Mcgyver.............do some experimentation, THEN when you're more familiar with the subject at hand, we can discuss it further. What I stated was an ABSOLUTE fact that you can take to the bank......................nuff said.

 

Maybe I haven't made myself clear enough in the past, so I'll remedy that right now.

You're WRONG!

I AM familiar with the subject at hand...I hold an MSEE from a top-ten university, I have DESIGNED circuits for amplifiers for a MAJOR manufacturer in the past (you may actually have some of my circuits in your car amplifiers), I have BUILT and TESTED these same circuits. I believe all of the above makes me immenently qualified to make my previous statements.

What qualifications do YOU have (a question that has been asked before but you have yet to answer)? If the best answer you can give us is you've installed stereos in vehicles for 30 years and THAT makes you qualified, get real. So far you've made a lot of bold statements with exactly ZERO facts to back them up.

Maybe when YOU'RE more familiar with the subject at hand we can all have an intelligent discussion...until then, you're nothing more than a sheet metal jockey who's read too many advertising pamphlets and made too many incorrect assumptions about why things go BOOM. I gave you the benefit of the doubt in the beginning, but you've quickly proven yourself to be ignorant of the facts.

Don't try to play the sympathy card anymore about being a newbie who's caught under the tyrannical heel of us old-timers, it embarasses you and insults our intelligence. Unless you can come up with some cold, hard facts, you're just another troll who hasn't a clue. And believe you me, the members here know who to trust to give them CORRECT information when it comes to debates like this...and you aren't one of them.

The flag has been flown, you're standing under it. Prove us wrong, but don't think for a second that pathetic arguments like "I've seen it happen in the shop" will work. You do everyone a disservice spreading false information...you either don't know any better or don't care, and I'm not sure which is worse. At least the person who doesn't know any better can learn...the person who doesn't care will be incorrect most of the time and correct when lucky, but they'll never know the difference.

Saying "when you're more familiar with the subject at hand, we can discuss it further" is the prime sign of a weak argument and a logical fallacy. In fewer words, "Put up, or shut up." Unless you can step up to the plate and do that, your 15 minutes of fame as an "expert" are almost over.

 

oneaudiopro -- you're way off here...

by this statement:
if i were to use a 1 watt amp, i would more easily 'blow' speakers whereas if i were using a 1,000 watt amp, i would never blow speakers, SIMPLY because the smaller amp will distort sooner and the more powerful amp would rarely distort?

of course not. mine is a ludicrous and clearly false statement, but it is the logical conclusion based upon your statement, and that is because your conclusion is wrong.... as usual, Mac is right.
power (or WLaurent w/ a screwdriver ) destroys speakers, not the lack of power or distorted power. now, the frequencies generated during clipping distortion can have adverse effects on tweeters, causing them to blow at much lower power levels than clean power would, but this is an special case and is dependant upon the nature of a crossover and is not the norm at all.

so, i would really recommend that you make sure that absolute fact is really fact before you go off on your little tirades...

"nuff said"?

yes, i think enough has been said for me to make my opinion about earning respect.

 

Let me make something perfectly clear...................I don't much care if you believe me or not. I deal with these problems on an almost daily basis.......AND.......find solutions for them. As far as my qualifications.............I've been employed in the audio/video industry for 30yrs now, was a corporate sales and product trainer for 5 of those 30yrs, was an IASCA judge for 3yrs, and hav done product evaluations from autosound systems to high-end home audio components for approx 10yrs. I know what I'm talking about! If you want to continue to spread rumors and misconceptions to the naive and uninformed people in here, thats your thing, not mine. If you want to argue and split hairs on an audio subject in here, you better come more prepared if you expect to earn MY respect! I may be a "newbie" in this forum, but I'm not a newbie to the subject at hand. Do your homework, check with other "experts" in this field..........THEN maybe we can chat some more. You'll probably find that I make a better friend than an enemy...................................Bob

 

You all knew this was coming

Top 10 Ways to destroy a speaker (some previously stated but so classic they had to make the list):
[list]
[*]Throw it from a tall building
[*]Toss in front of a speeding train
[*]Poke a screwdriver through the surround or cone
[*]Play John Tesh, Michael Bolton or Barry Manilow for extended periods of time (thanks Mac and others)
[*]Apply so much power that the thermal limit of the driver is exceeded (thanks modifry)
[*]Connect to an extension cord and plug into 120VAC (thanks for the pics PJK3)
[*]Forget that you left the subwoofer sitting on the ground behind the car
[*]Fasten mounting screws with hammer
[*]Rinse dust from your speakers with water prior to installation
[*]And the #1 way to detroy your speakers - Have your system installed by a "self-proclaimed expert"[/list=]

Just for the record: I have 2 engineering degrees (1 of which is electrical), 15 years of experience in car/home audio, 3 dogs, and an S2000 - yet the only things I claim to be an expert in are poking screwdrivers through speakers (as previously mentioned) and pissing off my wife (I am sure she could testify to facts in this case).

oneaudiopro - you will find that this site is packed full of extremely intelligent people from all disciplines. I have seen some of the most unique/exciting inventions, creations, developments, etc.. on this site. At times I am in awe of the technical and creative capabilities that are resident here at S2KI (and I spent 4 years designing pacemakers and 3 years designing and writing control system software for passenger jets). I, and you will find true with most other site members, have a lot of respect for people like modifry and MacGyver when it comes to electrical/technical issues and the lengths these guys will go to help other site members.

Everyone (with the exception of some of the Australian boys ) gets along pretty well. This site is a wealth of knowledge regarding the S2000 and just about any topic you could start a thread on. So if you have a pacemaker troubleshooting problem or are looking to design a control system for a plane - feel free to shoot me a PM. (I can also provide you some good points on poking screwdrivers into speakers ).

 

The voice coil can also be damaged if the excursion (Xmax parameter if anyone cares) exceeds the length of the voice coil. When it comes down, it can touch the sides and be damaged...

 

LOL I haven't seen that one yet, but it rings with so much truth. I'm sure some of the older members can remember the past "discussions" in this forum about some pretty misunderstood topics (several on distortion and speakers, at least one on how CD-R discs supposedly ruin a CD player's motor bearings , etc.)

Of course, the few people who make these claims have all been self-proclaimed "experts" in their field...which always turned out to be? Yep, you guessed it...INSTALLERS! I have no idea what makes these guys think that because they have handed out pamphlets, judged an SPL competition, or carpeted a sub box, that they are now "experts" in what actually makes those things work and fail. Maybe it's the lack of oxygen from standing on their head to reach a tightly-placed fusebox, or maybe they just didn't ventilate the room enough when slathering on the epoxy for a fiberglass enclosure.

In the end, though, they're just one more troll to amuse those of us who DO understand what's going on. It's still amusing that the less someone understands a subject, the less they care about what others think they know...kind of funny that way

You have GOT to remind me of this when I finally get around to making the replacement ECU...I'll need someone more versed in control theory than I am. My poor little noggin' couldn't hold on to all of the info I was taught all those years ago...still have the notes and books, but the knowledge is VERY rusty.

 

[QUOTE]Originally posted by MacGyver
You have GOT to remind me of this when I finally get around to making the replacement ECU...I'll need someone more versed in control theory than I am.

 

Macgyver..............Like I said in my previous post, very few people in here really get to know someone or their level of expertice. I have never claimed to be an installer.............nor am I one now, and yes, they can be amusing some times.

 

oneaudiopro - Nice to see you still hangin' in there.

I think we may be closer to agreeing than it seems. Your choice of words and phrasing is the problem, and maybe mine too. I'll try to do better and see how close we can get.

The distortion, of itself, is not what blows the speaker, rather the increased power delivered to it because the amp is distorting. Fine points I know, but we engineer-types are sticklers over the details.

Distortion is defined as a waveform that is shaped differently than the original. A bigger (proportionately) waveform is not distortion, since that's what amps are supposed to do - make the waveform bigger without changing the shape of it. Saying distortion kills speakers means (to me) that it's the shape of the waveform that damages the speaker (not the amplitude), and I just can't believe that.

If you said jumping off the Empire State building would kill you I would disagree - the jumping part is no problem, it's the stopping suddenly that's hard to survive. And after witnessing many people jump off and die, you might be tempted to say "After 30 years of experience I can definitely say jumping off the Empire State building will kill you". But you'd still be wrong as far as we're concerned, being anal engineers. And while it would be good advice to the general public to never jump off the Empire State building because "certain death will result", it would be slightly misleading, since you don't die when you jump, rather when you hit, plus there are circumstances where it won't be fatal (stunt men, person with parachute, etc).

I believe that nearly every blown driver you see is a result of a system being driven to distortion levels. I believe that not because of your experiences, but because I understand that high distortion brings with it high power levels. But I think it would be near-impossible to pump 50 watts of the worst distortion you can come up with into a driver capable of handling 100 watts and do it any damage.

It's important to note that in the above 'near-impossible' scenario I'm talking about a driver and the actual power dissipated by it. You may not be. You may be talking about speaker systems (multiple drivers in a box with a cross-over) and amplifier power ratings. The difference is the cross-over, and here's why:

In the above example, I talked about a 100 watt driver, not a 100 watt system. In a system the cross-over directs only the high frequencies to the tweeter, and that's typically less than 10% of total system power. (let's assume for this discussion that it really is 10%) So because the tweeter normally would never see more than 10 watts the manufacturer could easily have a 15 watt tweeter in your 100 watt system. If you drive it with 150 watts of clean power (over-driving it with clean power), the cross-over will still direct only 10% of the power to the tweeter (15 watts) and it can handle it. But if you drive the system with a 50 watt amp at serious clipping levels you might generate 30 watts of high frequency distortion, which will go through the cross-over into the tweeter and fry it.

So in this "system" example we can safely drive a 100 watt speaker system with a 150 watt amp but can damage it by using a 50 watt amp. You might say "We have blown a 100 watt speaker with only 50 watts", right? The engineer would say "We have blown the tweeter in a 100 watt system by overdriving a 50 watt amp to the point of clipping, which forced 30 watts into the 15 watt tweeter and cooked the voice coil." There is a big difference between these two statements, at least as far as engineers are concerned. You see the distortion as the cause (it didn't blow up with clean power did it?), we see the excess power (30 watts into a 15 watt driver) as the cause.

So waddya think? Are we close?

P.S. - Please don't think I'm talking 'down' to you because of my phrasing and explanations of obvious (to you) concepts. I worded it for everyone on this forum, not just the audiophiles.