Wattage

As I said, anyone can make a mistake.

It would have been nice if, when *I* mis-spoke, you had simply corrected me without piling on a bunch of insults. You can always go back and flame someone after treating them with respect, but once you start calling someone names, you can never go back to having a professional conversation with them.

Reply to
Guy Macon
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My bad! I forgot that there were unemployed "engineers" who have a need to sell s**te to make the mortgage payment. Perhaps one really *does* need to maximize the "experience", even if it means enhancing the "RMS power" of the power-point presentation.

Reply to
Keith R. Williams

Your clipping is interesting. You were clearly wrong in your position. I added the word "average" into my list of terms to be discarded and made the correction. "Average" is the *only* term that can be used with power (average implies time, so pick the time).

It would have been nice if you acknowledged that you were

*wrong*. Clipping posts to show your side amounts to a lie! ..at least by omission.

Please learn how to quote your opponent's position so you don't look so shallow.

Wow! You're a big talker. However, you don't quote your opponents, but berate them. ...perhaps to make you look somehow superior? Please! Learn the rules of the Usenet and quote and respond. If you can't take heat, leave the kitchen. The Usenet isn't your mother's tea party.

Reply to
Keith R. Williams

Actually, the impedance of the speaker has nothing to do with how much power it can handle. The op said: "I am trying to measure the max wattage of a sub woofer"

Did you have that in mind when you posted the above? Or are you thinking of doing the calculation based on wire size in the coil of the speaker? If the latter - you would have to measure the wire size in addition to the impedance. I guess I'm totally missing your point.

Reply to
ehsjr

There is also the issue of the power dissipation of the coil, and the temperature allowed in said coil. Wire size isn't all! Think about the wire size on a microprocessor chip with 100A flowing through it.

Reply to
Keith R. Williams

I am pretty sure that I have admitted that at least once already, but in case I didn't, here it is again; I was wrong. I mis-spoke. I read in haste, and failed to notice the reference to power rather than voltage. My mistake. I erred. It wasn't really a "position", but rather a simple error. We al make errors

It would have been nice if you had simply corrected me without piling on a bunch of insults.

Did I mention that I was wrong? I was wrong, you know. Not only that, but I was also wrong. In other words, I was wrong. What I am getting at is that I was wrong. Do I make myself clear?

It would have been nice if you had simply corrected me without piling on a bunch of insults.

Reply to
Guy Macon

Yup! And I didn't even think of it. Where's the dunce cap when I need it?

Reply to
ehsjr

message

--------- Wire size is not necessarily a good measure of current rating. Note that nominal ratings apply to wire in air- not wire wound in a coil and enclosed. There may be charts for this situation which fit particular devices (they cannot be general) - in fact, I am sure that there are. However this does beg the question- if one knows the manufacturer and the speaker model, then the manufacturer will have the information needed, without the need to run tests. If not, then the impedance test won't tell you anything about the power capability of the speaker and looking at the wires won't help. .

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---------- No problem, It is like using a fuse tester which runs the current up until the fuse blows. Then one knows that the fuse good.

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---------- I thought that I said or at least implied or assumed as "a priori" knowledge that the load determines the current for a given voltage. It is true that one doesn't control the power directly- in fact I don't know of a device where this is true- one controls something else to control the power and often the power change is a side result of trying to control some other variable. In this case: Double the voltage- double the current and quadruple the power- This is true at any frequency independent of the impedance at that frequency. I stated fixed frequency to avoid comparing thepower/voltage relationship at one frequency to that at another frequency.

---------

--------- Upper limit -true. But is an upper limit useful? What is the lower limit? Failure will be somewhere in between and if I am putting $$ into speakers, I want to stay below the lower limit.

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-- Don Kelly snipped-for-privacy@peeshaw.ca remove the urine to answer

Reply to
Don Kelly

Well, I'd say that an impedance matched driver (perhaps a transmitter) varies the power to the load directly. ;-)

Sure, in most audio circuits the output impedance is nil, so you're varying the voltage.

Reply to
Keith R. Williams

Cite? Now you're making yourself out to be the Audio Fool.

The output impedance of most audio circuits is *never* nil - it is always some intrinsic value. Some examples: Speakers = 2/4/8ohms, Balanced Line = 600ohms, AES/EBU Digital audio = 110ohm..

Have fun.

Cameron:-)

Reply to
Cameron Dorrough

You've missed the point. It's an ellipsis, based on the content of the post he was replying to, where the impedance changes with changes in the frequency.

Ellipsis: "the omission of one or more words that are obviously understood but that must be supplied to make a construction grammatically complete." (From Webster's)

Had Keith not used that ellipsis, he would have written something like: "Sure, in most audio circuits the output impedance DELTA is nil, so you're varying the voltage."

Reply to
ehsjr

Yes, I guess I *did* miss the point. I let his groundless insults get to me - and I shouldn't have done that (this is Usenet after all).

In my (brief) time doing concert audio, all we ever needed to do to measure speaker characteristics was to hook them up to a Tektronix impedance analyser, run the tests, print the graphs and hand them over to the cabinet designers.

I have learnt quite a bit though this discussion - thanks to you and Don.

Keep up the good work :-)

Cameron:-)

Reply to
Cameron Dorrough

On 29 Oct 2003 21:46:39 GMT, snipped-for-privacy@aol.comGreg (Gfretwell) Gave us:

Not if it is a reputable maker. Amp specs are true to form correct from many reliable producers of home audio equipment.

Reply to
DarkMatter

On Fri, 31 Oct 2003 22:22:53 -0500, Keith R. Williams Gave us:

Still trolling eh, Keith?

Reply to
DarkMatter

In what way does wattage differ from power? :=(

Bill

Reply to
Repeating Decimal

Well, that puts you one up (at least) on me. Never did concert audio. With my tin ear, they wouldn't send out for a cello - they'd send out for a Smith & Wesson to provide me with some "negative feedback".

Reply to
ehsjr

Coool! :-) Concert audio is over-rated. Lots of lugging large crates around and shuffling them into the right order - cables running everywhere - lots of noise (from fussy musicians) - lots of standing for hours on end eating free pizza and drinking litres of free Coke - early mornings, followed by the next early morning.

Don't get me wrong, it is *very* satisfying to get a good mix, with the mid-highs tuned just right and the reverb bouncing off the walls (and to see the punters thoroughly enjoying themselves)..

Audiophool stuff it's not (more like drown out the echoes!)... but these days I value my sleep (and my ears).

Cameron:-)

Reply to
Cameron Dorrough

Oh, it most certainly is.

"intrinsic"?

I didn't realize speakers had electrical (I don't want to get into acoustic "impedance") *outputs*.

Check what's driving that line. The input may well be (or not)

600 ohms, but not likely the output.

Digital cable. Check the output impedance. You;ll likely find this is rather lower that 110 ohms. ...though this is a digital signal, and not audio.

Perhaps you don't understand the terms you're slinging around?

Reply to
Keith R. Williams

No, I *meant* the "OUTPUT IMPEDANCE OF MOST AUDIO CIRCUITS IS NIL". Not any variation in impedance.

Most audio circuits these days are emitter-follower sorts of things, and as such have damned near zero output impedance. THis is particularly true of amplifiers. They're in reality beefy op- amps.

Reply to
Keith R. Williams

No, I *meant* the "OUTPUT IMPEDANCE OF MOST AUDIO CIRCUITS IS NIL". Not any variation in impedance.

Most audio circuits these days are emitter-follower sorts of things, and as such have damned near zero output impedance. THis is particularly true of amplifiers. They're in reality beefy op- amps.

Reply to
Keith R. Williams

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