nobb

Hey.
I'm just wondering. Sometimes I like to play my music with a little more volume. My front speakers sound fine, but my rears distort. However, the distortion is inaudible when I am sitting in the front and only audible if I sit in the back. The speakers I am using are the crappy stock paper speakers that came with my car, and I dont really care if they blow, because I am planning on replacing them anyways. I am powering these speakers from my 4 channel amp which puts out 75 watts/channel. My stock speakers are rated at 50 watts, and I'm pretty sure that my amplifier is more than capable of putting out more than enough power for clean sound. Therefore, the distortion is a result of the crappy speakers, not the amp.

So my question is, can the distortion caused by the speaker cause damage to my amp? I'm guessing no?

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brhestir

I understand the following to be technically correct:

1) The simple resistance of copper conductors increases as its temperature increases (not referring to the complex impedance of the speaker to the signal). From this, as the voice coils in your rear speakers heat up, their simple resistance will go up, causing the power dissipation of the channel of the amplifier attached to go down. If power dissipation (watts) goes down, 2 things happen in the amp: a) heat dissipation in the power stage of the respective channel goes down, and b) b/c less power is being dissipated, the effective load on the amp is less, there is less of a total voltage drop across the respective channel, leaving more voltage for the rest of the amplifier to use. For these reasons, I think your amplifier channel will be just fine.

2) If the moving mass of the speaker is being thrown to its maximum +/- displacement due to excessive voltage and being kept from moving further by the surround holding it in place in both extremes, the following would happen: since speaker movement is resisted at the extremes of cone travel, the magnetic field of the current flowing through the voice coil will be resisted greatly by the permanent magnetic field of the magnets in the speaker. Because of this greatly increased physical resistance to movement between the two magnetic fields, the resistance of the voice coil will go up when it is at its +/- extreme physical travel. For the same reasons as item (1), this should not harm the amplifer, as power dissipation will go down.

In summary, I think you amp will be fine, as long as you dont have the gain for the channels that are distorting turned up past where it should be. I have heard through the grapevine that too little power kills speakers before too much power would. Worst case scenario is that you will blow your factory rear speakers. Then you would be in a great position to replace them with some more capable speakers!

Hope this helped, good luck on your audio system. -Brian

BenOBS

I dont think you can arm the amps like brhestir said, unless if the voice coil burn and short himself... Then the resistance would drop as far as 0 ohms... That would hurt the map if it does'nt get into protect.

Note that the 50w they are rated for is'nt rms, so 20w rms would be there maximum heat dissipation.

The best thing you could do is unplug or remove them... They just give you distortion anyway...

My 2 cent

Ben

Megalomaniac

you can harm the amps with a clipped signal


i say just unlplug the rear fill stock speakers, whats the point in listening to unwanted distortion

nobb

Yea it makes sense that the amp wont be harmed, I just wanted to confirm. The reason why I am leaving in the rear speakers is because they add extra bass. The sound is very thin without them. Like I mentioned, I cannot hear the distortion when I am seated in the front. I plan on upgrading my speakers and getting a sub, but not yet.

Megalomaniac

get them crossed over then so they arent playing full range

comet28024

This is not a clipped signal. A clipped signal is when you are overdriving your amp not when you are overdriving your speakers. Your amp will be fine.

furball69

Like BenOBS said, if the amp doesn't have short circuit protect mode, and you burn/short a voice coil, you could kill the amp.

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Megalomaniac

if ur over powering those speakers. u can start a fire. usually those stock speakers are rated at what? 25watts. so if ur giving them a lot more power u will blow the coils then you will melt the tinsels if u keep playin them blown. and then u melt the tinsel and it lands on the spiders it will catch fire since the spiders and glue are flammable.

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