# To bit perfect or not to bit perfect.....



## prerich (Mar 26, 2008)

In order to achieve bit perfect you mustn't use any type of DRC (Digital Room Correction) at the PC level - all DRC would have to come after the PC and before the amps (i.e. using a Neptune or Audyssey outboard processor). I see that there are more people that use HTPC's here than in other theads I'm involved in (or they are just more vocal here) - so I want to pose a question. How important is bit perfect to you? 

I performed an experiment - I watched a movie (Despicable Me 2) via Total Theater 6 - it was bit perfect however, it didn't sound as good as playing it back in JRiver Media Center 19. Now in JRiver - I have Room Correction, Convolution settings and eq filters on individual speakers (all with the aid of REW - Best value in a program....EVER!!!!). I've played music back ....and JRiver sounds better, even though it's not bit perfect anymore - it's "room better and room friendly"!!!! 

I used to obsess over being bit perfect, but with the DRC programs included in JRiver, not to mention the greats like DIRAC Live, Audiolense, and Accorate just to name a few....bit perfect has become less of a priority (at least to me). Does the music or movie sound believable? That's the major thing - my system may no longer be "bit perfect", but it sounds right in my room! (Thanks REW, Ethan Winer for acoustic help, and foam companies everywhere)!!! I would like to know - how many of you apply processing to your digital signals (such as Room Correction, hey I even applied a LTC to my 2 sealed subs)! I believe the enjoying the music/movie is paramount - isn't this the real reason we're in this hobby? What say you - to Bit Perfect or Not to Bit Perfect (I can even see those who do bit perfect because they have treated their rooms to the degree that they need no room correction - but for multi channel, IMHO, I believe you will always need some type of eq and room correction - but that's just me).


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## mechman (Feb 8, 2007)

Apparently it's not that important I guess? :scratch:


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## antoninus9 (Nov 25, 2013)

Do you mean bit matching, or bit perfect from the original source?


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## prerich (Mar 26, 2008)

antoninus9 said:


> Do you mean bit matching, or bit perfect from the original source?


Bit perfect from the source...once you apply DRC or any DSP you are no longer bit perfect.


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## antoninus9 (Nov 25, 2013)

I seldom, if ever, employ bit perfect while listening. Like you, I'm more interested in enjoying the music or movie. Sometimes I switch to bit perfect for testing purposes. Just recently I switched to bit perfect while working through an issue with J. River. Once it was resolved I switched back to DSP.


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## prerich (Mar 26, 2008)

antoninus9 said:


> I seldom, if ever, employ bit perfect while listening. Like you, I'm more interested in enjoying the music or movie. Sometimes I switch to bit perfect for testing purposes. Just recently I switched to bit perfect while working through an issue with J. River. Once it was resolved I switched back to DSP.


what type of DSP are you using? I've also found a new VST plugin that will allow multiple convolutions simultaneously! It's called MixIR2 and it cost $49, this will allow me to implement FIR filters to correct phase as well as PEQ filters generated by REW 

Sent from my iPad using HTShack


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## gdstupak (Jul 13, 2010)

My end product is not bit perfect.
When setting everything up, my signal starts out as bit perfect. I keep everything out of the chain that is definitely bad (i.e. Windows audio kernel, Windows Volume...). Then DRC is added to correct timings and achieve flatter eq. I think eq is the most noticeable imporovement available. I use software based eq and outboard hardware eq for all speakers.


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## prerich (Mar 26, 2008)

gdstupak said:


> My end product is not bit perfect.
> When setting everything up, my signal starts out as bit perfect. I keep everything out of the chain that is definitely bad (i.e. Windows audio kernel, Windows Volume...). Then DRC is added to correct timings and achieve flatter eq. I think eq is the most noticeable imporovement available. I use software based eq and outboard hardware eq for all speakers.


Excellent!!!! That's the way to do it! Windows kmixer is a known problem and best to remove it from the chain with ASIO or WASPAI. I use software EQ on all channels myself' but back in the 90's I used hardware EQ's on every channel.


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## Sonnie (Apr 11, 2006)

We may need a primer in what is "bit perfect" and who is JRiver? Never heard of either myself.


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## prerich (Mar 26, 2008)

Sonnie said:


> We may need a primer in what is "bit perfect" and who is JRiver? Never heard of either myself.


Wow!!!! You don't know what JRiver is?!!! Ok, I've got my work cut out for me. I'll try to work on a primer this weekend!

Sent from my iPad using HTShack


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## Sonnie (Apr 11, 2006)

Well... I did go look him up... and found it wasn't a him, but a her. Joan? j/k

I found their site... looks like a pretty respectable media software.

A primer for this section of the forum would be nice though... maybe worth a sticky thread if it is detailed enough. :T


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## gdstupak (Jul 13, 2010)

For the type of person that prefers the "DIRECT AUDIO" or "PURE AUDIO" modes on AVRs, a truly bit perfect path is the way to go.

J River Media Center (JRMC) is usually near the top of the list when it comes to audiophile grade media servers. It is not for the timid, there is a steep learning curve to using this very customizable tool. There is an abundance of great online articles that describe how to set up JRMC to eek out the best sound possible. Even if not interested in using JRMC, these articles are an educational resource for understanding what is good and bad with the Windows audio path.


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## Sonnie (Apr 11, 2006)

I prefer Pure Audio mode for two-channel music listening, although occasionally I will set it to stereo and let the sub kick in.


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## alatham (Jan 9, 2014)

I have jRiver and Bitperfect for mac. Would love to learn more about how to best configure and use them.


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## Savjac (Apr 17, 2008)

This is interesting information for sure. I use Jriver as well and have for a good long time, its wonderful. Jriver has EAC built in so when ripping you will get a bit perfect copy. 
Now comes the part I need help with if you don't mind. 

Are you saying that once the item is ripped onto the hd and during playback the file is no longer bit perfect ?
It would seem that any changes put into play by a processor would occur post HD as it is going to the next part of the playback chain. 

Am I way off base here ?


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## Savjac (Apr 17, 2008)

Sonnie said:


> I prefer Pure Audio mode for two-channel music listening, although occasionally I will set it to stereo and let the sub kick in.


Absolutely, Pure Audio, Pure Direct or whatever the name is seems to be the way to go when using hdmi or one of the processors digital inputs. The signal will still go through the AVR's processor but will have much less changes in sound quality that stereo or some other choice.

The MOST pure sound will come when you run your music through the ext inputs on the processor. 

For example: Attach a left and right rca cable to the left and right outputs of your Oppo, there are a couple choices on the Oppo and either one is fine. Now take the other end of the stereo rca cables and attach them to the left and right ext terminals on the back of the Onkyo and set the controls on the AVR accordingly and now you will hear what un processed music sounds like. Its good. :T


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## gdstupak (Jul 13, 2010)

I know management doesn't want us to use links that take us away from this website but sometimes I don't feel like writing a 10,000 word essay that is already written somewhere else (and probably written more better). 
So with that in mind, here is a link to one of the many great articles concerning J River and bit perfectness...
http://www.computeraudiophile.com/content/520-fun-digital-audio-%96-bit-perfect-audibility-testing/

DIRECT and PURE AUIDO bypasses Audessey room correction. My room needs correction and Audyssey (and outboard EQs) definitely helps for a flatter freq response and better timings which gets the end result closer to the originators intent. I like that.
If I could have a dedicated room with proper room treatment and perfect equipment that delivered a flat freq response and correct timings, I would love to do away with all electronic processing.

EDIT: Here is a quote that sounds more professional concerning the benefits of DSP..."_*However, using the power of 64 bit digital signal processing (DSP), as in digital room correction software, I can alter the bit-stream to more closely match the bits stored in the original music file. Why would I want to do that? For me, the most musical enjoyment comes from knowing that I am getting the most accurate representation of the music stored in the media file on disk arriving at my ears in the listening position.*_"


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## prerich (Mar 26, 2008)

gdstupak said:


> I know management doesn't want us to use links that take us away from this website but sometimes I don't feel like writing a 10,000 word essay that is already written somewhere else (and probably written more better). So with that in mind, here is a link to one of the many great articles concerning J River and bit perfectness... http://www.computeraudiophile.com/content/520-fun-digital-audio-%96-bit-perfect-audibility-testing/ DIRECT and PURE AUIDO bypasses Audessey room correction. My room needs correction and Audyssey definitely helps for a flatter freq response and better timings which gets the end result closer to the originators intent. I like that.


I'm working on something now for this forum, although Vincent Kars has THE best and most exhaustive tutorial computer audio! To help out one of the other readers, ripping a byte for byte copy of a CD is different than Bitperfect playback. While your rip is perfect, playback of those bits can be altered by things in the digital audio chain. No DSP can be applied, this is why receivers turn off EQs and DRC (digital room correction) when using pure audio or Direct modes. Bitperfect playback must have the exact sample rate and bit depth as the original (no upsampling) -what goes in is what comes out. since I'm a fan of DRC, I'm not Bitperfect - my rips are byte for byte, but I apply DSP in the form of DRC.

Sent from my iPad using HTShack


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## gdstupak (Jul 13, 2010)

alatham said:


> I have jRiver and Bitperfect for mac. Would love to learn more about how to best configure and use them.


So far, it seems the set up for Windows and Mac are 'virtually' identical. The few differences there are, they say it is very easy to figure out for yourself.
Here is a great tutorial based on JRMC 17 for Windows....
http://www.computeraudiophile.com/content/436-jriver-media-center-17-detail/

Here is a great tutorial if you're wondering if there is a difference between Windows and Mac in audio quality delivered by JRMC (spoiler alert -- there is no difference)(near the end, there is also a quick analysis between two different USB cables (spoiler alert -- there is no difference (and there is a quick explanation as to why some might here a difference))...
http://www.computeraudiophile.com/content/513-jriver-mac-vs-jriver-windows-sound-quality-comparison/


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## alatham (Jan 9, 2014)

gdstupak said:


> So far, it seems the set up for Windows and Mac are 'virtually' identical. The few differences there are, they say it is very easy to figure out for yourself.
> Here is a great tutorial based on JRMC 17 for Windows....
> http://www.computeraudiophile.com/content/436-jriver-media-center-17-detail/
> 
> ...


Thanks gdstupak!


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## Sonnie (Apr 11, 2006)

Savjac said:


> Absolutely, Pure Audio, Pure Direct or whatever the name is seems to be the way to go when using hdmi or one of the processors digital inputs. The signal will still go through the AVR's processor but will have much less changes in sound quality that stereo or some other choice.
> 
> The MOST pure sound will come when you run your music through the ext inputs on the processor.
> 
> For example: Attach a left and right rca cable to the left and right outputs of your Oppo, there are a couple choices on the Oppo and either one is fine. Now take the other end of the stereo rca cables and attach them to the left and right ext terminals on the back of the Onkyo and set the controls on the AVR accordingly and now you will hear what un processed music sounds like. Its good. :T


Would the EXT be the same as the separate unprocessed RCA, Balanced and Digital Inputs offered on the Onkyo?




gdstupak said:


> I know management doesn't want us to use links that take us away from this website but sometimes I don't feel like writing a 10,000 word essay that is already written somewhere else (and probably written more better).
> So with that in mind, here is a link to one of the many great articles concerning J River and bit perfectness...
> http://www.computeraudiophile.com/content/520-fun-digital-audio-%96-bit-perfect-audibility-testing/
> 
> ...


No problem at all with that link... excellent info in that forum too. I just discovered it a couple of days ago.

Your reasoning makes sense. Wayne is going to be here this week and one of the things we are hopefully going to experiment with is using the miniDSP to equalize the MartinLogan Montis. Perhaps comparing that equalization with Audyssey could be interesting. 





prerich said:


> I'm working on something now for this forum, although Vincent Kars has THE best and most exhaustive tutorial computer audio! To help out one of the other readers, ripping a byte for byte copy of a CD is different than Bitperfect playback. While you rip is perfect, playback of those bits can be altered by things in the digital audio chain. No DSP can be applied, this is why receivers turn off EQs and DRC (digital room correction) when using pure audio or Direct modes. Bitperfect playback must have the exact sample rate and bit depth as the original (no upsampling) -what goes in is what comes out. since I'm a fan of DRC, I'm not Bitperfect - my rips are byte for byte, bug I apply DSP in the form of DRC.
> 
> Sent from my iPad using HTShack


I appreciate your willingness to do this for us... much appreciated.


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## prerich (Mar 26, 2008)

Sonnie said:


> Would the EXT be the same as the separate unprocessed RCA, Balanced and Digital Inputs offered on the Onkyo?
> 
> 
> 
> ...


Well. Sonnie - if you like the link to ComputerAudiophile - I'll also put down the link to Vincent Kars' The Well Tempered Computer ( http://thewelltemperedcomputer.com/ ). That site tells you almost everything you would want to know about computer audio! :T


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## alatham (Jan 9, 2014)

Great insight here folks. Thx!


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## Savjac (Apr 17, 2008)

Sonnie said:


> Would the EXT be the same as the separate unprocessed RCA, Balanced and Digital Inputs offered on the Onkyo?


For Onkyo it is called Multi Channel In. 
I do see that on some new ones, there is no multi channel in, only out.


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## Savjac (Apr 17, 2008)

prerich said:


> Well. Sonnie - if you like the link to ComputerAudiophile - I'll also put down the link to Vincent Kars' The Well Tempered Computer ( http://thewelltemperedcomputer.com/ ). That site tells you almost everything you would want to know about computer audio! :T


Thank You for this link. Lots of information there. 

I truly love his signature at the bottom:



_Many people seek advice and they choose who will give it to them. A person chooses an advisor who will give them the answers and advice that they want to hear._

Jean Paul Sartre


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## Sonnie (Apr 11, 2006)

Savjac said:


> Thank You for this link. Lots of information there.
> 
> I truly love his signature at the bottom:
> 
> ...


Not to get into a religious debate or discussion, but Paul coined that phrase a couple thousand years ago... albeit in a little different way. Interesting how he applied it to just about anything in life (although I figure he means this to be related to computer audio).

_For the time will come when they will not endure sound doctrine; but wanting to have their ears tickled, they will accumulate for themselves teachers in accordance to their own desires, and will turn away their ears from the truth and will turn aside to myths_ (2Timothy 4:3-4).


Wayne and I will try running HDMI out of one of our laptops into the Onkyo to see how it compares to the OPPO. The OPPO has received pretty high acclaim for its sound quality. Wayne also has several different bit rate recordings we are going to compare.


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## prerich (Mar 26, 2008)

Sonnie said:


> Would the EXT be the same as the separate unprocessed RCA, Balanced and Digital Inputs offered on the Onkyo?
> 
> 
> 
> ...





Sonnie said:


> Not to get into a religious debate or discussion, but Paul coined that phrase a couple thousand years ago... albeit in a little different way. Interesting how he applied it to just about anything in life (although I figure he means this to be related to computer audio).
> 
> _For the time will come when they will not endure sound doctrine; but wanting to have their ears tickled, they will accumulate for themselves teachers in accordance to their own desires, and will turn away their ears from the truth and will turn aside to myths_ (2Timothy 4:3-4).
> 
> ...


Agreed (very familiar with that passage too :T). The same argument - is also being debated about asynchronous DACS vs. firewire Adaptive or isochronous DACs. The high-end world bows at the feet of asynchronous DACs while professionals generally use isochronous DAC's to make the recordings we listen to....hmmmmm? Falling into group think without studying can be very dangerous. I for one have gone to the pro route....not because the pros told me to, but it works best for my application (multi-channel output, and it allows me to use the PC as an active Crossover for my mains in the future if I so desire). I'm interested in seeing how the HDMI compares to the OPPO. Most computer audio people do not like HDMI due to horrible jitter measurements - but how much of that is actually audible? I for one loved the DAC's in my old Onkyo RC-HT180/807, and my HTPC sounded great with them, but I wanted to reduce the number of components I had, and I wanted the ability to fix things myself - thus the HTPC as a prepro bit.


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## Savjac (Apr 17, 2008)

Sonnie said:


> Not to get into a religious debate or discussion, but Paul coined that phrase a couple thousand years ago... albeit in a little different way. Interesting how he applied it to just about anything in life (although I figure he means this to be related to computer audio).
> 
> _For the time will come when they will not endure sound doctrine; but wanting to have their ears tickled, they will accumulate for themselves teachers in accordance to their own desires, and will turn away their ears from the truth and will turn aside to myths_ (2Timothy 4:3-4).
> 
> ...


I did not know that phrase could be attributed to "THAT" Paul, I had never actually heard it before so Thank You Sonnie for getting me right. Paul surely is relating this to audio, not only computer audio but other dyed in the sheeps wool beliefs as well. Good on Paul, he knows some cool stuff.

I am not sure that using the HDMI out of a laptop to the Onkyo will tell you very much and it certainly will not improve on the Oppo. When using an hdmi cable one must remember that it is the settings inside the electronics that will determine what is sent. For example, which component is doing the decoding of the software and which component is doing any conversions. If you send out the signal from the computer via LCPM then the computer will do the decoding and windows will have its way with the signal, whereas if you send the audio out via bitstream, it should not be decoded by Windows and will be decoded and worked over by the Onkyo. Same for the Oppo of course but in that case, if you connect the Oppo to your multi channel inputs then the Oppo will send a very nice clean feed to the Onkyo in analog form. Anything else, HDMI, Toslink or Coax could then be decoded by the Onkyo. The PS3 works this way as well. 

So I am not really sure what you would be accomplishing by doing this sound wise. I am sure it is something I have missed as I do that alot these days. :gulp:


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## Sonnie (Apr 11, 2006)

I can verify that there is zero difference in the sound quality switching between the HDMI out on the OPPO to the HDMI input on the Onkyo vs. the Balanced out on the OPPO going to the dedicated two-channel Balanced input on the OPPO... or switching between the HDMI and Optical (both to the Onkyo).


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## prerich (Mar 26, 2008)

Savjac said:


> I did not know that phrase could be attributed to "THAT" Paul, I had never actually heard it before so Thank You Sonnie for getting me right. Paul surely is relating this to audio, not only computer audio but other dyed in the sheeps wool beliefs as well. Good on Paul, he knows some cool stuff. I am not sure that using the HDMI out of a laptop to the Onkyo will tell you very much and it certainly will not improve on the Oppo. When using an hdmi cable one must remember that it is the settings inside the electronics that will determine what is sent. For example, which component is doing the decoding of the software and which component is doing any conversions. If you send out the signal from the computer via LCPM then the computer will do the decoding and windows will have its way with the signal, whereas if you send the audio out via bitstream, it should not be decoded by Windows and will be decoded and worked over by the Onkyo. Same for the Oppo of course but in that case, if you connect the Oppo to your multi channel inputs then the Oppo will send a very nice clean feed to the Onkyo in analog form. Anything else, HDMI, Toslink or Coax could then be decoded by the Onkyo. The PS3 works this way as well. So I am not really sure what you would be accomplishing by doing this sound wise. I am sure it is something I have missed as I do that alot these days. :gulp:


If he uses the JRiver trial, set everything to bitstream, and use WASAPI to get windows KMixer out the way, he should be able to compare the OPPO (using it's multi out ) DAC to the DAC of the Onkyo.

Sent from my iPad using HTShack


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## Savjac (Apr 17, 2008)

prerich said:


> If he uses the JRiver trial, set everything to bitstream, and use WASAPI to get windows KMixer out the way, he should be able to compare the OPPO (using it's multi out ) DAC to the DAC of the Onkyo.
> 
> Sent from my iPad using HTShack


Yes, and this is how I have been running Jriver.
Thanks for posting.


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## antoninus9 (Nov 25, 2013)

I too prefer J. River, and agree that by-passing the Windows and soundcard mixers is the way to go. 

WASAPI can be unstable and cause system crashes. ASIO is the more stable choice. If your hardware doesn't support ASIO then download ASIO4All. It's free and works well. (Note: ASIO4All needs to be configured through its tray icon which is only visible when music is being played.)

J. River's 'Tools' popup panel shows exactly how the signal is being processed based on current settings. It also allows you direct access to the DSP control panel for on-the-fly changes.

Setting J. River to 3D album view is a great way to browse your library from your high-def TV.

For those just getting started here is a list of good software to help:

dBpoweramp - secure ripper and auto-tagger
MediaMonkey - media player, but it's the best library manager I've found
J. River MC - Excellent media player, and easier to use than Foobar2000
MP3TAG - a wonderful tool for fixing tagging issues (free) (works with FLAC)


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## prerich (Mar 26, 2008)

antoninus9 said:


> I too prefer J. River, and agree that by-passing the Windows and soundcard mixers is the way to go.
> 
> *WASAPI can be unstable and cause system crashes.* ASIO is the more stable choice. If your hardware doesn't support ASIO then download ASIO4All. It's free and works well. (Note: ASIO4All needs to be configured through its tray icon which is only visible when music is being played.)
> 
> ...


Wow!!!! You've had issues with WASAPI? I've never had a crash using WASAPI - (I use ASIO now due to my DAC being a firewire unit), but this is a first for me (crashes with WASAPI).


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## antoninus9 (Nov 25, 2013)

I've had problems with WASAPI using Windows Vista, 7, 8, and now 8.1. Both MediaMonkey and J. River will crash after awhile, and need to be restarted. The problem may not be WASAPI. It could be how my SoundBlaster X-Fi Elite Pro interacts with it. If you haven't experienced any problems, then it's probably my card and drivers.


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## prerich (Mar 26, 2008)

antoninus9 said:


> I've had problems with WASAPI using Windows Vista, 7, 8, and now 8.1. Both MediaMonkey and J. River will crash after awhile, and need to be restarted. The problem may not be WASAPI. It could be how my SoundBlaster X-Fi Elite Pro interacts with it. If you haven't experienced any problems, then it's probably my card and drivers.


Ahhhh!!!!!! That's the issue - its the Soundblaster card for sure!!!! I used an ASUS Essence ST/H6 and an Omega HT Claro Halo XT - the only card that I had any trouble with was the one before those...my old SB Audigy IIzs pro!!!! I definitely think it was the the drivers.


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## antoninus9 (Nov 25, 2013)

Those are both better cards for analogue out to an amp than mine. I don't use the SB for output anymore. It injects bit-matched into my DAC, and I use its external module to interface with my phono preamp for ripping vinyl.


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## ninouchka (Jan 19, 2014)

As a former composer and recording studio owner, I really like that people rip my cd's as lossless files.
I use Jriver MC 19 as client and server, going the bitperfect way sometimes via hdmi, but mostly
via analog outs from my firewire DAC to a pre amp or receiver, I just love all the posibilities of JRiver,
asio support, using multiple zones, fantastic DSP, specially the PEQ, you can nearly do anything with it etc etc
It was a steep curve to learn all the options, but worth every penny it costs.
I don't hear the difference between bitperfect and ASIO + DSP, well in fact it sounds better when correctly
using the room corrections and filters from REW.

cheers,

Nina


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## prerich (Mar 26, 2008)

ninouchka said:


> As a former composer and recording studio owner, I really like that people rip my cd's as lossless files. I use Jriver MC 19 as client and server, going the bitperfect way sometimes via hdmi, but mostly via analog outs from my firewire DAC to a pre amp or receiver, I just love all the posibilities of JRiver, asio support, using multiple zones, fantastic DSP, specially the PEQ, you can nearly do anything with it etc etc It was a steep curve to learn all the options, but worth every penny it costs. I don't hear the difference between bitperfect and ASIO + DSP, well in fact it sounds better when correctly using the room corrections and filters from REW. cheers, Nina


i agree with your last sentence greatly!!!!!!!

Sent from my iPad using HTShack


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## antoninus9 (Nov 25, 2013)

Do you have any examples of your music that you can share with us?


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## ninouchka (Jan 19, 2014)

I had a few hits in Germany on maxi-single, I still have to find a record player to rip it to pc..
I have the master tapes on DAT. But still am looking for a DAT player that works. I guess, it is antique :sweat:
the song was a House Version of Satisfaction Guaranteed. Maybe youtube?
And wrote a few songs for Frank Galan, known in Belgium, Holland, and Germany.
And lot's more, but I still have to write my Welcome/newbie post, I will put it in there.


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## AudiocRaver (Jun 6, 2012)

My understanding about one piece of the signal chain: Pure Audio mode through an AVR remains unprocessed except for the volume change, which occurs in the analog realm after D to A conversion. A digitally-controlled attenuator does the volume change, basically a resistive network controlled by digital switches. So an audio stream can remain bit perfect all the way through the digital path of the AVR.


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## AudiocRaver (Jun 6, 2012)

My understanding about one piece of the signal chain: Pure Audio mode through an AVR remains unprocessed except for the volume change, which occurs in the analog realm after D to A conversion. A digitally-controlled attenuator does the volume change, basically a resistive network controlled by digital switches. So an audio stream can remain bit perfect all the way through the digital path of the AVR.

Edit: How important is bit perfect? There are many ways for the signal to become NOT bit perfect, and some might be seen as more sonically acceptable than others. The main idea seems to have control of the audio path so that the signal only changes when you choose for it to. Windows mixer and volume controls are bit imperfect by nature and fairly easily bypassed. Any DSP or DRC will of course change bits, but to accomplish a desired sonic change.


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## Savjac (Apr 17, 2008)

AudiocRaver said:


> My understanding about one piece of the signal chain: Pure Audio mode through an AVR remains unprocessed except for the volume change, which occurs in the analog realm after D to A conversion. A digitally-controlled attenuator does the volume change, basically a resistive network controlled by digital switches. So an audio stream can remain bit perfect all the way through the digital path of the AVR.


May I respectfully request that this situation be examined a bit further ?
I "Think", and yes I am still in the trials of proving this, that even though Pure Audio may be chosen on the remote or front panel of the AVR, does not necessarily mean that all processing has been shut down in any given signal chain.
I have noted that if I run the rca cables of my DAC or Oppo into lets say the "CD" input. When connected and the "Stereo" setting is engaged, the sound is thick, heavy and seems overly processed. When I engage the "Direct" mode on the Denon, things do clean up a good but, that foreboding sound cloud of thickness and darkness dissipates and the sun shines through like a much clearer day, not totally clear but clearer. "Pure Direct" does not seem to assist much so I use it but cannot tell the difference. What I have noticed is that if the Audyssey DSP was engaged at the time I chose "Direct", as I mentioned things sound pretty good however, if I now go back an set the DSP to Bypass L&R, the sound, for me at least gets even a bit clearer. This tells me that even in Direct or Pure Direct mode the DSP still has lingering effects, maybe they are wanted, maybe they are not.

I then discovered that if I connect my analog rca cables to the 7.1 inputs on the back of the AVR, with the DSP set to bypass, I get the most pure sound of all, it seems that essentially all DSP inclusive of management of any kind is bypassed and I like it. 

It would appear however, based upon your thoughtful post and the amount of time you and others have spent experimenting that I may not be spot on, so, I shall re-do my listening and report back.


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## Sonnie (Apr 11, 2006)

I am not diggin' Pure Audio like I was in the beginning... not now that I have some good listening sessions with Audyssey Music. It is much cleaner, smoother, creates even more detail... and I am getting closer to hearing the music the way the studio intended me to hear it. The more I listen to it this way, the more unnatural Pure Audio begins to sound when I switch over. 

As I understand it, Audyssey uses impulse response filters in the time-frequency domain, corrects for phase shifts and can reduce ringing in lower frequencies. I don't really understand it that well, but as Wayne explained it, Audyssey does a very nice job of fixing some things that are otherwise difficult to correct in a room. So... if that negates bit-perfect, so be it. I would rather have the more accurately engineered processing of Audyssey than I had allow my room to do its own processing that I know is not accurate.


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## AudiocRaver (Jun 6, 2012)

Savjac said:


> May I respectfully request that this situation be examined a bit further ?
> I "Think", and yes I am still in the trials of proving this, that even though Pure Audio may be chosen on the remote or front panel of the AVR, does not necessarily mean that all processing has been shut down in any given signal chain.
> I have noted that if I run the rca cables of my DAC or Oppo into lets say the "CD" input. When connected and the "Stereo" setting is engaged, the sound is thick, heavy and seems overly processed. When I engage the "Direct" mode on the Denon, things do clean up a good but, that foreboding sound cloud of thickness and darkness dissipates and the sun shines through like a much clearer day, not totally clear but clearer. "Pure Direct" does not seem to assist much so I use it but cannot tell the difference. What I have noticed is that if the Audyssey DSP was engaged at the time I chose "Direct", as I mentioned things sound pretty good however, if I now go back an set the DSP to Bypass L&R, the sound, for me at least gets even a bit clearer. This tells me that even in Direct or Pure Direct mode the DSP still has lingering effects, maybe they are wanted, maybe they are not.
> 
> ...


I do not claim it to be an authoritative answer, and I will certainly be on the lookout for more detailed info.

One thing I noticed with an Onkyo AVR awhile back, with speakers accidentally left on monitoring the source, is that in Pure Audio mode, delay through the AVR dropped to zero or near zero. Stereo mode with its processing added a delay of a half second or more. No big surprise.

How Pure is Pure? To be determined.:bigsmile:


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## AudiocRaver (Jun 6, 2012)

Pure audio has its place, if it gives a desired result. Sonnie's system with Audyssey MultEQ _properly applied_ sounds _absolutely *STUNNING!*_


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## antoninus9 (Nov 25, 2013)

Jack, 

Have you ever tried the Denon's DAC? Just direct inject the bit-stream from J. River. I'm curious if you perceive any significant difference between it and the stand-alone DAC and OPPO. 

While experimenting with J.River I discovered that it too can introduce a dark heavy sound with some settings.

My experience has been that there are few, if any, differences when I try this on my system with J. River set to bit-stream. Only when the external DAC was asked to up-sample did differences appear, and they were subtle. This makes me wonder if it's true for others as well.

Jeff


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## Savjac (Apr 17, 2008)

AudiocRaver said:


> Pure audio has its place, if it gives a desired result. Sonnie's system with Audyssey MultEQ _properly applied_ sounds _absolutely *STUNNING!*_



Understood and am glad you mentioned this and I see absolutely nothing wrong with this at all. I am all for setting the system up to obtain the best sound you can, Audyssey is there to help do that if at all possible. 
I am still torn on whether I like mine on or off because On gives the music a bit of a nice sheen if you will, it sounds a bit closer to what I would deem reality.


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## Savjac (Apr 17, 2008)

Hi Jeff, Thank You for the suggestions.

Yes I have gone through the Denon's Dac a good bit using HDMI, Toslink and Coax with similar results in that the Denon, while quite capable of making beautiful music with a deep and wide soundspace adds this dark tonality that is not JRiver related. it happens with iTunes and Cd's played through the Oppo or my Denon disc player. 

I never up sample anything coming off of JRiver, I really do not see the purpose of that, although now that you mention it, maybe I should try just to see what happens. Thanks for the idea. 
I will report back. 



antoninus9 said:


> Jack,
> 
> Have you ever tried the Denon's DAC? Just direct inject the bit-stream from J. River. I'm curious if you perceive any significant difference between it and the stand-alone DAC and OPPO.
> 
> ...


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## antoninus9 (Nov 25, 2013)

Jack,

My up-sampler is doing more than adding zeroes. It actually modifies the signal as a part of its design. It tries to rebuild the waveform more accurately. I thought I should point that out for clarification.

Personally, I've been able to achieve the best results on my system with the processor's DSP off 'Direct Mode' while using the DSP functions within J. River. (This applies to two channel audio only.)


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## Savjac (Apr 17, 2008)

Interesting, I will have to try that, thanks for the suggestion.

I do not think any of my present Dacs upconvert so any conversions i do would have to be in the software in the computer. I may try that to, what the .


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## Sonnie (Apr 11, 2006)

Do you guys have some way of directly and immediately A/B'ing the differences... as in switching back and forth with your remote?

I find myself thinking I may hear something... or not knowing if I am really hearing anything or not, until I am able to setup the A/B switching. For example... we could easily setup the analog out from the OPPO to the Onkyo analog input... and connect the optical out from the OPPO to the optical input on the Onkyo so that we could switch between the OPPO DAC and the Onkyo DAC with nothing more than an push of the button on the remote... I just coded the two inputs on two buttons of the remote. I have compared HDMI, Optical, Coaxial, and Balanced Analog with no differences heard when doing the immediate switching.


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## antoninus9 (Nov 25, 2013)

Sonnie said:


> Do you guys have some way of directly and immediately A/B'ing the differences... as in switching back and forth with your remote?
> 
> I find myself thinking I may hear something... or not knowing if I am really hearing anything or not, until I am able to setup the A/B switching. For example... we could easily setup the analog out from the OPPO to the Onkyo analog input... and connect the optical out from the OPPO to the optical input on the Onkyo so that we could switch between the OPPO DAC and the Onkyo DAC with nothing more than an push of the button on the remote... I just coded the two inputs on two buttons of the remote. I have compared HDMI, Optical, Coaxial, and Balanced Analog with no differences heard when doing the immediate switching.


Yes. I even added the Cd player in for A/B/C comparison. 

I spent two days tracking down the J. River sound problem. You need to use ASIO or WASAPI, set J. River to bit-streaming, and in the Sound settings in control panel set it to 16 bit 44.1 kHz. Once I did this TOSLINK, HDMI, and Coax all sounded the same. 

If anyone knows how to improve upon this please post it.


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## Sonnie (Apr 11, 2006)

Did you compare different bit rates too?


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