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Post by algreen345 on Mar 1, 2010 15:27:17 GMT -5
Just playing with my oppo bps-83 today. I played with bitstream vs LPCM out over HDMI and noticed that Bitstream sounds better. But more importantly, there is a 4 second delay when playing tracks over LPCM that isn't there with Bitstream. The LPCM delay happens when I pause and play, start new songs, stop and start.
Anyone else able to repeat this?
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Post by acsubie on Mar 1, 2010 17:16:07 GMT -5
After only using LPCM with my PS3 and then switching to bitstream with my Oppo bdp-80 I definitelty noticed a vast improvement in sound.
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Post by House on Mar 1, 2010 17:24:33 GMT -5
i have wondered about this for months...i honestly didnt notice any difference from Bit. to PCM.
I guess maybe i need to hook an optical cable up again and see if i notice anything now that it has been a few months...
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Post by moparmudder on Mar 1, 2010 17:29:07 GMT -5
i have wondered about this for months...i honestly didnt notice any difference from Bit. to PCM. I guess maybe i need to hook an optical cable up again and see if i notice anything now that it has been a few months... You can't get multi channel LPCM (or bit stream) over optical or digital coax, it is limited to 2 channel. HDMI is the only way to get multi channel LPCM. |
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Post by House on Mar 1, 2010 17:30:32 GMT -5
so what is really the difference? I mean I have listened to movies/music using both methods and heard no difference...
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DYohn
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Post by DYohn on Mar 1, 2010 17:33:22 GMT -5
so what is really the difference? I mean I have listened to movies/music using both methods and heard no difference... In general setting a device to bitstream means that it sends out whatever is on the disc and all signal conversion and decoding is done downstream (in the UMC-1) while setting it to PCM output means the player will convert the signal from however it is recorded into a PCM signal before it sends it out. If you hear a quality difference it is because the device doing the decoding (either your Oppo or your UMC-1) has superior electronics. |
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Post by House on Mar 1, 2010 17:43:49 GMT -5
so is the general preference to be bitstreem? or is it really just dependant up on what equipment you are using? I currently use a PS3 and just us HDMI..obviously PCM...but I am not opposed to running a optical cable for bitstream if it is proven to really be any better....
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Post by Mike Ronesia on Mar 1, 2010 17:50:33 GMT -5
So what i'm hearing based on the first two posts is the UMC-1 is doing a better job of audio processing then both the Oppo 80 and 83. If this is true then no reason to spend the extra on the 83 unless the video is better.
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Post by moparmudder on Mar 1, 2010 17:59:09 GMT -5
so is the general preference to be bitstreem? or is it really just dependant up on what equipment you are using? I currently use a PS3 and just us HDMI..obviously PCM...but I am not opposed to running a optical cable for bitstream if it is proven to really be any better.... Again you CAN NOT bitstream HD Audio or get multi channel LPCM over optical, only HDMI. Optical is good for 2 channel, DD, or DTS thats about it... |
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Post by House on Mar 1, 2010 18:01:42 GMT -5
ah.....sorry i totally mind blanked lossless and blu ray HD audio....makes sense now..
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Post by mcg on Mar 1, 2010 18:03:57 GMT -5
so what is really the difference? I mean I have listened to movies/music using both methods and heard no difference... In general setting a device to bitstream means that it sends out whatever is on the disc and all signal conversion and decoding is done downstream (in the UMC-1) while setting it to PCM output means the player will convert the signal from however it is recorded into a PCM signal before it sends it out. If you hear a quality difference it is because the device doing the decoding (either your Oppo or your UMC-1) has superior electronics. I'm not sure this is correct. The PCM signal that ultimately gets processed by the UMC and sent to the amp is the same, regardless of where it gets decoded. There should be precisely zero difference between the PCM signals. Any difference is one of perception (or perhaps levels...sometimes louder sound "better"). |
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Post by autocrat on Mar 1, 2010 18:21:29 GMT -5
I'm not sure this is correct. The PCM signal that ultimately gets processed by the UMC and sent to the amp is the same, regardless of where it gets decoded. There should be precisely zero difference between the PCM signals. Any difference is one of perception (or perhaps levels...sometimes louder sound "better"). I'm pretty sure that this is only true for the lossless compression schemes (Truehd, DST master). |
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DYohn
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Post by DYohn on Mar 1, 2010 18:23:10 GMT -5
In general setting a device to bitstream means that it sends out whatever is on the disc and all signal conversion and decoding is done downstream (in the UMC-1) while setting it to PCM output means the player will convert the signal from however it is recorded into a PCM signal before it sends it out. If you hear a quality difference it is because the device doing the decoding (either your Oppo or your UMC-1) has superior electronics. I'm not sure this is correct. The PCM signal that ultimately gets processed by the UMC and sent to the amp is the same, regardless of where it gets decoded. There should be precisely zero difference between the PCM signals. Any difference is one of perception (or perhaps levels...sometimes louder sound "better"). If multichannel PCM is coming straight off the disc and being handed by the same DAC in either case then yes you are correct. If a PCM signal is 2-channel or is being created or decoded from other recording schemes on the disc, then it would depend on the device doing the decoding and could explain why bitstream sounds better. |
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dfdo
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Post by dfdo on Mar 1, 2010 18:28:51 GMT -5
I thought lossless over bitstream or LPCM should sound the same whether it is decoded at the source or downstream. All it should be doing is unpacking the channels.
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Post by mcg on Mar 1, 2010 18:43:21 GMT -5
Yes, LCPM is LCPM.
The perceived improvement in sound quality with bitstreaming is a common misconception.
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ntrain42
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Post by ntrain42 on Mar 1, 2010 19:08:58 GMT -5
Cant you bitstream over HDMI?
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cgolf
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Post by cgolf on Mar 1, 2010 19:23:49 GMT -5
Yes, LCPM is LCPM. The perceived improvement in sound quality with bitstreaming is a common misconception. Then back to the original question. Why are there 2 different names / streams? Is the only difference where the stream is decoded? Seems that the less decoding the better so bitstream should be the preferred at least with HDMI.??  |
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osogovo
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Post by osogovo on Mar 1, 2010 19:23:53 GMT -5
There is no difference ,but you have to apply one of the surround modes when in PCM.Otherwise the UMC's bass management isn't used .
BTW has anyone run the tests on AIX HD Sample?There is no signal from most of the speakers when you play 7.1 or 5.1 LPCM channel identification tests.
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Post by monkumonku on Mar 1, 2010 19:30:03 GMT -5
There is no difference ,but you have to apply one of the surround modes when in PCM.Otherwise the UMC's bass management isn't used . BTW has anyone run the tests on AIX HD Sample?There is no signal from most of the speakers when you play 7.1 or 5.1 LPCM channel identification tests. I had an odd experience with the UMC-1 using the Avia HT disc's pink noise reference tones for the different channels to set the levels. This is just a regular DVD, not blu ray and the tones were in Dolby Digital, being fed bitstream to the UMC-1 from an Oppo BDP83. Cycling through frome the left front to the left surround was fine, but then when I clicked on the remote to go to the previous chapter (previous speaker), the speaker on the screen did not match where the tones were coming from. That is, as I went back to the left front, the sound was actually coming from the right speaker. The center speaker was the same way - it showed center on the screen but the sound came from the subwoofer. They were all mixed up like that. I had to exit and go back to the top menu and come back in again starting from the left front in order for the speaker indicator on the screen to match where the tones were actually coming from. Very weird. |
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Post by moe on Mar 1, 2010 19:54:19 GMT -5
There is no difference ,but you have to apply one of the surround modes when in PCM.Otherwise the UMC's bass management isn't used . BTW has anyone run the tests on AIX HD Sample?There is no signal from most of the speakers when you play 7.1 or 5.1 LPCM channel identification tests. I had an odd experience with the UMC-1 using the Avia HT disc's pink noise reference tones for the different channels to set the levels. This is just a regular DVD, not blu ray and the tones were in Dolby Digital, being fed bitstream to the UMC-1 from an Oppo BDP83. Cycling through frome the left front to the left surround was fine, but then when I clicked on the remote to go to the previous chapter (previous speaker), the speaker on the screen did not match where the tones were coming from. That is, as I went back to the left front, the sound was actually coming from the right speaker. The center speaker was the same way - it showed center on the screen but the sound came from the subwoofer. They were all mixed up like that. I had to exit and go back to the top menu and come back in again starting from the left front in order for the speaker indicator on the screen to match where the tones were actually coming from. Very weird. Yes I had the same thing happen on my ps3 with avia,after working correctly,right displayed,left played visa versa.I don't know this has anything to do with the umc,but it happened.I thought maybe my disc was screwy. |
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