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M_N
Joined: 13 Dec 2007 Posts: 1
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Posted: Thu Dec 13, 2007 10:42 am Post subject: Does PS3 automatically align LFE of SACD to DD/DTS etc? |
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As all of you probably know, the LFE channel in DD and DTS content is recorded with an offset of -10 dB vs the other channels. (As specified by Dolby, DTS etc.) The receiver's decoder then automatically boosts the LFE channel by 10 dB. This has been working correctly for years. (Please note that this has nothing to do with the usual subwoofer level adjustment wich affects the LFE plus any redirected bass from "small" channels/speakers.)
But, SACD does not record LFE with a -10 dB offset. All channels are recorded at the same level. With the PS3 decoding DSD to PCM and then transmitting over HDMI, there is a potential risk for different LFE levels for "SACD as PCM" vs DD/DTS content (DD/DTS sent as bitstream or decoded to PCM, no difference in that case).
Very few receivers that I know of can set LFE level individually for DD, DTS, PCM etc during decoding . Onkyo 705 and upwards have that possibility.
Does anyone know how the PS3 handles the LFE level of SACD content when decoding DSD->PCM? Is LFE attenuated 10 dB to align to various forms of DD/DTS content?
Test discs for SACD are a bit rare but Telarc has a title (Tchaikovsky: 1812 Overture, SACD-60541) that on the SACD multi channel layer at least contains one track/channel with pink or white noise for setting the levels:
http://www.telarc.com/sacd/title.asp?sku=SACD%2D60541&mscssid=F3KM1TS4CP3K8LAHKWE9M29J1WFV5308.
More reading for those interested:
http://www.avsforum.com/avs-vb/showthread.php?t=748147
// MN |
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The Seventh Taylor
Joined: 17 Aug 2007 Posts: 401
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Posted: Fri Dec 14, 2007 6:38 am Post subject: |
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Interesting question. I'm not aware of any such specification for multichannel PCM. I would assume it follows the conventions of DSD rather than those of DTS/DD.
But there's another question still. SACD is actually not a 5.1-channel medium but a 6-channel one, with all channels providing full bandwidth. The odd thing is it's not defined in the standard how to use the sixth channel and there are no bits defined (yet) that tell the equipment what to expect. It can be used in various ways. Of course, most SACDs that hold a sixth channel use it to feed the subwoofer but they may also use it as a rear center channel and there's even (at least) one title, Sacred Feast, that uses it as a height channel, requiring a ceiling-mounted speaker for proper reproduction.
The question then is whether multichannel PCM is a "5.1" or a 6-channel signal. |
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FunkyMonkey
Joined: 09 Nov 2007 Posts: 77
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Posted: Fri Dec 14, 2007 11:02 am Post subject: |
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SACD on the PS3 sounds the same, in terms of bass levels, as it does from my Philips, so I woudl guess, just from hearing it, that the bass levels are corrected if required internally in the PS3. |
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Brandon B
Joined: 14 Oct 2007 Posts: 392
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Posted: Wed Dec 19, 2007 8:01 pm Post subject: |
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I am positive, lacking documented proof, that it does. My previous setup did not and the elevated bass level was apparent. It is correct with the PS3.
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KorbenDallas
Joined: 26 Mar 2008 Posts: 1
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Posted: Wed Mar 26, 2008 3:17 pm Post subject: |
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So does this mean that SACD over the PS3 is -10dB down on the LFE when compared to DD / DTS?
Please clarify 100%, thanks |
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FunkyMonkey
Joined: 09 Nov 2007 Posts: 77
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Posted: Wed Mar 26, 2008 4:35 pm Post subject: |
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KorbenDallas wrote: | So does this mean that SACD over the PS3 is -10dB down on the LFE when compared to DD / DTS?
Please clarify 100%, thanks |
To answer your question, I will say that the bass levels are correct for all sound and disc formats playable on the PS3. |
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