THD has a much bigger effect on sound than you think

[Blumlein 88]

I know I can't ignore IMD. What else can I use to illustrate an approximation?

Also, Amir used that to simulate real music playback. What else can I use to illustrate that when bass is loud, high distortion amp likely to contribute to extra db in the highs?

And why do you keep saying masking issue? Our hearing sensitivity in the highs are much better than the bass, right? Even bass is at 90db, we can hear 1200hz at 65db just fine. If the noise at 1200hz is at 70db, then I am sure I can sense 5+dB increase in 1200hz even when bass are in 90db.

Try Pkanes software. You can construct any distortion profile you want. Do one clean, do one dirty, and measure the level difference.

Distort audibility tester | Distort documentation

distortaudio.org

 

[Pdxwayne]

Try Pkanes software. You can construct any distortion profile you want. Do one clean, do one dirty, and measure the level difference.

Distort audibility tester | Distort documentation

distortaudio.org

You already have examples? Please share if you do.
: )

 

[Blumlein 88]

You already have examples? Please share if you do.
: )

I don't, and I didn't want to build an example that isn't whatever you have in mind. I can tell you the results aren't going to be what you are thinking, but it needs doing to convince you.

 

[mike7877]

If you play a chord and each note has a third harmonic added, the harmonics will clash with each other and the other root notes. With enough added harmonics, low level detail is masked. Like hundreds of human voices sound like white noise, hundreds of harmonics will sound like white noise (complicated passages with textured instruments)

 

[Pdxwayne]

I don't, and I didn't want to build an example that isn't whatever you have in mind. I can tell you the results aren't going to be what you are thinking, but it needs doing to convince you.

Can the app create two charts for the following?

All across -80db distortion for 5th harmonic. Fundamental tones from 200 to 300 Hz at 90db, and 1000 hz to 1500 Hz at 65db.

All across -110db distortion for 5th harmonic. Fundamental tones from 200 to 300 Hz at 90db, and 1000 to 1500 Hz at 65db.


Thanks!

 

[Blumlein 88]

Can the app create two charts for the following?

All across -80db distortion for 5th harmonic. Fundamental tones from 200 to 300 Hz at 90db, and 1000 hz to 1500 Hz at 65db.

All across -110db distortion for 5th harmonic. Fundamental tones from 200 to 300 Hz at 90db, and 1000 to 1500 Hz at 65db.


Thanks!

I've not used it all that much. I'm more familiar with Deltawave by Paul. But from memory yes it can do what you wish. Its free, and just playing with it a few minutes will show you what it can do.

 

[Blumlein 88]

Can the app create two charts for the following?

All across -80db distortion for 5th harmonic. Fundamental tones from 200 to 300 Hz at 90db, and 1000 hz to 1500 Hz at 65db.

All across -110db distortion for 5th harmonic. Fundamental tones from 200 to 300 Hz at 90db, and 1000 to 1500 Hz at 65db.


Thanks!

So how many fundamentals you want in that 200 to 300 hz range?

 

[Pdxwayne]

So how many fundamentals you want in that 200 to 300 hz range?

All of them. From 200 to 300hz. Is it a valid assumption or should I select fewer?

 

[Blumlein 88]

All of them. From 200 to 300hz. Is it a valid assumption or should I select fewer?

How many is all of them? 200 hz, 201 hz, 202 hz? Or 200 hz, 200.5 hz, 201 hz, 201.5 hz?

 

[pkane]

Can the app create two charts for the following?

All across -80db distortion for 5th harmonic. Fundamental tones from 200 to 300 Hz at 90db, and 1000 hz to 1500 Hz at 65db.

All across -110db distortion for 5th harmonic. Fundamental tones from 200 to 300 Hz at 90db, and 1000 to 1500 Hz at 65db.


Thanks!

Here's what the app can do: take any music or signal/generated track with as many fundamental frequencies as you want. Can be a single sine wave or the whole orchestra playing. Then, decide what harmonic distortions you want to add in and at what level, enter them into the app. Once you do this, you can listen to the distorted track in the app, save it and listen to it through your system, analyze it in any software you want (including DeltaWave) or use it for ABX testing.

 

[Pdxwayne]

How many is all of them? 200 hz, 201 hz, 202 hz? Or 200 hz, 200.5 hz, 201 hz, 201.5 hz?

Hmm, I wonder if I need to manually create each tones.....I guess maybe using a real music clip is easier....

 

[Pdxwayne]

I don't, and I didn't want to build an example that isn't whatever you have in mind. I can tell you the results aren't going to be what you are thinking, but it needs doing to convince you.

I tried -80db for 2nd to 5th and the test song became dull and lacking details. So, no, not like what I expected....

I tried -100db for 2nd to 4th, -80db for 5th, again, seems lack details....

 

[Pdxwayne]

Here's what the app can do: take any music or signal/generated track with as many fundamental frequencies as you want. Can be a single sine wave or the whole orchestra playing. Then, decide what harmonic distortions you want to add in and at what level, enter them into the app. Once you do this, you can listen to the distorted track in the app, save it and listen to it through your system, analyze it in any software you want (including DeltaWave) or use it for ABX testing.
View attachment 160806

That is odd. I saved the adjusted file and checked with audacity. Your app seem to reduce the overall volume of the files by several dB. How can adding distortion reduce overall dB?

 

[pkane]

That is odd. I saved the adjusted file and checked with audacity. Your app seem to reduce the overall volume of the files by several dB. How can adding distortion reduce overall dB?

There's a volume control that lets you adjust it. Check that it's set to zero.

 

[Pdxwayne]

There's a volume control that lets you adjust it. Check that it's set to zero.

This is how my gui looks like. I don't think this will simulate a real amp. Your app is applying same distrotions to all freq. But, in the case I talked about, only bass notes are providing the significant distortions and not the trebles.

 

[pkane]

This is how my gui looks like. I don't think this will simulate a real amp. Your app is applying same distrotions to all freq. But, in the case I talked about, only bass notes are providing the significant distortions and not the trebles.

View attachment 160813

The app simulates a static non-linearity, it is frequency independent. There is an option to simulate a positive/negative feedback of an amp that can help produce a more variable non-linearity, but it's not meant to simulate any specific amp.

What would make an amp produce much more significant distortions in bass?

 

[Pdxwayne]

...

What would make an amp produce much more significant distortions in bass?

For example, if 200hz is at 90db and 1200hz is at 65db, I would assume that amp would produce much more distortion from bass notes.

 

[pkane]

For example, if 200hz is at 90db and 1200hz is at 65db, I would assume that amp would produce much more distortion from bass notes.

But that's exactly what will happen with DISTORT. The magnitude of the fundamental frequency drives the magnitudes of all the harmonics and any IMD caused by the combination of distortion and fundamentals.

 

[Pdxwayne]

But that's exactly what will happen with DISTORT. The magnitude of the fundamental frequency drives the magnitudes of all the harmonics and any IMD caused by the combination of distortion and fundamentals.

But amp distortion level changes from 1 watt, 2 watts, 5 watts, etc. Can your app account for different playback level distortions?

 

[pkane]

But amp distortion level changes from 1 watt, 2 watts, 5 watts, etc. Can your app account for different playback level distortions?

I think you may need a little tutorial to understand distortion better, what causes it and how it manifests itself. Yes, DISTORT will produce different levels of distortions at different sound levels. This is how distortion works. DISTORT works by computing and simulating the non-linear behavior of the device with respect to all possible volume levels. It is this non-linearity that causes harmonics at varying levels, just like it does in real devices, from DACs to amps.