are being pushed by the rockford fosgate 4002 punch amplifier. i think that the amp is 400rms and about 800 max. i have never had a cross over that was worth a crap. will it really increase the output of these subs. i have had people tell me it would double the sound and some have said it makes no differnce. and you were right the cd player is old. i have never had trouble out of a pioneer that hasnt been slap wore out so, i cant complain on that. these subs are actually doing quite a bit like they are. but i want the bass that grabs you and just shakes the hell out of ya. thanks again man i really do appreciate your knowledge and willingness to share.
AnswerWell, I was hoping for more detail on ALL of your speakers, but here's my thoughts on the topic anyway:
It is critical for a sub to have a filter. You can not hit any speaker with full-bandwidth audio (relying on the natural frequency response of the speaker to filter audio) and expect it to perform well.
The possible exception to this is a band-pass sub, but conceptually even there you are relying on the natural band-pass resonance of the box design to couple with the drivers to work as an electro-mechanical filter.
Depending on how well your mids handle the low end, I would recommend a crossover point between 100 and 120Hz. The slope should be relatively steep, so 18 to 24dB/octave (12dB/octv in a pinch, especially at 100Hz).
In cars you don't have to worry about topology as much, phase and alignment just aren't the worst of your worries in that environment.
The thing to watch out for is redundancy.
In your old setup there was a dedicated subwoofer output that probably had an electronic crossover associated with it in the receiver, so everything below 120Hz was sent automatically to the sub and your mains automatically had a high-pass fitler set at 120Hz.
Now that you're running off your mains you need to make sure you're sending FULL bandwidth (20Hz to 20kHz) out of the "front output". This may require combing through the manual to find a way to disable the subwoofer setting.
Having done that you've now got the opposite problem - your mains are trying to play down to 20Hz, and you don't want that either - you've got this great subwoofer to do that for you.
At this point there are a few ways you could go:
1) All active:
Get yourself a three-way active cross. You'll also need four more channels of amp (however it matches up best with your front speakers). Now you can go out from the "front output", split from the active cross, and power up each driver seperately. This is definately the Hi-fi choice, and gives you a great deal more flexibility to experiment and fine-tune performance.
It's a bit more of an investment, though over the years the cost of active filters and amplifiers has really dropped.
Here's an example of a three-way active X-over (though not necessarily an endorsement):
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=265-119
-you might enjoy the 45Hz boost feature on this one.
(You can still run the rears off the head-unit, see my note on in-line filters below).
2) Active sub, passive mains:
If your sub really does lack a X-over, you'll need to buy an active low-pass no matter what. Example:
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=267-766
Set that as discussed above.
If you're wanting to go cheap and not buy/install a whole rack of amps, you'll probably need to stop-gap with passive high-pass filters on the mains (probably the rears too) to take out the signal below your sub cross setting. For that you can install the corresponding in-line filter, like these:
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=266-160
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=266-200
This is definately time consuming, and doesn't give you the felxibility of an active 3-way cross, but it sure is cheaper. Also, typically the high-wattage filters aren't quite as "good" as an active cross would be for a variety of reasons - but that's a game of inches and even in an above-average car install I doubt you'll notice much of a difference.
3) Get a new head-unit.
If you don't want to monkey with anything, why not just buy a new Pioneer stereo and swap it out?
The last possiblity to account for a difference in sound is simply that your old Pioneer unit had a "Bass boost" EQ that altered the signal going to the sub. Most active sub crosses have something similar you can play with to get what you want.
I wish you luck!
*One last note - I just wanted to highlight the point that if your sub is a band-pass box you should omit any directions for a crossover filter to it. Adding filters to the mains still applies.
