Do we crave distortion?

[Keith_W]

For some time now, I have been running @pkane's PKHarmonic VST which has the ability to add various amounts of harmonic distortion. I have also played with some Exciter VST plugins which (unlike PK) allow for targeted addition of harmonic distortion - for example, you can add high frequency harmonic spectra and produce the illusion of clarity, or low frequency spectra which makes playback sound fuller.

A number of people have visited me and listened to my system. They do not know that I am adding harmonic distortion to my system. I simply ask them if they prefer A or B (single blind test). Without exception, everybody has preferred the sound of some harmonic distortion added to the signal. About 10 people so far. The adjectives they have used are the same as what I described - it sounds more full, and has more clarity. Of course, I add the harmonic distortion to taste and I avoid adding so much that it sounds screechy or bloated because both outcomes are certainly possible. But it seems, everybody who has listened to my system (including some objectivists), prefers the sound of a little bit of harmonic distortion. The looks on their faces when I tell them what I am doing is quite priceless, ranging from disbelief to disgust. But hey - they voted for the distortion as sounding better!

This has lead me to wonder if there have been any studies that have been performed to show whether or not there is actually a preference for some distortion. This might explain why so many in our hobby love the sound of poorly measuring equipment. I know that it is religion among many in our hobby that the signal remain as unmolested as possible for high fidelity reproduction - it is not my aim to discuss this in this thread. What I want to know is whether other people have tried it and preferred the sound of a bit of distortion, and whether there have been any studies showing preference for some types of distortion.

 

[AnalogSteph]

I kind of doubt that very many metalheads would agree, for one... adding distortion, while it may be considered beneficial with more sparse recordings, tends to wreak havoc on dense and complex material.

 

[Keith_W]

I kind of doubt that very many metalheads would agree, for one... adding distortion, while it may be considered beneficial with more sparse recordings, tends to wreak havoc on dense and complex material.

Good point, it is probably music dependent. I should have added that I only listen to classical music, and so do the majority of people who came over to visit.

 

[Chr1]

I am of the belief that it can be beneficial to some recordings and some speakers.

I use valves in the amplification for Tannoy V12s and believe they sound best with the added "warmth".
With most inferior recordings I prefer the sound of the Tannoys to my other setup, which is Neumann KH310s. To me the added valve warmth definitely improves/masks a lot of the flaws in sub-par recordings, where the transparency of the Neumanns makes it all the more aparent.

 

[JSmith]

adding harmonic distortion

music dependent

Yes, this is why it's best to do what you are doing and add some HD to taste if desired, which may relate to the music being listened to... rather than having a baked in distortion profile that can't be altered.


JSmith

 

[Galliardist]

"Classical music" covers a whole range of sins though, from solo guitar at the quiet end to the 1812-style bombast at the other. I know that I may prefer your distortion test on some orchestral music, but I doubt I would on harpsichord (assuming that a lot of what you add is second harmonic).

Could you be more specific about music choice and what you are actually adding?

 

[Purité Audio]

No.
Keith

 

[solderdude]

For some time now, I have been running @pkane's PKHarmonic VST which has the ability to add various amounts of harmonic distortion. I have also played with some Exciter VST plugins which (unlike PK) allow for targeted addition of harmonic distortion - for example, you can add high frequency harmonic spectra and produce the illusion of clarity, or low frequency spectra which makes playback sound fuller.

A number of people have visited me and listened to my system. They do not know that I am adding harmonic distortion to my system. I simply ask them if they prefer A or B (single blind test). Without exception, everybody has preferred the sound of some harmonic distortion added to the signal. About 10 people so far. The adjectives they have used are the same as what I described - it sounds more full, and has more clarity. Of course, I add the harmonic distortion to taste and I avoid adding so much that it sounds screechy or bloated because both outcomes are certainly possible. But it seems, everybody who has listened to my system (including some objectivists), prefers the sound of a little bit of harmonic distortion. The looks on their faces when I tell them what I am doing is quite priceless, ranging from disbelief to disgust. But hey - they voted for the distortion as sounding better!

This has lead me to wonder if there have been any studies that have been performed to show whether or not there is actually a preference for some distortion. This might explain why so many in our hobby love the sound of poorly measuring equipment. I know that it is religion among many in our hobby that the signal remain as unmolested as possible for high fidelity reproduction - it is not my aim to discuss this in this thread. What I want to know is whether other people have tried it and preferred the sound of a bit of distortion, and whether there have been any studies showing preference for some types of distortion.

In what amount of harmonics do you feel it 'improves' sound and when does it get 'objectionable'.
What is the harmonic spectrum you add in ?

 

[IAtaman]

Well, what we called harmonic distortion from reproduction point of view is just overtones in absolute terms isn't it. Interesting experiment. Do you have a recipe that works the best, that people liked the most, i.e. how much overtones you add to what range?

 

[Rja4000]

Harmonics are like salt and pepper in audio.
You need some, but not too much.

Instruments are generating a lot of harmonics.
Some renowned microphone preamps add some as well.

In my opinion, being able to add some harmonics "to taste" is the best solution.

Buy a perfectly transparent system, add some plugin, as you do, and you'll be able to mimic (and best) any of those fancy "high end" systems for a fraction of their price.
And in a much more flexible/sensible way.

And the rest of the time, you'll have a better sounding system

 

[IAtaman]

On a related note, is there a way to change the harmonics of a musical instrument acoustically / mechanically in a controlled manner. Say, if I turn this lever this way and this much, the guitar produces 10% more second harmonics or such? I was thinking whether it would be possible to turn this into a controlled experiment but there are so many variables in recorded music I thought might be easier to test for it without any recording / reproduction system, not even sure if it makes any sense.

 

[Sokel]

Do you add to the point it's clearly audible with (some) music?
I have tested and as others say it's music dependent and settings depended (I tested high H2,high H3,both,etc)

With classical which is my gender I found no use,either in nice mellow few instrument plays or in grand beautiful ones.
Where it seems beneficial is in some rock plays,in some of them it's absolute fun!

 

[Keith_W]

In what amount of harmonics do you feel it 'improves' sound and when does it get 'objectionable'.
What is the harmonic spectrum you add in ?

These are the settings I am using in PKHarmonic. I remember seeing this profile many years ago as a "desirable" distortion profile, so I applied it without thinking. Now that you asked the question, I am reminded that there was a study on distortion in audio by Jean Hiraga where a distortion profile that looks like this was suggested as sounding the best (I have to go look it up, I am probably mis-remembering).

Well, what we called harmonic distortion from reproduction point of view is just overtones in absolute terms isn't it. Interesting experiment. Do you have a recipe that works the best, that people liked the most, i.e. how much overtones you add to what range?

Above is my recipe. It works on my system and with my music. It may or may not work with yours. As @Rja4000 said, it's like salt and pepper.

Do you add to the point it's clearly audible with (some) music?
I have tested and as others say it's music dependent and settings depended (I tested high H2,high H3,both,etc)

Yes I do add it to the point where it is audible. My intention is not to demonstrate at what point distortion is audible or inaudible, my intention was to see if I could subjectively improve the sound.

 

[Killingbeans]

I kind of doubt that very many metalheads would agree, for one... adding distortion, while it may be considered beneficial with more sparse recordings, tends to wreak havoc on dense and complex material.

Yes, I agree. I mostly listen to thrash/speed metal and "busy" electronica. Some parts of it are absolutely smothered in distortion by design, but if the playback system adds more, the whole thing falls apart.

 

[Rja4000]

is there a way to change the harmonics of a musical instrument acoustically / mechanically in a controlled manner.

I'm pretty sure there is for most instruments.
That's part of a musician's skills, I suppose.

EDIT:
Some interesting reading here

 

[solderdude]

These are the settings I am using in PKHarmonic. I remember seeing this profile many years ago as a "desirable" distortion profile, so I applied it without thinking. Now that you asked the question, I am reminded that there was a study on distortion in audio by Jean Hiraga where a distortion profile that looks like this was suggested as sounding the best (I have to go look it up, I am probably mis-remembering).

Above is my recipe. It works on my system and with my music. It may or may not work with yours. As @Rja4000 said, it's like salt and pepper.



Yes I do add it to the point where it is audible. My intention is not to demonstrate at what point distortion is audible or inaudible, my intention was to see if I could subjectively improve the sound.

It is safe to say H4, H5, H6 and H7 can be set to -200 as these are all inaudible.
Leaves 0.2% H2 and 0.0035% H3 where the H3 is not really considered audible so you could probably set that to -200dB as well.

You can test this by creating 2 files, one with only 0.2% and the other one as described above and run that through an ABX test in foobar.

 

[Sokel]

I'm pretty sure there is for most instruments.
That's part of a musician's skills, I suppose.

On some instruments depending on the pressure or dumbing (I have language barriers here to explain it) on the string you can even output a tone similar to an impulse, a single *tik* true to frequency but with minimal duration.

 

[Lieglein]

To my experience, it really depends on the instrumentation and interpretation.

In general one can say, the more dense the frequency spectrum of a piece or instrument is, the more distortion is acceptable. Synths for example in general really have a more dense frequency spectrum and they are pretty much made for sound design through adding harmonic distortion. The same goes for the electric guitar and bass.

Classical instruments really do not have a dense frequency spectrum. You will hear added distortion immediately. Try playing a chamber orchestra piece with added distortion to people.

I do not think they will think that this would be better. Adding harmonics is just synthesizing. And it works better with instruments that are made for sound design. Acoustical instruments are rather not.

 

[ahofer]

To my experience, it really depends on the instrumentation and interpretation.

In general one can say, the more dense the frequency spectrum of a piece or instrument is, the more distortion is acceptable. Synths for example in general really have a more dense frequency spectrum and they are pretty much made for sound design through adding harmonic distortion. The same goes for the electric guitar and bass.

Classical instruments really do not have a dense frequency spectrum. You will hear added distortion immediately. Try playing a chamber orchestra piece with added distortion to people.

I do not think they will think that this would be better. Adding harmonics is just synthesizing. And it works better with instruments that are made for sound design. Acoustical instruments are rather not.

He used classical (not sure about chamber) and got the opposite result from your prediction….

 

[Rednaxela]

No.
Keith

Seeing Keith post this right after @Galliardist's question got me completely puzzled for a second.