Maker Pro
Maker Pro

perceptible audio distortion

E

Eeyore

Jan 1, 1970
0
With Lateral MOSFETS, right?

Correct. They are superb devices. They present some design challenges but simplify others.

Genuine 'selected' Hitachis. Selected for voltage only btw ( 200Vds) to get the required swing without device failure.

Graham
 
The higher the output impedance of the amplifier, the less it controls
the speaker. Thus damping factor can effect sound.


Do you mean the LOWER the output impedance of the amplifier...?

Douglas Self's text mentioned that an amp driving 4-ohm speakers will
always have more distortion than with driving 8-ohm speakers.

Michael
 
J

JosephKK

Jan 1, 1970
0
Assuming everything else is up to scratch.

I believe ribbon (plus leaf) and electrostatic speakers provide the lowest
THD at typical listening levels.

Graham

AFAIK ribbon speakers beat electrostatic out by a small margin. But
individual speaker designs may flip that one way or the other.

What is the (plus leaf)?
 
P

Phil Allison

Jan 1, 1970
0
"JosephKK"
AFAIK ribbon speakers beat electrostatic out by a small margin.


** But YOU are a know NOTHING fuckwit.

ESLs ( eg Quad ESL63 etc) have way lower THD than any ribbon and are full
range too.



...... Phil
 
E

Eeyore

Jan 1, 1970
0
Do you mean the LOWER the output impedance of the amplifier...?
No.


Douglas Self's text mentioned that an amp driving 4-ohm speakers will
always have more distortion than with driving 8-ohm speakers.

That's an entirely different matter.

Graham
 
L

LVMarc

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
Hearing perception is a funny and tricky area. The type of distortion
will factor into the amount you can stand or detect. I know that odd
harmonics are less obnoxious, often dsirablee compared to even mode
harmonics.. So, best have a look at the wave form and not just a % THD
meter for this one. Non harmonics related would even be worse and more
disrubing to human perception.

Best Regards,

Marc
 
D

Don Klipstein

Jan 1, 1970
0
Hearing perception is a funny and tricky area. The type of distortion
will factor into the amount you can stand or detect. I know that odd
harmonics are less obnoxious, often dsirablee compared to even mode
harmonics..

I have indeed built distortion circuits to cause either odd or even type
of harmonic distortion, primarily for use with electric guitars but also
tested to a lesser extent on other audio signals such as mixed music and
voice-only signals.

There is a lot of "conventional wisdom" that odd harmonic distortion is
supposed to be worse than even harmonic distortion. What I have found is
that lower order even is worse than lower order odd. (Mash down peaks
of one side and "expand" the other side, or [lesser] do nothing but mash
down peaks of one side, sounds to me worse than mashing down peaks in a
symmetric manner.)

It appears to me that the intermodulation distortion is worse when
harmonic distortion of a sinewave is towards the 2nd harmonic than when
harmonic distortion is towards the 3rd.

As for audibility of distortion of a single frequency sinewave signal -
to a fair extent audibility of harmonic distortion increases with harmonic
number until the harmonics approach ultrasonic frequencies. Especially,
distortion harmonics at frequencies below 2 KHz will be less audible than
ones in or a little above the human hearing frequency response hump
centered around 2.7-2.8 KHz.
Also, when a distortion test is on audibility of specific harmonics from
distortion of a pure sine wave as opposed to testing for audible
intermodulation distortion, 2nd harmonic "passes-as-least-offensive".
2nd harmonic is same-note 1-octave-up from fundamental.
Audibility of harmonics in a distortion test on a pure sine wave largely
increases as harmonic number increases (as long as the harmonic is not
ultrasonic or approaching ultrasonic), and also is less if it is a whole
number of octaves from the fundamental, second-least if it is a "fifth"
above (1.5 times higher in frequency) a whole number of octaves above the
fundamental.
However, when there is significant harmonic distortion towards 2nd
harmonic as opposed to higher harmonics, ratio of audible offensiveness
from IM distortion to ausible offensiveness of harmonic distortion appears
to me to be maximized.
So, best have a look at the wave form and not just a % THD
meter for this one. Non harmonics related would even be worse and more
disrubing to human perception.

- Don Klipstein ([email protected])
 
R

Rich Grise

Jan 1, 1970
0
Hearing perception is a funny and tricky area. The type of distortion
will factor into the amount you can stand or detect. I know that odd
harmonics are less obnoxious, often dsirablee compared to even mode
harmonics.. So, best have a look at the wave form and not just a % THD
meter for this one. Non harmonics related would even be worse and more
disrubing to human perception.

I've finally seen a double-bind test on PBS:
http://www.pbs.org/kcet/wiredscience/story/67-audio_files.html

But this write-up is just a teaser - they put two audiophiles and two
engineers in a room, and behind the scenes, "randomly" switched between
analog and digital (without interrupting the piece), and the listeners
had two little paddles - "analog" and "digital", which they'd raise
or lower, as they perceived the difference.

The result? The audiophiles guessed right 55% of the time, and the
engineers guessed right 52% of the time.

Not much better than random chance! ;-)

Cheers!
Rich
 
Top