Hi,
I've been using alt-preset standard for my portable needs and I must say I am extremely pleased with the performance. However, I have been thinking that I could maybe squeeze a bit more space from my MP3-CDs by using a lower bitrate setting, considering that most of the time I listen to my portable during noisy bus/subway trips, on the street with cars honking around or in a lab which is anything but quiet. Moreover, the earbuds that I normally use aren't probably prone to showing any less-than-obvious artifacts. (I haven't noticed any yet).
Has any non-audiophile experimented on this? What line would give me the lowest bitrate without compromising quality too much? I don't know if I am the only one, but I would really love to see an --alt-preset portable VBR setting which would yield ~120-150 kbps. I wonder what Dibrom and the others think about this.

~Dologan

I think, for portables the old --r3mix setting is enough regarding the noise outside and even if you use very good headphones.
Bitrates ~148 kbits/s for classical, ~160 kbits/s for metal.

If I want to sqeeze a certain amount of albums on a single CD-R I sometimes calculate the exact bitrate that just fits my CD-R700 and use --alt-preset bitrate.

I just compiled to CD-Rs with --alt-preset 140, and this was still o.k. for my Riovolt.

try "--alt-preset standard -Y", that's what i use for my portable with 128mb of CF.

the bitrates seem to stay under 192k even for metal.

What is the -Y switch for?

Supposedly it disables sfb21, therefore acts like a 16kHz lowpass filter

I think 96 Kbps should be enough for portable devices or CDs...
Wanna know the best settings for 96 Kbps

right now the best settings for 96 kb/s mp3s should be --alt preset 96 for abr and --alt preset cbr 96 for cbr

I use --alt-preset 112 for portable and find that it suits me fine

auldyin

My setting for portables is --alt-preset 96 and to me it sound good enogh to be portable
X

I can't believe ppl are using 96k CBR... uggh. Put those 32 meg portables up on Ebay & get at least a 3rd generation MP3-CD player... they're getting amazingly good (battery life nearly as good as the ones with no moving parts). Try the AVC Soul, latest Riovolts, or the new Iriver slim.

Of course, if you listen to N'Sync or Brittney might as well encode at 64kbps... it ain't gonna sound any worse than at 320

For portable use, you don't really need anything more than 192. If you throw in some background noise and average quality headphones, then 128 should be more than enough. If you listen to classical music, 96 will suffice.

Mebbe so, but anyone who encodes a bunch of CD's at 96k & 128k, then later decides to hook their portable to a quality home stereo system is gonna be sorry...

Edit -- with an MP3-CD player, what does it matter if a $0.30 CD can hold 12 albums instead of 9 or 10?

I've encoded my music with musepack, and when I use my portable I use mpc>mp3 and choose my setting every time. I never used higher as 128, yet, but maybe if I ever plan to hook it to a stereo. but mosty - 96 will do. the background noise is destroying more than the low bitrate

what does everyone thing of something like this:
--alt-preset standard -V4

It's been said (somewhere in the source code, i don't remember where) that ABR would be better than increasing -V beyond 4, so i take that to mean -V4 will give me the smallest VBR files that have an advantage over ABR(which seems about as pointless as CBR to me).

ABR is actually the best mode. The problem with VBR is that it relies heavily on the psychoacoustical model to determine the bitrate for a particular frame. If the model errs on the side of over-aggression (i.e. picks too low of a bitrate), then you might hear artifacts. With ABR, the bitrate range is a bit more limited, so that if you encode @ 192kbps ABR then it is quite unlikely the encoder will choose frames smaller than 128kbps, for instance. I've seen some online reports showing that few listeners benefit from encodes exceeding 192kbps in ABR mode.

There's a reason why --r3mix and --alt-preset incorporate the -b switch to limit the minimum bitrate...because VBR has a tendency to encode too aggressively on some musical passages.

If I want to hear music through a high quality home stereo system, then I'd use the original CD.

Errrm... you've got a point.

This is an interesting thread for me cos I have been trying to choose what bit rate and settings for portable use and for archival. Archival is easy - alt preset insane. I have been using alt-preset standard for portable...but then I decided to do some tests with both my NJB and Rio SP100 using a broad spectrum of presets.

...they all sounded pretty much the same! Terrible when the portable was played through a very expensive Arcam amp and Eltax speakers. Dull and compressed with no dynamic range.

So I resorted to headphones and I could just about detect the differences between alt preset 128 and alt preset insane. I then performed the same listening tests by hooking up the output of my Sonic Fury sound card to the Arcam amp - boy...I cud hear the difference then.

Conclusion? Portables have crap output stages and higher bit rates weren't worth bothering with (btw I can tell the difference that decent interconnects on my hi-fi make)

I can clearly hear the crappy quality of (say) Blade encoded MP3's at 160kbps on my portable, altho I gotta say there's not much audible difference between aps and --alt-preset insane, even with quality headphones.

I kind of know what you mean about the lack of dynamic range and "flat" sound. It's not too bad on the AVC Soul but the sound quality is far from ideal.

As for archiving, I don't use MP3 at all anymore for that... having realized the format is not really that great for archiving. I wouldn't want to create a music CD out of decoded MP3's (even 320kbps) if avoidable. LPAC does the job for me as far as "serious archiving" goes, and MP3 for casual listening and when saving space is important.

It is indeed clear to me that one can hear the difference between a bad encoder (like blade, yes, but Xing is worse too) and a good encoder like lame. But lame doesnt perform that bad at 80 kb/sec, I use it for my portable all the time. yes, even with metal. I can hear artifacts, of course, but 30 minutes (128 kb/sec) is too short, now i can store some 50 mins...

and again, for the backup of my cd collection on h'disk I use Musepack with Normal compression. when SV8 is out, I'm gonna encode all my cd's with it. transcoding to mp3 is easy with mpc2mp3.