[Peter Larsen]

Bret Ludwig wrote:

I would like to add to this.

Thank you for so doing. I do not understand why those guys would want to
have 2 10" units side by side instead of using just one and a short
horn. If they want two 10" units it would make more sense to build a
d'Appolito type top box for wall or corner mounting.

http://home.comcast.net/~wooferboy/Page_3.html


Peter Larsen

[Steven Sullivan]

Eeyore wrote:


Randy Yates wrote:

Eeyore writes:
Randy Yates wrote:
Eeyore writes:
Randy Yates wrote:
Eeyore writes:
Randy Yates wrote:

I don't know a lot of moderately-priced 400-watt per
channel amplifiers, do you?

Look at pro-audio amplifiers. They're two-a-penny.

For example?

http://www.thomann.de/gb/behringer_e...r_endstufe.htm

Fair enough. So if you buy one of these and want to play at
the levels discussed, you'd be coming damn close to clipping.

So ?

I'm sorry, Eeyore - I assumed you were familiar with music dynamics
and their interaction with reproduction equipment at these levels.

I'm *very* familiar with musical dynamics. You might be surprised how little
there is in much modern 'pop' music btw and especially 'dance' music.

To paraphrase Ian Gillian of Deep Purple (which used to hold the Guinness world
record for loudest band) today it's 'everything louder than everything else'


___
-S
"As human beings, we understand the world through simile, analogy,
metaphor, narrative and, sometimes, claymation." - B. Mason

[Steven Sullivan]

Karl Uppiano wrote:

"Randy Yates" wrote in message
...
"Karl Uppiano" writes:
[...]
I wonder what would be a good replacement for my aging DIY ElectroVoice
SP12B-based building-block speakers, at the sub-$5000.00 price point.

Karl, why don't you simply get out and do some listening? (Klipschorn
or otherwise) Regardless of what is said here, your ears should be the
final judge.

Partly because there are no decent audio outlets within 100 miles of here. I
want to have some things in mind before I hike all the way to Seattle or
Vancouver B.C. All we have around here is Circuit City and Best Buy. The
merchandise in there is a joke, and the listening environment is worse.


I'm skeptical of in-store auditions anyway -- there's a signficiant element
of crapshoot there, since the room acoustics, not to mention placement of
speakers, will certainly be different from yours at home.

Have you investigated the higher end of the JBL family (JBL, Infinity, Revel)? AIUI, they
have Floyd Toole's research behind them, and that's pretty much the state of the art for
consumer loudsepeakers these days as far as relating speaker and room measurements to
perception of quality.


___
-S
"As human beings, we understand the world through simile, analogy,
metaphor, narrative and, sometimes, claymation." - B. Mason

[Arny Krueger]

"isw" wrote in message

In article ,
"Arny Krueger" wrote:

"Randy Yates" wrote in message

"Trevor Wilson"
writes:

"Randy Yates" wrote in message
...
Peter Larsen writes:


Really? Why is it then that when Audio magazine
reviewed the Klipshorn's some decades ago, they
attained of the lowest distortion measurements in the
low frequencies ever?

**Because it was 30 years ago.

Actually, it was about 1989 or so, if memory serves.

By then the bell had already tolled for Klipsch horn
technology.

The rest of us have moved on. There are MUCH lower
distortion products available, at lower cost and in a
much smaller package.

For example?

I suspect that one of these in an appropriate box with
appropriate amplification and equalization could do
everything that a Klipschorn could do, and not even have
to catch its figurative breath:

http://www.adireaudio.com/Home/TumultSeries.htm (15D4)

http://mobile.jlaudio.com/products_s...p?series_id=10

http://www.mtxaudio.com/caraudio/pro...hunder9500.cfm

http://www.tcsounds.com/lms4000.htm

Do you think that any of them could deliver a sustained
125+dBc level at two meters in a domestic environment,
driven by, say, Bach Organ material, and do it without
noticeable clipping or distortion?

Yes, no sweat. Organ music is pretty tame by modern standards. Most of the
energy is in the harmonics. The lowest fundamental is above 30 Hz.

If you want to stress a subwoofer, try hip-hop music. BTW, I'm serious.

A single K-Horn can (I measured it, years ago, with a GR SPL box and
calibrated
mic). Then I compared that to the same material on an
AR-3, which barely made 95dB before the cone hit the
stops -- audibly.

These modern drivers aren't anything like AR-3 drivers. As I recall, the
original AR-3 driver had less than 5 mm Xmax. That was half-a-century ago
technology.

Not saying that you'd *want* to do that, but you said "do everything".

[Trevor Wilson]

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:

**Pretty much any decent, modern subwoofer.

Trevor, forgive me for not taking your word for it. I was looking for
a specific review of a specific speaker that measured this sort of the
thing.

And a subwoofer isn't really a fair comparison. Give me a full-range
system that performs MUCH better (which would mean 1% THD at 41 Hz
or so).

**How about the 20 year old Duntech Sovereign? Good enough? Best of
all,
you
get:

* Relative independence of room location (compared to the K-Horns)
* Relative independence of room size.
* A good HF response.
* Excellent time alignment.

Yes, these DO look marvelous. Thanks for the reference. How much are
they? I'm thinking we're in the $50,000 range.

**Back in 1987, they were about US$12,000.00, here in Australia. The
current
model is probably US$50k. Nonetheless, I figured you'd want a 20 year old
reference.

Why would you figure such a thing?

**Because the K-Horn is an ancient design. Why compare it to modern systems,
which possess such clear advantages?

Your assertion was that "any
decent, modern subwoofer" would have good low-frequency distortion
performance. To give an example that is out of reach for practically
every one of us is not exactly "any decent" speaker.

**OK, then. A Klipsch Forte' or Forte' II then. Both systems offer clear and
unequivocal advantages over the K-Horn. Both were significantly less
expensive too.


**What more do you want?

If your assertion is true, and you are as up on speaker design as
you want us to think, then I would think that you could rattle
off any of a number of "modern" speakers (not just the ones
in the stratosphere of $50,000) that prove your point.

**The Klipsch Forte' and Forte' II.


--
Trevor Wilson
www.rageaudio.com.au



--
Posted via a free Usenet account from http://www.teranews.com

[Randy Yates]

"Trevor Wilson" writes:
[...]
**The Klipsch Forte' and Forte' II.

What is their low-frequency distortion? I noticed that Stereophile does
not publish these numbers in their reviews, and Audio Magazine (which
used to) has long been defunct. How do you know what their distortion
is?

And "I just know" or somesuch bull**** won't cut it. Back your claims
or they will be considered invalid.
--
% Randy Yates % "I met someone who looks alot like you,
%% Fuquay-Varina, NC % she does the things you do,
%%% 919-577-9882 % but she is an IBM."
%%%% % 'Yours Truly, 2095', *Time*, ELO
http://home.earthlink.net/~yatescr

[Trevor Wilson]

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:
[...]
**The Klipsch Forte' and Forte' II.

What is their low-frequency distortion?

**I don't know.

I noticed that Stereophile does
not publish these numbers in their reviews, and Audio Magazine (which
used to) has long been defunct. How do you know what their distortion
is?

**I don't. Why are you preoccupied with distortion (at what frequency?),
when the K-Horn has far more serious and obvious flaws? THD is ONE facet of
a speaker's performance which is relevant. There are others. Some of them
(like frequency linearity) are more important. Others are important to some
listeners (like time alignment). The K-Horn is particularly bad at both
these performance parameters. If you want low distortion, then other
products (electrostatics, for instance) can provide very low distortion over
quite a wide frequency range. No tine alignment problems either.


And "I just know" or somesuch bull**** won't cut it. Back your claims
or they will be considered invalid.

**What claims? That K-Horns have serious problems? I've already outlined
those problems and why they occur. You can measure them if you wish.

The bottom line is this: The K-Horn achieves high efficiency in a modest
package. To do this, sacrifices have been made. Those sacrifices are too
great for most listeners.


--
Trevor Wilson
www.rageaudio.com.au



--
Posted via a free Usenet account from http://www.teranews.com

[Randy Yates]

"Trevor Wilson" writes:

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:
[...]
**The Klipsch Forte' and Forte' II.

What is their low-frequency distortion?

**I don't know.

I noticed that Stereophile does
not publish these numbers in their reviews, and Audio Magazine (which
used to) has long been defunct. How do you know what their distortion
is?

**I don't. Why are you preoccupied with distortion (at what frequency?),
when the K-Horn has far more serious and obvious flaws?

If low-frequency distorion isn't that significant, then why did
you spend the energy to attempt to refute it?

In my opinion the K-Horns have had two significant advantages over
other speakers: high efficiency and "accurate" bass.

I've always liked the sound of the K-Horns' bass over other
speakers. When the Audio review revealed their low low-frequency
distortion, I figured this was a good part of the reason.

The bottom line is this: The K-Horn achieves high efficiency in a modest
package. To do this, sacrifices have been made. Those sacrifices are too
great for most listeners.

I claim, lacking any hard evidence to the contrary, that another one
of their advantages is low low-frequency distortion. If this advantage
has been neutralized by modern speaker technology (and as yet I
haven't seen this to be the case), then that is a significant
mitigation of the K-Horn advantage.
--
% Randy Yates % "Bird, on the wing,
%% Fuquay-Varina, NC % goes floating by
%%% 919-577-9882 % but there's a teardrop in his eye..."
%%%% % 'One Summer Dream', *Face The Music*, ELO
http://home.earthlink.net/~yatescr

[Randy Yates]

"Trevor Wilson" writes:
[...]
(at what frequency?),

I believe the lowest frequency measured in the old Audio magazine reviews
was 41.5 Hz.
--
% Randy Yates % "Watching all the days go by...
%% Fuquay-Varina, NC % Who are you and who am I?"
%%% 919-577-9882 % 'Mission (A World Record)',
%%%% % *A New World Record*, ELO
http://home.earthlink.net/~yatescr

[Trevor Wilson]

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:
[...]
**The Klipsch Forte' and Forte' II.

What is their low-frequency distortion?

**I don't know.

I noticed that Stereophile does
not publish these numbers in their reviews, and Audio Magazine (which
used to) has long been defunct. How do you know what their distortion
is?

**I don't. Why are you preoccupied with distortion (at what frequency?),
when the K-Horn has far more serious and obvious flaws?

If low-frequency distorion isn't that significant, then why did
you spend the energy to attempt to refute it?

**Non-sequitur. I never attempted to refute it.


In my opinion the K-Horns have had two significant advantages over
other speakers: high efficiency and "accurate" bass.

**You're entitled to your opinion. In fact, they have ONE advantage: High
efficiency. 33Hz @ 4dB is not super accurate. Moreover, in order to gain
that efficiency, in a small package, very serious compromises have been made
in the most critical part of the human hearing spectrum.


I've always liked the sound of the K-Horns' bass over other
speakers.

**I am not discounting your opinion. I am dealing in facts.

When the Audio review revealed their low low-frequency
distortion, I figured this was a good part of the reason.

**You may or may not be correct. It would depend on how many speakers you've
compared the K-Horns to, in your room.


The bottom line is this: The K-Horn achieves high efficiency in a modest
package. To do this, sacrifices have been made. Those sacrifices are too
great for most listeners.

I claim, lacking any hard evidence to the contrary, that another one
of their advantages is low low-frequency distortion.

**You can keep banging away obout LF distortion all you wish. More serious
audible problems occur at higher frequencies, when the human ear is most
sensitive.

If this advantage
has been neutralized by modern speaker technology (and as yet I
haven't seen this to be the case), then that is a significant
mitigation of the K-Horn advantage.

**It HAS been mitigated by more modern designs. Those designs do not share
the serious problems which afflict the K-Horns.


--
Trevor Wilson
www.rageaudio.com.au



--
Posted via a free Usenet account from http://www.teranews.com

[Randy Yates]

"Trevor Wilson" writes:

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:
[...]
**The Klipsch Forte' and Forte' II.

What is their low-frequency distortion?

**I don't know.

I noticed that Stereophile does
not publish these numbers in their reviews, and Audio Magazine (which
used to) has long been defunct. How do you know what their distortion
is?

**I don't. Why are you preoccupied with distortion (at what frequency?),
when the K-Horn has far more serious and obvious flaws?

If low-frequency distorion isn't that significant, then why did
you spend the energy to attempt to refute it?

**Non-sequitur. I never attempted to refute it.

You're either very forgetful or a liar:

"Randy Yates" wrote in message
...
Peter Larsen writes:


Really? Why is it then that when Audio magazine reviewed the
Klipshorn's some decades ago, they attained of the lowest distortion
measurements in the low frequencies ever?

**Because it was 30 years ago. The rest of us have moved on. There are MUCH
lower distortion products available, at lower cost and in a much smaller
package.


--
Trevor Wilson
www.rageaudio.com.au


--Still waiting for the "much lower distortion products."

--
% Randy Yates % "Ticket to the moon, flight leaves here today
%% Fuquay-Varina, NC % from Satellite 2"
%%% 919-577-9882 % 'Ticket To The Moon'
%%%% % *Time*, Electric Light Orchestra
http://home.earthlink.net/~yatescr

[Trevor Wilson]

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:

"Randy Yates" wrote in message
...
"Trevor Wilson" writes:
[...]
**The Klipsch Forte' and Forte' II.

What is their low-frequency distortion?

**I don't know.

I noticed that Stereophile does
not publish these numbers in their reviews, and Audio Magazine (which
used to) has long been defunct. How do you know what their distortion
is?

**I don't. Why are you preoccupied with distortion (at what
frequency?),
when the K-Horn has far more serious and obvious flaws?

If low-frequency distorion isn't that significant, then why did
you spend the energy to attempt to refute it?

**Non-sequitur. I never attempted to refute it.

You're either very forgetful or a liar:

**Read your question and my answer. I NEVER attempted to refute it. The
Klipsch K-Horns do possess quite good THD figures over some parts of their
operating range. Unfortunately, to achieve that low THD serious compromises
have been made.


"Randy Yates" wrote in message
...
Peter Larsen writes:


Really? Why is it then that when Audio magazine reviewed the
Klipshorn's some decades ago, they attained of the lowest distortion
measurements in the low frequencies ever?

**Because it was 30 years ago. The rest of us have moved on. There are
MUCH
lower distortion products available, at lower cost and in a much smaller
package.


--
Trevor Wilson
www.rageaudio.com.au


--Still waiting for the "much lower distortion products."

**Quad ESL 63s. Duntech Sovereigns. Duntech Crown Princes. Various Dunlavy
speakers. Et al. All of which not only have low distortion across the entire
frequency range, but include very good time alignment and a linear frequency
response.


--
Trevor Wilson
www.rageaudio.com.au



--
Posted via a free Usenet account from http://www.teranews.com

[Mr.T]

"Eeyore" wrote in message
...
You ought to hear some modern 'dance' music ! That is to say I don't
recommend
it but you might be surprised.

Are you suggesting that's what Randy actually listens to?

MrT.

[Mr.T]

"Randy Yates" wrote in message
...
So are you still claiming 110dB *average* levels, or have you come to
your
senses?

Reality and I really don't give a **** what you think.

OK, I didn't realise you were stone deaf. No need for abuse though.

MrT.

[Mr.T]

"Randy Yates" wrote in message
...
The real problem is his claim that it is *average* SPL at the
listening position with normal music!

1. It was not peak, but rather average, I observed on my RS power meter.
Average in the sense that the needle was "hovering" most of the time in
the area of 105 to 110 dB (perhaps 110 to 115 was 5 dB high).


And perhaps you have NO idea how to make accurate SPL measurements.


The peaks, as registered by the meter, were definitely not any where near
20 dB over that (125 to 130), but rather were more like 110 to 115.

Again, this was *unweighted*, which I'm sure some boneheads around here
still don't understand.


The bone head is the one who claims measured figures without having a clue
what he is measuring.
Whatever a RatShack meter tells you bears little resemblance to any real
calibrated data, even IF you knew how to use it.

MrT.

[Mr.T]

"Trevor Wilson" wrote in message
.. .
**I don't. Why are you preoccupied with distortion (at what frequency?),
when the K-Horn has far more serious and obvious flaws? THD is ONE facet
of
a speaker's performance which is relevant. There are others. Some of them
(like frequency linearity) are more important.

Interesting statement. Obviously the respective amounts and frequencies are
paramount to making any such comparison.

MrT.

[Mr.T]

"Randy Yates" wrote in message
...
I claim, lacking any hard evidence to the contrary, that another one
of their advantages is low low-frequency distortion. If this advantage
has been neutralized by modern speaker technology (and as yet I
haven't seen this to be the case), then that is a significant
mitigation of the K-Horn advantage.

You haven't heard a good sub woofer like the Whise then obviously.

MrT.

[Mr.T]

"Trevor Wilson" wrote in message
.. .
**Quad ESL 63s. Duntech Sovereigns. Duntech Crown Princes. Various Dunlavy
speakers. Et al. All of which not only have low distortion across the
entire
frequency range, but include very good time alignment and a linear
frequency
response.

Actually I've never seen a real frequency response measurement for the Quad
ESL 63's which showed a linear frequency response. I've definitely seen some
very non linear measurements however.

MrT.

[Randy Yates]

Peter, Trevor, et al.

I must apologize to all of you.

I ran out and bought a new RS SPL meter today (after having
mine stolen some 9 or 10 years back). The short result is
that 110 dB SPL C weighted (the unweighted position is
not available on the new meters - it's just A or C weighting
now) is FRICKING LOUD.

Even bumping down 5 dB or more, so that peaks were occuring
at 105 to 110 dB, was really really loud - not something I
would listen to for pleasure.

I must be getting alzheimer's. I could have sworn that
in the past I had listened pleasantly to 105 to 110 dB
unweighted. Perhaps there's more difference between unweighted
and C weighted than I would expect from the plots,

http://www.ptpart.co.uk/show.php?contentid=70

Or perhaps the old meter was inaccurate, or perhaps the
new one is inaccurate.

Or perhaps my memory was wrong.

--Randy Yates



Peter Larsen writes:

Randy Yates wrote:

[playback SPL]

I am beginning to read that as meaning the quite probable
typical meter max deflection on FAST during playback.

1. It was not peak, but rather average, I observed on my RS
power meter. Average in the sense that the needle was "hovering"
most of the time in the area of 105 to 110 dB (perhaps 110 to
115 was 5 dB high).

That instrument belong to a class of instruments that are likely to
under-display peaks with at least 10 dB.

The peaks, as registered by the meter, were definitely not any
where near 20 dB over that (125 to 130), but rather were more
like 110 to 115.

So my guesstimate a C weighted SPL stands. Even a standard PPM
underdisplays peaks with 10 dB. Your average listening level at the
occasion was in the range 100 to 105 dB SPL C and 90 to 95 dB A.

Again, this was *unweighted*, which I'm sure some boneheads
around here still don't understand.

"Unweighted" and C-weighted gives results within a dB on typical music.

% Randy Yates


Peter Larsen

--
% Randy Yates % "She has an IQ of 1001, she has a jumpsuit
%% Fuquay-Varina, NC % on, and she's also a telephone."
%%% 919-577-9882 %
%%%% % 'Yours Truly, 2095', *Time*, ELO
http://home.earthlink.net/~yatescr

[CC]

Karl Uppiano wrote:
[edit]
On my old Heathkit AA-1214 (15+15 W), I put a 20dB pad in the tape monitor
loop (what my college roommate and I referred to the TAPE MON button as the
"low axle") so that we could play music during "quiet hours" without having
to turn the VC down into the critical range, but that still means that the
PA is running down in the crossover region all the time.

Is that a bad thing? I mean, do you have some reason to believe that
"running down in the crossover region" on your amp results in audible
distortion?

I would expect any decent amp to not produce audible distortion or other
artifacts (except perhaps crummy volume tracking, which the pad should
fix) at just about any volume level.

Don't let the "amplifier sound" audiophiles fool you.


Good day!

--
_____________________
Christopher R. Carlen

SuSE 9.1 Linux 2.6.5

[Mr.T]

"Bret Ludwig" wrote in message
ups.com...
I do not mean to impugn JBL but I do not think any of their current
consumer offerings are in a league with a hot rodded Klipschhorn, or
many vintage systems using the best JBL pro parts. The JBL 2404 tweeter
and 2123J drivers are as far as I know not remotely equaled by the
stuff used in the home JBL products with which I am familiar.


But the JBL pro stuff is still available, and the top line models are pretty
good. The cheaper Chinese crap is what you would expect.

MrT.

[Mr.T]

"Randy Yates" wrote in message
...
Or perhaps the old meter was inaccurate, or perhaps the
new one is inaccurate.

Or perhaps my memory was wrong.

Yep, all possibilities. I'm glad you have learned something anyway.

MrT.

[Peter Larsen]

Randy Yates wrote:

Peter, Trevor, et al.

I must apologize to all of you.

No grave need to apologize, but thanks anyway. We all learn as we go ...

I ran out and bought a new RS SPL meter today (after having
mine stolen some 9 or 10 years back). The short result is
that 110 dB SPL C weighted (the unweighted position is
not available on the new meters - it's just A or C weighting
now) is FRICKING LOUD.

There seems to be general agreement about that.

Even bumping down 5 dB or more, so that peaks were occuring
at 105 to 110 dB, was really really loud - not something I
would listen to for pleasure.

Please not that it does not display true peaks, a meter that does is
costs considerably more, but there is a way around that: record
digitally via a calibrated setup.

Or perhaps the old meter was inaccurate,

It makes a lot of sense to assume that it has had an undamped movement
and thus display overshoot on lower frequency transients, you may also
have measured on a room node.

or perhaps the new one is inaccurate.

There are some standardized integration times for "FAST" and "SLOW",
perhaps someone knows what they are.

Or perhaps my memory was wrong.

Possibly an "all of the above" as the most likely explanation.

Now to getting the things to perform better, did you tried to add foam
to the edge of the midrange and treble horn mouth? - is this something I
ought illustrate on my web site?

Randy Yates


Seasons greetings

Peter Larsen

[Arny Krueger]

"CC" wrote in message

Karl Uppiano wrote:
[edit]
On my old Heathkit AA-1214 (15+15 W), I put a 20dB pad
in the tape monitor loop (what my college roommate and I
referred to the TAPE MON button as the "low axle") so
that we could play music during "quiet hours" without
having to turn the VC down into the critical range, but
that still means that the PA is running down in the
crossover region all the time.

Is that a bad thing? I mean, do you have some reason to
believe that "running down in the crossover region" on
your amp results in audible distortion?

The AA 1214 was pretty cheap and crude, but it still had functional bias
circuitry that minimized crossover distortion.

Also, being only 12 watts, it never saw operation at say 1 watt in the same
light as say a 400 wpc amp.

I would expect any decent amp to not produce audible
distortion or other artifacts (except perhaps crummy
volume tracking, which the pad should fix) at just about
any volume level.

Agreed

Don't let the "amplifier sound" audiophiles fool you.

Agreed.

[isw]

In article , Randy Yates
wrote:

Peter, Trevor, et al.

I must apologize to all of you.

I ran out and bought a new RS SPL meter today (after having
mine stolen some 9 or 10 years back). The short result is
that 110 dB SPL C weighted (the unweighted position is
not available on the new meters - it's just A or C weighting
now) is FRICKING LOUD.

If the sound is distorted, you'll perceive it as being a lot louder than
if it's not.

One of the interesting things about speakers that are capable of
reproducing high volume levels *cleanly*, is that they don't sound as
loud when compared to less-capable speakers. See if you can find a pair
of K-Horns to listen to at that same measured level.

Isaac

[Eeyore]

isw wrote:

One of the interesting things about speakers that are capable of
reproducing high volume levels *cleanly*, is that they don't sound as
loud when compared to less-capable speakers.

This is absolutely true. The same can be said about the amplifier too.

DJs often seem to like running their systems into clipping since it sounds
'louder'.

It's infuriating.

Graham

[Karl Uppiano]

"CC" wrote in message
...
Karl Uppiano wrote:
[edit]
On my old Heathkit AA-1214 (15+15 W), I put a 20dB pad in the tape
monitor loop (what my college roommate and I referred to the TAPE MON
button as the "low axle") so that we could play music during "quiet
hours" without having to turn the VC down into the critical range, but
that still means that the PA is running down in the crossover region all
the time.

Is that a bad thing? I mean, do you have some reason to believe that
"running down in the crossover region" on your amp results in audible
distortion?

Not the ones I designed. The SPL we're talking about is below my tinnitus
anyway. :-)
So I don't know how much distortion there is unless I test. Bias could be
out of adjustment.

I would expect any decent amp to not produce audible distortion or other
artifacts (except perhaps crummy volume tracking, which the pad should
fix) at just about any volume level.

That's exactly what I did for about 20 years.

Don't let the "amplifier sound" audiophiles fool you.

Not to worry.

[Karl Uppiano]

"Arny Krueger" wrote in message
. ..
"CC" wrote in message

Karl Uppiano wrote:
[edit]
On my old Heathkit AA-1214 (15+15 W), I put a 20dB pad
in the tape monitor loop (what my college roommate and I
referred to the TAPE MON button as the "low axle") so
that we could play music during "quiet hours" without
having to turn the VC down into the critical range, but
that still means that the PA is running down in the
crossover region all the time.

Is that a bad thing? I mean, do you have some reason to
believe that "running down in the crossover region" on
your amp results in audible distortion?

The AA 1214 was pretty cheap and crude, but it still had functional bias
circuitry that minimized crossover distortion.

It was a solid, entry level amp that did very well with efficient speakers.
At 35 years old, it still works just fine at the office. I replaced a some
dried out electrolytics in the signal path a few years ago. The main filter
caps are still just fine. My main objection, and the reason I finally
replaced in my primary system it after 20 years, was that the PCB layout
induced a fairly high level of 120 hz hum into the phono preamp (but still
within spec). It was not a problem with the line-level and power sections.

The finals used "stabistors" - temperature compensated diodes to bias the
output transistors a couple of Vbe into conduction, but adequate temperature
feedback was questionable, since the stabistors were simply mounted on the
PCB. At 15WRMS, it could probably be a bit over-biased without much ill
effect.

Also, being only 12 watts, it never saw operation at say 1 watt in the
same light as say a 400 wpc amp.

Rated 15WRMS per channel. Today, it still tests at 18WRMS per channel 20Hz -
20KHz.

I would expect any decent amp to not produce audible
distortion or other artifacts (except perhaps crummy
volume tracking, which the pad should fix) at just about
any volume level.

Agreed

Don't let the "amplifier sound" audiophiles fool you.

Agreed.

[Arny Krueger]

"Karl Uppiano" wrote in message
news:USBih.4494$uq5.4260@trndny04
"Arny Krueger" wrote in message
. ..
"CC" wrote in message

Karl Uppiano wrote:
[edit]
On my old Heathkit AA-1214 (15+15 W), I put a 20dB pad
in the tape monitor loop (what my college roommate and
I referred to the TAPE MON button as the "low axle") so
that we could play music during "quiet hours" without
having to turn the VC down into the critical range, but
that still means that the PA is running down in the
crossover region all the time.

Is that a bad thing? I mean, do you have some reason to
believe that "running down in the crossover region" on
your amp results in audible distortion?

The AA 1214 was pretty cheap and crude, but it still
had functional bias circuitry that minimized crossover
distortion.

It was a solid, entry level amp that did very well with
efficient speakers. At 35 years old, it still works just
fine at the office. I replaced a some dried out
electrolytics in the signal path a few years ago. The
main filter caps are still just fine.

Mine was taken out of service because it didn't have enough power. I
replaced it with a Sherwood 100wpc receiver.

My main objection,
and the reason I finally replaced in my primary system it
after 20 years, was that the PCB layout induced a fairly
high level of 120 hz hum into the phono preamp (but still
within spec). It was not a problem with the line-level
and power sections.

Heath had some problems with PCB layout. I never tackled my AA1214's hum
problem, but I did find similar problems in other Heath kits, notably the SS
THD analyzer.

At one time I previously owned a AR1214 receiver.

The finals used "stabistors" - temperature compensated
diodes to bias the output transistors a couple of Vbe
into conduction, but adequate temperature feedback was
questionable, since the stabistors were simply mounted on
the PCB. At 15WRMS, it could probably be a bit
over-biased without much ill effect.

The bias diodes shown in the schematic are 1N3754 silicon switching diodes,
100 PIV rating, 0.13 amperes.

Also, being only 12 watts, it never saw operation at say
1 watt in the same light as say a 400 wpc amp.

Rated 15WRMS per channel. Today, it still tests at 18WRMS
per channel 20Hz - 20KHz.

You must have a good one or relatively high power line voltage. ;-)

[Karl Uppiano]

"Arny Krueger" wrote in message
. ..
"Karl Uppiano" wrote in message
news:USBih.4494$uq5.4260@trndny04
"Arny Krueger" wrote in message
. ..
"CC" wrote in message

Karl Uppiano wrote:
[edit]
On my old Heathkit AA-1214 (15+15 W), I put a 20dB pad
in the tape monitor loop (what my college roommate and
I referred to the TAPE MON button as the "low axle") so
that we could play music during "quiet hours" without
having to turn the VC down into the critical range, but
that still means that the PA is running down in the
crossover region all the time.

Is that a bad thing? I mean, do you have some reason to
believe that "running down in the crossover region" on
your amp results in audible distortion?

The AA 1214 was pretty cheap and crude, but it still
had functional bias circuitry that minimized crossover
distortion.

It was a solid, entry level amp that did very well with
efficient speakers. At 35 years old, it still works just
fine at the office. I replaced a some dried out
electrolytics in the signal path a few years ago. The
main filter caps are still just fine.

Mine was taken out of service because it didn't have enough power. I
replaced it with a Sherwood 100wpc receiver.

My main objection,
and the reason I finally replaced in my primary system it
after 20 years, was that the PCB layout induced a fairly
high level of 120 hz hum into the phono preamp (but still
within spec). It was not a problem with the line-level
and power sections.

Heath had some problems with PCB layout. I never tackled my AA1214's hum
problem, but I did find similar problems in other Heath kits, notably the
SS THD analyzer.

At one time I previously owned a AR1214 receiver.

Did the AR1214 have hum in the phono preamp? I opted for the separates
(AA-1214/AJ-1214) because I figured it would perform better. I wonder if it
really did.

The finals used "stabistors" - temperature compensated
diodes to bias the output transistors a couple of Vbe
into conduction, but adequate temperature feedback was
questionable, since the stabistors were simply mounted on
the PCB. At 15WRMS, it could probably be a bit
over-biased without much ill effect.

The bias diodes shown in the schematic are 1N3754 silicon switching
diodes, 100 PIV rating, 0.13 amperes.

I wonder if they changed the design at some point. In my schematic (which I
can't find at the moment but IIRC), they are called out as stabistors, and
show as three P-N junctions in a single device. My memory could be failing
me, but I spent weeks in high school reverse-engineering that amplifier. At
one point, I could have drawn the schematic from memory.

Also, being only 12 watts, it never saw operation at say
1 watt in the same light as say a 400 wpc amp.

Rated 15WRMS per channel. Today, it still tests at 18WRMS
per channel 20Hz - 20KHz.

You must have a good one or relatively high power line voltage. ;-)

Maybe they changed the power transformer at some point.

[Arny Krueger]

"Karl Uppiano" wrote in message
news:2qCih.4512$uq5.2496@trndny04
"Arny Krueger" wrote in message
. ..
"Karl Uppiano" wrote in
message news:USBih.4494$uq5.4260@trndny04
"Arny Krueger" wrote in message
. ..
"CC" wrote in message

Karl Uppiano wrote:
[edit]
On my old Heathkit AA-1214 (15+15 W), I put a 20dB
pad in the tape monitor loop (what my college
roommate and I referred to the TAPE MON button as
the "low axle") so that we could play music during
"quiet hours" without having to turn the VC down
into the critical range, but that still means that
the PA is running down in the crossover region all
the time.

Is that a bad thing? I mean, do you have some reason
to believe that "running down in the crossover
region" on your amp results in audible distortion?

The AA 1214 was pretty cheap and crude, but it still
had functional bias circuitry that minimized crossover
distortion.

It was a solid, entry level amp that did very well with
efficient speakers. At 35 years old, it still works just
fine at the office. I replaced a some dried out
electrolytics in the signal path a few years ago. The
main filter caps are still just fine.

Mine was taken out of service because it didn't have
enough power. I replaced it with a Sherwood 100wpc
receiver.
My main objection,
and the reason I finally replaced in my primary system
it after 20 years, was that the PCB layout induced a
fairly high level of 120 hz hum into the phono preamp
(but still within spec). It was not a problem with the
line-level and power sections.

Heath had some problems with PCB layout. I never tackled
my AA1214's hum problem, but I did find similar problems
in other Heath kits, notably the SS THD analyzer.

At one time I previously owned a AR1214 receiver.

Did the AR1214 have hum in the phono preamp? I opted for
the separates (AA-1214/AJ-1214) because I figured it
would perform better. I wonder if it really did.

I don't recall any difference. This was a long time ago - late 1960s.

The finals used "stabistors" - temperature compensated
diodes to bias the output transistors a couple of Vbe
into conduction, but adequate temperature feedback was
questionable, since the stabistors were simply mounted
on the PCB. At 15WRMS, it could probably be a bit
over-biased without much ill effect.

The bias diodes shown in the schematic are 1N3754
silicon switching diodes, 100 PIV rating, 0.13 amperes.

I wonder if they changed the design at some point. In my
schematic (which I can't find at the moment but IIRC),
they are called out as stabistors, and show as three P-N
junctions in a single device. My memory could be failing
me, but I spent weeks in high school reverse-engineering
that amplifier. At one point, I could have drawn the
schematic from memory.

I have no idea. I just know what I read about it, these days.

Also, being only 12 watts, it never saw operation at
say 1 watt in the same light as say a 400 wpc amp.

Rated 15WRMS per channel. Today, it still tests at
18WRMS per channel 20Hz - 20KHz.

You must have a good one or relatively high power line
voltage. ;-)

Maybe they changed the power transformer at some point.

Could be. Heath did do things like that.

[Mr.T]

"isw" wrote in message
...
I ran out and bought a new RS SPL meter today (after having
mine stolen some 9 or 10 years back). The short result is
that 110 dB SPL C weighted (the unweighted position is
not available on the new meters - it's just A or C weighting
now) is FRICKING LOUD.

If the sound is distorted, you'll perceive it as being a lot louder than
if it's not.

Yes a well known observation.

One of the interesting things about speakers that are capable of
reproducing high volume levels *cleanly*, is that they don't sound as
loud when compared to less-capable speakers. See if you can find a pair
of K-Horns to listen to at that same measured level.

Randy already has a pair.
Why don't YOU try some at a *genuine* 115dB *average* SPL and tell us
whether *you* think it's LOUD or not? :-)

MrT.

[Mr.T]

"Bret Ludwig" wrote in message
ups.com...
In many cases when working with horn loudspeakers and very big modern
amplifiers the place for the pad is between amp and speaker.

But then you need high power resistors or a jug element or something that
can handle the extra power you feel it is necessary to dissipate.
Far better, cheaper and easier just to use a lower power amp in the first
place.

MrT.

[Randy Yates]

"Mr.T" MrT@home writes:

"Randy Yates" wrote in message
...
Or perhaps the old meter was inaccurate, or perhaps the
new one is inaccurate.

Or perhaps my memory was wrong.

Yep, all possibilities. I'm glad you have learned something anyway.

Well, perhaps I was premature. I suspect not, but I'm still not
sure. For example, if the new meter is inaccurate, AND the C weighting
curve misses more energy than I suspect, then those two factors
together could account for a great deal of average SPL difference
between what I'm observing now and what the true unweighted average
SPL is.

I'm working on investigating both. A colleague at a nearby acoustic
lab is willing to give the RS a test, and I'm in the process of
evaluating the C weighting curve in Matlab/Octave/
--
% Randy Yates % "Though you ride on the wheels of tomorrow,
%% Fuquay-Varina, NC % you still wander the fields of your
%%% 919-577-9882 % sorrow."
%%%% % '21st Century Man', *Time*, ELO
http://home.earthlink.net/~yatescr

[Mr.T]

"Randy Yates" wrote in message
...
Well, perhaps I was premature. I suspect not, but I'm still not
sure. For example, if the new meter is inaccurate, AND the C weighting
curve misses more energy than I suspect, then those two factors
together could account for a great deal of average SPL difference
between what I'm observing now and what the true unweighted average
SPL is.

I'm working on investigating both. A colleague at a nearby acoustic
lab is willing to give the RS a test,


Good, at least you might have some idea how the readings correspond to
reality then.

and I'm in the process of
evaluating the C weighting curve in Matlab/Octave/

This is just not a big enough issue to affect the current argument
substantially.

MrT.

[isw]

In article ,
"Mr.T" MrT@home wrote:

"isw" wrote in message
...
I ran out and bought a new RS SPL meter today (after having
mine stolen some 9 or 10 years back). The short result is
that 110 dB SPL C weighted (the unweighted position is
not available on the new meters - it's just A or C weighting
now) is FRICKING LOUD.

If the sound is distorted, you'll perceive it as being a lot louder than
if it's not.

Yes a well known observation.

One of the interesting things about speakers that are capable of
reproducing high volume levels *cleanly*, is that they don't sound as
loud when compared to less-capable speakers. See if you can find a pair
of K-Horns to listen to at that same measured level.

Randy already has a pair.
Why don't YOU try some at a *genuine* 115dB *average* SPL and tell us
whether *you* think it's LOUD or not? :-)

I have, many times. I've owned a pair of K-Horns for over 30 years. I
don't play them at those levels for myself, but I have been known to
show folks what loud *clean* sound is like, as most have never heard it.
I have run them at 125+ dB on music source *measured* at two meters on
more than one occasion. ("music source" here means Bach organ pieces,
and the needle was not popping up to 125 dB on peaks; it was hovering
there).

But that said, what I was talking about earlier was not that 115 dB was
not loud -- of course it is -- but only that 115 dB of *clean* sound is
not perceived as being as loud as 115 dB of distorted sound. Perhaps the
reason you think that level is so loud is because you're hearing
distortion.

I don't like the K-Horns because they play really loud; I like them
because (as I said before) they create the best stereo perspective I've
ever heard (although electrostats come close if you only like soft
music). Also, they sound very open at background levels -- something
that a lot of direct radiators seem not to do all that well. The "sweet
spot" with horns is a lot larger than with direct radiators, too.
Another interesting thing about them is that you can "flood" several
rooms with sound while not deafening folks in the same room as the
speakers. That doesn't work so well with direct radiators either.

Of course, even when the *average* output level is more reasonable,
triple-forte peaks can rise into the 110+ dB region pretty easily, and I
don't like it when speakers clip any more than I do when amplifiers do
it. Klipshorns won't even break a sweat at that level, and neither will
the amplifiers that are driving them.

All speakers -- more correctly all *types* of speakers -- have their
problems and their strong points. You decide what's important to you and
what makes sense to you, and then you make your choice. I prefer the
characteristics of bipolar radiators and horns (they have a lot in
common) much more than direct radiators. YMMV.

Isaac

[Randy Yates]

"Mr.T" MrT@home writes:

"Randy Yates" wrote in message
...
Well, perhaps I was premature. I suspect not, but I'm still not
sure. For example, if the new meter is inaccurate, AND the C weighting
curve misses more energy than I suspect, then those two factors
together could account for a great deal of average SPL difference
between what I'm observing now and what the true unweighted average
SPL is.

I'm working on investigating both. A colleague at a nearby acoustic
lab is willing to give the RS a test,


Good, at least you might have some idea how the readings correspond to
reality then.

and I'm in the process of
evaluating the C weighting curve in Matlab/Octave/

This is just not a big enough issue to affect the current argument
substantially.

Why trust intuition when objective measurement is possible without
a whole lot of effort?
--
% Randy Yates % "Midnight, on the water...
%% Fuquay-Varina, NC % I saw... the ocean's daughter."
%%% 919-577-9882 % 'Can't Get It Out Of My Head'
%%%% % *El Dorado*, Electric Light Orchestra
http://home.earthlink.net/~yatescr

[isw]

In article ,
Eeyore wrote:

isw wrote:

One of the interesting things about speakers that are capable of
reproducing high volume levels *cleanly*, is that they don't sound as
loud when compared to less-capable speakers.

This is absolutely true. The same can be said about the amplifier too.

DJs often seem to like running their systems into clipping since it sounds
'louder'.

It's infuriating.

Paul Klipsch used to tell a story about that. Seems he was demo'ing a
pair of his horns to a rock group, using a pair of 100 watt Futtermans
to drive them. The band said the sound was very nice, but not loud
enough (!).

Paul told the local dealer to take the guys to lunch while he worked on
the problem.

When they came back, he ran the demo again, the band guys clapped their
hands over their ears, and yelled "Wonderful. But turn it down; it's way
too loud now!"

Paul had replaced the Futtermans with a pair of ten-watt PA amps, and
added back-to-back diodes across the inputs to ensure the signal was
heavily clipped (and so severely distorted).

Isaac

[isw]

In article . com,
"Bret Ludwig" wrote:

Peter Larsen wrote:
Karl Uppiano wrote:

If anything, the problem with my old ElectroVoice SP12B-based
building-block speakers is that they are too sensitive for
today's high-powered amplifiers.

A 12 dB attenuator on the input of the power amp, or after the volume
control if an integrated, can be very useful.

Now this quote make more sense: "What this country needs is a
good 5-watt amplifier" -- Paul Klipsch


In many cases when working with horn loudspeakers and very big modern
amplifiers the place for the pad is between amp and speaker. This
reduces the damping factor, but because most classic designs were
iteratively tweaked to run with amps with high output impedances, or in
some cases off 70 or 100 volt distribution and stepdown transformers,
this is an improvement sometimes.

Damping factor is not particularly important to any speaker, and that is
even more true of horns. According to Beranek, horns perform best (and
most efficiently) when driven from a matched impedance source.

By my own test, a Klipschorn (not a "perfect" horn) delivers equal
output whether driven directly from a low-impedance amplifier, or with a
16 ohm resistor in series.

Isaac

[isw]

In article ,
"Mr.T" MrT@home wrote:

"Bret Ludwig" wrote in message
ups.com...
In many cases when working with horn loudspeakers and very big modern
amplifiers the place for the pad is between amp and speaker.

But then you need high power resistors or a jug element or something that
can handle the extra power you feel it is necessary to dissipate.
Far better, cheaper and easier just to use a lower power amp in the first
place.

Even with efficient speakers, it's interesting just how big an amplifier
is needed to avoid clipping on peaks. That problem was bad enough with
vinyl source, and it's far worse with the extended dynamic range of CDs.

Isaac