Hello everyone. I've been reading numerous threads here the last few days trying to decide if I want to start using AAC on future rips. I would like use something with a lower bitrate than LAME -V2. In the past I've been able to hear artifacts on Itunes AAC 128kbps, but rarely ever on LAME -V2 or Itunes AAC 192kbps.

Anyway, to make a long story short, I've been using LAME v2 for my Ipod tracks. At home I'm still using the original CDs, so these are just for the car or for jogging, etc. I had been reading about the efficiency of the Nero AAC encoder and decided to come over and so some research. I really would like to take advantage of the small file sizes if I can do so without any perceptual quality loss.

I have the following questions:

1) Nero AAC HE is not supported by the Ipod....it only reads the LC "core" but not the HE "extensions". However, ripping at bitrate higher than 85kbps, this won't be an issue. Is that a correct statement? I know Foobar2000 needs to be setup with .m4a filenames instead of .mp4.

2) From what I've read here, the general consensus is that LAME -V3 is transparent to most people. What would be the equivalent setting on the Nero AAC?

3) I would like to do an ABX test just so I could test this myself but I can't find it anywhere on Foobar2000. Did they eliminate it from the latest version? I tried a link to download a plugin but the link was dead.


Thanks for the help!

Select two tracks and the ABX tool will be visible under Utils menu (rightclick selected tracks).

Right. Except it isn't there. Only "Save As Playlist" and "Create Album List View From These Items" are there. I'm using v0.9.5.3.

Go to File -> Preferences and then to the Components section and see if you have the ABX Comparator component. If not, I could upload the DLL to rapidshare or something.

Personally, I'm using the latest Nero 1.1.34.2 and 0.45. It's fine for me, the file sizes are smaller than LAME V2 and the quality is superb.

1. You are right, iPods will only read the LC core of HE-AAC audio. This is true for all iPods, iTunes, and QuickTime. It seems that Apple has no intentions of properly supporting HE-AAC audio.

2. I would say that -q0.45 or -q0.5 settings correspond to what is normally considered to be transparent with Nero AAC. Your mileage will vary though. -q0.5 is Nero's default setting but, from my own ABX tests, I was able to drop down to -q0.45 without any quality issues. Another reason why I suggest going down to -q0.45 is that it has a lower bitrate than -q0.5 and -V 3 Lame mp3. Both -q0.5 and -V 3 end up having around the same overall bitrates of 170kbps VBR. So, in my mind, if I am going to use AAC, I am going to use it at a lower bitrate setting than mp3.

3. You must have the ABX option installed. You can either download the DLL from someone here or you can re-download foobar2000, re-install it, and make sure to select the ABX plug-in before the installation process.

On a side note, you should also look into using the iTunes AAC encoder. When you say that you heard artifacts at 128kbps, did you ABX this or just listen? Past listening tests have shown that the iTunes AAC encoder at 128kbps VBR is very efficient and able to produce transparent results for many samples for many people. Remember to always ABX for the differences, otherwise anything that you think about the audio quality of a sample is null and void.

OK, I didn't have it but was able to find a link that worked for the plug-in.

I've done quite a few tests and I must say that I'm baffled! I failed miserably on every ABX test I've done. I've compared WAV/MP3v2, MP3v2/AACq.042 and finally WAV/AACq.042 and I just can't seem to identify which was which. I've tested several different genres and the only thing left to try is classical.

I'm content at this point just using AAC q.042 since it tested so well for me and it gives me more space to work with. My only question left is in regards to Ipod compatibility.

How do I configure it so that it won't use AAC-HE? I can't find a setting and I want to make sure my rips work fine on the Ipod.

Thanks for everyone's help!

When using foobar2000, you won't be able to force Nero into LC mode. That is alright though as the Nero AAC encoder is smart enough to know when to go into HE-AAC mode or LC-AAC mode. I believe that you will be fine as long as you encode at -q0.35 and above. I am not 100% sure about that -q value though so you might want to search around. I think that -q0.42 is high enough that you won't encode any HE-AAC files though.

Why is that so? Can't Foobar pass any parameters to a CLI encoder?

OK. I think I'll bump it up to -q0.45 and leave it there.


I haven't done any ABX test with Itunes AAC yet. To be honest, I haven't used Itunes AAC 128kbps since 2004 and I changed to 192 after the first few CDs I encoded. I'm sure they've made improvements since then though. I will try a few and see how it sounds.

Thanks!

According to this post, no, foobar2000 can't force the LC option when using Nero's AAC encoder. I would think it could but I myself have never tried it out.

Jackinbox, yes, the iTunes AAC encoder has seen many improvements over the years. Back when it first came out (2003), in my opinion, it didn't really provide any benefits over the Lame mp3 encoder. Times have changed though and, for the most part, the iTunes AAC encoder has increased in quality with each release. I believe that some people perceive iTunes 7.5 to be better than the current 7.6 though.

I remember when I ABX'd, I couldn't tell 128 AAC from the original. 0.45 lops a good 20-30kbs off of 0.5. 0.5 actually is larger than LAME v2 in many cases, which defeats the purpose.

Also, it seemed like sharp sounds, like symbol taps, are a little clearer using AAC compared to LAME mp3.

You can force LC if you bind the Nero encoder as custom CLI encoder.

I think I have it set up that way. Is this correct?:

-q 0.45 --lc -ignorelength -if - -of %d

Well, I've done some more tests during the past several days. I tried Itunes AAC 128kbps. Here's the results:

foo_abx 1.3.1 report
foobar2000 v0.9.5.3
2008/07/06 20:23:26

File A: D:\Music\02 - ACDC - Shoot To Thrill.wav
File B: D:\Itunes\Unknown Artist\Unknown Album\02 - ACDC - Shoot To Thrill.m4a

20:23:26 : Test started.
20:24:38 : 01/01 50.0%
20:25:18 : 02/02 25.0%
20:27:22 : 03/03 12.5%
20:27:55 : 04/04 6.3%
20:28:56 : 05/05 3.1%
20:29:29 : 06/06 1.6%
20:30:05 : 07/07 0.8%
20:31:08 : 08/08 0.4%
20:33:33 : 09/09 0.2%
20:35:32 : 10/10 0.1%
20:35:34 : Test finished.

----------
Total: 10/10 (0.1%)


As you can see, it was pretty easy to ABX. Parts of the vocals still sound muddy to me, although I will say it was a huge improvement over the encoder they had in 2004. But I don't think I would be happy with Itunes 128 even though it's not bad.

I've done quite a few tests of Nero AAC q.45 vs. LAME 3.98 -V2, and although it was very difficult to distinguish the two on most tests, I think the Nero sounds slightly more natural in the few instances where I could hear a difference.

The one annoyance I've found with Nero AAC is that it doesn't seem to work with AudioShell. Has anyone else noticed this?

I have an application that requires 100 % iTunes compatible code to play. Files that I encoded with dbPoweramp and Nero Digital forced at LC-AAC wouldn't play. I could fix this with a program called Zen Compatibility. But the files wouldn't play back gaplessly. The m4a optimize utility in dbPoweramp didn't work either - the program would play only 2-3 seconds of each song.

I hope that a future version of Nero Digital will be more compatible. I would like to use AAC, but I want to avoid iTunes.

I think both aac or mp3 will rarely be less than transparent if you consider a 160 - 200 k bitrate. No one can say for sure if 175k AAC is better than V3 Mp3 (minus the mp3 native flaws) across a wide range of music. Below 128k AAC is king.

I haven't had any issues with Nero AAC compatibility other than my Xbox 360 and Creative Zen conflicting with each other. But, right now, Nero can produce 100% iTunes compatible files. There was one point when I started to transcode my lossless library down to -q0.45 using Nero AAC and the files worked in iTunes, my 5G 60GB iPod, my 2.5G iPod shuffle, and my 1G 16GB iPod touch. The files also worked on my Zune and with the Zune software. iTunes compatibility doesn't mean anything though in the grand scheme of being compatible with other software and hardware. I can run that Zen tool to make them work on my Zen but then I have to optimize the AAC files to get them running on my Xbox 360. Optimizing them breaks Zen compatibility though and I have to go back and rerun that tool. Doing that though breaks Xbox 360 compatibility. It is a never ending cycle. So that is the main reason why I have yet to switch to using the AAC format. The next Nero AAC encoder will fix this though and it should be coming out any day now.

Just for kicks, what program are you trying to play the AAC files in?

Make sure it's -lc



You mean it doesn't show the tags? I assume that's a problem with Audioshell. Does it show tags for files from iTunes?

Regarding that Zen compatibility thing, that should be solved with the next version as we figured out exactly what was causing that.

It's a program for Pocket PC's (Windows mobile) called Phantasm Music Player from 40th Floor. Very nice program, but picky about the iTunes LC-AAC. It also supports ALAC, FLAC, all varietys of WMA, plus of course MP3.

I checked and it's not just Nero AAC. The Apple AAC doesn't work the same either. You can right click on the file and get the info by going into properties. However you can't get the bitrate or encoder by just running the mouse over the file in Windows Explorer like you can with MP3. Maybe I need to change something with my file associations to make it work right.

It's not a big deal but just something that I really found convenient.

That is due to Windows, not the Nero AAC or iTunes AAC encoders. It sounds like the AudioShell program/tool that you installed isn't working properly. I think there are a couple others out there. I also know that dBpowerAMP can display information like that through Windows Explorer by either right-clicking on the song or hovering your mouse over it.