[cjl]

   
 
320 kbps can be both ABR and CBR.

Are you sure this is true for MP3? As I said, I was under the impression that 320 was the max supported bit rate for the mp3 format, which makes it rather difficult to have a 320 average VBR (since you can never exceed 320). That's why the highest quality VBR mp3s tend to be ~240kbps (with peaks of 320 where needed).

 

[bigshot]

Generally, codecs only go up to 320 for two channel. VBR will "steal" bitrate from simple to encode areas and boost difficult to encode areas up to the maximum of 320. So if a file is already at 320, there is no where to go but down when you use VBR. You might as well just encode 320 CBR. (ABR is basically the same thing as VBR.)
 
Sometimes you'll see references to 480Kbps AAC files. These are multichannel 5:1 files. There are five discrete channels in them, so the bit rate is the same as 192 AAC stereo or 96 mono.

 

[Music Alchemist]

  Are you sure this is true for MP3? As I said, I was under the impression that 320 was the max supported bit rate for the mp3 format, which makes it rather difficult to have a 320 average VBR (since you can never exceed 320). That's why the highest quality VBR mp3s tend to be ~240kbps (with peaks of 320 where needed).

 
Yes, I'm sure. I just converted a 1,411 kbps lossless file to MP3 using the highest quality settings in dBpoweramp.
 
Here are the results, in kbps.
VBR: 251
ABR: 274
CBR: 320 (naturally)
 
Free Format MP3s can also go up to 640 kbps, but there are compatibility issues and no reason to use this format anyway.
 

  Generally, codecs only go up to 320 for two channel. VBR will "steal" bitrate from simple to encode areas and boost difficult to encode areas up to the maximum of 320. So if a file is already at 320, there is no where to go but down when you use VBR. You might as well just encode 320 CBR. (ABR is basically the same thing as VBR.)
 
Sometimes you'll see references to 480Kbps AAC files. These are multichannel 5:1 files. There are five discrete channels in them, so the bit rate is the same as 192 AAC stereo or 96 mono.

 
"codecs only go up to 320 for two channel" Not true for AAC. Actually, some of the AAC files I converted in the past exceeded 400 kbps, and they were just from CD rips.
 
"So if a file is already at 320, there is no where to go but down when you use VBR." Everyone here likely already knows it's a bad idea to convert lossy to lossy. (I'm sure that's not what you meant; your wording just made it sound that way.)
 
"You might as well just encode 320 CBR." One of the purposes of VBR is to save file space while retaining quality. Some have even argued that VBR is better quality than CBR, but that doesn't really interest me.
 
I also converted that lossless file to AAC using the highest quality settings.
 
Here are the results, in kbps.
Nero VBR: 379
Nero ABR: 370
Nero CBR: 399
QuickTime tVBR: 399
QuickTime ABR: 301
QuickTime cVBR: 312
QuickTime CBR: 319

 

[Chris J]

Right on topic!

 

[Music Alchemist]

Right on topic!

 
Yeah, sorry...but comparing audio encodings and cables is similar enough in some ways.

 

[Chris J]

Yeah, sorry...but comparing audio encodings and cables is similar enough in some ways.

Nobody knows why they sound different?
:rolleyes:

 

[Happy Camper]

Nobody knows why they sound different?
:rolleyes:

Cables.....

 

[bigshot]

  Yeah, sorry...but comparing audio encodings and cables is similar enough in some ways.

 
The process of doing a line level matched A/B switchable comparison is exactly the same.

 

[Music Alchemist]

  The process of doing a line level matched A/B switchable comparison is exactly the same.

 
Exactly the same to what? If you mean comparing two different cable setups via A/B, wouldn't you need two identical systems to perform that comparison without switching the cables out? Maybe you could connect another set of cables to intermediary components like the preamp technique you described.

 

[bigshot]

Right. Comparisons of anything... CD players, DAPs, amps, etc... all involve switching between line level matched sources.

 

[Claritas]

You two love birds need your own thread. I guess you can have this one because I'm outta here.

 

[bigshot]

I did some googling. Apparently Nero is the encoder that will encode AAC up to 420. That's only for PC, which is why I had never heard of it. But there are two types of VBR... true VBR and constrained VBR. I can't translate the tech heads' discussions of it, but I did notice that with 320 VBR iTunes can go up to 400 without telling you.
 
It's all kind of moot though, because AAC is pretty much transparent at 192 for almost all music, and completely transparent by 256. Beyond that, you're just stuffing your file with inaudible digital packing peanuts.

 

[Chris J]

You two love birds need your own thread. I guess you can have this one because I'm outta here.

Can't they just PM each other? :rolleyes:

 

[Music Alchemist]

Some of you may be interested in this Hi-Fi News Group Test PDF. I received the link in an email from Nordost.
 

While it is commonly accepted that audio cables do, in fact, make a significant difference in the performance of a hifi audio system, there are still skeptics when it comes to USB cables. Although USB signals are comprised from a stream of ones and zeros, the construction of the USB cable makes a big difference in how that binary signal is transmitted.

For the second year in a row, Hi-Fi News conducted a group test that shows both the audible and measurable differences between different USB cables.

 

[Roly1650]

Some of you may be interested in this Hi-Fi News Group Test PDF. I received the link in an email from Nordost.

The results of this "test" are already being discussed on this thread:
http://www.head-fi.org/t/572588/audiophile-cables-an-interesting-question/990#post_10810466