Dumb Questions about Digital Music sources

I am using my laptop as a program source and find the convenience addictive.
I am under the impression that playback audio quality is (only) determined at the point at which the digital signal is converted to analogue; before this point, as long as the digital stream can be supplied with sufficient speed to avoid 'glitching', Windows media player, VLC player, etc, should not affect sound quality.

Second Ignorance bombshell; I purchased a Creative Sound-Blaster-X-Fi-HD external sound card. It claims 114 db S/N and 96 kHz 24 bit D/A capabilities.
What is this difference between this sound card and a DAC?

Thanks for all your help repairing my Crest and BGW amplifiers. Diyaudio.com has been one of the most valuable and interesting resources on the web ,for me.
 

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Hi Nico
Thanks for your response. I have downloaded a program (Room Equalization Wizard) Initial setup requires calibration of the sound card. This immediately revealed the poor quality of the internal sound card.
I find the Creative Sound Blaster to be extremely good, considering the cost, approx $120 Canadian.
Can you tell me if using VLC player as my 'player' is degrading the sound, or is there a better program in regards to fidelity. I like VLC player because of the many formats it can handle (audio and video) but I would like to know if this software has an effect on sound quality
 
I am using my laptop as a program source and find the convenience addictive.
I am under the impression that playback audio quality is (only) determined at the point at which the digital signal is converted to analogue; before this point, as long as the digital stream can be supplied with sufficient speed to avoid 'glitching', Windows media player, VLC player, etc, should not affect sound quality.

Pretty much correct, yes. The DAC is the more critical part.
 

TNT

Member
Paid Member
2003-04-26 10:25 pm
Sweden
I think you are correct in your thinking about the digital signal. A problem is that various boxes (HW), operative systems, drivers and applications do operations on the data and when so performed, it is no longer the original that you are listening to.

The absence of such manipulation is often referred to as "bit correct" or bit transparent.

To your last question above.. no sure. How can you test? Tricky!

You should also know that almost all D/A converter chipset do indeed perform computation of the source 16bit (24) words that contain the music information for a couple of reasons; filtering, up-sampling and sample rate adaption are some example.

You will need a 16 bit 44,1 khz no oversampling DAC to get close to "zero manipulation" CD playback. Will this be the ultimate reproduction - I'm not so sure. MP3 coding has of course quite severely recalculated a linear PCM source file.

//
 
before this point, as long as the digital stream can be supplied with sufficient speed to avoid 'glitching', Windows media player, VLC player, etc, should not affect sound quality.

True, but it is fairly easy to get a PC to glitch. It seems that anything you can do to not have the PC access its power supply with dynamic requests can improve sonic performance. A good example are player software that grabs the file off the disk and stores it into memory before playing.

dave
 
Thanks for answering, next silly question;
I have 'ripped' music from CD's using Windows media player. I have ripped as WAV files when selecting the format. Beside the 'Quality' selection, it says 1411.2 Kbps. Is this the bit rate of the (new) format?

I guess what I'm asking is, is there a difference between listening to a wave file and listening to a CD directly?

Thanks also, TNT; Is a WAV file 'bit correct', and if not what are the sacrifices compared to listening to a CD directly?
 
I guess what I'm asking is, is there a difference between listening to a wave file and listening to a CD directly?

Thanks also, TNT; Is a WAV file 'bit correct', and if not what are the sacrifices compared to listening to a CD directly?

In order, no, and yes. A .wav is lossless. I haven't experienced glitching on any of the four PCs I've used to play music, and my computers are decidedly plebian.

It's amazing- a well-engineered system works exactly as intended.
 
Thanks SY;
Pardon my 'thickness', but regarding the use of VLC player as my program software,is this an audiophile no-no?

Under the tools menu, there are EQ, compressor, etc. options. Would simply leaving them unchecked (disabled) assure me of an unadulterated digital signal?

I am not a fanatical purist; I prefer Digital audio over vinyl. I grew up tinkering with push-pull parallel 6L6 amps, but am in love with my Crest 1000 W/ch amp for my sub woofers. (Very large home theatre system) The Crest is a class H, although Mr. Doug Self, I believe claims that this design is actually class G. I'm getting off-topic..

I have made considerable changes to my system and a lot of tweaking to do, so my concern is that I'm starting with a clean signal. RE: my so called 'DAC' the Creative Sound-Blaster-X-Fi-HD external sound card, I have just noticed with horror that a Distortion spec is not listed. Would that be the primary difference between this sound card and and the high priced DAC's?
 
About foobar2000: It is worth it to use it or a similar program if only to gain access to "bit-perfect" ASIO, Kernel streaming, or WASAPI. Foobar can also do resampling, tag and use Replaygain, get freedb data, and has a built in library. (And many more features and plugins) VLC uses the Windows audio stack which is not guaranteed to give an accurate signal out.

Have you have done a loopback test at some point? Arta is a good software to use for that but for free you could also use HolmImpulse. It will give you an option to show the distortion/nose levels as traces but AFAIK doesn't give a single summed THD or noise value like Arta does. May be instructive.

Just found that Arta has a shareware trial here ARTA Download
It can use ASIO so either use Creative ASIO drivers if they exist for that product or install ASIO4ALL
 
WOW, Thanks SY;
Can't be any more clear than that! Just leave volume at 100%.

Can I get your opinion on a similar issue; I purchased at great expense, a Rane DEQ 60L 'digital' EQ, thinking it would solve all my problems. Someone suggested that, inspite of the EQ's 24-bit 96kHz internal DAC's, there is altogether too much converting back and forth.
I have replaced it with an older style Rane GE 60 Equalizer, to keep the signal in the analogue form. Does this make sense or is it a backwards move?
 
Can't be any more clear than that! Just leave volume at 100%.

If you are not worried about what windows may do to the sound, then yes.
However, most prefer to use one of the drivers I mentioned above.

My 2 cents about your digital crossover: whether analog is better would depend on your ears/measurements. For me, the ideal thing would be to use digital filters/vst on your computer. With it being a home theater the only downfall of digital filters might be latency. Searching for zero latency filter or zero latency fir filter gives a lot of hits.
 
Hi Vladimire;
Thanks for your input; your info is quickly getting beyond my scope of understanding, thank goodness for Wiki. If I understand correctly, an ASIO driver will bypass a lot windows software, primarily reducing latency. I am simply playing back audio for listening, so latency concerns are not apparent to me.
Regarding a loopback test, I have REW (Room Equalization Wizard) which has a tone sweep and RTA function, as well a number of features slightly beyond me. It require a loopback test to calibrate my external sound card. No mention of Distortion Analysis.

After all that, my question; Is Windows changing the bit stream (if volumes are set at 100) or just delaying it? You may have answered this, apologies, my brain is still a little frozen up here in Canada.
 
I do confess I don't know the ins and outs of Windows 7 Audio and have heard that it is better than previous Windows.

The main problem I have heard of with the Windows audio is that it doesn't resample well. You can resample in foobar instead but AFAIK not in VLC.

It may also perform some computations that are less than ideal, and I have never cared to try to prove that it sounds any different than ASIO.

Just know that native Win7 audio is for sure not better, avoid the guesswork and waste of time comparing and go with ASIO, KS, or WASAPI.

You might ask which is better. Well these people (Windows 7 ASIO vs. WASAPI) seem to like WASAPI over ASIO. WASAPI gave my system some hiccups, and KS puked while playing the other day, so I am happily using ASIO now.
 
Thanks Vladimire,
Your info has shown me some directions to follow up on. Not to shock you with my ignorance, but I believe I have learned at least a couple of things today. It seems the nature of CD-DA is to record the entire disc in one 'file' or data stream and use a (cue) file to find the track sections. If I have that right.
This may explain why a number of albums I have downloaded are one continuous track without out any apparent chapter or indexing. Still trying to hang on to my user-friendly VLC player, can VLC utilize the accompanying .cue files to find titles?

Second Question; Regarding "pre-emphasis". Could this be why many of my downloaded flac file sound horrible, others sound great. This pre-emphasis sounds like dolby from the 70's, a 9 db boost on the HF, requiring a corresponding de-emphasis on playback. When I switch from movies to music flac files, radical adjustments to bass and treble controls have to be made, just to keep things listenable. Could this emphasis thing be the reason? Are there different degrees of pre-emphasis?
 
About cuesheets: They can be multiple or single audio files. I use multiple in order to play the files individually. I just use the cuesheet to write a CD when needed. In that case foobar can easily decode Flac back to original wav. The only drawback with this is that there is no space between files when played back. I don't mind it. I then use Burrrn to write CDs. One trick with Burrrn is if your cuesheet says wav, instead of converting to wav you can just edit the cuesheet to say flac and burn away.

In EAC, to make compressed files, see the "Test and copy selected tracks" for multiple and "Copy image and create cuesheet -> compressed" for single files


Get cue by "Create Cuesheet -> Multiple wav files with gaps (noncompliant)"
for a multiple file cuesheet

Regarding VLC, it does support cue sheets. I tried it with a single file one. If you want to use a regular multi file cuesheet in VLC you will have to go in and change all the .wav to .flac.

You can find tutorials for setting up EAC for flac on hydrogenaudio wiki, but it seems to be down. I would take some time to learn about EAC, foobar, replaygain, and par2 and decide on a directory structure before you start ripping. Ripping is not something you want to do multiple times. VLC may be good for you now but if you ever want something with a library you will have to look elsewhere. I see that VLC actually does do replaygain which is good. What you do in foobar and EAC will end up helping you learn.

About your audio quality: is there a chance you are getting vinyl rips? A lot of the time they just say [24-96] but if you look closer they are vinyl.
 
But to respond to the Digital vs analog crossover I would:
1. Get Arta and latest X-Fi drivers
2. See if it has an ASIO driver with X-Fi drivers and install Asio4all if not
3. Test sine with:
a) RCA to RCA Loopback
b)RCA to Digital crossover back to RCA in
c)RCA to Analog equalizer back to RCA in

If your digital crossover has Optical in you can play around with that as well (Digital out to crossover to analog back to RCA)

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