smoking sub followed by clicky noises and no bass. whats up?
 

hey guys. i was running my polk momo m2124 jsut like i do everyday at nominal volume with just a lil bit of bump. my pioneer 760 watt amp has the bass boost turned up all the way and the level only set to around 1/2 way. i start smelling smoke, i was thinking it was this guys cigarette in the car next to me, no biggie. then i get out to get my backpack because i just got home from school in the trunk and end up seeing a very noticeable plume of colorless smoke coming from my sub box. :eek: :hithead: i take the sub out of the box and let the smoke out of the box. everything LOOKS fine but now the sub doesnt hit anymore and all i hear is a very weak clicking noise when ever there is a bass hit. what happened? is it fixable? or do i need a new sub :( the sub is probably less than a month old... same with the amp... the sub says it runs at 400 rms and the amp is at 370 rms.

The sub is definately no good and possibly the amp. Take them to a car audio shop and tell them what happened and see if they can bench test your amp to see if it's still good...

when you press inwards on the sub, does it hit or grind? if so, the voice coil is ****ed

sounds like you melted the lacquer on the voice coil, if it smells burnt its toast. When you replace the sub, turn the bass boost down. Bass boost increases clipping, clipping builds up heat in the speaker and thats what causes speakers to die.

I've had that happen to 1 sub before. Get a new one. Lower gain and bass boost on amp. Be more careful. Sorry to hear it though.

:( so in other words i was pushing the sub too hard? it sounded fine and so clean then all of a sudden it conked out on me.. yea it smelled burnt and nothing happens when i push the sub in. so my problem can be solved by turning down all the aspects of the amp? i am guessing this applies to the headunit bass settings as well? man this sucks :hithead:

oh whats clipping?

Here is an explination of what clipping is:
The voltage going to a speaker from an amplifier is an AC sine wave. So the voltage goes up and down, positive and negative, in one continous wave. This continous change from positive to negative and back is what moves the speaker in and out.

When you try to push an amplifier too much, the tops of these sine waves try to exceed the maximum voltage possible to output, so you end up with the tops becoming flat. This effectively is pushing the sub out, and holding it out, before pulling it back in, then holding it in. The movement is no longer fluid. Sound is distorted because the subwoofer is now stopping twice during 1 wavelength.

Does that make sense?

Check these out:
http://www.st-andrews.ac.uk/~www_pa/...ing/page1.html
http://en.wikipedia.org/wiki/Clipping_(music)

So you need to remove any bass boost you have on the amp (causes more clipping), and turn down the gain (gain is input sensitivity, so can cause more clipping) a little bit. You should tune your system without any bass boost on anywhere, and you should try to avoid it later on.

Clipping occurs when the amp is asked to deliver more current to a speaker than the amp is really capable of doing. When an amplifier clips, it literally cuts off (or ... clips) the tops and bottoms of the musical waveforms that its trying to reproduce. This phenomenon introduces a huge amount of distortion into the output signal, and it is that distortion that kills speakers. The maximum power-handling amount stated on a speaker basically assumes that the amplifier is going to "clip" or start to produce distortion at its maximum output. So, if you use a low-quality amplifier, it will start to run out of gas at its max output, and might do damage to your speakers.

Clipping occurs when an amplifier is asked to deliver more current to a speaker than the amp is really capable of doing. When an amplifier clips, it literally cuts off the tops and bottoms of the musical waveforms that its trying to reproduce, thus the term. This phenomenon introduces a huge amount of distortion into the output signal. Clipping can be heard as a crunching sound on musical peaks.

The above two are from about.com, i didn't feel like typing...

http://www.bcae1.com/2ltlpwr.htm
http://www.rane.com/note128.html

You've fried your sub. Have the amp tested to see if it's fried. It's not the amp though, it's the person tuning it, and handling the volume knob. Turn the boost off, tune it with the gain, and don't turn the volume up so loud. Blockrocking is out.

What is really happening in an amplifier when it clips:
The amplifier uses some basic circuitry to step up the available voltages within the amp to say, something like +70 and -70 volts.

There is no possible way for it to supply more than +70 and -70 volts because it can't output a voltage higher than what it has available.
So when the amplifier is clipping, the sine wave is as normal till +/- 70 volts, and it stays there until the sine wave is supposed to be lower/higher. That is what is happening from a hardware point of view.

it sounds like a smoked coil. pushing on the sub doesnt do anything except misalign the motor structure and could possibly sieze the sub. DO NOT PUSH DOWN on any speaker/sub that could possibly be good or any good speaker you wish to keep. stinky speaker = burt ass for like a month in your car. the ticking isprobably from the speaker just running into itself when power runs through it.

bass boost is just a tweak for bass in a certain frequency is amplified, think like a single band equalizer for your sub. so if you played a sweep from various frequencies, it would show a peak at where you turned it up, when normally it would be a pretty linear curve. by raising this peak, you could potentially boost it above the playable spectrum and introduce clipping. The power going to a speaker during clipping can be much greater than what the amp is supposed to put out.

This is a post of WhiteRabbit's in the Helpful tips thread...

as a general rule best sq/spl mix is factory spec box? I wish I came up with this statement. A functional and useful tip for someone who is an audio beginner, or perhaps a honda enthusiast first and an audio enthusiast second. Its the perfect tip.

some of these tips have been 7th genners here on the war horse trying ot combat common myths about car stereo; some of these myths are even perpetrated by young enthusiasts on the audio boards! others are not myths but rather features that should not be used at all; I personally belive bass boost is one of them.

So I would reword the tip to say "bass boost should not be used at all, tune with the gain instead" or something of that nature.

also might be more politic to use less definitive terms when describing the effect clipping has on a stereo. its easy for a scrub to pick out the statement and say "but I heard that subwoofers in cars play like 10% distortion anyways, why shoudl I care baout bass boost?" so I might say something like "clipping may damage a speaker" rather than "clipping will kill a speaker", or of that nature. just using a terminology to help make the tips watertight...

this might be a good point in the tips to suggest that power doesnt blow speakers, people blow speakers.

If I were writing this tip line, I might combine the bullets in this general area into something like this:

there are 3 basic ways to kill a speaker: mechanical overload, thermal overload, thermal fatigue. power will not blow a speaker, whether too much or too little. you may feed a subwoofer any amount of power you wish. As a general rule, if you can't hear distortion, you will not blow the speaker.

unfortunately, even this is a misleading and fallacious statement. the bandpass box user will be delighted and crank the volume, hearing no distortion and thinking himself set. No relationship is made between the three methods of speaker destruction and power handling, such a discussion would most likely be too long and drawn out for a general bulleted tip list.

I dunno, I guess if I had to compress it down to a bullet, I would say something like: "power doesnt kill speakers, whether too much or too little. overuse of the gain know plus overuse of the volume knob kills speakers"

and again, its still not enough, it doesnt call for how much gain or volume! its a tricky one to bullet, I dont think I can come up with anything thatll be good.

Found in this thread:
http://www.7thgencivic.com/forums/sh...ping+kill+subs

well more power = more heat usually. and if the speaker cant get rid of the heat fast enough then well the speaker does "melt". white rabbit is a buddy of mine and he knows a great deal more than what i do =) mostly what everyone said is truthful though.