Minor victory thread

Bubble181

Bubble181

fade and PatrThom -> I only clicked informative on one of each post, but I foudn the conversation interesting, obviously. I love pipe organ, and I've often wondered why it seemed to me that pipe organ suffered much more from being played on low-quality devices than most other things I listen to. Now I know.

But why are you both going "only" to 96 kHz? I've listened to SACD's that claimed 128 kHz (not that I could tell much of a difference - my speakers aren't gold plated :p)
 
PatrThom

PatrThom

My understanding Bubble181 is that the best digital reproduction of analog sound is limited to 1/2 your total sample frequency (which is what Fade and I were discussing), which means a 128k SACD would adequately reproduce up to 64kHz. I have some 24bit 96kHz DVD-audio media which was included with my Soundblaster card in an effort to show off its ability to reproduce really high fidelity sound*. Thus, even if your sample rate is as high as 192kHz (which is ridiculous for human use), that halfway mark of 'best reproduction' would top out at 96kHz. Human hearing tops out around 20-24kHz, which is part of why CD audio is sampled at 44kHz (44/2 = 22kHz).

The sample rate is only half the equation, of course. To imagine sound as waveforms on a graph, the sample rate is akin to the X-axis. The higher the sample rate, the closer together and more fine-grained your reproduction of the frequencies involved. Here's a crude representation:
medgrid.gif

Sample rate:16bit 44kHz

finegrid.gif

Sample rate: 16bit 88kHz (double the above)

If you could only draw your sound wave by completely filling in existing boxes, you can see that using the second grid has a better chance of being closer to the original, and the higher the sample rate goes, the closer and closer it gets. But to get even better reproduction, you also need to increase the sample size. Going from 16bit to 24bit gives you a 50% finer-grained Y-axis and lets you more accurately reproduce the amplitude of the frequencies involved.

tinygrid.gif

Sample rate 24bit 88kHz

Again, as the quantized boxes get smaller and smaller (in height, width, or both), the approximation of the original smooth and curvy analog waveform loses more of its 'jaggies' and becomes more accurate...but at the cost of greater and greater file size. 96kHz just seems to be where the world decided audio was "good enough" for even the discerning people, the same way that 600dpi became "good enough" for scanners/printers, or 1080p (1920x1080) at 60Hz was chosen as "good enough" for televisions/monitors.

fade may jump back in with a thing or two to check my work, I look forward to his comments. :)

--Patrick
*There were a lot of safeguards built in to make sure you couldn't digitally extract the high-quality audio, too. It would disable digital out, for instance. It was like the early days of HDCP.
 
fade

fade

Staff member
It all depends on the DAC and the hardware/software that comes before the DAC stage. The thing is that unlike a picture, we know what the fundamental components of a sound wave are. I wondered after this discussion if the original WAV file designers misapplied the Nyquist theorem. The Nyquist theorem says that a signal up to half the sampling frequency can be exactly reproduced in analog. No jaggies at all. But there is an analysis and synthesis stage that has to happen for that to be true. The problem is that if the signal gets dumped straight to a DAC, that never happens, and PatrThom is exactly right. I'm sure that's what really cheap players do.

I'm talking off the top of my head here, but I'm guessing that that is not what happens in a better player. There is some attempt to smooth the jaggies since you know precisely what they should look like up to the Nyquist frequency. Again, sheer guesswork based on a lot of experience, but I would say it upsamples an interpolates at the very least. A really nice player probably does full analysis and synthesis. That's why your digital receiver looks like a computer and runs hot. It is.

(EDIT: found the surveys, they were about lossy v lossless.) I'll confess, I've never noticed a difference. That's kind of why I got in this discussion to begin with. If you can tell, go for it. I definitely agree that sharp, short duration, static type sounds will sound better. Snares for example. But for melodic tones, it's probably almost the same.
 
Bubble181

Bubble181

So, just to get this straight: this is now the "Did you know..." thread; the "pictures" thread is now the "car" thread, and the "Did you know..." is...What, exactly? :-P

Also, you guys rock. I bet you'd sound live even through my laptop speakers ;)
 
fade

fade

Staff member
Plus, this is what I do for a job. Only it's geophysical signals, not sound. I actually used to teach a class on this stuff.
 
Bubble181

Bubble181

Gared said:
Hey now, better not say that too loudly; wouldn't want Fade to face a trial in Italy.
Click to expand...
Pfft, Italian justice, what're they going to do? Raping a girl in a miniskirt's not illegal 'cause she asked for it, sleeping with 16 year old prostitutes isn't illegal if you can claim ignorance, lying about your income is OK as long as you stay maximum 1 tax level below where you should be.... Italian judges aren't exactly known for making good decisions :p (all three are actual verdicts)
 
sixpackshaker

sixpackshaker

Or throwing two school-kids in jail for murder with absolutely no evidence, when you have the real killer in prison... love that Italian Justice...
 
Adam

Adam

Been nominated for North America's next top credit union executive. Have had my idea rattling around in my head for a while and now I have to put pen to paper and get it started for the competition.
 
Frank

Frank

Adam said:
Been nominated for North America's next top credit union executive. Have had my idea rattling around in my head for a while and now I have to put pen to paper and get it started for the competition.
Click to expand...
I know who to call when I need a high risk loan then.
 
Adam

Adam

Frank said:
Oh shit, I read this out loud and realized it could be taken as an idictment about what Adam does. It's just a little joke about knowing someone in high places.
Click to expand...
My skin is pretty thick about my job. Being a banker is like being a prostitute, I screw people for their money. Unfortunately, I don't get paid as well.
 
Cajungal

Cajungal

Staff member
Adam said:
My skin is pretty thick about my job. Being a banker is like being a prostitute, I screw people for their money. Unfortunately, I don't get paid as well.
Click to expand...
And you don't even get to wear your favorite tube top and thigh highs to work. :(
 
M

makare

I might not care so much about my bank screwing me if they at least dressed sexy...
 
Null

Null

I switched over to my local credit union from PNC Bank and it's been a fantastic improvement. The only downside is that I wind up being charged a small transaction fee at most ATMs but the customer service and lack of punishing policies are a win.
 
You must log in or register to reply here.
Top