HOW TO UNDERSTAND DIFFERENT IMPEDANCE RATES?!!!

God god at almighty.com
Mon Jun 9 20:18:04 EST 1997


>You really are a most unsatisfactory god, you know (of course you
>know!). If this goes on I shall have to stop worshipping you, and then
>where will you be? You have the inequality sign the wrong way round; at
>least, I suppose you did not mean 'greater than'!

Would you quit picking on my name? It has nothing to do with whether
you or I am correct. And yes, the signs should be reversed. If you
caught this, you should understand my final point.

>>3) We assume that both "speakers" in 1) and 2) have the same
>>efficiency (and identical except for their impedances.)
>
>Yes, the following reasoning is correct if, and only if, you mean
>efficiency in the strict sense of sound power out divided by electrical
>power in, but hardly anybody uses that because it is difficult to
>measure and not of great practical use.

No, John. THIS WAS A PREMISE STATED BY THE ORIGINAL POSTER. I was
merely breaking down his premises + conclusion into an easy to
understand format.

>>4) Ergo, a 16 ohm speaker is less sensitive than an 8 ohm because at
>>the same WATTAGE, the former produces a lower SPL ** from 1) and 2)
>>
>>He did prove his
>>point that the higher impedance speaker would produce lower SPL at a
>>given voltage. However, when he translated this to lower SPL at a
>>given wattage, he committed the fallacy of four terms, a non sequitur
>>fallacy of ambiguity. 


>If by 'he', you mean me (John Woodgate),

Since I was replying to you, he would have to be someone else. Of
course, you didn't committ fallacy of four terms, dolt. :-)

> I certainly did not 'translate
>that to a lower SPL at a given power' (I would even more certainly not
>have written 'wattage' - ugh!). I fail to disceren any meaning at all in
>the phrase 'a non sequitur fallacy of ambiguity'. A non sequitur is
>false reasoning - the conclusion 'does not follow' from the premise(s).
>An ambiguity is a language-dependent construct - what is ambiguous in
>one language may not be in another (e.g. if the ambiguity arises from a
>pair of homophones).

N.B.: This is where your inexperience with formal logic comes in. The
group non sequitur comprises the formal fallacies, fallacies of
irrelevance (ignoratio elenchi), and the FALLACIES OF AMBIGUITY. The
fallacies of ambiguity group comprises amphiboly and equivocation,
which includes composition/division AND FALLACY OF FOUR TERMS. You're
out of your league here, John.

Take the time to look back at my numbered summary of the original
poster's (which is not you, John) argument. All of the numbered
bullets except for the last are the poster's premises. The last
numbered bullet is the poster's conclusion. 
>>
>>>The
>>>article in question assumed sensitivity was inversely related to
>>>impedance and then proved it from the same starting point. That 'begs
>>>the question',without doubt.
>>
>>He never made that assumption. Read the post again.
>
>If one says that 'the loudspeakers are identical except for their
>impedance' (whether 'efficiency' is mentioned explicitly or not), that
>is indeed a statement in which it is inherent that sensitivity,
>correctly expressed as pascals per volt (these are quantities of the
>same nature, known as 'field quantities', which can rigorously be
>presented as a ratio), is inversely proportional to impedance. That is
>where the question was begged - it applies ONLY to transducers that are
>identical except for impedance.

I give you credit for trying, John, you're still not DIRECTLY
addressing where the petitio principii occurs. Just because his
conclusion only applies to transducers are identical except for
impedance does not constitute begging the question. I seriously want
to understand you, John, but it's very difficult to interpret this to
be what you say it is.

>>Then how on earth can the software ACCURATELY calculate the reference
>>efficiency from the sensitivity referenced to 1 watt. As far as I
>>know, JBL speaker shop does not have a random number generator for its
>>speaker parameters.
>
>Wanna bet? (;-) Why not ask JBL how they do it? I suspect they include
>the directivity index without telling you.

Well, if they include the directivity index, it must not be that
critical a variable. Or, are you implying that JBL made an egregious
error in its Speaker Shop software (not shareware or PD, BTW)?

>Well either you want a proper technical discussion, in which precision
>is necessary, or you want a thread full of folk-lore and hand-waving. If
>the latter, I will not join you.

I don't see how you can take it as the latter, but let's put it this
way. You seem to be challenging a fairly solid source on this matter.
You would make your case a lot better if either
a) you are a higher authority on this matter
b) you produce a reference from a more reliable source
I'm willing to entertain the possiblity that JBL screwed up, John. 

>>> You call making unjustified assumptions about people's
>>>motives for posting 'courtesy'?
>>
>>What other motive can you offer for why your response was so rude? Is
>>it in your nature? 
>
>Oh, dear, accused of blasphemy, now! Peccavi. Mea culpa. Mea maxima
>culpa.

te absolvo. :-)

How did I accuse you of blasphemy in that sentence, an interrogative
one at that?

>If you think what I wrote was rude, you are very inexperienced in
>Abusenet! However, I did not intend to be rude, and if you feel that
>something I wrote was rude, I regret that. My intention is only to
>hinder the propagation of factually incorrect information.

Okay. 



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