[KinGensai]

I’m not working in my own studio for a few weeks so I can’t analyse your wav files and all I have to go on is your Deltawave results. There seems to be delta content all over the place that shouldn’t be there, so it’s difficult to tell what you’ve done or what’s going on. Have you used a pink noise generator or a pink noise file? Theres a big peak around 4kHz that obviously shouldn’t be there. If that were an alias product it would have been caused by an equivalent peak at around 40kHz, remember that aliases mirror around the Nyquist freq. You could try oversampling, that would eliminate any aliasing but my guess would be that it’s caused by some other type of distortion product.

G

That report is based on a 16k sine wave test tone that I added a severe high shelf EQ to (15kHz Q0.9 10dB) vs stock. I tried recorded pink noise first, but the delta was difficult to interpret, so I switched out to a single frequency to isolate and exaggerate the effect. I didn't consider comparing oversampling, I'll do that when I'm back in front of my computer.

 

[gregorio]

That report is based on a 16k sine wave test tone that I added a severe high shelf EQ to (15kHz Q0.9 10dB) vs stock.

Then I don’t know and would have to examine it more carefully. My initial impression is that it’s clipping somewhere, ISP clipping possibly but another possibility could be that the EQ is deliberately adding some sort of distortion. A significantly lesser probability, assuming it’s a decent professional EQ, is some fault in the programming. Presumably it’s a 32bit EQ which means it has to reduce it’s output back down to 16bit, so the only difference, apart from the boost in the 16kHz sine wave, should be random noise (dither) down around -90dB.

G

 

[71 dB]

That isn’t true of the expensive things I mentioned there. A house is home and becomes more of a home the longer you live there.

People need a home. It is for the most part about basic needs unlike (luxury) audio products (for music lover audio products feel like basic needs ). Now, if your home is a 10,000 sq ft mansion with six bedrooms, you are doing more than just basic needs...

Travel creates memories that last a lifetime.

For sensors yes. For intuitives, especially autistic ones, the massive sensory stimuli offered by traveling can be quite overwhelming!

Art, education and a library are things you can call upon every day for ideas and inspiration.

Not sure how all of this is linked to consumerism of luxury products... ...but I agree.

I didn’t mention it before, but musical instruments are expensive things that improve your lifestyle day in day out. Those things are different than expensive sound equipment or status symbols.

I can't comment on this since I have never owned a music instrument. It seems as a mildly autistic person acquiring skillsets such as playing a musical instrument is very difficult for me. I am physically clumsy.

The trick to being happy is being satisfied.

Yes, and that's why I try to be content with the audio gear I have and not think about anything "better." My problems with being happy are connected to my neurotype and the state of the World. My strongly intuitive mind generates predictions for the future and what is happening in the World gives a lot of fuel for dark predictions. It would be that bad if this was all, but the way my brain deals with feelings means all these dark predictions generated by my intuition are food for my feelings as if those things were true (doesn't matter if those predictions are false or not). Feeling these things can even feed my intuition and a feedback loop is created! I can only try and block dark predictions feed my feelings, but since I have become aware of this mental mechanism in my brain only recently, I am not that good at it yet. Exposing myself to sensory stimuli from the "real World" provides alternative stimuli for feelings that can override the stimuli created by my intuition. This means looking out of a window (that's the real World out there), going out for a walk etc. Also, I try to minimize how much I follow the news. It is enough to hear about what was happened in the World once and the move on. Watching every news broadcast on TV and reading about the same news 5 times online is no a good idea for someone like me.

Thanks to the internet I can find information vital to reverse-engineer what kind of biological creature (and mind) I am, but I lived decades of my live without the idea I am autistic because I have high functioning autism and I am able to some degree of social interaction (albeit clumsily). However, I always felt something was "off" compared to other people around me and I was about 40 when my sister suggested I might be autistic (asperger was the term at the time).

My other problem has been the difficulty of finding my place/purpose in the World. The World doesn't seem to need people like me for anything. That leads to the frustration of being misunderstood and even ignored despite of trying. Especially extroverted people have great difficulty understanding very introverted autistic people and this World is made for extroverts. Introverts may run it in the background, but extroverts strive in it.

If you’re satisfied you don’t spend money buying things for the sake of buying things. And you don’t waste precious days of your life fretting over what you don’t have.

Yes.

 

[KinGensai]

Then I don’t know and would have to examine it more carefully. My initial impression is that it’s clipping somewhere, ISP clipping possibly but another possibility could be that the EQ is deliberately adding some sort of distortion. A significantly lesser probability, assuming it’s a decent professional EQ, is some fault in the programming. Presumably it’s a 32bit EQ which means it has to reduce it’s output back down to 16bit, so the only difference, apart from the boost in the 16kHz sine wave, should be random noise (dither) down around -90dB.

G

I did as you prescribed and applied 16x oversampling to compare to no oversampling, and the difference suggests that much of the noise is aliasing if I'm interpreting it right.

I split it up so you can see clearly, the deltawave report is really confusing to try to look at lol. I uploaded the recordings to the mega link. As you can see in the first image, there are a few progressively decreasing artifacts that seem to me to be IMD, and it looks like the 16x oversampling did the trick and eliminated the other peaks occurring in the second graph. I'm not quite sure how to interpret what kind of distortion this actually is, the 3 peaks below 16k are spaced at roughly 4k intervals.

https://mega.nz/folder/9oABmIyZ#wkzZve6Edg2Af-nZDEmB2Q

 

[KinGensai]

@71 dB
I wouldn't be so quick to assume extroverts have it any easier than introverts. The negative feedback loop you are talking about is not exclusive to you, that applies to everyone, and it's what social control depends on.

Introverts have an internal locus of control, so the struggle is contending with other people who disrupt the introvert's flow. Extroverts have an external locus of control, so the same kind of discomfort you experience when you are interacting with other people is the feeling they have when they are alone. In a way, they are even more vulnerable than introverts because their entire identity revolves around how others perceive them. They need social interaction, they need to be liked or even just acknowledged, so they need other people desperately to feel normal at all. Introverts have more agency in controlling their mental state because it depends on just them, extroverts need to placate and manipulate and try everything they know to get other people to give them what they want.

 

[bigshot]

I'm a happy person because I've decided to be happy and won't allow myself to be any other way. You have to work on being happy and not surrender. I surround myself with people I care about and things that inspire and excite me. I spend a lot of time doing things for other people and support them, and that doesn't give me time to worry about myself. I don't envy other people- I'm happy for them if they succeed. I don't judge myself by others, only by myself and what I know I can do. I'm always thinking about what's next, not something I don't have any more, and I have plans for how to get to the next level. I'm like a shark. If I stand still I die, so I'm always working on being satisfied with life and I am. I've accomplished a lot and I still have more to accomplish.

 

[gregorio]

I split it up so you can see clearly, the deltawave report is really confusing to try to look at lol.

Yep, not sure what I’m looking at. Is the top “Original Spectrum” just the 16kHz sine or with the shelf already applied?

G

 

[KinGensai]

Yep, not sure what I’m looking at. Is the top “Original Spectrum” just the 16kHz sine or with the shelf already applied?

G

The only factor changing in those two files is oversampling. Both have the 10dB high shelf EQ applied with the same settings and recorded using the same settings in Neutron MP.

 

[gregorio]

The only factor changing in those two files is oversampling.

Then I don’t know. There’s either something wrong with your test procedure or what EQ and other settings you’re using.

G

 

[KinGensai]

Then I don’t know. There’s either something wrong with your test procedure or what EQ and other settings you’re using.

G

Well, I accept that the EQ is not being used properly here as I'm not reducing the pre-amp gain to prevent overloading the audio like this (this observation is how I learned the importance of compensating with pre-amp gain), I'm just curious if this is an example of aliasing or IMD. You said in the previous post that oversampling would eliminate any possible aliasing, thus leaving other distortion products that are not aliasing, so I followed your prescription and got that result. If you would like, I'll leave the original unmodified file in the mega link so you can run your own quick battery of tests to see if they coincide with my findings.

 

[VNandor]

Based on the pictures of the spectrum and your description of how you're using the EQ, I'm almost sure you are clipping the digital signal. Clipping the digital signal indeed does cause aliasing. Oversampling could reduce aliasing if the oversampling (and the implied low-pass filtering) were inserted in the correct place of the signal flow. I think, as of now, the signal gets clipped which generates harmonics over the nyquist frequency (~20kHz) that wraps back into the audible range. The signal that already has the aliasing then gets oversampled and lowpassed which doesn't help. The oversampling should increase the nyquist frequency before the clipping occurs (and the signal should NOT get downsampled back), so the harmonics don't wrap back from around ~20kHz but from ~80kHz if you used 4x oversampling as an example.

By the way, do you not use the pre-amp when you're listening regularly?

 

[KinGensai]

Based on the pictures of the spectrum and your description of how you're using the EQ, I'm almost sure you are clipping the digital signal. Clipping the digital signal indeed does cause aliasing. Oversampling could reduce aliasing if the oversampling (and the implied low-pass filtering) were inserted in the correct place of the signal flow. I think, as of now, the signal gets clipped which generates harmonics over the nyquist frequency (~20kHz) that wraps back into the audible range. The signal that already has the aliasing then gets oversampled and lowpassed which doesn't help. The oversampling should increase the nyquist frequency before the clipping occurs, so the harmonics don't wrap back from around ~20kHz but from ~80kHz if you used 4x oversampling as an example.

By the way, do you not use the pre-amp when you're listening regularly?

I ran into what I recorded here early on when learning how to use a PEQ, so after I noticed this happening I made sure to reduce pre-amp gain by at least the highest peak.

I learned thanks to this thread that the DAC filter does not affect this in any way, just images in the source file that shouldn't be there.

 

[gregorio]

Well, I accept that the EQ is not being used properly here as I'm not reducing the pre-amp gain to prevent overloading the audio like this (this observation is how I learned the importance of compensating with pre-amp gain) …

I ran into what I recorded here early on when learning how to use a PEQ, so after I noticed this happening I made sure to reduce pre-amp gain by at least the highest peak.

Clipping was my very first suggestion as a cause and when you posted the second batch of files I naturally assumed you’d eliminated that possibility but now it’s unclear if you’ve actually done that or not, the two quotes above appear contradictory. Overload clipping is the obvious cause looking at the spectrum.

Also, what do you mean by “pre-amp gain”? I assume/hope you mean the “input gain”, the level of the digital signal going into the EQ. The input gain is what you should be reducing, not the gain on your (analogue) pre-amp which would NOT “compensate”. All that would do is lower the level of the signal that you’ve already clipped/overloaded in the digital domain.

G

 

[KinGensai]

Clipping was my very first suggestion as a cause and when you posted the second batch of files I naturally assumed you’d eliminated that possibility but now it’s unclear if you’ve actually done that or not, the two quotes above appear contradictory. Overload clipping is the obvious cause looking at the spectrum.

Also, what do you mean by “pre-amp gain”? I assume/hope you mean the “input gain”, the level of the digital signal going into the EQ. The input gain is what you should be reducing, not the gain on your (analogue) pre-amp which would NOT “compensate”. All that would do is lower the level of the signal that you’ve already clipped/overloaded in the digital domain.

G

Oh, I see what the problem here is, let me clarify what I am saying.

The objective of this exercise was to determine if I was identifying the type of distortion caused by this misuse of EQ correctly, which you said I was not doing correctly. I don't want to have a misconception about what I'm hearing, so I wanted your help confirming what type of artifact this misuse of EQ causes.

I was intentionally misusing the EQ to recreate the conditions under which I heard the distortion. The input gain (going by your description, that's what I'm adjusting) is labeled as "pre-amp gain" in Neutron MP, which is just gain in the toneboosters PEQ in USB audio player pro.

I was mistaken in thinking the DAC filter had anything to do with this, so thank you for that.

 

[gregorio]

The objective of this exercise was to determine if I was identifying the type of distortion caused by this misuse of EQ correctly …

It is entirely the wrong type of test for that! Firstly, you are not initially causing clipping, your EQ will almost certainly be operating at 32 or 64bit float, so effectively there is no clipping point. However, you’re then writing a 16bit file so at some stage the 32/64bit signal has to be converted back to 16bit fixed and at that point all bets are off. In theory you’d get a whole slew of ultrasonic odd harmonics, plus a bunch of harmonic distortion in the audible band but what you really end up with is entirely down to the coding. For example the coding may employ some sort of gain reduction to scale the 32/64bit output back to the clipping limit of a fixed point format, it might apply a limiter to do that, it may apply dither, an anti-alias filter, any or all of these things in combination, do something different or do nothing at all and just truncate the result (although that would be pretty incompetent), in which case you’d get aliasing along with truncation, harmonic and probably every other type of distortion. So it’s useless for “identifying the type of distortion” because it could be almost any type of distortion or even pretty much every type of distortion at the same time!

G