Sense I am new to this section of the board let me piont out that I am not just some guy with a system. I have been into audio sense i was about 8 years old. Started into car audio when I was about 14 when was the youngest person at the time to get the Master certification from the MECP back when part of the test was on how to install in car cell phone.....boy I am old. I biult my first home speakers before highschool. I got my degree in electronics just so I could design, biuld and repair audio gear. I built my know subwoofers ( the draw driver, not the box) and an amp or two in collage. I have been an electronics tech for some 15 years now with a full tech bench here at home. Not bragging because for the most part it nothing overly exiting, just wanted to piont out I am trying to give the facts of how things work from a factual electronics standpiont and from what I have seen over my many years working with audio. There was exeptions to every rule I am sure.

With that being said I am going to try not and flame you here but present the facts.

When I say poeple in this industry I am not talking shop owners, reps or even most installers. I am talking the people that design and biuld the stuff we use every day. People like Manvel Smith, one of the guys that started JL Audio back in the early 80s becuase their shop did not like the current offering of subwoofers so the shop started biulding there own. That turned into JL Audio. Hmmm, guys that biuld their own subs, I am going to take a guess that they acutally do know what they are talking about. People like Andy Wehmeyer and Gary Biggs of JBL. The list goes on and on. These are people that know there product better then anyone because they helped design, market and use their products. These same people are quit nice and are willing to teach you not only about their product but about audio. Goto forums like Carsound, Elitecaraudio or DYIcaraudio and start a post about how you think distortion does not kill speakers and that the speaker does not know its being distorted and these very same people with tell you otherwise. Now if you think they dont know what they are talking about then I think you need to start your own company and prove them wrong. Up to you.

Thats great. I have some 1953 Acoustic Research home speakers that I restored years ago that play perfectly and I have about 3X there rated power (back then big power did not exist). In my Line Array home speakers I built each driver is only getting about 1/10 there rated power and I have never blow then either. I also dont push the amp into clipping (kind of helps that there are 24 6.5" mids and 104 tweeters total). Also keep in mind its a general statement. If your driver has enough cooling capasity to handle the added heat then it will never blow. On the other hand if you over power it you can still blow it because it does not have enough cooling to overcome the added power.

That is false. Read my pervious post a little better. I think I explained to well enough.


Hmmm, funny, the last time I looked at my scope (about 2 seconds ago....sitting right next to the monitor) a flat horivontal line on a scope represents a DC voltage. Also the last time I know a sinewave that is clipping the top and bottom peaks are a flat line on the scope. Hmm, flat line on scope is DC, flat line on winewave...still DC. Here, below is straight off a speaker manufactors website:

CLIPPING
The DISTORTION caused when the GAIN or INPUT of an amplifier is increased to a point where the high points, or peaks, of the SIGNAL or WAVEFORM are cut off at a level where the amplifying circuits are driven beyond their overload point. Also called over-MODULATION.

If you cut the top off of a mountain you get a flat top. Flat line+scope=DC voltage.

And where do you think that voltage potentail is coming from in the amp, the power supply. What type of voltage do you think that power supply is putting out, DC Yes it will not put out more then the design and the power supply, if how that voltage is applied to the speaker that can be bad.

Again, that peak voltage potential is the output voltage of the power supply section of the amp. Yes, once you surpass that, the amp will clip. But that really did not tell what actually happens. Please by all means tell me what you think the clipping of the wave does to the output of the amp.

I can see there you are getting that but you have to take into account that a speaker is only supposed to move so fair with a certain amount of enery aplied. But if you think about a speaker being a true linear motor, which it is, but without mechanical limits it would move in one direction forever until you took the voltage away. A speaker is just like any other electric motor but it has limits, ie Xmax. If the speaker had no mechanical limits, ie suspension, spiders, suurounds, magnet gap lenght, the cone would never stop moving. Now apply 18 volts and the cone would be moving twice as fast. Take the voltage away and it would stop. Its the drivers suspension that pervents it from going any farther but the motor, ie voice and magnets working together, is still trying to push the cone out farther. If you do this test and you push on the cone you can feel it pushing back. Of course we all know that speakers would not do much good of they did not go back and forth so they are not design to handle this DC votlage.

I think if you realize what clipping really is, how it increases the amount of time a voice coil sees a DC singal and the fact that is not design to handle it over long periods of time you will see what I am talking about. Again if you dont want to take me work for it read this page from someone that knows WAY more then I do:http://sound.westhost.com/clipping.htm I hope I at least help someone out here.

Rick

 

That's nice that you've been around for so long and a very cute story, but were talking about a pretty simple topic here which doesn't require 20 years to grasp. This topic only includes some simple high school physics and freshmen/sophomore year college electronics.

I was playing with records and my dad's Sears radio when I was 2 years old. Some people have been driving cars for 60+ years and are considered some of the worst drivers.


That's good that you know these people but if your going to tell me top people in audio feel less powerful amp will do more damage than a more powerful amp there's something seriously wrong. Common sense will even tell you that. Remember more powerful amps can clip just like the little one's.

I'm a member of two of these forums (elite, carsound, sounddomain, termpro) for years and I've learned a lot from them. Distortion in itself doesn't kill speakers. Distortion can enter in system from multiple different points including the microphone in the recording booth, the editor on a computer, the equalizer in your car, etc. Most people have determined that the speaker itself causes the majority of distortion. This isn't something I just thought of the other day. This is something I have learned from these forum believe it or not (because I was misinformed by best buy employees). However, extensive distortion produced by a speaker can obviously be a great detector that the speaker is being pushed to its limits. Distortion is just unwanted portions of a received signal compared to the original signal.


I like this statement a lot better. You talk about the thermal limitations of speakers as well as power handling which are things that can determine the life of a speaker.


We're talking about a signal, which still has something to listen to. You can have a clipped signal coming from an amp and you can still enjoy listening to this doesn't automatically give the whole signal a DC description. If it was DC you wouldn't hear anything and no movement of air will be produced. Not to mention there are multiple frequencies going through the amplifier. I would not describe whole signal being DC all of the sudden because of one instantaneous point (a millisecond or so) becomes flat. There's a lot more going on there that you scope is apparently not cable of seeing. Even if that's the case then whenever you play a cd or mp3 you are automatically listening to straight dc even when it’s not clipping. If you zoom in enough you see flat points all along the graph.

Your thoughts, the people you know, and years you've been around doesn't disprove that clipping and distortion doesn't cause speaker failure. You do have a very nice system though looking at your thread. It's light years ahead of mine.