[Zeebra]

Seen that hi-fi as a whole has a plenty of terms you might not be familiar with in your everyday life, I would love to have a few audible examples that make it very clear to the listener, what sort of a feature or flaw in the sound are they listening for. Another reason for this "reference library" would be, that some features are difficult to spot and learn by themselves even if they would be present, but an exaggerated example would make it much easier to spot them in the future, and it would act as a very good reference for newcomers into the audio world, in my opinion.

Some things I thought might be difficult actually understand what they sound like, without hearing them first:

• intermodulation and harmonic distortion
• track fed through a tube (of course, heavily exaggerating the tube's distortion etc)
• compression and limiting
• aliasing
• bit depth (for example: gradually going down from 24 to 1 much akin to what bit crusher effects do but I don't know are they accurate)
• frequency response (recessed/emphasized low/mid/high)
  

few questions arise:
1. would this sort of a library actually make sense, what terms should it include?
2. what would be a good reference track, and who would actually feel like doing all this?
3. format? I suppose 24-bit/44.1KHz lossless but nothing less would do.
4. would it be most sensitive to stick to measurable terms, and not venture into the dark/warm/natural/neutral/analytical-terms?

 

[stv014]

I can do all of these, with the exception of "track fed through a tube".
 

 

[Zeebra]

Someone else could do that, or if there's a way to accurately simulate tubes with a VST plugin, and we could get a green light from someone who knows how tube distortion sounds like (in headphone and speaker amplifiers, not guitar or bass cabinet amplifiers), then that would be swell!

 

[Zeebra]

Jitter is one thing I would like to hear in an example like this, too!
I found this cool video with some things, like noise at several volumes among music material and bit crushing; http://www.youtube.com/watch?v=BYTlN6wjcvQgives some scale to things, high quality samples in description

 

[stv014]

Quote:

Jitter is one thing I would like to hear in an example like this, too!

It can be simulated, too, although I had to make it really bad to be clearly audible. Do you have a good sample file to apply the various effects to (preferably not very long, as the total size would get fairly large due to the number of different effects) ?
 

 

[Zeebra]

it's cool, gives a very good sense of scale if you've got it audible only in massive jitter vs the miniscule differences between transports and DACs etc.
I could try getting a good sample, was thinking of classical, a short passage of Canon in D Major or the such

 

[jlo]

you can try this soft :
http://www.ohl.to/about-audio/audio-softwares/distorder

 

[Clarkmc2]

Quote:

It can be simulated, too, although I had to make it really bad to be clearly audible.

That is because any normally encountered jitter is inaudible. I am amazed how much people worry about it.

 

[Zeebra]

That is because any normally encountered jitter is inaudible. I am amazed how much people worry about it.

That's what I've been told and what I've read, and due to it's inability to be heard during situations where equipment is functional, I'd love to hear it, to give some perspective how little of it there is in ACTUAL usage scenarios. Cheers!

 

[Clarkmc2]

Quote:

That's what I've been told and what I've read, and due to it's inability to be heard during situations where equipment is functional, I'd love to hear it, to give some perspective how little of it there is in ACTUAL usage scenarios. Cheers!

Cool! Let us know what it sounds like when you get to hear a sample. I'm curious too.

 

[Zeebra]

Cool! Let us know what it sounds like when you get to hear a sample. I'm curious too.

The idea was to publish the short examples in a downloadable form for everyone so it could be used as a reference when searching for faults in playback equipment. I think it would benefit a lot of people, seen that many speaker and headphone reviews paint very expressionist scenery with the language they use in reviews, without saying much facts about the reviewed equipment. It's better to be able to hear the features you're avoiding yourself, always better trust your own ears and actual measurable factors than "darkness" or the such, although admittedly many of those terms are quite easily understood as something more down-to-earth

 

[stv014]

Here is a set of FLAC files that attempt to show some audible jitter-like effects that I implemented by frequency modulating the original signal with a mix of pink or brown noise and some tones. The "jitter" is the same on both channels, so the effect is mono (it could easily have been made stereo, though, or mostly mono with partly stereo noise). jitter1.flac to jitter3.flac have decreasing amounts (and slightly different types) of jitter. jitter4.flac is recorded from Realtek ALC887 on-board audio for comparison. orig.flac is of course the original sample. It includes the jitter test signal at the end (warning: lout high pitched tone), so you can check with an FFT display how bad the jitter is. I have also added a simple piano note before that, on which the effect may be more easily audible than on complex music.
 
EDIT: another file with mainly noise jitter and also some stereo effect (delay modulated by pink noise): jitter5.flac
 

 

[LFF]

Quote:

Seen that hi-fi as a whole has a plenty of terms you might not be familiar with in your everyday life, I would love to have a few audible examples that make it very clear to the listener, what sort of a feature or flaw in the sound are they listening for. Another reason for this "reference library" would be, that some features are difficult to spot and learn by themselves even if they would be present, but an exaggerated example would make it much easier to spot them in the future, and it would act as a very good reference for newcomers into the audio world, in my opinion.
Some things I thought might be difficult actually understand what they sound like, without hearing them first:

1.  
2. intermodulation and harmonic distortion
3. track fed through a tube (of course, heavily exaggerating the tube's distortion etc)
4. compression and limiting
5. aliasing
6. bit depth (for example: gradually going down from 24 to 1 much akin to what bit crusher effects do but I don't know are they accurate)
7. frequency response (recessed/emphasized low/mid/high)

few questions arise:
1. would this sort of a library actually make sense, what terms should it include?
2. what would be a good reference track, and who would actually feel like doing all this?
3. format? I suppose 24-bit/44.1KHz lossless but nothing less would do.
4. would it be most sensitive to stick to measurable terms, and not venture into the dark/warm/natural/neutral/analytical-terms?

 
You're basically asking for a studio set-up/training disc. There are a few you can buy but most are very expensive just because it's such a niche product - especially if you want it with all of the things you listed.
 
A studio owner I know recently hired a new guy (ie, non-paid intern) and the new guy purchased a training CD for the cool sum of $120.00 and it completely missed out on common artifacts like space monkeys or warping.
 
Still....neat idea.
 
 

 

[liamstrain]

Haha! I wasn't sure how far flung the "space monkey" name is for that...for some reason I thought that was something my boss just called them. A quick web search shows me wrong tho.  
 
Example: http://www.emusician.com/emusician/web_clips/AudioRes.WC01.mp3

 

[nick_charles]

Quote:

That is because any normally encountered jitter is inaudible. I am amazed how much people worry about it.

 
That would be a combination of OCD and egregious scaremongering marketing by some manufacturers and some hifi mag writers. To date, to the best of my knowledge there has never been any properly controlled test that indicates that even the worst form of jitter (signal correlated) is audible below 10ns, a figure that indicates truly incompetent engineering and which can only be found in a very small number of commercially available components, inc the McIntosh Music server. Such jitter figures are always a sign that something else is also fundamentally crappy. Stereophile measurements show that poor jitter is always accompanied by other serious flaws.
 
On the other hand the makers of and proponents of $1k+ reclockers and other specialized jitter busting devices cannot point to good empirical listening data for relevance only to poorly controlled demos and endless anecdotes. The Benjamin and Gannon paper of 1998 really should have put this issue out to grass.
 
 
Here is an old thread with some more jittered samples from a forum in blighty  http://hddaudio.net/viewtopic.php?id=63