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perceptible audio distortion

At what point is audio distortion perceptible by the general public?

0.1% THD? 1% THD?

I googled double blind distortion, but didn't get much quantitative
data.

Thanks,

Michael
 
M

Martin Griffith

Jan 1, 1970
0
On Thu, 24 Jul 2008 16:17:11 -0700 (PDT), in sci.electronics.design
At what point is audio distortion perceptible by the general public?

0.1% THD? 1% THD?

I googled double blind distortion, but didn't get much quantitative
data.

Thanks,

Michael
Depends on the enviroment, and a great deal on how you specify
distortion

20% in a supermarket
30% in a swmming pool
110% Parliament/congress


martin
 
M

mpm

Jan 1, 1970
0
At what point is audio distortion perceptible by the general public?

0.1% THD? �1% THD?

I googled double blind distortion, but didn't get much quantitative
data.

Thanks,

Michael

I believe from my days at Nakamichi that the level is in the
neighborhood of 6% or so.
Obviously, it is measureable at levels much less than this, and quite
often, easily obtained.

Why do you ask?
 
G

Glenn Gundlach

Jan 1, 1970
0
At what point is audio distortion perceptible by the general public?

0.1% THD?  1% THD?

I googled double blind distortion, but didn't get much quantitative
data.

Thanks,

Michael

Since you've been asking about biasing your amp, are you hearing a
'raspiness' at low levels? That could be classic crossover distortion.
The way I used to adjust on the bench (long ago) was to run 30kHz into
the amp at a low level of 1 or 2 V p-p into the dummy load. Watch the
output on the scope and advance the bias until the 0 cross notches go
away. You'll find that happens close to the 20 mA Phil Allison
mentioned earlier.

Many assume the distortion increases with signal but I haven't found
that to be the case. Of course at clipping all bets are off and
depending on program material may or may not be annoying. The other
classic annoyance is the crossover notch. Keep in mind it sounds a LOT
like a rubbing/sticking voice coil. Also, some old opamps have
crossover problems as well.

 
P

Phil Allison

Jan 1, 1970
0
"Glenn Gundlach"

The other
classic annoyance is the crossover notch. Keep in mind it sounds a LOT
like a rubbing/sticking voice coil. Also, some old opamps have
crossover problems as well.


** Really ?

Maybe only the uA709 with zero bias on the output followers.




...... Phil
 
M

mpm

Jan 1, 1970
0
"Glenn Gundlach"


�** �Really ?

Maybe only the uA709 with zero bias on the output followers.

..... �Phil

My immediate thought was the TLO-74, but I'm not sure why.
Probably some piece of crap I had to repair in my earlier years....
 
M

mpm

Jan 1, 1970
0
It depends on cross-modulation and transient intermodulation more than
raw THD.

Since I played in an orchestra, clarinet right in front of the oboe,
bassoon and French horn, I go bananas on a Mozart woodwind ensemble,
with nearly immeasurable THD numbers, because I can hear the beat note
:-(

� � � � � � � � � � � � � � � � � � � � ...Jim Thompson
--
| James E.Thompson, P.E. � � � � � � � � � � � � � | � �mens � � |
| Analog Innovations, Inc. � � � � � � � � � � � � |� � et � � �|
| Analog/Mixed-Signal ASIC's and Discrete Systems �| � �manus � �|
| Phoenix, Arizona �85048 � �Skype: Contacts Only�| � � � � � � |
| Voice:(480)460-2350 �Fax: Available upon request | �Brass Rat �|
| E-mail Icon athttp://www.analog-innovations.com| � �1962 � � |

Obama the liar...

http://politicalticker.blogs.cnn.com/2008/07/23/obama-incorrectly-cla...-Hide quoted text -

- Show quoted text -

So Jim,
When / If you get a chance, the famous song: Streetbeater (Quincy
Jones), better known as the Sanford and Son TV theme song...

Is that a big barritone sax booming, or a mic'd harmonica?
My brother said it was the latter (and he's a professional musician),
but I honestly don't know.
It's not the sort of sound you hear very often.

-mpm
 
P

Phil Allison

Jan 1, 1970
0
"mpm"
"Phil Allison"
"Glenn Gundlach"


?** ?Really ?

Maybe only the uA709 with zero bias on the output followers.

..... ?Phil


My immediate thought was the TLO-74, but I'm not sure why.
Probably some piece of crap I had to repair in my earlier years....


** The TL07x series has no crossover distortion problem.

Would not be one of the most popular IC op-amps in pro and consumer audio if
it did.



...... Phil
 
M

mpm

Jan 1, 1970
0
"mpm"
�"Phil Allison"





My immediate thought was the TLO-74, but I'm not sure why.
Probably some piece of crap I had to repair in my earlier years....

** The TL07x series has no crossover distortion problem.

Would not be one of the most popular IC op-amps in pro and consumer audioif
it did.

..... � Phil

Oh yeah. Now I remember.
I think it was a BGW guitar amplifier.

One of the worst designs I ever had to repair!!.
Right next in-line to the Motorola Starpoint (microwave transmitter),
the NovaBeam TV, and a little known Litton inertial navigation
system, oh, and a Pagecom low-band pager.

In that order. Actually, you can move the NovaBeam to the head of the
line. :)
 
P

Phil Allison

Jan 1, 1970
0
"mpm" >



Oh yeah. Now I remember.
I think it was a BGW guitar amplifier.



** BGW have never made a guitar amp.

Yawnnn......




..... Phil
 
M

mpm

Jan 1, 1970
0
P

Phil Allison

Jan 1, 1970
0
"mpm" ...
"Phil Allison"
Oh yeah. ?Now I remember.

I think it was a BGW guitar amplifier.

** BGW have never made a guitar amp.

? Yawnnn......

You mean, like they never made this one?

http://cgi.ebay.com/BGW-SYSTEMS-POW...ryZ14983QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


** ROTFL !!!

There are TWO separate items in that rack case -

one of them is an old BGW " Model 100 "

** STEREO POWER AMPLIFIER ** !!!!!


YOU STUPID ASS !!


It must really be cool to be like you and know everything.....



** Go get fucked - you ridiculous moron.




...... Phil
 
M

mpm

Jan 1, 1970
0
"mpm" <[email protected]>

( snip asinine �DRIVEL )

** Go get fucked �- � you ridiculous �moron.

..... � �Phil

So I provide you two excellent examples illustrating that you are
completely wrong (again), and you resort to explitives. Typical.

-mpm
 
E

Eeyore

Jan 1, 1970
0
At what point is audio distortion perceptible by the general public?

0.1% THD? 1% THD?

I googled double blind distortion, but didn't get much quantitative
data.

It's very subjective and depends highly on the harmonic structure of the
distortion. Odd higher order harmonics tend to sound the worst. 2nd may
be virtually inaudible at several percent.

Graham
 
E

Eeyore

Jan 1, 1970
0
mpm said:
I believe from my days at Nakamichi that the level is in the
neighborhood of 6% or so.
Obviously, it is measureable at levels much less than this, and quite
often, easily obtained.

I have heard clear differences between amps *specified* at 0.1% and 0.01%
THD.

Graham
 
E

Eeyore

Jan 1, 1970
0
Glenn said:
Since you've been asking about biasing your amp, are you hearing a
'raspiness' at low levels? That could be classic crossover distortion.

Which sounds very unpleasant.

The way I used to adjust on the bench (long ago) was to run 30kHz into
the amp at a low level of 1 or 2 V p-p into the dummy load. Watch the
output on the scope and advance the bias until the 0 cross notches go
away. You'll find that happens close to the 20 mA Phil Allison
mentioned earlier.

Many assume the distortion increases with signal but I haven't found
that to be the case.

Indeed, it will vary with technology and topology.

Graham
 
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