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trypan
2009-01-25, 16:52
I have a Duet hooked up wirelessly and I've noticed that the audio quality is somewhat sub-par. Is this to be expected? Internet streaming (Pandora, for example) sounds particularly bad. 256 bit rate AAC files playing from my computer sound a little better , but still not very good. It is very clearly inferior to playing a CD on the same setup. I don't really know that much about wireless systems, so I have a bit more info. and some questions.

1) I haven't connected the Squeezebox to the A/V receiver with a digital cable yet, but will that make a huge difference?
2) I don't have any problems with streaming (it doesn't break up at all), but is it possible to have partial packet loss that would hurt the playback quality? The signal from my router to the Duet can be weak at times.

Thanks for any info you can provide.

st2000
2009-01-25, 17:45
trypan wrote:
> I have a Duet hooked up wirelessly and I've noticed that the audio
> quality is somewhat sub-par. Is this to be expected? Internet
> streaming (Pandora, for example) sounds particularly bad. 256 bit rate
> AAC files playing from my computer sound a little better , but still not
> very good. It is very clearly inferior to playing a CD on the same
> setup. I don't really know that much about wireless systems, so I have
> a bit more info. and some questions.
>
> 1) I haven't connected the Squeezebox to the A/V receiver with a
> digital cable yet, but will that make a huge difference?

It shouldn't make much difference unless you have horrible analog
cables, suffering from ground loops or the like. Most people don't have
these problem. And if you have connected other items like DVD, CD or
VCR players similarly with good results - well that just proves you know
how to do connect analog audio cables properly.

> 2) I don't have any problems with streaming (it doesn't break up at
> all), but is it possible to have partial packet loss that would hurt
> the playback quality? The signal from my router to the Duet can be
> weak at times.

I don't think so. With digital, you usually get the signal or you
don't. But, that said, not all source material is the same. Streaming
sources may use a slower sampling rate to reduce the likelihood of drop
outs. I once put an entire audio book (over a dozen CDs) onto 1 mp3
compressed CD (normally about a 10:1 compression ratio) by reducing the
sampling rate (achieving about a 15:1 compression ratio). However, it
sounded like the narrator was talking over the phone.

> Thanks for any info you can provide.

Hum, I thought you were going to ask if connecting the duet w/a 10BaseT
cable was going to help. Were you? Well, the answer is probably not.
A bad wireless connection manifests it's self as drop outs. The player
will generally stop playing or stutter. Not play badly with out
interruption. Have you listen to the same files on the computer serving
up the music?

Hey, wait a minute. You are not playing back mp3s or flac or other
commonly used file formats. You are playing back AAC files. Hum, can
SBs natively play AAC files? If they can, I wonder if the AAC files you
have have been correctly formed. If they can not, I wonder if the
transcoding on the server is being done correctly. Regardless, I would
test your set up by ripping some audio CDs to either FLAC or, better
yet, as you are running wireless, MP3s and trying them on your SB. I
bet the results will be more of what you expected.

SuperQ
2009-01-25, 17:49
Packet loss is not an issue at all for the Squeezebox. It buffers and automatically re-sends packets. As long as the buffer doesn't get empty it will sound the same wireless or not. The buffer getting empty will cause dropouts, like a CD skipping, playing nothing for a long time (seconds).

To help you figure out why things sound worse, we need a lot more info.

* What CD player are you comparing
* What amplifier
* What speakers
* How is the squeezebox connected
* How is the CD player connected

My first observation is that of course internet stream is going to not sound as good as a good CD ripped to FLAC.

My first suggestion is try ripping using a "secure" CD extractor like dbPoweramp, EAC, grip, or Max. Then rip a CD to FLAC. FLAC is lossless, and will probably be better than a normal CD player because the secure extraction will protect against damaged CDs.

http://www.dbpoweramp.com/
http://www.exactaudiocopy.de/
http://nostatic.org/grip/
http://sbooth.org/Max/

trypan
2009-01-25, 18:23
Thanks for the info. I'll assume from the responses that if I'm getting a steady signal to the squeezebox, then any issues with audio quality would be associated with the source (i.e., internet stream or music file type).

The "CD" I was referring to contains MP3 files copied from the original discs and then ripped to a new CD.
The audio setup:
1) A very old Sony DVD player (circa 1998)
2) An onyko receiver (circa 1998)
3) DVD player connected via optical digital
4) Squeezebox connected via supplied analog cable
5) Speakers are a simple stereo setup with an 8" sub. I have 4 Orb audio speakers (2 for left front, 2 for right front)
While this system is nothing particularly fancy, it can create some nice sound.

The music files I was streaming from my computer are just non-DRM iTunes files.

Does any of this information shed any more light?

Thanks.




Packet loss is not an issue at all for the Squeezebox. It buffers and automatically re-sends packets. As long as the buffer doesn't get empty it will sound the same wireless or not. The buffer getting empty will cause dropouts, like a CD skipping, playing nothing for a long time (seconds).

To help you figure out why things sound worse, we need a lot more info.

* What CD player are you comparing
* What amplifier
* What speakers
* How is the squeezebox connected
* How is the CD player connected

My first observation is that of course internet stream is going to not sound as good as a good CD ripped to FLAC.

My first suggestion is try ripping using a "secure" CD extractor like dbPoweramp, EAC, grip, or Max. Then rip a CD to FLAC. FLAC is lossless, and will probably be better than a normal CD player because the secure extraction will protect against damaged CDs.

badbob
2009-01-25, 18:37
Try lossless audio, not compressed. Use fixed output from the SB. If you have a high quality CDP most likely better sound quality than the SB.

Since you said the CDP sounds better than doing this won't improve the sound on SB (DAC will) - uy a stereo integrated amp to use with main channels instead of your av receiver (av amps are rubbish in sound quality) Buy a DAC, use that between SB and the stereo amp.

radish
2009-01-25, 21:10
Seriously, buying an external DAC isn't going to help here. The SB is more than a match for the DAC in a 90's Onkyo amp, particularly when the "CD" is a re-burn of mp3 tracks.

There's something more fundamental going on. Two obvious things to check - are your sources level matched? Louder sources always sound better to the human ear when comparing, so if they're not the same level you're not doing a fair comparison. Second, which input are you using on the amp? If it's one designed for a turntable it'll sound terrible. To be sure, use the one labeled CD.

You also should try switching out the cable in case it's bad, and it's worth using the digital cable from the DVD player just so you're comparing apples with apples.

seanadams
2009-01-25, 21:44
Wireless isn't the problem. Are you using the "phono" input on your a/v receiver?

st2000
2009-01-25, 22:28
seanadams wrote:
> Wireless isn't the problem. Are you using the "phono" input?

Oh, that's an excellent question Seandadams!

The phonograph input is very high gain (do they still put these on
amps?). The SB's output will surely be clipped (i.e. sound just
horrible) if you do that. Of course, that doesn't explain the good
results you are getting from streaming sources.

One thing to note. Most people here are *very* particular about their
music. Therefore, most will rip to and recommend you use FLAC.
However, since you are using wireless and are indicating your wireless
is not that strong or dependable, I would again recommend you first test
using MP3's. MP3s are 1/10 the side of the original file on an audio CD
and probably about 1/5 the size of a FLAC file. If those work, then try
FLAC - but with the understanding you are going to be pushing about 5
times the amount of data through the same wireless arrangement.

Looking at your responses, I'm not sure what you music source is. Try
to rip a commercially made CD to MP3 files. I'm not knocking FLAC or
AAC. I just want to do what is the least demanding on your system
during play back to eliminate most if any problems.

pfarrell
2009-01-25, 22:34
stuart wrote:
>> Wireless isn't the problem. Are you using the "phono" input?

> The phonograph input is very high gain (do they still put these on
> amps?).

Yes, vinyl is making a comeback and thus phono inputs are getting more
popular. In addition to high gain, a phonograph input has heavy
equalization (the RIAA equalization curve) for use with 33 and 45
records. (78s are a separate topic)


--
Pat Farrell
http://www.pfarrell.com/

dcote
2009-01-27, 05:12
AAC will be transcoded in SC. did you check to make sure you are transcoding to wav or FLAC? you could be transcoding to mp3, thereby transoding lossy to lossy which _will_ degrade soundquality.