What's best kHz “encoder setting” for Windows Media Audio 10 Pro codec @ Quality VBR?

[PackersOwner4]

I’m a newby & in the process of using dBpoweramp CD Ripper on a duo-core Vista laptop to convert my WMA Lossless files for loading into my Sony NWZ-S739F (16GB; supports MP3, WMA, AAC-LC, & Linear PCM; good quality 20-20,000 Hz noise canceling head-set).

I’d greatly appreciate anyone’s help or advice on optimal “encoder settings”.

If Windows Media Audio 10 Professional codec and the Quality VBR level is selected for the above purpose, what kHz level should be selected or is optimal: 44, 48, 88, or 96?

44 kHz appears to be the default, but shouldn’t I select at least 48 kHz? Or, what are the practical differences, trade-offs, or limits as higher values are selected? I didn’t find much via Google, Windows Media online, etc., and would appreciate any advice or web reference.

I’d also appreciate advice or other suggestions if I’m “off” in thinking WMA 10 & Quality VBR is among the best choices for my unit or purpose. From what I’ve read (and my limited listening comparisons so far), going beyond WMA 10 & Quality VBR wouldn’t result in a discernable audio difference on today’s portable players. I have limited experience, so any advice from others more experienced and knowledgeable is greatly appreciated!

[jtbse]

Re: What's best kHz “encoder setting” for Windows Media Audio 10 Pro codec @ Quality

I know almost nothing about WMA or WMAL, so please excuse me if the following shows some ignorance of these formats/codecs; but as a general rule, I would say the sampling frequency you should use for your lossy files would depend on 2 things:

1) What is the sampling frequency of the source material? I don't think much, if anything would be accomplished by upsampling a 44kHz lossless file to a 48kHz lossy one. In fact you could introduce quantization error by doing this, which might be audible unless you are able to add dither in some way.

2) What sampling frequency is supported for playback on your portable device? Some decoders (albeit fewer, these days) can't deal with anything above 44kHz.

I don't know, but I expect that Spoon chose 44kHz as the default because that's consistent with the Redbook CD standard, and is therefore assumed to be cd-quality.

[LtData]

Re: What's best kHz “encoder setting” for Windows Media Audio 10 Pro codec @ Quality

CDs are 44.1KHz, so use that for ripping to WMA. Changing the sampling rate is a lossy process, so while it would not result in much quality loss with Professional Frequency Conversion enabled (Reference-only feature, found in dBpoweramp Configuration), you are still losing data when you resample.

Peronsonally, I would use m4a (which is AAC-LC) over WMA, but that's just me.

[PackersOwner4]

Re: What's best kHz “encoder setting” for Windows Media Audio 10 Pro codec @ Quality

Thanks for the responses thus far. Just some update.

Re. Codec Choice. LtData: thanks for pointing to the m4a/AAC-LC codec – I’ll try it ASAP.

I received a “file format not supported” error in trying to play tracks converted from an older CD using WM 10 codec and the VBR and 44 kHz settings, but had no such problem with recently released CDs.

Might the “not supported” error for the older CD have anything to do with encryption, locks, or something WM 10 expects to find? Thus far I found these statements (from Microsoft “WM DRM FAQS” 1.2 & 1.3, http://www.microsoft.com/windows/win...x#drmfaq_1_2):

“The latest release of Windows Media DRM technology makes it possible to protect, deliver, and play individual, subscription, and promotional digital media content on computers, portable audio devices, Portable Media Center devices, or networked devices.”

“You can use Windows Media Rights Manager to encrypt a given digital media file, lock it with a key, and bundle additional information from the content provider.”

I’m only guessing & searching here, and will definitely try AAC-LC next in any case & will give an update later. My NWZ-S739F manual’s “supported codecs” WMA listing has “Sampling Frequencies” asterisked with comments: “Compatible with WM-DRM 10”, and (in a more general reference applying to other codecs, including AAC-LC) “Sampling frequency may not correspond to all encoders.” The older WM 9.2 or MP3 codecs at 192 bitrate or so are always fall-backs.

Re. Frequency Selection. After finding and reading the “Frequency” section from “Spoon’s Audio Guide” (http://www.dbpoweramp.com/spoons-aud...e-starting.htm), I was going to remove this from my post, but thought other newbies might also have that question. Here’s a relevant portion from Spoon:

“The higher the frequency, the more accurate a representation, up to a point...human hearing can not hear above 20 KHz, so reproducing 50,000 KHz would be a waste of space (each sample takes up space). Nyquist's theorem states: that to reproduce a 22 KHz sound signal, it must sampled (recorded) at more than 2x the required frequency, a sample rate of 44.1 KHz can reproduce a 22 KHz signal.”

Thus, I’d understand there’s no need or benefit in converting standard 44.1 kHz CDs to use anything other than 44.1. I haven’t converted any 96 or 192 kHz DVD audio tracks, or in 5.1 surround sound, but even there 44.1 would appear apply for portable player use. (Other newbies should take these statements as only “learning mode” updates, and consult Spoon & other experts.)

Again, thanks for the assistance.