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John Carrod
2005-12-01, 07:48
I have just bought a Squeezebox 3 and my main question is this.
I have used EAC configured as per, to rip a cd.
I have then used another prog to convert to 24 bit 48,000 hz
This has caused no end of problems.
Slow playback, distortion and jumping/sticking and non use of the fast forward button.
Is this due to the computer, the hub or squeezebox.
If I save at 96Khz the whole thing slows down to snails pace.
I have had a 24 Bit CD player for some time and enjoy its level of presentation over a conventional 16 bit player.
I am merely trying to get a sound close to my present cd player using the above.
JC

radish
2005-12-01, 08:05
I really don't think you'll get any improvement by resampling a 16bit 44.1kHz source file to anything else, you can't magically create data that's not there to start with. In fact, you're quite likely to lose quality due to aliasing etc. Of course, if your source material is 24/96 then that's a different matter, but that's not the case by the sound of it.

RADIO ARCHIE
2005-12-01, 08:26
Hi,
I follow your drift, but when listening to a 16 bit cd in a 24 bit player there is a marked difference in the overall ambiance of the sound and as the Squeezebox has a 24 bit dac one may as well use it.
Taking 16 bits data and changing its format can I think alter its wave form and therfore its presentation to the ear.

RA

radish
2005-12-01, 09:03
A 24bit CD player is taking 16bit material (from the CD) and running it through a 24bit DAC, and the sound benefits because the inaccuracy at the bottom end of the DAC is below the LSB of the signal (at least that's how I understand it, happy to be corrected). Taking a regular 16bit file your SB does the exact same thing. However, if you resample that 16bit file to a 24bit file first, you're expanding the width of the signal, possibly adding quantisation effects and pushing the LSB of the signal back into the bottom of the DAC.

In short - you still benefit from the 24bit DAC even if the source is 16bit.


Taking 16 bits data and changing its format can I think alter its wave form and therfore its presentation to the ear.

Exactly. And that's what most people spend all their time trying to avoid.

John Carrod
2005-12-01, 10:32
I am most certainly trying to acheive this.
As the 24 bit sound has more of what actually happened in the studio.....

radish
2005-12-01, 11:18
I am most certainly trying to acheive this.
As the 24 bit sound has more of what actually happened in the studio.....
No, it doesn't. Go back to my previous posting - you cannot get back data which has been lost. Impossible, not going to happen, end of story. It's like turning a WAV into an MP3 and then back to WAV and expecting somehow to magically end up with the same sound, or ripping 1 out of every 3 pages from a book and asking someone to make up whats missing.

When the recording was made (assuming it was at 24/96) you had 24 bits of resolution. Then the CD was mastered at 16 bits - you've lost those 8 bits forever, it's essentially a form of lossy data compression.

John Carrod
2005-12-01, 14:29
I think maybe I have misinformed,
I am trying to get the same result as playing a cd on a 24 bit cd player, by:
1, recording the cd using EAC to 16 bit
2, using a prog to change that to 24 bit 44,100 hz flac signal.
it actually gives an output close to using a 24 bit cd player.
which of course the squeezebox is.
If the output from a 24 bit cd player improves the cd signal then altering the wav signal to 24 bit signal has the same effect.
I am as I say just aiming for an overall ambience from the squeezebox.

RADIO ARCHIE
2005-12-01, 14:45
I think we will agree to disagree............

abdomen
2005-12-01, 15:01
I think maybe I have misinformed,
I am trying to get the same result as playing a cd on a 24 bit cd player, by:
1, recording the cd using EAC to 16 bit
2, using a prog to change that to 24 bit 44,100 hz flac signal.
it actually gives an output close to using a 24 bit cd player.
which of course the squeezebox is.
If the output from a 24 bit cd player improves the cd signal then altering the wav signal to 24 bit signal has the same effect.
I am as I say just aiming for an overall ambience from the squeezebox.
What folks have been trying to explain is that the 24-bit piece of your CD player is its DAC (digital/analog conversion). That's the part, to be simplistic, that takes the numbers on the CD and turns them into the electrical impulses that, once amplified, will drive your speakers. The Squeezebox has a 24-bit DAC and will use those bits during playback the same way your CD player does as long as you send the Squeezebox all the data as it is on the CD (i.e. in 16 bit form). The digital to digital bit-depth-increase conversion you have been playing with does the equivalent of removing the number 50 from a slot that can hold numbers up to 100 and putting it into a slot that can hold numbers up to 1000. The numbers have not changed. I hope this alternate explanation may help. *shrugs*

radish
2005-12-01, 15:16
If the output from a 24 bit cd player improves the cd signal then altering the wav signal to 24 bit signal has the same effect.


No, it won't.

What is the input to a 24 bit CD player? 16 bit.
What is the width of the DAC in a 24 bit CD player? 24 bit.
How many "spare" bits are available on the DAC? 8.

Those extra 8 unused bits are what gives the CD player it's advantage over a 16 bit one, the conversion noise is pushed way down below the signal, improving SNR.

What is the input to a SB3 with a regular flac file? 16 bit.
What is the width of the DAC in a SB3? 24 bit.
How many "spare" bits are available on the DAC? 8.

Exactly the same as the CD player.

What is the input to a SB3 with a resampled flac file? 24 bit.
What is the width of the DAC in a SB3? 24 bit.
How many "spare" bits are available on the DAC? 0.

Oops. By resampling your input to 24 bit you are losing that unused space, and thus, getting the same output as if your DAC was only 16 bit. In other words, you are making the final sound quality worse. Don't do it.

radish
2005-12-01, 15:21
I think we will agree to disagree............

I'm not saying a 24bit DAC doesn't improve sound compared to a 16bit one, of course it does, as I have stated a number of times. Luckily, the SB has a 24 bit DAC, hence that improvement is already present when you feed it 16bit files. But resampling a file from 16 to 24 WILL NOT HELP ANYTHING, in fact it will make the sound LESS like the original recording, as you will be lowering the SNR. If that's more pleasing to your ears, great, go for it. But do not kid yourself that you're getting closer to the original, you're going further away.

And if you disagree with that, I give up.