Computer Audio - which software player?

I'd always take a native conversion over an asynchronous one wherever possible, but I have no good sound quality reason for holding that bias.

 

How many shares do you have in Apple, exactly, JC?

I do use iTunes. I have a iPod Touch which I use as a control point for my Akurate DS, and for listening to music on the go

So I have to use that bloody program to transfer stuff from the computer to the Touch. It is truly a bag of shite IMO.

Some questions, which you as an avid Apple fan may know the answers to:

1. WTF does the touch and iTunes not support FLAC?
2. What is the best way to jailbreak the Touch so that I do not have to rely upon bloody iTunes.

Chris

 

1. Proprietary software and the 'not invented here' syndrome
2. Try mediamonkey's neat little partial iTunes by-pass (see 'Necessary Components'): http://www.mediamonkey.com/wiki/index.php/Guide_to_ipod_sync

If you turn your Touch into an iBrick, don't blame me!

 

So, you're telling me that every CD ever made is fatally flawed are you ? .....

....... I don't think so ...................

If it is happening to you, you possibly need to repair your equipment.

What's AVI got to do with it ? ..... or is this just an attempt to inject some thread crapping. ..... get a life

JC.

 

A few, .... like many people don't you ?

If you had bought Apple shares 5 years ago for £1000 they would be worth £6000 by now. That's your investment paid back every year six times over .......... sems a no-brainer to me ........... but there again some people have no brains.

Well done, .... shame about the Akurate ........ another poor decision I'm afraid (imo of course)

Your opinions don't seem to be getting you very far, on the basis of what you've told me so far, perhaps a re-think might help ?

My answers ......

1. Flac is ok, it's lossless, but beyond that it's just not very useful. Apple use lossless as a transmission protocol across their range of software and hardware devices and hence they need that protocol to be under their control so that they can maintain their high standards of sound quality and satisfactory use with their highly integrated devices and systems. Lossless is lossless, and you can convert flacs to something more appropriate very easily and quickly. I do it whenever necessary, but generally I don't bother with flacs.

2. Imo the iTouch is heavily integrated with iTunes, .... perhaps with your views and opinions it was yet another mistake to buy an iTouch. Quite what you would choose as an alternative though, I dread to imagine. You might make another decision which brings you nothing but trouble and grief. From what you've told me so far, as I said earlier, you possibly need to re-think. I hope you get it right next time.

JC.

 

Apple lossless is Flac, the compression is the same it's just a different file wrapper.

 

Close, but not correct, ........

ALAC data is stored within an MP4 container with the filename extension .m4a.

ALAC is a lossless format that uses linear prediction similar to other lossless codecs such as FLAC.

FLAC version development is not subject to Apple regulation, whereas ALAC is, in order to maintain compatibility and consistent compliance with Apple's required specifications.

However lossless is lossless so in the real world just use it or convert it either way. It doesn't affect the sound.

JC

 

I think maybe you need to read more carefully?

Your response proves my point!

Paul

 

Paul, ... I can read perfectly well thanks, ...... you have failed to take my point ....

24/96 is a perfectly valid, and indeed very common, format used in professional recording technique, and used almost universally for producing master recordings intended for release on CD.

Those masters are then converted to 44.1 for final release, without spoiling the sound quality, and to use your term, without 'something missing'. Otherwise all Cd's would be flawed, which obviously, they are not.

If when using this process on your equipment, then 'something is missing', it's very likely that your equipment is causing the loss, since we know that not all CD's are faulty in this respect.

Obviously you need to re-think your problem, re-examine your equipment, and not just automatically assume that it is the process which is at fault.

I still cannot see what AVI has to do with it ? .... and since you have not provided a proper answer, ......

......... I can only assume that your snide remark about AVI is merely thread crapping, and an attempt to de-rail the thread with inappropriate insults.

If you have a better, and more relevant explanation let's hear it

JC

 

John, I raised earlier the possible problems of non-integer down sampling?

Clearly they are thought to be unimportant, but in CD production would it not be tidier to master at 24/88.2 (or 24/ 176.4) and then go down to 16/44.1?

We seem to be caught by the history - CDs came out at 14/44.1 but early DAT had a sampling rate of 48k.

 

CD was developed from Phillips laser disc, which was originally a video standard, and that's how 44.1 got used.

DAT was developed by Sony using VCR helical scan technology, as opposed to laserdisc.

The DAT standard allows for four sampling modes: 32 kHz at 12 bits, and 32 kHz, 44.1 kHz or 48 kHz at 16 bits.

Both DAT and CD are 16 bit standards, and for all intents and purposes DAT is obsolete, and CD is obsolescent.

What has replaced them is equipment based around 24 bits, which gives big advantages in headroom for recording and mixing purposes. The commonly preferred sampling rate is now 96kHz because it is effective and cheap to implement now that all professional recording is done in the solid state or hard disk environment.

CD recorders and Tape recorders are dead and gone.

However CD contains no copy protection facilities, and there is still widespread use of this format in domestic audio reproduction.

So, the producers of recorded music are faced with the dilemma of having to record with one standard and publish with another. It is perfectly possible to translate from one to another and a dithering method is usually chosen which avoids the problem raised by Brian (Labarum) of "96 into 44.1 don't go".

This dithering process is entirely successful on good equipment, and does not result in any detectable audio quality loss, as can be confirmed by the many excellent recordings published on CD.

JC.

 

You have no way of knowing this.

IME with recordings I've made at 96k, downsampling to 44k1 is 'worse' than to 48k. Not catastrophically worse but worse. This is an opinion. The loss, if there really is one, is minute compared to the mastering deficiencies of most modern CDs.

You are associated with AVI and I knew you'd disagree in a black and white way.

Paul

 

FWIW dithering really isn't relevant to the resampling process, other than generating the output from the higher precision internal values.

And the only way you can determine 'detectable audio quality loss' is with the original, the downsampled result, and a very competent player and monitoring system. The fact that some CDs sound excellent tells us nothing other than some CDs sound excellent.

Paul

 

Yes I do, I have produced CD's for distribution, from original recordings made from live performances.

Agreed (about the mastering deficiencies), but you should still take my advice. It may improve your results.

I am simply an AVI equipment owner and user who has become friends with Ashley and Martin. There are many owners in that category.

I have no commercial association with AVI other than to have repaired their computer equipment when it was producing distorted sound. That was over three years ago now. they were using Dell equipment at the time, and I understand they mainly use Apple equipment now, which they tell me is largely trouble free.

You seem to be somewhat confused about the facts.

JC.

 

These notes (not mine btw) may help you understand a bit better Paul.


"Are you one of those who thinks 96 khz (DVD-A) is more precise than 44.1 khz (CD)?
Well, it's not.. In fact, it's as precise as analog... Find out why.


Before going into the issue, let me let you know that I work in 96 khz, or 48 khz (enough) or above (192 khz for fun as I write), but not because 44.1 khz is less precise - the higher sample rate tends to compensate for worst A/D conversion stage, ergo, it's a cheaper way of making good converters, at the expense of more storage and CPU.

More ahead... In English, as much as possible.


Fourier and Nyquist

Nyquist tell us that to accurately get a sampled wave you must use a sampling frequency equal to twice the frequency you wish to sample. With 44.1 khz you can sample up to 22.05 khz bandwidth signals. Fourier tells us that every wave is but an addition of sine-waves at different frequencies and amplitudes. So, at any given point, what you sample is an addition of sine waves.
Ok, now lets introduce and examine false argument #1 towards 96 khz being more precise than 44.1 khz.

Maximum frequency

Each sample is a "photo" of the sound wave position in time. A sound is but a "wave" that wobbles up and down at a certain frequency and we hear it. Many will say that between a 44.1 khz sample and the next one there will be a lot of "unsampled" variations. Agreed. But now here's an issue...

All the things "in between" the 44.1 khz samples HAVE to be signals at a frequency SUPERIOR to 22.05 khz, hence, we don't care anyway! (Our ears, for that matter.)

Precision

So here's a shocking truth: the precision at 20 hz-20 khz of a sampled signal at 44.1 khz, 96 khz or even analog is EXACTLY the same, all are equally precise in the below Nyquist limit bandwidth.

Why 96 khz then?

Now things get complex, but first it's because it's cheaper to produce a more accurate sampler /converter using 96 khz, whereas to achieve the same degree of fidelity with a 44.1 khz one would require more expensive design.
But I digress, as I said, a sound wave is a wobbling signal that goes up and down. This up/down can vary up to 22.05 thousand times per second to be sampled by 44.1 khz rate accurately."

In fact all that is lost when correctly converting higher sampling rates down to 44.1 is stuff that was inaudible by humans in the first place.

That is why 16/44.1 was correctly defined in the first place as entirely adequate for high quality sound reproduction, but 24 bits are necessary in the recording environment.

Beyond 44.1 sampling rates, the improvement in sound quality is not audible by humans, but the equipment is much easier and cheaper to manufacture to the required standard.

JC.

 

I thought the issue was not the sampling rate, but the non-integer re-sampling which must necessarily introduce computational approximations.

 

The point is Brian, that the nyquist calculations show, that using an appropriate down-sampling technique to 44.1, all that is lost is the super-sonic information above 22kHz contained in the higher sample rate file, but which is not audible to humans anyway.

If you can actually hear a difference, rather than just imagining you can, then your process or equipment is possibly at fault somewhere.

John. (JC to the rest of you)

 

They do not address the resampling issue.

The issue is essentially that you have to upsample the 96k sequence to 14MHz and then downsample to 44k1. Which is a non-trivial process to do correctly and quickly.

Paul

 

It might be non-trivial for you as a human to perceive, but computers, in the digital domain, do it easily.

 

Anyway that is only one way of achieving the desired result.

The real point is that millions of CD's are produced to the 16/44.1 standard without compromise of the kind under discussion.

Poor recording and mixing technique, and excessive use of audio compression is another matter entirely.

There is absolutely nothing wrong with releasing the music for publec consumption in its original, say 24/96, format, except that it then implies downloads, and a problem with the large file sizes, or distribution on usb flash-rom sticks or similar cards, and the requirement for users to have equipment capable of using those formats.

Generally Disc media is on the way out, but at the moment CD red book 16/44.1 is ubiquitous and entirely satisfactory as far as audio quality is concerned.

JC.