Alpine,dual Jl W3 Issue Clipping Seeking Resolve

[geriatricjlhits]

Clipping (or sounds of farting through sub box in certain songs, or tones) is occurring, and even after having a alpine mrp 1000 amp, a jl w3v3 dual subs from a very well know distributor of high end audio, and a alpine 9886 head unit, all are under one month. old. Previously had a dual jl w1 and 500 watt system. I have called the dealer of the jl box, and the amplifier distributor, and each plot me against the other blaming issues. I need an intelligent person, or technician that can be honest about how to do something. I am alot older than most that would listen, much less own high end audio, but shortly after getting the alpine 1000 amp, I noticed that clipping occurs and sounds very damaging, but the OHM load is still between 1.8 and 2.0 on subs. I have four gage wires installed on the system. But, I have not done the big three upgrade, and I know a CAP will not make a difference. my alternator is ONLY putting out 80 amps (wimpy) and there is no aftermarket alternator that will work on a 1999 Nissan sentra, 1.6, gxe. I need to know when using a bass mekanik CD, playing one or two songs, the why and how to solve the clipping on brand new gear. One says amp is starving, the other says subs are blown, and have been tested to show they are not (even though I can't see the former, or spider) blown. Is there a remedy, to deliver to dealer of sub box with two jl's, which will have them think that I have a legitimate gripe? or does anyone here have, or had a relative problem such as this? Anyone with any input is highly encouraged. Thank you for your valuable time reading this lengthily message post.

Here are product links, or pictures to what is involved in my problem (issue).

http://www.alpine-usa.com/US-en/products/product.php?model=CDA-9886

http://www.alpine-usa.com/US-en/products/product.php?model=MRP-M1000

http://mobile.jlaudio.com/products_enclosures.php?menu=9&prod_id=426

Click to read more...

 

[PV Audio 5,000+ posts]

Good lord man, learn how to type. I can't even figure out what the problem that you're having is. My question to you is: how do you know that clipping is occurring? It sounds to me like you're simply over-driving your W3s. That farting sound might not even be the output of a clipped signal, but exceeding the mechanical limits of your JL's and bottoming them out.

 

[geriatricjlhits]

FYI...I am presently engaged within my second semester of my masters degree in information assurance, and I would appreciate if you would curb your observations of others. Have you ever had a typo? Clipping is still the issue, and thats what a tech said. Do you have any intelligence to share?

 

[misfit138 5,000+ posts]

Put that superior intellect of yours to good use, man. Buy a dmm and study a gain setting tutorial...

 

[gunz4me2 10+ year member]

Call me crazy, but I don't think the stock alternator in the OP's vehicle is strong enough to run 1000 watts RMS AND provide juice to the vehicle's accessories if he is running a stock equivalent battery.

To the OP, at what volume level are you experiencing your clipping issues? Low volume, Maximum volume, or somewhere in between?

 

[PV Audio 5,000+ posts]

FYI...I am presently engaged within my second semester of my masters degree in information assurance, and I would appreciate if you would curb your observations of others. Have you ever had a typo? Clipping is still the issue, and thats what a tech said. Do you have any intelligence to share?

Outstanding. That still doesn't change the fact that your post is incredibly hard to understand. Moreover, I ask you again: how do you KNOW that clipping is the issue? Did the tech sit there with an oscilloscope and check the outputs, or is he going by what you told him? There are many reasons to get odd sounds from a speaker system, and clipping is just one of them.

Call me crazy, but I don't think the stock alternator in the OP's vehicle is strong enough to run 1000 watts RMS AND provide juice to the vehicle's accessories if he is running a stock equivalent battery.
To the OP, at what volume level are you experiencing your clipping issues? Low volume, Maximum volume, or somewhere in between?

This might be the issue, but then again, there are other reasons. I'm thinking about this two ways: the way an amplifier works, and the way people listening to audio work. Note: if you don't want to hear me rambling, just scroll down to the bolded word "basically". //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

The reason why people get defensive about others claiming the gain is just a volume knob "because it makes the output louder" is the following: the gain and the volume are the exact opposite things. The gain alters the input signal, while the volume alters the output signal.

Giving an amplifier insufficient voltage will consequently lower your gain, and again as a consequence, lower the output. With the gain fixed, raising and lowering the volume has little effect on the prior stages. So basically, it's like this: you can have a clipped signal if you crank up the gain, but have the volume set to one. You're just adjusting how large the outputted clipped signal is at that point. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

So, why did I go through all of that since it seems to have nothing to do with this? The reason is because the OP is complaining about clipping, when given what he's been told is the cause is likely not the issue. An amplifier basically has two sources of power: a steady state source used to bias whatever is doing the amplification (let's assume it's just a transistor amp, and assume the bias voltage is 12V from your battery), and an input signal which is going to be amplified (let's say it's Young Jeezy - Hypnotize). He's saying that there is not enough bias voltage.

What is basically happening is that when you have higher gain amplifiers, you are using an amplifier that can take the set bias voltage and create a much larger gain. If you don't have sufficient bias voltage, you will have a proportionally lower gain. The gain "knob" merely controls how much gain, so for all intents and purposes, let's assume that all amps in this discussion have the gain set to maximum or let's assume the gain is fixed. If he's clipping, then that means that somewhere along the line, the input signal is being clipped at some stage in the amplifier. By relation, by the logic that his tech told him, a larger amplifier with the same output would also be clipping. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

So, if you add it all together, what we're saying is that if you are trying to extract 1000W from any amplifier, a 2500W amp will be clipping while a 1000W amp might not be given the same input voltage. The problem with that reasoning is that if you try to extract 1000W from a 500W amplifier, you will DEFINITELY be getting clipping, but by this reasoning, amplifiers whose biasing needs exceed what the car can give will be clipping. That probably won't happen, because that's assuming that a lower gain = more distortion, which is preposterous. In other words, lets again state you want 1000W of output, one from a 900w amp, and one from a 10kw amp. The 900w amp will need a moderate gain to output 900w and has a high probability of clipping. The 10kw amp will have a far lower gain to make 1kw output, so the output will NOT be clipped, although the car might not be starting. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Basically what I'm trying to say is this: can his car supply sufficient current to his amplifier and his vehicle? I don't know, but let's assume it can't. Is that in itself causing the clipping because the amplifier is too large? No. Again, let's assume he can get the same output he's getting now with a smaller amplifier whose needs the car can supply, and by this logic, this amplifier will NOT be clipping, even though if the output needs are great, then it will be far more likely to produce a clipped output than another larger amplifier with insufficient input needs. There is likely a much simpler solution to the problem either being the gain knob being cranked too high, or there isn't clipping at all and it's another noise such as mechanical slapping. //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

If this doesn't make sense or is flat out wrong, please let me know. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Immacomputer 10+ year member]

What JL box are they in? Sealed? Ported? Also, can you give the specific Bass Mekanik song titles that you were listening to when you noticed it and at what point in the songs they sound terrible?

Those JL pre-fab enclosures aren't very great for bottom end extension and with all that power, you could be bottoming the drivers out. Does it sound muddy or do you notice loud popping sounds?