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Post by moe on Mar 1, 2010 19:59:08 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 also have this disc and noticed only 2chs played,center starts for 1/2 second then stops,then right plays,then nothing.With the ps3 there are so many crazy settings who knows but I did see this. |
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Post by saginawjuggalo on Mar 1, 2010 20:16:57 GMT -5
I can't tell any Bitstream difference simply because it takes far too long to go into the menu, switch to bitstream, restart the Blu-ray and than compare. I've read this debate more times than I care to count and from what I've gathered, when bitstreaming lossless audio the difference is subtle at best (and even placebo effect to some)
I use bitstream MAINLY because it takes a while for the UMC-1 to lock into a multiple PCM signal compared to bitstreaming.... That and because this leaves less room for doubt. Sometimes I miss those neat menu sound effects and PIP + sound functions. My Blu-ray player handles all audio correctly (I will make a thread about this soon.) Once the lag of multi PCM audio is taking care of, I might just switch back to PCM out.
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cgolf
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Post by cgolf on Mar 1, 2010 20:21:25 GMT -5
I can't tell any Bitstream difference simply because it takes far too long to go into the menu, switch to bitstream, restart the Blu-ray and than compare. I've read this debate more times than I care to count and from what I've gathered, when bitstreaming lossless audio the difference is subtle at best (and even placebo effect to some) I use bitstream MAINLY because it takes a while for the UMC-1 to lock into a multiple PCM signal compared to bitstreaming.... That and because this leaves less room for doubt. Sometimes I miss those neat menu sound effects and PIP + sound functions. My Blu-ray player handles all audio correctly (I will make a thread about this soon.) Once the lag of multi PCM audio is taking care of, I might just switch back to PCM out. If you switch to PCM, doesn't that take the UMC processing out of the loop? or does it still have to process the audio before sending it out? |
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Post by saginawjuggalo on Mar 1, 2010 20:24:39 GMT -5
Are you referring to bass management, crossovers and such? If so, they work with both. I believe you can use direct mode to bypass processing.
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Post by littlesaint on Mar 1, 2010 20:35:48 GMT -5
If both signals are going over HDMI, there should be no difference in the decoded audio. You're simply moving the point it is decoded from the source to the processor. The quality of the processor makes no difference since it is a unpacking operation. How the processor handles the LPCM once it gets it can result in a difference in sound, but for quality processors this should also be the same either way.
Blu-ray and HD-DVD groups never intended for sending raw bitstream HD audio over HDMI. The specs called for it to be decoded in the player and sent as LPCM to processors or using analog outputs. This allowed for secondary audio streams without compromising the HD audio. Sending raw bitstreams was created in an effort to sell new AVRs with the HDMI 1.3 spec. That's why many of the early BD players like the PS3 and pretty much all HD-DVD players required a firmware update to enable bitstream transmissions.
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Post by monkumonku on Mar 1, 2010 20:53:01 GMT -5
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. I have used that disc before with my Onkyo 706 to set levels and don't recall anything like that ever happening. Now, I don't remember specifically going back to the previous channel with the Onkyo but I am sure I must have because I would do that just to make sure the level settings were correct. Also, on the Avia disc in that section when played correctly, there is no subwoofer tone so that is what makes it even more mysterious as to why a sub tone played when it was supposed to be on the center channel according to the screen.  |
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ntrain42
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Post by ntrain42 on Mar 1, 2010 21:14:59 GMT -5
Um, if your bistreaming out, then your using the processors DAC's and decoding, if your using PCM out, then your using the sources DAC's and decoding abilities if I am correct.
SO there is a potential to be a marginal change if anything in sound quality, or there can be a significant difference in SQ. It all depends on the DAC/decoding ability of the hardware in question.
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Post by threxx on Mar 1, 2010 21:18:33 GMT -5
Yeah from what I read before LPCM and bitstream should sound identical... just a question of where the decoding happens. Granted, as mentioned before, if the UMC-1's sound processing is somehow superior to the PS3's then that could improve the sound... but is there really any wiggle room there? It seems that would be the equivalent to somebody telling me their MP3 sounds better because they upgraded their PC's CPU.
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Post by littlesaint on Mar 1, 2010 21:37:23 GMT -5
Um, if your bistreaming out, then your using the processors DAC's and decoding, if your using PCM out, then your using the sources DAC's and decoding abilities if I am correct. SO there is a potential to be a marginal change if anything in sound quality, or there can be a significant difference in SQ. It all depends on the DAC/decoding ability of the hardware in question. DACs are for analog conversion. No analog conversion if your sending the decoded LPCM over HDMI. |
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Post by mcg on Mar 1, 2010 21:38:40 GMT -5
Um, if your bistreaming out, then your using the processors DAC's and decoding, if your using PCM out, then your using the sources DAC's and decoding abilities if I am correct. SO there is a potential to be a marginal change if anything in sound quality, or there can be a significant difference in SQ. It all depends on the DAC/decoding ability of the hardware in question. No...that's the whole point. PCM is PCM until it hits the processors DACs and other processing circuitry. Whether that PCM signal is decoded in the player prior to hitting processor or just after it hits the pre/pro makes no difference. It's the same stream. |
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Post by mcg on Mar 1, 2010 21:41:32 GMT -5
Yeah from what I read before LPCM and bitstream should sound identical... just a question of where the decoding happens. Granted, as mentioned before, if the UMC-1's sound processing is somehow superior to the PS3's then that could improve the sound... but is there really any wiggle room there? It seems that would be the equivalent to somebody telling me their MP3 sounds better because they upgraded their PC's CPU. More like someone telling you that their MP3 sounds better because they accessed it off their Kingston usb stick instead of their patriot usb stick. |
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ntrain42
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Post by ntrain42 on Mar 1, 2010 22:10:06 GMT -5
Um, if your bistreaming out, then your using the processors DAC's and decoding, if your using PCM out, then your using the sources DAC's and decoding abilities if I am correct. SO there is a potential to be a marginal change if anything in sound quality, or there can be a significant difference in SQ. It all depends on the DAC/decoding ability of the hardware in question. DACs are for analog conversion. No analog conversion if your sending the decoded LPCM over HDMI. Thats true, but if the source is doing the decoding, whether in the digital domain or not, there is still potential for varying SQ issues depending the chipset used. THis is my understanding, I will definetly say I am not an expert in this domain of A/V theatre, but from my understanding there is the potential for varying levels of SQ. |
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Post by mcg on Mar 1, 2010 22:13:38 GMT -5
DACs are for analog conversion. No analog conversion if your sending the decoded LPCM over HDMI. Thats true, but if the source is doing the decoding, whether in the digital domain or not, there is still potential for varying SQ issues depending the chipset used. THis is my understanding, I will definetly say I am not an expert in this domain of A/V theatre, but from my understanding there is the potential for varying levels of SQ. I see what you're saying, but it's not really the case. The bits are all the same, regardless of where they are unpacked into the LPCM stream. Any difference would be the equivalent of your typical audio voodoo myths like the crazy power cables, and other such things. |
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Post by teedub21 on Mar 2, 2010 2:04:02 GMT -5
I'm blown away by how often I read statements by people that amps all sound the same, or DAC's all sound the same, or one I read earlier on this forum that there were no differences in all speakers mid priced to exotic. Even if both the PS3 and the UMC used exactly the same dac chip set, they wouldn't sound the same. There is no way the power supply in the PS3 is equal to that in a stand alone pre/pro, and that has a pretty big effect on sound too.
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Post by mcg on Mar 2, 2010 2:32:39 GMT -5
I'm blown away by how often I read statements by people that amps all sound the same, or DAC's all sound the same, or one I read earlier on this forum that there were no differences in all speakers mid priced to exotic. Even if both the PS3 and the UMC used exactly the same dac chip set, they wouldn't sound the same. There is no way the power supply in the PS3 is equal to that in a stand alone pre/pro, and that has a pretty big effect on sound too. at which point does the PS3 DAC touch the LPCM stream? |
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Post by fantom on Mar 2, 2010 2:49:08 GMT -5
teedub21: No one is saying that all things sound the same. The PS3's DAC is certainly different. We are all saying that the PS3's DAC is irrelevant. If you convert Dolby TrueHD, DTS HD:MA, DTS, Dolby Digital, Dolby Surround, AAC, MP3, WAV, FLAC, etc. into LPCM, it follows a spec. If it fails to do this properly, it's unlikely the sound will be *slightly* off. More like you'd just get a jumbled mess. It's like if you took this post and zipped it (it is rather long). Then you wanted to email it to your friend. You can: a) unzip it, put it in an email, and send the full text (just like decoding in player). b) send the zipped file, your friend unzips it, and then sees the full text (just like sending bitstream) Would the letter M come out slightly different for your friend? No. If something failed along the way, he'd prob just get a corrupt file that was unreadable. What might be different? 1. Bandwidth usage over the HDMI cable, but the cable can handle it without loss either way. 2. Lag. The player might take less/more time to decode the audio than your processor. Either way if you dial in the lip sync, this should not matter. 3. Secondary audio stream (used for menu clicks and PiP sound). You MUST decode to LPCM IN PLAYER to get this feature. Players that meet profile 1.1 (all are 2.0 now) are required to be able to decode the primary audio stream, decode a secondary audio stream (the secondary streams allowed are much more limited), and then (in PCM space) mix them together. The HDMI spec (incl. 1.4) DOES NOT allow for sending two audio streams. 4. Processor locking onto the signal might differ. It's certainly possible that a processor will take more/less time to lock onto an MultiCh LPCM signal than a bitstream signal. It's also possible that a player may handle audio communication during FF/RW/pause differently (as in, the player may stop the audio signal all together during a RW where there is NO audio anyway, but this may cause your speakers to pop or processor to have to resync). So if one method causes you more time spent waiting for your processor to lock onto the signal, you may want to choose the other just on annoyance factor. Bottom line: Nothing is lost sound quality-wise by decoding in the player. Either way you use the DACs in your processor. If you use bitstream, you cannot get menu-click/PiP/secondary audio, which is a feature loss if you care to use it. By the way, I zipped and RARed this post and then decoded it before posting. Sorry for the loss of quality.
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Post by jimsfield on Mar 2, 2010 8:28:04 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. I experienced a similar thing using the AIX setup disc. |
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ntrain42
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Post by ntrain42 on Mar 2, 2010 10:59:22 GMT -5
I'm blown away by how often I read statements by people that amps all sound the same, or DAC's all sound the same, or one I read earlier on this forum that there were no differences in all speakers mid priced to exotic. Even if both the PS3 and the UMC used exactly the same dac chip set, they wouldn't sound the same. There is no way the power supply in the PS3 is equal to that in a stand alone pre/pro, and that has a pretty big effect on sound too. Technically in a sense all amps do "sound" the same. But how they handle impedance load swings(and how much power they put out at a specific impedance load) will alter the output power to the speakers at a give frequency range and chance the EQ curve of the speaker. DIstortion levels at specific frequencies can also play a role. But technically a watt is a watt. DAC's can also sound very different too. SPeakers though, hehe, they all sound different. As for bitstream vs. LPCM, I dont doubt the signal is going to be identical, I guess the question on some folks end is if there is a difference in SQ between the 2 if potentially there are different electronics in the path of the signal for coded or uncoded output, or even the same. |
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ntrain42
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Post by ntrain42 on Mar 2, 2010 11:32:24 GMT -5
I got a question though..........there are ALOT of people who say long or "poor" runs of HDMI cables(which transmit 0's and 1's in packets)can affect video quality, and have dropouts........if this really is the case(which I honestly have yet to experience, even with a long 50foot HDMI cable run), then can't there be some potential detrimental effect to sound in some form too?
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Post by ryan08 on Mar 2, 2010 14:34:15 GMT -5
OK I called EMO yesterday because I could not get TrueHD sound to work. Nick told me to try switching from pcm to bitstream on my DVD and it should show up on the menu. I did and the sound is much better, however the read-out still won't say TrueHD when I try to select it. He told me in pcm the read-out would list stereo, but I would be getting multi channel sound. OK I was, but the sound was disappointing at best and what is the point of having the menu of sound processing? Anyway..bitstream sounds way better than pcm from my Sony350BR.
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