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Old 13 January 2017, 00:13   #41
demolition
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Quote:
Originally Posted by Thorham View Post
My A1200 sounds pretty good when playing back WAV files, so I don't know where you got that from
I know many people don't like it if you say that Paula sounds bad, but objectively it does, no matter how good you feel that it sounds.
It cannot reach CD quality on neither bandwidth nor signal-to-noise ratio and that is why 16 bit 44.1kHz is enough for sampling Paula audio. Yes, it does generate >20kHz harmonics which are removed when sampling it, but unless you're a labrador you cannot hear that anyway..
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Old 13 January 2017, 01:25   #42
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Originally Posted by demolition View Post
I know many people don't like it if you say that Paula sounds bad, but objectively it does, no matter how good you feel that it sounds.
There's no such thing as objective sound quality, because sound only exists in the mind, just like color

As for it sounding bad, I've played back many 16 bit stereo 28khz WAVs (down sampled with Sox) on my A1200, and most sound fine. My peecee can do better, but bad? No... although some classical music doesn't sound great.
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Old 13 January 2017, 01:30   #43
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Originally Posted by Thorham View Post
There's no such thing as objective sound quality, because sound only exists in the mind, just like color
Sound is physics and so are colors. Thus it can be treated 100% objectively. Sound quality on the other hand can be a subjective term, but it can also be treated objectively in terms of noise, distortion etc. and that is what am referring to.
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Old 13 January 2017, 01:43   #44
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Sound is physics and so are colors.
Not exactly. Sound is the brain's interpretation of vibrations in a physical medium measured by the ears. Color is the brain's interpretation of the frequency of photons measured by the color receptors in the retina. Sound and color don't exist physically.

This is the same as measuring sound with a sampler and displaying it as a wave form, as a bitmap, or as a bunch of numbers. The data that comes into the brain as measured by the sensory organs is just that, data, and that has to be interpreted before it means anything.

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Originally Posted by demolition View Post
Sound quality on the other hand can be a subjective term, but it can also be treated objectively in terms of noise, distortion etc. and that is what am referring to.
No argument there.
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Old 13 January 2017, 01:45   #45
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https://www.google.com/search?q=sound+definition
Quote:
noun
1.
vibrations that travel through the air or another medium and can be heard when they reach a person's or animal's ear.
"light travels faster than sound"
2.
sound produced by continuous and regular vibrations, as opposed to noise.
Nothing to do with interpretation here..
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Old 13 January 2017, 02:02   #46
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Originally Posted by demolition View Post
https://www.google.com/search?q=sound+definition

Nothing to do with interpretation here..
That's what air vibrations are commonly called, yes. Physically it's still just vibrations, and you don't hear anything until the brains interprets the incoming data as sound. If this wasn't the case, then why can you hear sound and see color in your mind when dreaming, for example?

Vibrations in a medium and the frequency of photons are physical properties, sound and color are interpretations of these.

Just check out this page: https://www.washingtonpost.com/news/...=.36f02e15f94a
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Old 13 January 2017, 02:14   #47
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If nobody's around when a tree falls in the forest, does it then not make a sound?
According to you it doesn't - according to me it does.

Sorry, but I stick to the dictionary definitions of sound and color as being physics..
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Old 13 January 2017, 02:18   #48
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Sorry, but I stick to the dictionary definitions of sound and color as being physics..
The dictionary definition is just the common way of referring to these phenomena. Strictly speaking they're not physical properties.
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Old 13 January 2017, 02:19   #49
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I guess I'll stop here or it might turn into this:
[ Show youtube player ]

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Old 13 January 2017, 02:35   #50
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Quote:
Originally Posted by demolition View Post
I guess I'll stop here or it might turn into this:
[ Show youtube player ]

While you certainly have a point here, what I'm referring to is the difference between common definitions and science. Gravity is a good example:
Quote:
Originally Posted by Google
the force that attracts a body towards the centre of the earth, or towards any other physical body having mass.
If you know Einstein's theory of general relativity, then you know that that definition is wrong, because in Eintein's model gravity isn't a force.

Common definitions aren't always scientifically accurate, and they shouldn't. Saying 'Those are some mighty fine air vibration interpretations' just isn't a practical way of saying things, so we commonly call those vibrations sound, even though it's not scientifically accurate.

Anyway, this is quite off-topic
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Old 13 January 2017, 02:36   #51
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My turn to say: Wow.
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Old 13 January 2017, 02:39   #52
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My turn to say: Wow.
Yeah, it's VERY off-topic, sorry about that
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Old 13 January 2017, 05:58   #53
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Wow... not sure the original point of this, but I'll chime in.

So, you're starting with Amiga 8-bit samples. That's 8-bits of information per channel. If you actually have two left and two right, you can mix them for a 9-bit result. That is all of the original information you will ever have.

And sure, you can convert this to 16-bits. But you still only have 9-bits of actual information, or 54dB DNR, if you want to look at it that way. You can convert that to 24-bit or 32-bit, doesn't matter, you still only have 9-bits of information. The converted format (no point, really, in going beyond 16-bit) will make it easier to manipulate with modern tools, but it's not going to make it sound any than the 8-bit sample. Of course, converting the original digital versus playing through Paula, that ought to be an improvement.

Same thing basically goes with sample-rate upconversion. The software is going to interpolate, and there's very good software for that, but your'e still going to have sound frequency limited.

Not sure why you'd mix left and right channels... maybe you get a more natural sound that way. I haven't specifically played with anything like this, and after a point, all sound tweaking is more art than science.

I have absolutely no idea why there's a compressor even being mentioned. The very last thing I want is to take my 8-bit or 9-bit sample and reduce its resolution any more. Maybe I'd play around with an expander, but no, never a compressor. And absolutely not one that's clipping ... that's just bad work.

I have zillions of various audio plug-ins designed for various purposes. It's possible that you might find something that would make the sound more pleasing. That's of course changing the original sound -- all you can ever do is reduce the amount of information from the original sample. But again, it's the art... perhaps a DSP algorithm meant for
"clarity" or some other generic function would be useful.
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Old 13 January 2017, 06:11   #54
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Creating music is an art so there are no definite rules as to how one should do it. If you think something sounds good, then go ahead with it no matter what other people say is 'correct'.

From a purely technical perspective it makes a lot of sense to use a compressor prior to applying an 8 bit quantization so you can squeeze as much detail as possible into that limited dynamic range. It is harder though to see the reason why one would apply even more dynamic compression on the audio after this quantization. One reason could be if you like the effect of the quantization noise which is not totally weird. It is one of the reasons why 8 bit audio has this 'crunchy' sound that many people like.
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Old 13 January 2017, 07:19   #55
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I don't get it either. A1200 + Delitracker's 14bit headphone mixer and the original mods already sounds better.
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Old 13 January 2017, 08:27   #56
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Originally Posted by Pat the Cat View Post
Too late, I've found out what your issue is - your levels suck. Your version is so quiet, you have to listen at 80% volume to hear anything.

My version, 30% volume is plenty. That's why you think mine is distorting - it will unless you turn your levels down.
Whoa you really did not lie when you said you are not an audio engineer, did you?

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Or are you saying that clipped audio automatically = crap audio, and therefore, the Prodigy produce crap music?
Clipped audio is of course by definition "crap audio". Unless, of course, clipping is used as a deliberate effect like Prodigy does. Are you Prodigy?
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Old 13 January 2017, 09:16   #57
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Nice flame wars in here. May I participate ?

Accuracy doesn't always mean quality.
If your sound contains bad noises to start with, if you play it with max accuracy you will hear all its shortcomings, i.e. poor quality.
The Amiga audio does a good job filtering these away, which means some kind of distortion, but this is nevertheless good quality. So no, it's not "bad" at all, at least not when playing mods.

Of course excessive clipping damages the sound further but, like any sound change, it may be intentional by the musician.

Oh, by the way... (I couldn't resist)
According to quantum physics, if nobody's around when a tree falls in the forest, it both makes a sound and doesn't make it
(and worse, in fact it won't really have fallen unless someone is there to see it )
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Old 13 January 2017, 10:09   #58
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Oh, by the way... (I couldn't resist)
According to quantum physics, if nobody's around when a tree falls in the forest, it both makes a sound and doesn't make it
(and worse, in fact it won't really have fallen unless someone is there to see it )
Okay, let's go off-topic again

1. Observers don't have to be conscious entities.
2. Sound isn't a physical phenomenon if you forget about the common definition.
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Old 13 January 2017, 14:46   #59
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Let's please stop with this and stick to topic, what's left to do here, talk about the Earth being flat and Pizzagate?
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Old 13 January 2017, 15:12   #60
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Originally Posted by paul1981 View Post
Amigas have 4 channels each with independent programmable non-conformant sampling rates - it can't be 100% accurately recorded or emulated by ANY computer system or digital recorder...it can only be approximated.

A healthy starting point in this project would have been to individually save the instruments and upscale them seperately, but that would obviously entail rewriting the song.

To be honest, my extent would be to put the Amiga audio filter on, record at 192 KHz 24 bit or above straight out of the Amiga phono jacks, then apply compression and eq to taste. Job done! I don't have 192 KHz capability, only 96 KHz 24-bit but that would be okay too.

Could add some echo I suppose if it needed it, but it would have to be decided amount and type for each song. Perhaps some stereo reduction too, perhaps not in some parts of the song though, or perhaps in most parts of the song and then full stereo in particular places (could have fun with echo here and things).
Hooray! Somebody who actually understands Amiga audio. I wasn't trying for best quality possible, I was trying to emulate a viable hardware sound enhancer realistically. Indeed, capturing each of the 4 channels individually, and then mixing them, would give better fidelity.

Here's the way it really works - you have two 8 bits channels on left, two on right. Each 8 bit channel also has an amplitude control (volume), 0 being off, 1 being 36.5 dB loss, and the others arranged on a logarithmic scale with regard to decibel level up to 64 (full volume). So it isn't QUITE 14 bits on each channel, and when you sum that together, you get a 15 bit number, on each of the left and right channels.

A 16 bit sampler should in theory cope, but that's assuming that it has the same mid point as Paula output DACs. Even a .1% difference, you start losing some information. But 44.1KHz isn't enough sometimes - some audio can outshoot that.

The Amiga has two ways of doing Audio - Paula and the CPU. Paula limits you to 28,867 samples per second playback on NTSC, a little higher on PAL (which is why a tiny minotiry of Amiga audio doesn't play on NTSC systems).

So it's a completely different ball game if the sound playback uses the CPU to time things, which was used on some demos. Suddenly you are not limited to 28.867 KHz and can even output faster than the 44.1KHz of CD, as far as sampling and playback rate go.

This is why you should not depend on 16 bit hardware sampling of Amiga audio. It cannot capture the entire dynamic range. It will give you 99% guaranteed, but if you want complete accuracy, then things are a lot trickier.

The original demo samples usually came from vinyl or tape. Often the sources were speeded up when sampling, either to save memory space for the sample, or to capture sound at a high sample rate and play it back.

Don't think all Amiga audio is limited to 28KHz 8 bit 4 channel. It wasn't and isn't. Paula was, but even then, the volume control of each channel adds more dynamic range to what you can play back.

If you don't believe the above, check out the "Audio Hardware" section of the Amiga Hardware Reference Manual (any edition should do).

Quote:
Originally Posted by Thorham View Post
My A1200 sounds pretty good when playing back WAV files, so I don't know where you got that from
I would love to have uploaded some WAV equivalents for Amiga users to play back... but github limits to a 25mb file size. I guess I could put a zipped wav up, or lha maybe... nope, didn't work. Zipped version is even bigger than the original wav. Sorry.

Last edited by Pat the Cat; 14 January 2017 at 15:05.
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