Help required - Understanding of HD sound options

[admin_exported]

Hi all,

Doing quite a bit of research before finally letting my wallet loose - I have a few queries regarding production of HD sound from Blue ray disks....

From what I understand, there are 3 ways of decoding HD sound to drive the speakers (can you confirm this is correct - as the possibilities are driving me mad now):

1.) HDMI - BD Player passes picture and music to Receiver via HDMI. Receiver seperates and decodes the HD signal from the HDMI input to drive the speakers. Receiver requires the ability to decode HD signal and receive HDMI, Player needs very little capability (other than HDMI out).

2.) Multichannel - BD Player decodes HD sound signal and passes to Recevier via Multichannel (analogue) connections, picture being passed via HDMI to either Receiver or straight to TV/display. Receiver requires Multichannel and HDMI inputs, Player needs multichannel outputs. Connection between Receiver and Player is made with a HDMI lead and 4 pairs of RCA Analogue leads (for 7.1). 

3.)  LPCM ** - BD Player decodes HD sound signal and reencodes as LPCM - the LPCM signal can either be sent via

3a) digital coax,

3b) optical digital,

3c) or over HDMI, coupled with the picture signal.

** This is really where my knowledge gets fuzzy - if a Receiver supports LPCM, can it strip the decoded HD audio from any of the above inputs (3a, 3b, 3c)??

Also, which of the above will give the best sound overall?

 

Many humbled thanks in advance. 

 

[nads]

HD sound. 2 options.

BD player decodes. or Amp decodes.

if BD plyer decods it can be out putted two ways. HDMI cable or the Analogue cables.

if the Amp is to decode the HDMI cable needs to be used.

all other connections can not pass the HD sounds.

 

[Anonymous]

thanks for such a quick response.ÿ

ÿSo I guess it comes down to which has the best HD decoder and DAC - The player or the Amp?

ÿ

Reason I was asking was I need a receiver which is good with films and music. I saw the reduced price of the Arcam AVR280 recently, and wondered if I should get this and a BD Player which can decode the HD sound (passed through multichannel), rather than a HD Yamaha amp and a more basic BD player.

Decisions, decisions... ÿwhat's your thoughts?

 

[Anonymous]

LPCM is not really a re-encoding. A 5.1 soundtrack say will comprise of 6 LPCM channels (5 surround + 1 sub). These are raw uncompressed PCM channels of digital data.

To save space on a DVD/BD these channels are usually compressed using one of Dolby's or DTS's (or both) algorithms. The current two Dolby True HD and DTS Master HD compress and can be uncompressed (decoded) without loss of data.

All others involve throwing away some of the data.

Once decoded the data becomes separate LPCM channels again which are fed through converters and then amplified.

If a bluray player decodes, it will send the LPCM channels either across HDMI, or across analogue multichannel if present on the player. Some bluray movies actually have the uncompressed LPCM channels as the soundtrack so no decoding is necessary but at the cost of memory space on the disc. An encoded digital signal - such as the Dolby or DTS multichannel ones - are usually referred to as bitstreams.

 

[Anonymous]

Thanks. One more Q - What does LPCM actually stand for?

ÿ

 

[Anonymous]

Linear Pulse Code Modulation.

A CD contains two channels (2.0) of PCM digital data. The 'L' is often dropped.