What's the best way to change a 320kbs mp3 to 190kbs?

[aceplace57]

I'm using db power amp converter, but I imagine the other rippers have similar options.

I'm looking under DSP effects. I see Bit Depth and Resample. I don't think I want to change bit depth. Do I? 8, 16, 24, 32. Resample has options for Resample to Freq 22050, 24,000, 32000, 44,100. That doesn't sound like what I need either.

I just want to go from 320kbs mp3 to a more standard 190kbs mp3. Takes less space and its easier for these cheap $50 players to decode.

The setting I use is VBR and I have the slider set to Standard. That gives....
Varible Bit Rate Quality -V 2, 190kbs, Encoding (Slow, High Quality) Which should be a standard & compatible mp3.

[Mangetout]

(I expect you already realise) It'll incur a loss of quality - not just because you're reducing the bit rate, but also because you're lossy-recompressing an already-lossy-compressed object.

If this is a track ripped from a CD and you still have the CD, the best option would be to rip again at the desired settings - if your existing ripper can't do that, I'm pretty sure CDex will.

If you're stuck with transcoding an existing file, Audacity will do it (using the LAME encoder).

You don't want to change the sampling frequency, if you can help it.

[aceplace57]

hmm, I hadn't thought about recompressing. I was hoping it could simply reduce the bit rate without recompressing. I can't hear the difference between 190kbs and 320kbs. I know audiophiles swear they can.

I'll look around for the original CD. This was one of the first that I ripped years ago. I thought bigger was better and went with 320kbs. I've been playing them with Win media player. I wanted to put them on my cheap mp3 player. I've heard those players will sometimes stutter or freeze with 320kbs mp3. I even recall a thread here a few months ago about that.

[psychonaut]

Originally Posted by aceplace57

I just want to go from 320kbs mp3 to a more standard 190kbs mp3. Takes less space and its easier for these cheap $50 players to decode.

The setting I use is VBR…

I'm not familiar with the software you're using, but from your description it seems like there's a contradiction between what you want and what you're setting the software to give you. VBR means "variable bit rate", so by definition a VBR-encoded track can't be fixed at a certain rate. If you really want a 192* kbps file, you need to tell the encoder to use a constant bit rate (CBS). Some encoders support fancier VBR options, such as capping the bit rate at a certain maximum (allowing the actual bit rate to fall as low as 32 kbps), or aiming to achieve an average bit rate (while still allowing the bit rate to fluctuate between 32 and 320 kbps).

* Note that MP3 doesn't support bit rates of 190 kbps. The closest you can get is 192 kbps.

[Gagundathar]

I vote for Audacity with the LAME encoder. But I was already nijaed.
Audacity rocks. Really easy to use after about 10 minutes of playing around with it.
Much easier than Cake Walk.
And, it is free.

[aceplace57]

I checked my Encoder settings again. it says estimated bit rate 190kbs. I've noticed the actual VBR rate varies from file to file. Under file proerties, the Audio Properties tab sometimes the reported rate is much lower than 190kbs or it can go up some. 190 seems to be a general target the encoder shoots for. VBR seems to give what I want. I tried encoding some CBS and they were much larger files.

I have Audacity. I'll try opening a couple of these 320kbs mp3 files and re-encoding. See what they sound like. I think Audacity will save as a wav? Then my db power amp encoder can convert that without any more loss? IIRC wav isn't lossy

Originally Posted by psychonaut

I'm not familiar with the software you're using, but from your description it seems like there's a contradiction between what you want and what you're setting the software to give you. VBR means "variable bit rate", so by definition a VBR-encoded track can't be fixed at a certain rate. If you really want a 192* kbps file, you need to tell the encoder to use a constant bit rate (CBS). Some encoders support fancier VBR options, such as capping the bit rate at a certain maximum (allowing the actual bit rate to fall as low as 32 kbps), or aiming to achieve an average bit rate (while still allowing the bit rate to fluctuate between 32 and 320 kbps).

* Note that MP3 doesn't support bit rates of 190 kbps. The closest you can get is 192 kbps.

[Mangetout]

Originally Posted by aceplace57

hmm, I hadn't thought about recompressing. I was hoping it could simply reduce the bit rate without recompressing.

Unfortunately not - there are things you can change in an MP3 without recompressing (for example, the volume can be normalised), bit rate is an intrinsic part of the compression process - esentially, when you choose, say, 192 kbit/s , you're specifying that the encoder should compress the data to that level, from its natural uncompressed rate of something like 1400 kbit/s.

I can't hear the difference between 190kbs and 320kbs. I know audiophiles swear they can.

The point is that a file compressed initially to 320 kbit/s, then recompressed to 192 kbit/s will almost certainly have a measurable loss of fidelity compared to the same track compressed once directly to 192 kbit/s. This difference might still be well below the limit of perception for many people - so it may not be an issue, but in general, it's best to avoid recompressing anything that has already been lossy-compressed previously.

[aceplace57]

Thanks. I appreciate the help.

While I'm here. Are most people encoding in VBR these days? Is there any reason to ever use CBR? I've noticed CBR files are bigger.

When I rip my CD's, I use FLAC. Then encode to the most generic, vanilla mp3 as possible. So it will play with practically any player I might use.

I just started ripping to FLAC about a year ago. My older stuff went straight to mp3 from the CD.

[Mangetout]

Originally Posted by aceplace57

While I'm here. Are most people encoding in VBR these days? Is there any reason to ever use CBR? I've noticed CBR files are bigger.

CBR files will be of predictable size, but I'm not sure that's ever really an advantage, as VBR files are usually smaller for the same level of quality.

The only reason I can think of that someone might not want to use VBR is if they've got some legacy player that doesn't support it. In some cases, older players of compressed streams (including DVD players - it's all the same thing really) could run into trouble with VBR if the encoding had not been properly constrained - they might encounter a chunk of data that was compressed at a high bit rate and crash due to buffer or processing/decompression limitations.

But that's not likely to be a problem on any of today's devices.

[HumanMonkeyGod]

There's a freeware program called MP3-Quality-Modifier. I've used it to do exactly as you're looking to do, reduce size of high quality mp3s (folders at a time if you like - with Audacity I think you'll be doing one at a time) to fit on portable players - never had a problem with it.

[yoyodyne]

I don't understand what problem you're having with dBpoweramp. If you select the files, right-click and select Convert to, then mp3 and the bit rate it doesn't work?

[psychonaut]

Originally Posted by Mangetout

CBR files will be of predictable size, but I'm not sure that's ever really an advantage, as VBR files are usually smaller for the same level of quality.

CBR may be appropriate in some space- or bandwidth-constrained environments. For example, if you're going to be streaming an MP3 over a 32 kbps connection, then you're pretty much limited to (probably horrible-sounding) 32 kbps CBR-encoded files. Also, given only the length of an audio track in seconds, you can more or less accurately predict the size in bytes of a CBR-encoded MP3, whereas you can't do so for VBR. So if you're selecting some tracks to rip onto a device with limited storage, you can quickly calculate in advance which ones will fit at a given bit rate. Or alternatively, if you already have the the tracks selected, you can calculate an encoding bit rate such that they will all fit.

[aceplace57]

I'm going to give this a try right now. I'll keep a backup of my originals and see how these sound on my portable player.

Originally Posted by HumanMonkeyGod

There's a freeware program called MP3-Quality-Modifier. I've used it to do exactly as you're looking to do, reduce size of high quality mp3s (folders at a time if you like - with Audacity I think you'll be doing one at a time) to fit on portable players - never had a problem with it.