a class d amplifer uses a square wave, which is full on or full off. once the speaker reaches the full travel that the given amount of power will push it. the square wave keeps the same amount of power to the coil. it can't disapate the engery in the coil, then it turns to heat. which intern burns a hole in the coil wire. basically the cone moves in a sign wave, and the square wave of the power source doesn't match it means there are mismatchs in power/cone movement i.e. heat ..........blown woofer.... no matter how much power you put to it, the cone doesn't move and there is still power going to it. it may take a year to do it if you don't totally pound the system or have a small amp, but it will happen. if you do get a class d make sure it has a high dampening factor, it will help prolong the setup's life. but since you'll probably want new crap in 2 years anyway none of this really matters.... class a amps and high ohm ratings are why home stereos can last for 30 years with no problem. but in the car audio world since products come and go every year, equipment longevity doesn't matter so much. its like running 12:1 compression in an engine. it'd be easier if i could post diagrams.

 

thats because the sound waves of music are sine waves, which the speaker can easily recreate, however what i'm saying is the class d amp creates a square wave, not the dynamic musical sine wave.

the reason speakers burn in a large box is because the speaker doesn't have the air in the box to dampen the cone movement, so it will reach the its x max easier and when it does it creates the infamous square wave, it goes out stops on the the x max, still recieves power but cannot dissapate it(burns) and then power is taken away, the speaker returns to resting(with a new burn spot).






trust me i know what i'm telling you. the only thing thats helping these class d amps is as of just recently they've started putting filters on the output circuit to make the power wave more like a sine wave. but they don't really work that well.

 

......well actually if a speaker is underpowered it will blow eventually to, although this takes awhile usualy. What happens is the speaker doesn't have enough power to move the coil an adequate amount to dissepate the energy. so then it burns again.

stereo equiptment is alot more complicated than matching power ratings and box sizes. it is a science, college actually offer degrees in it.

 

Underpowering doesn't blow speakers, either. It's an underpowered amp (either external or the HU's amp) that is clipped to hell that will do the damage. People try to make up for the lack of power by cranking the volume **** up, introducing clipping, and as noted above, clipping (or at least, the excessive heat clipping creates. Clipping itself, obviously, doesn't kill speakers) can kill speakers.

I know exacltly what a big/small box does to a speaker, I know exactly what a Class D amp can/can't do, I know what clipping is, I know underpowering in and of itself won't harm a speaker one iota, and I've explained this on numerous forums a million times. There seems to be a lot of myths that are still alive. It seems the myths in this thread are being perpetuated for no other reason than to argue with me...valid or not.

I'll just go in my garage and think about all this...while listening to my severely underpowered speakers (they get 50 watts/per...rec. power is 100) that I've owned for 13 yrs. Or maybe just visit a friend who has been running a 8100D for over 3 yrs. on his Comp 4 VR's...if they're not blown.

 

http://www.mbquart.com/ha-techpapers.htm

scroll to the bottom of the page

 

Swamper -- I'm not sure what specifically you're referring to, but the paper seems to be saying the same thing that DefTonz is: that too little power is a problem *only* if you try to get 110 MPH out of the Buick, to use the term from the paper.

Too much power -- TOTALLY clean and undistorted -- can and will fry a driver that's not meant to take so heavy a load. Too *little* power will *only* damage a driver if cranked to the point where severe clipping occurs. Do you disagree with this?

 

yeah thats what i was trying to get across,

but some class d amp work well like mtx's (the only ones i ever heard that actually don't burn stuff up) because they don't go cheap on components, so they have output filters that do what they are supposed to... however most other class d amps don't because good filters are expensive and minimize profits because most people would never know/care about the differences. an unfiltered class d amp is like plugging your sub into the wall outlet. a poorly filter amp will do the same thing just over a longer period of time. so luvdeftonz, you can go listen to you friends mtx for atleast acouple more years, but sooner or later the 2 ohm configuration is going to catch up to the amp as well but by then your friend will want something new guarenteed so it won't matter.


mzimmers when the voice coil is not able to disspate the energy from either over or underpowering the speaker so yes you can fry a speaker 200w speaker with a 600w shot

i pretty much agrees with deftonz on the clipping thing my original point was is that class d amplifiers output signal is the same pattern as clipping there for unless you get an absolutely top notch one you they are more likely to blow subs much sooner than class a amps.

 

Wow I didn't realize such a debate would arise from a simple post...eitherway pretty interesting stuff...it's just sad that I don't understand half of what most of you said.

Dave

 

I'm overpowering my subs by about 400watts and they are fine. The amp is a class BD and I put the poor subs to the test.

 

wow not this all over again. its been proven that under powering a driver will not blow it, but as luvdef said, when it is forced to be clipped, then it will cause some nasty stuff to happen. u can overpower a woofer and still have it play sufficently, just make sure the gain settings are low. from what i understand, when an amp is clipped it forms a square wave and that causes the sub to blow? im not really into this technical jumbo but id rather push my woofers with an efficent class D then an a/b.

 

so does nobody care about the actual facts about how their stereo equiptment and only listen to what crutchfield says is good?

 

I care swamper..especially if I'm going to buy one!

 

yeah I'm surprised Tempe hasn't gotten here yet....lol
Superswamper I hear what your saying and dont listen to crutchfield but I feel having more power and turning the amp down a bit is something one should do no matter what class amp one has. As far as Lightning audio amp, the Co. I believe is owned by rockford and from what I hear the FandF series is the best you can get (from lightning audio). Qiuck question?, How does the class of an amp affect the the sound wave?

 

Prplayboy, any pics of that explorer you driving around with? Sounds like some tite *** ride you got there...I'm gonna take some of mine when I finish hooking it up...I got a lot of **** one there already.


Dave

 

Here is a link to some pics. I will take some of the truck soon.