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tube guitar combo frequency ranges

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Anonymous
May 29, 2005 11:42:14 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Do the power amps in tube combos cover 20 Hz to 20,000 Hz like home
stereo tube amplifiers +/- 1 dB or are tube guitar amps made
different/cheaper and cover less of a range with less accuracy say 60 Hz
to 15,000 Hz +/- 3dB ??? I've been looking for specs but they don't
seem to list them.
Anonymous
May 29, 2005 11:42:15 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

NGS wrote:

>Do the power amps in tube combos cover 20 Hz to 20,000 Hz like home
>stereo tube amplifiers +/- 1 dB or are tube guitar amps made
>different/cheaper and cover less of a range with less accuracy say 60 Hz
>to 15,000 Hz +/- 3dB ???

Guitar amplifiers are used to produce rather than to reproduce sound and
accuracy is therefore not a concern. They may or may not cover the entire
audible frequency range and they may or may not be flat within the range
that they cover depending on the intended application. Noise and distortion
performance may similarly vary.

> I've been looking for specs but they don't
>seem to list them.

That's because those who purchase guitar amplifers choose them based on
the sound they can produce as part of a guitar/amplifier/speaker system
rather than on specs.

--
========================================================================
Michael Kesti | "And like, one and one don't make
| two, one and one make one."
mrkesti at comcast dot net | - The Who, Bargain
Anonymous
May 29, 2005 11:42:16 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

"Guitar amplifiers are used to produce rather than to reproduce sound
and
accuracy is therefore not a concern"

I would say this instead. Audio amps and PA systems that are used to
amplify music or any sounds from a source material that is already
produced are very dependant on predictable frequency response. When a
producer mixes an audio CD or a film editor makes the final edits on a
film they use what are known as "studio monitors". The expectation is
that these monitors are going to amplify the sounds with very little to
zero deviance. This is called "flat frequency response".

In home or industrial amplifiers and speakers, the closer the system
comes to the studio monitors, the closer the sound will be to the
producer or director's artistic vision. Also, for sound effects in film
to be highly realistic, the same level of precision is needed.

Contrast that with guitar or bass amps (by the way the ideal acoustic
guitar, keyboard, anyything with a microphone and PA amps are more like
audio gear and SHOULD be reviewed for precision before investing). The
reasons are that guitar amps more than any other are expected to not
only derive character from the distortion, but most importantly are
expected derive their tonal character from the voicing of the amp and
speaker combination. In fact, the term "voicing" means the unique (as
opposed to predictable or flat) frequency response of these systems. If
you want to get an idea on how this works, plug a CD player in to your
guitar's input of your amp. Compare the guitar input with an aux. input
if you have a chance and the difference will indicate how much the
preamp contributes to the voicing of your system. You can also
carefully connect a home audio speaker to your guitar amp and see how
much the speaker contributes to the voice or character. If you do, you
will see just how much brighter the home audio speaker is. That means
that the frequency response of guitar speakers starts to taper off very
dramatically. Wel think about it. Have you ever seen a 12" woofer in a
home audio system that did not have at least one other driver to handle
the higher freqs? Shoot, even with 1 or 2 more drivers it is hard to
build a speaker system for home audio that has a nice flat freq
response. The 8" - 12" speakers that are in virtually all guitar
systems use are more at home in the very lowest range that we call
"subwoofer" range. I have an 8" subwoofer to handle the lowest special
effects for films and I also have a practice amp with an 8" speaker
that sounds if anything a little bright compared to 12" systems.
Anyhow, if you have a chance to use a (audio) spectrum analyzer you
will see what I am talking about.

To wrap it up, the reason you only get to see the power (which is a max
rating BTW) is that none of the other numbers would make sense to most
people, especially of you wanted to compare one to the other! You might
end up heading away from what you really want. That is why modeling
amps are popular, because amp and speaker voices are so unique that the
only way anyone can even hope to get a sense for what it will sound
like is to compare it with something you already know.

Finally, DO look at performance numbers for any amp that I have
indicated as having "clean and flat" as the ideal freq. response. If
you need a PA or keyboard amp, brng a CD player with the right cords to
preview the amp and that the the best indicator other than playing it
as it will be used, including the volume.
Related resources
May 30, 2005 12:54:39 AM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

There wouldn't be much point in having the 20-20000hz range for a
guitar or bass amplifier. I mean, I have yet to hear a guitar produce
a note approaching the 20000hz range. The same for the bass end. What
is the point in having equipment produce the range of frequencies when
you won't ever be able to produce them? It would be a waste of
engineering and money.
Anonymous
May 30, 2005 3:15:59 AM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Actually the base note is not the only frequency heard. If what you say
was true, then nobody would ever notice when treble adjustments were
made. Harmonics are always a factor in guitar music and most sounds
have what are called "overtones". A rig with 20 - 20 k *flat* sounds
very bright relative to a typically voiced guitar rig. You *will*
notice if you try. It is preferred for acoustic guitar by the way.
May 30, 2005 5:06:07 AM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

"Ginger" <gingerjoyce@gmail.com> wrote in message
news:1117425279.659660.71980@f14g2000cwb.googlegroups.com...
> There wouldn't be much point in having the 20-20000hz range for a
> guitar or bass amplifier. I mean, I have yet to hear a guitar produce
> a note approaching the 20000hz range. The same for the bass end. What
> is the point in having equipment produce the range of frequencies when
> you won't ever be able to produce them? It would be a waste of
> engineering and money.

But a musical tone is much more than just the frequency of the note.
Musical instruments rarely produce pure sine waves. A piano or guitar
hitting, for instance, 880 Hz, will produce a complex waveform with
components at much higher frequencies. From 880 Hz to 14080 Hz is only 4
octaves.
May 30, 2005 8:03:17 AM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

with 20hz being the lowest end of human hearing and 20,000 the highest,
a guitar is not capable of producing those frequencies. You're open A
string is at 440hz, still nowhere near 20kz.

If you are not producing frequencies that low, or high, then you won't
notice it. Perhaps the speaker cones that they use for systems capable
of reproducing sounds between 20-20,000hz are not constructed using the
same materials.
Anonymous
May 30, 2005 2:34:44 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Right, I missed that one. Not the open A, the 5th fret on the high E is
440!!!

Dang, everything said was false.
Anonymous
May 30, 2005 3:55:45 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

>OK, the main thing I want to say is that you are absolutely
>wrong in stating that 20 - 20k is the range of the human ear.

Can we assume that since you state this with such conviction
that you are able to back this rather interesting claim up
with some fact?

>You have to be joking to post something like that. You know,
>newsgroups lose their value when people post statements like
>that when in reality that is merely your mistaken impression
>and yet someone might read that and take it as a fact.

Yes, you're right. That's why some newsgroups are moderated: to
keep yahoos like you from post the sort of ill-informed claptrap
that you are posting.

>Maybe that is how you got the idea (by reading it from another
>article). The human ear is FAR FAR more limited than 20 -
>20K!!!

Fine, you now stated it, now it's time to back up your claim
with something other than your clearly isinformed opinion, sir.

>There are plenty of excellent speaker systems that do not
>approach that response and you will never know because not only
>can your ear not hear that low or that high, but no music is ever
>recorded that low or high!

Not only are your claims here completely wrong, they are utterly
irrelevant.

>Until CDs came along, the software mediums were not even capable
>of that range!

Wrong, totally, completely utterly wrong. I have a 33 year old
Revox A-77 tape recorder that at 15 IPS measures 16 Hz to 22 kHz
+-2 dB. This was for a machine that was considered an "advanced
amateur" class machine.

>Do a bit of web surfing on a medical sight or perhaps a hearing
>aid site and you will get a better idea on what the ear can detect.

Clearly, if this is how YOU got YOUR information, this is really
bad advice.

>I am not aware of any animals that can even hear that high.
>I might be wrong but I know for certain humans can't.

Well, actually, you ARE wrong. Are you aware, for example, that
bats do echo location at frequencies far in excess of 20 kHz?
Or did you treasured medical and hearing aid websites not happen
to have that information.

>Please don't post your (likely erroneous) opinion about something
>that is fact.

It would very much be in your best interests to listen to your own
advice, kind sir.

As a point of fact, the range of human hearing had been a subject of
fairly intense research dataing back well over 100 years. There is
a tremendous amount of literature on the topic which you clearly
are either unaware of or have ignored, much to your deteriment.

Consider as far back as 1862 with H. Helmholtz's treatise, "The
Sensation of Tone." From there we then find the extensive amount
of quantative resarch performed at Bell Laboratories in the 1920's,
1930's and later, by notables such as Messrs Fletcher, Munson and
others, all easily available in simple literature searches. The
20-20 Khz range is quoted and verifed by any number of authors
and researches on the topic, e.g., Beranek (1954), Hirsch (1952),
and many, many others.

Yet you come by and state, contrary to an enormous volume of
research, that their data is wrong. How convenient it must be
to be able to be so cock cure of your "facts" without putting
in any of the hard work that these many practioners have expended
reach their conclusions.

Yeah, usenet newsgroups are often a joke, filled as they are
with uninformed opinion presented as "fact", and it's posts
just such as yours that make it the wasteland it is.

Go away, learn something real, and then come back, sire.
May 30, 2005 5:22:07 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Ummm, I studied and working in health care for a while and 20-20khz is
the "textbook" range of human hearing. Here is a quick link:
http://www.antonine-education.co.uk/Physics_A2/Options/...

There is a lot out there on hearing frequencies.

Yes, you lose hearing range as you age, but who didn't know that? How
many jokes are made about it. What is actually funny is that women
tend to lose the lower frequencies first as they age and men lose the
higher frequencies as they age. So, with men's voices having more
bass, and women's having more treble, it's no wonder that old people
argue. They can't hear each other properly.

One of the things that I like about the forums is that everyone can
slap up their own opinions, questions, answers, and experiences. Those
are things that I think that everyone can draw from and better
themselves. If someone is wrong in their facts, it's a lot better to
point them in a direction so that they can correct themself.
.......barring that does not work then ridicule them and give 'em a kick
in pants with a hob-nailed boot :) 
Anonymous
May 30, 2005 6:43:36 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

NGS wrote:

> Do the power amps in tube combos cover 20 Hz to 20,000 Hz like home
> stereo tube amplifiers +/- 1 dB or are tube guitar amps made
> different/cheaper and cover less of a range with less accuracy say 60 Hz
> to 15,000 Hz +/- 3dB ??? I've been looking for specs but they don't
> seem to list them.

It depends. Guitar amps aren't really designed to be flat across the
audible range. Most manufacturers don't give those type of specs, but
my Peavey 60/60 is rated +0/-3dB, 40Hz - 20 kHz.
Anonymous
May 30, 2005 6:46:12 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

I see in the text where that is stated (your numbers 20 - 20K) and I
see in their graphs and other statements from what I assume is their
source material that are contradictory. Maybe the statement you are
using for your source is a theoretical range. I have never heard of any
human that can detect sounds in that range. Age and other factors come
in to play, but the human ear can't hear changes above about 14K. I
don't recall if humans can hear an isolated tone above that range but I
think not. It could be that sensitivity drops off acutely 12+ db), I
just don't recall all of the details. In the context of this
discussion (sound reproduction) that means people can't tell the
difference between a sound system that can reproduce music only up to
14K vs. another that can reproduce sound up to 20K. I wish I had web
sources to point to, but my research predates the www popularity.

At least you have used what one can consider to be a legitimate source.
I thought you assumed based on typical audio specs since I have neaver
heard anyone claim what you have. I apologize.
Anonymous
May 30, 2005 6:46:43 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Chris M wrote:

> Actually the base note is not the only frequency heard. If what you say
> was true, then nobody would ever notice when treble adjustments were
> made. Harmonics are always a factor in guitar music and most sounds
> have what are called "overtones". A rig with 20 - 20 k *flat* sounds
> very bright relative to a typically voiced guitar rig. You *will*
> notice if you try. It is preferred for acoustic guitar by the way.

The speaker is generally the deciding factor in high frequency
reproduction, not the amplifier. Most guitar speakers don't do much
above 5 kHz.
Anonymous
May 30, 2005 6:49:44 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Ginger wrote:

> with 20hz being the lowest end of human hearing and 20,000 the highest,
> a guitar is not capable of producing those frequencies. You're open A
> string is at 440hz,

The fundamental frequency of an open low E is around 82Hz, even though
the harmonics are really more important.

still nowhere near 20kz.
>
> If you are not producing frequencies that low, or high, then you won't
> notice it. Perhaps the speaker cones that they use for systems capable
> of reproducing sounds between 20-20,000hz are not constructed using the
> same materials.

It's DESIGN. A driver designed to reproduce 20 Hz (and not many really
do) is usually very inefficient and has a LONG throw with rather loose
suspension. NOT good for guitar, with all of the dynamic range. Guitar
speakers are stiffer and more efficient, and many don't do much below
100 Hz.
Anonymous
May 30, 2005 7:23:36 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Chris M wrote:
> I see in the text where that is stated (your numbers 20 - 20K) and I
> see in their graphs and other statements from what I assume is their
> source material that are contradictory. Maybe the statement you are
> using for your source is a theoretical range. I have never heard of any
> human that can detect sounds in that range. Age and other factors come
> in to play, but the human ear can't hear changes above about 14K.

I guess I'm not human, then.

I
> don't recall if humans can hear an isolated tone above that range but I
> think not. It could be that sensitivity drops off acutely 12+ db), I
> just don't recall all of the details. In the context of this
> discussion (sound reproduction) that means people can't tell the
> difference between a sound system that can reproduce music only up to
> 14K vs. another that can reproduce sound up to 20K. I wish I had web
> sources to point to, but my research predates the www popularity.
>
> At least you have used what one can consider to be a legitimate source.
> I thought you assumed based on typical audio specs since I have neaver
> heard anyone claim what you have. I apologize.
>
May 30, 2005 7:25:53 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Ginger wrote:
> You're open A
> string is at 440hz,

You're a couple of octaves to high.
The fundamental of an open A string on a guitar is 110 Hz.
That doesn't mean you don't have to reproduce higher frequencies though.

Most guitar speakers will start to seriously drop off somewhere between
5 and 7 KHz. The amplifiers will usually easily exceed that by quite a
large margin.

Sander
Anonymous
May 30, 2005 8:33:15 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Chris M further intoned:
>I see in the text where that is stated (your numbers 20 - 20K) and
>I see in their graphs and other statements from what I assume is
>their source material that are contradictory. Maybe the statement
>you are using for your source is a theoretical range. I have never
>heard of any human that can detect sounds in that range.

Yes, that much is clear, you have NOT heard of such because you
haven't done the research.

>Age and
>other factors come in to play, but the human ear can't hear changes
>above about 14K.

You have made a very specific, unambiguous assertion here, one
which is testable and in fact contradicted by research performed
on a large number of subjects.

>I don't recall if humans can hear an isolated tone above that
>range but I think not.

So, explain to us then, how is this statement any better than the
ones you criticize? You don't know, you don't recall, but you think
not.

>I wish I had web sources to point to, but my research predates the
>www popularity.

How about REAL sources, as I pointed out earlier?

You are, in fact, no better than those you would criticize.

>At least you have used what one can consider to be a legitimate
>source.

What is the "loegitimate source" for YOUR claims, sir?
May 30, 2005 10:54:20 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Sometimes the ballasts used in flourescent lighting can create an
interference frequency with other electrical systems. The typical
store/building ballasts use some weird voltag. I can't remember the
exact voltage, but it has to do with a delta-transformer that they use
to take power off the main grid for the building. In your house they
use a different type of transformer (usually for the neighbourhood or
groups of houses). The voltage comes in off of one of the phases so it
makes it easy to route the power directly.

Because of the higher voltage they can create fields which interfere
with other equipment (like the PA systems in the ceilings). It could
be from that. It's just a guess.
Anonymous
May 30, 2005 11:24:37 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Ginger wrote:
> Sometimes the ballasts used in flourescent lighting can create an
> interference frequency with other electrical systems. The typical
> store/building ballasts use some weird voltag. I can't remember the
> exact voltage, but it has to do with a delta-transformer that they use
> to take power off the main grid for the building. In your house they
> use a different type of transformer (usually for the neighbourhood or
> groups of houses). The voltage comes in off of one of the phases so it
> makes it easy to route the power directly.
>
> Because of the higher voltage they can create fields which interfere
> with other equipment (like the PA systems in the ceilings). It could
> be from that. It's just a guess.

Whatever it was, I couldn't stand to be in that store. ...and other
people thought I was nuts, because they could not hear it.
Anonymous
May 31, 2005 2:05:55 AM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

I did QA testing of consumer audio gear (among other stuff). We had
labs where we did hearing tests too, to determine the hearing function
of the people doing QA. You learn lots of things in QA but you can't
always publish it. Normally you can't.

I don't think anyone that has ever had a hearing test would disagree
with me. Has anyone here had a hearing test that determined that they
were able hear tones above 15K? I thought those tests were common but
maybe not. So far everyone seems to either think they can or can't but
nobody aside from me know whether they themselves hear test tones in
this range.

That will settle it for me.
Anonymous
May 31, 2005 7:55:58 AM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Chris M. pontificated:
>I did QA testing of consumer audio gear (among other stuff). We
>had labs where we did hearing tests too, to determine the hearing
>function of the people doing QA.

So, in other words, you have no data, you did no research, you
possibly had a bottom-of-the-food-chain job doing QA on consumer
audio gear. That hardly qualifies, my friend, as research.

>You learn lots of things in QA
>but you can't always publish it. Normally you can't.

So, you did secret "research" but your forbidden to talk about it.
What a lame excuse that is.

>I don't think anyone that has ever had a hearing test would
>disagree with me.

A number of people did: I provided you with the specific references,
e.g., Hrisch, Fletcher, Munson and a number of others.

>Has anyone here had a hearing test that determined that they
>were able hear tones above 15K?

Yes, numerous people have, including the researchers I pointed out.

>I thought those tests were common but maybe not.

You "thought?" I thought you claimed you did "research." Now
you're saying you "thought." This is PRECISELY the arrogant
position you started this whole discussion with.

Most audiometric tests don't have the ability to test above 12kHz
to 15 kHz for a variety of reasons. Hearing above even 8 kHz is not
necessary for basic speech articulation, which is what most of the
tests are designed to measure. No common audimetric tests are designed
to measure high-frequency acuity, so they don't. Further, testing
extended bandwidth takes time and thus costs more, and these tests
are designed to cover as many people in as little time as possible.

>So far everyone seems to either think they can or can't but
>nobody aside from me know whether they themselves hear test
>tones in this range.

So if YOU don't know it, it doesn't exist?

>That will settle it for me.

You don't seem to get it. No one gives a rat's ass if it's been
settled for you. The research has been done and in place for
decades that says you're claims are just plain wrong. If you care
to cling to your viewpoint despite volumes of actual research to
the contrary you're certainly entitled to you ill-informed opinion.
But stop passing you drivvle of as fact. More importantly, stop
passing it off as fact and then ccomplaining about other people
passing there (better) informed opinion off as fact.

Face it: like it or not, your opinion about the range of human
auditory acuity is ill-informed and poorly supported. Your
description of what you originally termed as "research" is
laughable anecdote at best. Your reliance on "www resources" is
most telling.
Anonymous
May 31, 2005 1:26:40 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Chris M wrote:
> I see in the text where that is stated (your numbers 20 -
20K) and I
> see in their graphs and other statements from what I
assume is their
> source material that are contradictory. Maybe the
statement you are
> using for your source is a theoretical range. I have never
heard of
> any human that can detect sounds in that range. Age and
other factors
> come in to play, but the human ear can't hear changes
above about
> 14K.

Depends on what you mean by "changes". Humans, particularly
younger ones with undamaged hearing, can clearly hear pure
tones all by themselves, at frequencies higher than 14 KHz.
OTOH, hearing the reduction, or an increase in the
proportioning of frequencies above 14 KHz can be
surprisingly difficult for anybody of any age. I would put
the frequency for "can't hear a difference" at more like 15
or 16 Khz but that's splitting hairs a bit.

> I don't recall if humans can hear an isolated tone above
that
> range but I think not.

I know so.

>It could be that sensitivity drops off acutely
> 12+ db),

That, too.

>I just don't recall all of the details. In the context of
> this discussion (sound reproduction) that means people
can't tell the
> difference between a sound system that can reproduce music
only up to
> 14K vs. another that can reproduce sound up to 20K.

Change 14K to 16K and then I agree for sure. I now for sure
that in a clean audio system, applying a brick wall filter
at 14,15,16K or so basically makes no difference.

However, there's a lot of ambiguity in human expression, so
some people get confused between putting in a precise brick
wall filter, and a typical analog filter that cuts at
frequencies well below the design frequency.
May 31, 2005 2:07:25 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Thanks Steve. I couldn't remember the voltages coming out of the three
phases. It was quite a few years ago that I did some power theory
courses. The courses were interesting, but I never did even get to see
a delta transformer. It's hard to remember details when you only read
them and don't put them into practice. Thanks.
Anonymous
May 31, 2005 2:41:41 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Chris M wrote:

> I did QA testing of consumer audio gear (among other stuff). We had
> labs where we did hearing tests too, to determine the hearing function
> of the people doing QA. You learn lots of things in QA but you can't
> always publish it. Normally you can't.
>
> I don't think anyone that has ever had a hearing test would disagree
> with me. Has anyone here had a hearing test that determined that they
> were able hear tones above 15K? I thought those tests were common but
> maybe not. So far everyone seems to either think they can or can't but
> nobody aside from me know whether they themselves hear test tones in
> this range.
>
> That will settle it for me.

Chris, I STILL get bothered by the flyback on one of my TV's. That's
after playing Marshalls WAY TOO LOUD.

Yes, humans can hear above 15k. As we age, high frequencies get attenuated.

I read one audio-fool test that claimed that when they attenuated
frequencies around 16 to 20k, people perceived a dullness of sound.
Some people claim that ABOVE 20k makes a difference. To them, I say
"maybe to your dog..."

I have a CD that does a full sweep from 20 to 20k. I loose the tone
before the end, but that could be in part due to a roll off on the horn
tweeters that I was using at the time (I'm now using the 360 degree
linaeum type for home theater, at that time, it was my Klipshorn home
brews). But they were reproducing something, because my dog would go
NUTZ in the 18 to 20kHz range! Probably because that is not a very
common frequency in nature, and is mostly faint upper harmonics in music.
Anonymous
May 31, 2005 4:15:03 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

LOL, I am sure you already made money for them on licensing. Do I
remember a year ago? I think so. Don't worry, I have a life. If
anything, that is my problem here in trying to pound out a few
statements between everything else. It's funny because people attack
others for spelling errors (not you obviously) and then say "get a
life". Oh well, Usenet has its own culture and I am glad I don't really
belong. I thought I already had apologized to you for what I said.
Maybe if I have more time (and when you have a few beers and forget it
was me that was rude to you) then I can explain what my point was and
and why I said what I did about human ear performance. If it is 20 -
20K then not only was I not aware but I still do not know how that fact
is more relevant that what I was trying to say. Really quickly, I will
say that I wanted to make the point that specs can be misleading and
they can lead to concern about performance at the higher end (above
about 15K) that humans can't discern. Maybe they can hear it at very
high (or much higher) levels, I don't know. I just remember test tones
with headphones and people failed to hear the tones above 15K. I took
the test too with the similar results.

Thanks for the URLs but I really don't even have time or interest to
read those. I think I will just back off this thread since I don't see
it becoming productive again for now (my fault I realize). Funny you
say that about my mom. Of course this was 20 years ago but when I was
growing up (as a teen) I lived in a house on a hill and my brother and
I had bedrooms downstairs from the street level (since the second level
went down the hill). There was a large open area (not a basement
though) where my gear was set up and I played guitar amd jammed with a
few others. I was just telling this to someone that was asking about my
first years playing guitar but I don't think I posted it here? You are
just saying that as a random insult aren't you? Anyway, I am outa here
for now. The sumemr is here and I am not gonna stay inside when I can
have lunch outdoors.
Anonymous
May 31, 2005 6:29:03 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

On 30 May 2005 18:54:20 -0700, "Ginger" <gingerjoyce@gmail.com> wrote:

>Sometimes the ballasts used in flourescent lighting can create an
>interference frequency with other electrical systems. The typical
>store/building ballasts use some weird voltag. I can't remember the
>exact voltage, but it has to do with a delta-transformer that they use
>to take power off the main grid for the building. In your house they
>use a different type of transformer (usually for the neighbourhood or
>groups of houses). The voltage comes in off of one of the phases so it
>makes it easy to route the power directly.
Its 277V and it is only in buildings with 480V WYE feeds.
These ballasts may incorporate power factor corection, where the net
power factor of the fixture is 0.

, _
, | \ MKA: Steve Urbach
, | )erek No JUNK in my email please
, ____|_/ragonsclaw dragonsclawJUNK@JUNKmindspring.com
, / / / Running United Devices "Cure For Cancer" Project 24/7 Have you helped? http://www.grid.org
Anonymous
May 31, 2005 6:34:23 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

On 30 May 2005 18:54:20 -0700, "Ginger" <gingerjoyce@gmail.com> wrote:

>Because of the higher voltage they can create fields which interfere
>with other equipment (like the PA systems in the ceilings). It could
>be from that. It's just a guess.

Ultrasonic motion detectors, (they were LOUD) for secutity systems.

They were also used at some trafic light turn lanes (oval assembly on
a arm with 2 "eyes". They Pulsed High Freq sound. Beep,Beep,...


, _
, | \ MKA: Steve Urbach
, | )erek No JUNK in my email please
, ____|_/ragonsclaw dragonsclawJUNK@JUNKmindspring.com
, / / / Running United Devices "Cure For Cancer" Project 24/7 Have you helped? http://www.grid.org
Anonymous
May 31, 2005 6:34:24 PM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

Steve Urbach wrote:

> On 30 May 2005 18:54:20 -0700, "Ginger" <gingerjoyce@gmail.com> wrote:
>
>
>>Because of the higher voltage they can create fields which interfere
>>with other equipment (like the PA systems in the ceilings). It could
>>be from that. It's just a guess.
>
>
> Ultrasonic motion detectors, (they were LOUD) for secutity systems.

That was my suspicion, also. My sister actually WORKED at the store for
a while. I couldn't stand it. But no other stores at the same mall had
that problem. This was late 70's, early 80's.
Anonymous
June 1, 2005 12:37:16 AM

Archived from groups: alt.guitar,rec.audio.tech (More info?)

On 31 May 2005 10:07:25 -0700, "Ginger" <gingerjoyce@gmail.com> wrote:

>Thanks Steve. I couldn't remember the voltages coming out of the three
>phases. It was quite a few years ago that I did some power theory
>courses. The courses were interesting, but I never did even get to see
>a delta transformer.
Draw a triangle of 3 inductors (transformer windings), (Option: center
tap on one, connected to common/ground bus). Variation: Open Delta,
leave one of the non tapped windings out. The last phase phantoms
itself and should only be used for light (percentage of load) 3 phase
loading.

Wye: the windings look like a Y with the junction connected to
common/ground.

>It's hard to remember details when you only read
>them and don't put them into practice. Thanks.

, _
, | \ MKA: Steve Urbach
, | )erek No JUNK in my email please
, ____|_/ragonsclaw dragonsclawJUNK@JUNKmindspring.com
, / / / Running United Devices "Cure For Cancer" Project 24/7 Have you helped? http://www.grid.org
!