THD has a much bigger effect on sound than you think

[Pdxwayne]

DISTORT app doesn't do anything at 0dBFS -- it's up to the user to decide what signal to feed it as input and at what level. Internally, all computations are in 64-bit floating point, and any results that exceed 0dBFS are reported as clipping.

BTW, based on the graph below, what distortion numbers would you enter, when adding to a pure 0db tone in your app?

 

[Pdxwayne]

You'd best get canvassing for 99999 volunteers then.

I just need one fail test to prove his statement is wrong. Should not need 99999.

; )

 

[pkane]

BTW, based on the graph below, what distortion numbers would you enter, when adding to a pure 0db tone in your app?

View attachment 160910

None. That measurement doesn't describe the transfer function in any detail, so it can't be reproduced from this plot.

 

[Pdxwayne]

None. That measurement doesn't describe the transfer function in any detail, so it can't be reproduced from this plot.

Any useful info at all from the link to give you good clues?

Pass ACA Class A Power Amplifier Review

This is a review and detailed measurements of the Pass ACA Class A stereo power amplifier. It is a DIY design by the famous designer, Nelson Pass, meant to be starter amplifier for people new to audio electronics to build. There are many kits available. The one loaned to me from a long time...

www.audiosciencereview.com

 

[Killingbeans]

You claimed "everyone" can hear it.

What if I am one in a 100000 that could hear it and 99999 out of 100000 can't hear it?

If you push a man out of a moving plane, will you conclude that his death was "accidental" because the next 99999 people you push will have a chance to survive? I think it's fair to claim that "everyone" will die if you push them out of a moving plane

Same thing here. What we know about the nature of tones and masking is enough to disregard the minuscule "risk" of your experience being a fluke.

 

[Pdxwayne]

If you push a man out of a moving plane, will you conclude that his death was "accidental" because the next 99999 people you push will have a chance to survive? I think it's fair to claim that "everyone" will die if you push them out of a moving plane

Same thing here. What we know about the nature of tones and masking is enough to disregard the minuscule "risk" of your experience being a fluke.

Words.....

I need actions. So far I see none would step up to provide abx.

; )

 

[Jimbob54]

Thanks for the details explanations.

Hmm, talking about audibility.....

I played around with the distort app and able to get just 5th harmonic of 0.1% (-60db) added to 250hz pure tone.
Here is the deltawave spectrum comparison. As you can see, the second file got that 0.1% 5th harmonics.
View attachment 160828

I tried to ABX pure tone vs file with that 5th harmonic. Very difficult, but still able to get 8/8.
View attachment 160829

Post the 2 test files please.

 

[pkane]

Any useful info at all from the link to give you good clues?

Pass ACA Class A Power Amplifier Review

This is a review and detailed measurements of the Pass ACA Class A stereo power amplifier. It is a DIY design by the famous designer, Nelson Pass, meant to be starter amplifier for people new to audio electronics to build. There are many kits available. The one loaned to me from a long time...

www.audiosciencereview.com

Read up on the transfer function. Don't know how many times I have to repeat it. Don't keep asking me to teach you.

 

[Killingbeans]

Words.....

I need actions. So far I see none would step up to provide abx.

; )

It's finally dawning on me that you're joking. That's fine and all, but maybe we should just move on?

There's a risk that other users won't be able to read between the lines and will draw all kinds of bonkers conclusions from your writings.

 

[Jimbob54]

It's finally dawning on me that you're joking. That's fine and all, but maybe we should just move on?

There's a risk that other users won't be able to read between the lines and will draw all kinds of bonkers conclusions from your writings.

Alas, I think not.

 

[Pdxwayne]

Read up on the transfer function. Don't know how many times I have to repeat it. Don't keep asking me to teach you.

Should I assume you are talking about using 1 watts and 2 watts info to formulate a number that can calculate 5 watts, 10 watts, etc?

That one is straight forward.

But my main question is which watts distortion to use? Do you use 2 watts? Do you use 10 watts? If you are to simulate an amp in my example, which watt distortions numbers do you take?

 

[pma]

BTW, based on the graph below, what distortion numbers would you enter, when adding to a pure 0db tone in your app?

View attachment 160910

Read them from the spectrum below and it will be quite representative. This amp is useless above some 7W.

 

[Pdxwayne]

It's finally dawning on me that you're joking. That's fine and all, but maybe we should just move on?

There's a risk that other users won't be able to read between the lines and will draw all kinds of bonkers conclusions from your writings.

No not joking. When I made statements in my other threads, many would ask me to do actual blind tests, do abx, etc. So, fair game I do the same to someone who made an "everyone can hear" statement.

 

[Pdxwayne]

Read them from the spectrum below and it will be quite representative. This amp is useless above some 7W.

View attachment 160915

Thanks! Yes, but still 5 watts. So, is this a good enough value to use when trying to enter distortion in pkane's app? Or should I estimate for 7 watts and enter those distortion numbers?

Related question: For other amps that can do much higher wattages, what watts number do I use? Can't just use 5 watts, right?

 

[pma]

It is still good enough (7W makes 1.46 dB to 5W) however your sine input file must be close to 0dBFS to verify the distortion, with lower amplitude the distortion gets quickly decreased. This should be understood as elementary.

 

[pkane]

Should I assume you are talking about using 1 watts and 2 watts info to formulate a number that can calculate 5 watts, 10 watts, etc?

That one is straight forward.

But my main question is which watts distortion to use? Do you use 2 watts? Do you use 10 watts? If you are to simulate an amp in my example, which watt distortions numbers do you take?

An amp doesn't do something different with regards to distortion at some specific "watt" value. It is the result of a single transfer function that defines its behavior at all input levels. I've said this already, at least a few times. If you refuse to try to learn on your own, I really can't help you.

 

[Pdxwayne]

Post the 2 test files please.

250hz_h2_to_h4_120_h5_60.wav and 1 more file

2 files sent via WeTransfer, the simplest way to send your files around the world

we.tl

Glad that you wish to try. Thx!

 

[pma]

An amp doesn't do something different with regards to distortion at some specific "watt" value. It is the result of a single transfer function that defines its behavior at all input levels. I've said this already, at least a few times. If you refuse to try to learn on your own, I really can't help you.

Lost case. Many people spent hours or tens of hours of useless debates rather than 10 minutes of study. Such is life and the mix on the forum.

 

[Pdxwayne]

An amp doesn't do something different with regards to distortion at some specific "watt" value. It is the result of a single transfer function that defines its behavior at all input levels. I've said this already, at least a few times. If you refuse to try to learn on your own, I really can't help you.

At least point me to a few good sites for learning please?

 

[Pdxwayne]

Lost case. Many people spent hours or tens of hours of useless debates rather than 10 minutes of study. Such is life and the mix on the forum.

Well, you can also spend 1 minute to point me to good study links?

: )