THD has a much bigger effect on sound than you think

[mike7877]

The sound energy in music in the 1-4khz range is 30-40db lower than bass, 15-30db than midrange.

Harmonics from bass make their way into midrange, harmonics from mid into the 1-4khz range.

Even if these harmonics are at a low level compared to the original tone, in the octave they intrude upon, they are loud (the ear is sensitive there and sound from music is at much lower levels.

A simple example is the 5th harmonic of 200hz is 1khz. In music, there is significantly more energy at 200hz than 1khz. Harmonics at relatively high levels make their way into lower treble and higher midrange sound energy in music.

0.1% harmonic distortion is totally unacceptable. Treble from 2-3khz up is just 0.1-1% the level of bass. 0.1% harmonics from bass are a HUGE problem to 0.1-1% treble in the signal. Even 0.01% THD is still 1% distorted treble. 0.1% THD is 10% distorted treble. Discuss.

(yes, these aren't exact numbers, but they're close enough to reality - a bigger problem than most think)
Mostly talking about odd order from cheap poorly designed solid state amplifiers with higher amounts of it (this sentence addressing a post using THD from a speaker as an example)

 

[MakeMineVinyl]

Well, I couldn't say that distortion from bass is a huge problem, or really any problem at all in the real world. Any half way good solid state component is going to have distortion below audible levels. With tube electronics, the purchasers of these components usually consider distortion to be a secondary figure of merit, so its essentially a non-issue there as well.

 

[mike7877]

Well, I couldn't say that distortion from bass is a huge problem, or really any problem at all in the real world. Any half way good solid state component is going to have distortion below audible levels. With tube electronics, the purchasers of these components usually consider distortion to be a secondary figure of merit, so its essentially a non-issue there as well.

You didn't read. Please read. And it's common knowledge that the desirable tube distortion (desirable to some people...) is EVEN order, not odd order, like 3rd and 5th which take away from detail at low levels and literally cause ear pain at high levels

 

[Ron Texas]

What? Speakers have low frequency distortion well in excess of 1% and rarely drop below .1%.

 

[xaviescacs]

0.1% harmonic distortion is totally unacceptable, garbage.

Is that distortion in the bass region audible?

 

[Dro]

I generally agree with the reasoning that bass distortion is underestimated because the distortion frequencies are much more audible to us. No, 10% third harmonic at 30 Hz is not okay, it will sound louder than the fundamental.

But I think you are off regarding what is acceptable. I can hear a difference between 2% and 3% third harmonic distortion at 30 Hz, but not between 1% and 2%. That was tested with headphones that have well below 1% THD at 30 Hz and with reasonable SPL.

 

[DVDdoug]

I virtually NEVER hear ANY distortion unless something is defective or overdriven...

I CAN drive my Honda car stereo into distortion (especially in the bass) but it's OK as long as I don't push-it.

 

[abdo123]

You do realise that THD is mostly second harmonic, and thus there is barely anything leaking anywhere.

You have better odds forming a hypothesis with inter modular distortion.

 

[mike7877]

Is that distortion in the bass region audible?

The point is the harmonic tones from low range is heard in the upper mid and lower treble. The upper mid and lower treble signal are down 15-40db compared to bass. So 0.1% of it is LOUD

 

[mike7877]

I'm not here to argue, I'm stating a fact. And I'm done

 

[mike7877]

You do realise that THD is mostly second harmonic, and thus there is barely anything leaking anywhere.

You have better odds forming a hypothesis with inter modular distortion.

No it's not. Where do you get that THD is mostly second harmonic? I have to address this so nobody thinks you're right, because you're not. And second harmonic isn't GOOD, it's at best neutral because it blends into the sound as a tone one octave higher

 

[BDWoody]

The point is the harmonic tones from low range is heard in the upper mid and lower treble. The upper mid and lower treble signal are down 15-40db compared to bass. So 0.1% of it is LOUD

Where is the evidence of that being audible?

 

[mike7877]

I generally agree with the reasoning that bass distortion is underestimated because the distortion frequencies are much more audible to us. No, 10% third harmonic at 30 Hz is not okay, it will sound louder than the fundamental.

But I think you are off regarding what is acceptable. I can hear a difference between 2% and 3% third harmonic distortion at 30 Hz, but not between 1% and 2%. That was tested with headphones that have well below 1% THD at 30 Hz and with reasonable SPL.

Think more 5th harmonic of a snare with a lot of energy at 250hz (almost as much as bass) bleeding into the 1-2khz range

 

[abdo123]

No it's not. Where do you get that THD is mostly second harmonic? I have to address this so nobody thinks you're right, because you're not. And second harmonic isn't GOOD, it's at best neutral because it blends into the sound as a tone one octave higher

 

[mike7877]

Where is the evidence of that being audible?

It's self evident

 

[mike7877]

I'm talking solid state electronics, not speakers. Guess I should've made that clearer - not everything is self evident

 

[Chrispy]

You have your bass set to 30-40dB louder than the rest of the spectrum?

 

[BDWoody]

It's self evident

Ahhh...of course.

 

[BDWoody]

With half a brain and a little thought

I don't qualify I suppose.

You can take the edge off as well please.

 

[amirm]

Let's tone down the emotion folks ...