IPB

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
bits and frequency
cahklowor
post Jul 20 2006, 17:06
Post #1





Group: Members
Posts: 6
Joined: 4-May 06
Member No.: 30379



I have question.

Higher amplitude and frequency means higher bit needed to represent the signal. Is that right?

This post has been edited by cahklowor: Jul 20 2006, 17:07
Go to the top of the page
+Quote Post
Garf
post Jul 20 2006, 17:35
Post #2


Server Admin


Group: Admin
Posts: 4886
Joined: 24-September 01
Member No.: 13



What you are saying makes no sense whatsoever.
Go to the top of the page
+Quote Post
Pio2001
post Jul 20 2006, 19:31
Post #3


Moderator


Group: Super Moderator
Posts: 3936
Joined: 29-September 01
Member No.: 73



QUOTE (cahklowor @ Jul 20 2006, 18:06) *
I have question.

Higher amplitude and frequency means higher bit needed to represent the signal. Is that right?


The amplitude is adjusted before the ADC. Your 16 bits signal, for example, can represent a 10 mV, a 1 V, or a 1000 V signal. You don't need more bits to record a louder signal, you need an analog to digital converter whose input is suited for strong signals.

You need a higher sample rate to record higher frequencies. It means higher bitrate, but not higher bits per sample.
Go to the top of the page
+Quote Post
saratoga
post Jul 21 2006, 01:34
Post #4





Group: Members
Posts: 5147
Joined: 2-September 02
Member No.: 3264



QUOTE (cahklowor @ Jul 20 2006, 09:06) *
I have question.

Higher amplitude and frequency means higher bit needed to represent the signal. Is that right?


Amplitude just needs a bigger amplifier. You can make a 1 bit signal very, very loud with a strong amp smile.gif

SNR requires more bits though.
Go to the top of the page
+Quote Post
greynol
post Jul 21 2006, 01:55
Post #5





Group: Super Moderator
Posts: 10338
Joined: 1-April 04
From: San Francisco
Member No.: 13167



QUOTE (Mike Giacomelli @ Jul 20 2006, 17:34) *
Amplitude just needs a bigger amplifier. You can make a 1 bit signal very, very loud with a strong amp smile.gif

SNR requires more bits though.

Ah, but you never mentioned the encoding format. tongue.gif


--------------------
Your eyes cannot hear.
Go to the top of the page
+Quote Post
Garf
post Jul 23 2006, 09:54
Post #6


Server Admin


Group: Admin
Posts: 4886
Joined: 24-September 01
Member No.: 13



QUOTE (greynol @ Jul 21 2006, 02:55) *
QUOTE (Mike Giacomelli @ Jul 20 2006, 17:34) *
Amplitude just needs a bigger amplifier. You can make a 1 bit signal very, very loud with a strong amp smile.gif

SNR requires more bits though.

Ah, but you never mentioned the encoding format. tongue.gif


In what circumstance wouldn't it be true?
Go to the top of the page
+Quote Post
greynol
post Jul 23 2006, 18:50
Post #7





Group: Super Moderator
Posts: 10338
Joined: 1-April 04
From: San Francisco
Member No.: 13167



QUOTE (Garf @ Jul 23 2006, 01:54) *
QUOTE (greynol @ Jul 21 2006, 02:55) *
QUOTE (Mike Giacomelli @ Jul 20 2006, 17:34) *
Amplitude just needs a bigger amplifier. You can make a 1 bit signal very, very loud with a strong amp smile.gif

SNR requires more bits though.

Ah, but you never mentioned the encoding format. tongue.gif


In what circumstance wouldn't it be true?

sigma-delta???


--------------------
Your eyes cannot hear.
Go to the top of the page
+Quote Post
Garf
post Jul 23 2006, 19:11
Post #8


Server Admin


Group: Admin
Posts: 4886
Joined: 24-September 01
Member No.: 13



QUOTE (greynol @ Jul 23 2006, 19:50) *
QUOTE (Garf @ Jul 23 2006, 01:54) *

QUOTE (greynol @ Jul 21 2006, 02:55) *
QUOTE (Mike Giacomelli @ Jul 20 2006, 17:34) *
Amplitude just needs a bigger amplifier. You can make a 1 bit signal very, very loud with a strong amp smile.gif

SNR requires more bits though.

Ah, but you never mentioned the encoding format. tongue.gif


In what circumstance wouldn't it be true?

sigma-delta???


Uhm, those just trade SNR in one frequency range for SNR in another one.
Go to the top of the page
+Quote Post
solarflare
post Jan 29 2007, 21:43
Post #9





Group: Members
Posts: 26
Joined: 24-June 06
From: Helsinki
Member No.: 32205



QUOTE (Garf @ Jul 23 2006, 20:11) *
Uhm, those just trade SNR in one frequency range for SNR in another one.

But then again, 1 bit/2.8 MHz gives quite huge SNR over any modern 24 bit/96 kHz system. Right? smile.gif

This leads to my own question. Does Ogg Vorbis support multibit encoding? I mean, if I record something with say Korg MR-1, can I then encode the result with 24 bit/192 kHz Q10 settings? Does Ogg Vorbis handle such files? And would they be playable anywhere?
Go to the top of the page
+Quote Post
saratoga
post Jan 29 2007, 22:08
Post #10





Group: Members
Posts: 5147
Joined: 2-September 02
Member No.: 3264



QUOTE (solarflare @ Jan 29 2007, 13:43) *
QUOTE (Garf @ Jul 23 2006, 20:11) *
Uhm, those just trade SNR in one frequency range for SNR in another one.

But then again, 1 bit/2.8 MHz gives quite huge SNR over any modern 24 bit/96 kHz system. Right? smile.gif


Actually, it'd be a lot less. 24 bit gives a constant 144dB, while I believe 2.8MHz DSD maxes out at 120dB and decays from there.

QUOTE (solarflare @ Jan 29 2007, 13:43) *
This leads to my own question. Does Ogg Vorbis support multibit encoding?


Of course, PCM is supported.

QUOTE (solarflare @ Jan 29 2007, 13:43) *
I mean, if I record something with say Korg MR-1, can I then encode the result with 24 bit/192 kHz Q10 settings? Does Ogg Vorbis handle such files? And would they be playable anywhere?


Provided whatever software you're using to convert from DSD to 24 bit 192kHz works fine, sure. If you're asking if Vorbis will handle that conversion for you, then no it won't.
Go to the top of the page
+Quote Post
solarflare
post Jan 29 2007, 22:31
Post #11





Group: Members
Posts: 26
Joined: 24-June 06
From: Helsinki
Member No.: 32205



QUOTE (Mike Giacomelli @ Jan 29 2007, 23:08) *
Actually, it'd be a lot less. 24 bit gives a constant 144dB, while I believe 2.8MHz DSD maxes out at 120dB and decays from there.

So SNR-wise 1-bit/2.8MHz (Korg MR-1) is less than 24-bit/96 kHz (Zoom H4)? That's interesting, I'm just weighing different options for purchasing a real portable digital recorder that would be at least somewhat futureproof.

How about the frequency response then? The Korg (advertisement) dokumentation states that the 1-bit/2.8MHz format is far superior to a 24-bit/96 kHz recording, giving better results than an analog tape.

Knowing me I'm not a dog, at least as far as I know that, would there be any real advantage with the 40 kHz (Zoom H4) vs. 50 Hz-100 kHz (Korg MR-1) frequency response? It starts to sound that 24-bit/96 kHz wouln't be that bad after all.

QUOTE (Mike Giacomelli @ Jan 29 2007, 23:08) *
Provided whatever software you're using to convert from DSD to 24 bit 192kHz works fine, sure.

Ok, that was what I ment. smile.gif
Go to the top of the page
+Quote Post
saratoga
post Jan 29 2007, 22:42
Post #12





Group: Members
Posts: 5147
Joined: 2-September 02
Member No.: 3264



Unless you're not recording audio, I probably wouldn't care about frequency response, as long as everything supported 20-20KHz. If you're recording scientific signals, having more bandwidth might be useful (though I'd recommend a real DAQ device in that case).
Go to the top of the page
+Quote Post
solarflare
post Jan 30 2007, 21:24
Post #13





Group: Members
Posts: 26
Joined: 24-June 06
From: Helsinki
Member No.: 32205



QUOTE (Mike Giacomelli @ Jan 29 2007, 23:42) *
Unless you're not recording audio, I probably wouldn't care about frequency response, as long as everything supported 20-20KHz.

How about the ultrasonic harmonics, that is if they resonate with each other in the audible area? They must be captureable in those frequencies a lot better than in the audible area, musn't they?
Go to the top of the page
+Quote Post
Firon
post Jan 30 2007, 22:01
Post #14





Group: Members
Posts: 830
Joined: 3-November 05
Member No.: 25526



All they can really do is create beat frequencies, which is a pretty annoying artifact.
Go to the top of the page
+Quote Post
AndyH-ha
post Jan 31 2007, 01:20
Post #15





Group: Members
Posts: 2224
Joined: 31-August 05
Member No.: 24222



If any higher frequencies have a detectable result in the audible range, that result will be captured by a 44.1kHz recording.
Go to the top of the page
+Quote Post
solarflare
post Jan 31 2007, 07:29
Post #16





Group: Members
Posts: 26
Joined: 24-June 06
From: Helsinki
Member No.: 32205



QUOTE (Firon @ Jan 30 2007, 23:01) *
All they can really do is create beat frequencies, which is a pretty annoying artifact.

So if I want to make an Ogg Vorbis encoded file that in theory could sound better than a 16bit/44.1kHz Audio CD, the way to do it is to use 24bit/44.1kHz for recording settings instead?
Go to the top of the page
+Quote Post
AndyH-ha
post Jan 31 2007, 12:01
Post #17





Group: Members
Posts: 2224
Joined: 31-August 05
Member No.: 24222



There are physical differences (external world). However when you put in the "sound better than" you are into perception (internal world). It is quite uncertain that the very real physical differences are of any consequence what-so-ever for music.

It is possible to demonstrate hearable differences with simple test tones under controlled conditions, but I have yet to find any music where I can tell a difference. I think I have ask for recommendations and samples on every audio forum I've visited where the subject comes up (it always comes up -- repeatedly). The arguments always suddenly stop when I post such a challenge because none of the proponents of more is better can find an example where that is true.

When considering recording, getting in the air music into digital form, there are a couple of dozen factors that will have a much larger impact on how it sounds than a greater bit depth.

Recording at the greater bit depth can be important because of another definitely real characteristic: quantization errors. These occurs for almost every operation on digital audio data. At 16 bit they can become unpleasantly audible. At 24 bit, or better, 32 bit, they are too small to matter. However, after all mixing and mastering processes are completed, with proper dithering, 24 bit can be resampled to 16 bit without degrading the "sound."
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 19th December 2014 - 10:51