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Source for Home Cinema decoder
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Posted by: Major dude

Is there anybody out there with a Home cinema decoder?
Am I right in assuming that Nicam stereo is the most you can receive with a TiVo or NTL cable box or a freeview box.
I know some DAB tuners have digital outputs but other than that are DVDs are the only source for any true surround sound encoding options such as DTS or DD or THX?

Posted by: AMc

You can decode Dolby ProLogic surround sound from a stereo source (NICAM, cable, Freeview).
Shows like Star Trek NG and The Simpsons are encoded so if you connect a stereo output from a cable box/VCR/Freeview box to a decoder you will get surround sound - but not at the same quality as Dolby Digital 5.1.

Posted by: Major dude

Thanks for that.
Would that survive being routed through my Sony FX20 stereo out? Only, I use that at the moment as the stereo sound out, as it changes with the tv display; and I only have one source through the TV to deal with, rather than 3 - TV, NTL box & TiVo 1, Daewoo freeview box & TiVo 2.

I could then Line in to decoder from TV stereo out as well as a Toslink feed from the DVD.

Posted by: steveroe

Yes it should do, as long as the chain is stereo end to end then the dolby encoded signal will survive.

I take my output from my TV and push that through the surround system, same as you, it saves switching inputs on the amp when I switch inputs on the tv (obviously I also have a digital out from the dvd to the amp for DD5.1)

Posted by: Major dude

Thanks again,
Once I`ve rec`d & installed my AE Aego P5 thats on order I`ll be looking forward to watching the Simpsons with Dolby prologic.....Hmmmmmm

Posted by: AMc

Yup, that'll work. I have a Sony FX60U and use the stereo outs in the same way. The level of the output is controlled by the 'headphone' setting in the menus :)

If you connect them to the analogue DVD input and connect your DVD player to the DVD digital input you should find that the digital signal will override the analogue when you power up your DVD.
The upshot is you don't have to switch sources on your amp/decoder when watching DVD/TV or watching anything else - providing you turn your DVD player off when you're not using it.

Posted by: iankb

Ditto with a Sony FQ75.

Posted by: sjp

haven't noticed any mention of DPL 2... is it a standard on boxes these days???

if not then give it some serious consideration... DPL 2 is **way** better than DPL 1.

stuart

Posted by: steveroe

I think most modern boxes do DPL 2 as opposed to DPL

Posted by: Sneals2000

Yep - in the UK I believe that Sky Digital (and even then only with a Sky+ box) is the only real source of Dolby Digital broadcasts, and DVD is the only mainstream source of pre-recorded Dolby Digital and/or DTS content. AIUI there is no way of currently recording Sky Digital DD5.1 broadcasts apart from via a Sky+ box, though I believe Kiss are promising a DVD Recorder which will record DD5.1 soon.

Analogue TV with NICAM Stereo, Sky Digital (without a Sky + receiver), DTT/Freeview, Digital Cable, and UK Tivos etc. are limited to matrixed Dolby Surround (decoded via Dolby Surround, ProLogic or ProLogic II decoders) - though in some cases this can be carried via a digital audio output from a suitable receiver (Sony Sky box, some Freeview boxes etc.) rather than just an analogue connection?

There are exceptions : if you imported a D-VHS D-Theater HD VCR to the UK from the US you would get DD5.1 and/or DTS from this, and if you are a multi-satellite enthusiast you may be able to get DD5.1 broadcasts from some of the European satellite channels (I believe the German Pro7 channel carries DD5.1 on satellite - and DTT in Berlin?) including very high data rate radio broadcasts in surround (from Scandinavia?)

Not directly relevant - but might be of interest?

Posted by: iankb

And before you rush out to get Sky+ for DD5.1, I believe that it is only available on a handful of movie channels and, for some extraordinary reason, not available on PPV movies at all.

I think the problem is that, unlike surround sound, the digital tracks require additional bandwidth and, with the number of PPV and other movie channels, that could reduce the number of broadcast channels. Also, they need special broadcast equipment for DD5.1 channels, and they have a shortage of that.

Posted by: MarkE19

I watch all TV with sound via my AV system as I was not going to pay Ł300 for the speakers for my plasma. Even progs not encoded in DPL will be processed by DPL and create a psudo surround.
Now I'm just waiting to get enough pennies to upgrade and get DLP2x - will I never manage to find a cure for this upgrade bug :confused:

Mark.

Posted by: sanderton

Most shows are broadcast in DPL now; certainly pretty much all BBC drama/comedy, and Sky Sports.

Posted by: Sneals2000

quote:
Originally posted by iankb
And before you rush out to get Sky+ for DD5.1, I believe that it is only available on a handful of movie channels and, for some extraordinary reason, not available on PPV movies at all.

I think the problem is that, unlike surround sound, the digital tracks require additional bandwidth and, with the number of PPV and other movie channels, that could reduce the number of broadcast channels. Also, they need special broadcast equipment for DD5.1 channels, and they have a shortage of that.

Yep - the kit that used to be used for DD5.1 on the 16:9 Sky Box Office channels was redeployed to the Sky Movies (non-PPV) channels when they relaunched with all of them carrying 16:9 material, and shut Sky Premier Widescreen (or possibly when they merged Premier and MovieMax)

I believe that a lot of Sky footy is produced in multi-channel surround, currently broadcast as Dolby Surround (for ProLogic receivers etc.) but they hope to move to DD 5.1 when they sort out technical issues? (Links etc.)

Posted by: sanderton

Sky rugby certainly is. The hailstorm during the Gloucester game this afternoon was very impressive!

Posted by: sjp

quote:
Originally posted by steveroe
I think most modern boxes do DPL 2 as opposed to DPL

in that case... unless there is a substantial prices difference ignore any amp that has only got DPL 1. the difference is astounding and worth paying more for, it ain't DD but for just a surround sound/nicam stereo source it gets pretty damned close (at least to my 1 good ear and the working third/half of the other).

DPL 2 = mutts nutz

stuart

Posted by: iankb

DPL II is definitely superior and, since I doubt that there is any cost difference, I can't see why all modern equipment wouldn't use it. DPL I is dead.

Posted by: Major dude

My Aego P5 decoder has an auto prologic setting and I have not noticed it being triggered by any TV output as yet.

Mind you, as it only has three analogue phono inputs, and I wish to retain the option of outputing from all sources through my HiFi amp; I am using the tape out from my minidisc recorder as a source for the decoder. Then, I can switch sources on my amp, and providing the minidisc is in rec mode, it outputs that source through an input level control on the minidisc to the decoder.

So to summarise the line up we have

Daewoo to TiVo 2 to TiVo 1 (fed in turn by NTLCable) to Sony FX20 TV to Amp aux to Minidisc to AE Aego P5 decoder Aux.

Works great except for dolby prologic auto detection. If I switch manually the output to the rear speakers sounds very thin and distorted.

Any ideas

Posted by: iankb

If you have automatic volume control being applied, this might corrupt the pro-logic signal. Minidisc recorders often use automatic volume control to avoid clipping.

Posted by: Major dude

Having emailed both the decoder suppliers AE and dealer, they both state that prologic info is only passed through a digital input either optical or coaxial.

So as there is only a couple of phonos to output audio from either TiVo or my telly I think I`m probably stuffed as far as sourcing prologic from any of these sources.

Any comments about how good decoder generated prologic is compared with one that is produced at source?

Posted by: iankb

Dolby ProLogic Surround (I or II) is carried by phase information in the stereo channels. Only Dolby Digital 5.1 requires co-axial or optical connections. Unless the stereo signals are processed in some way that destroys the phase information, DPL will be carried by normal twin phono leads. I use phono leads from the output of my TV into my amp, and I get perfect surround sound.

Dolby Prologic Surround is true recorded surround sound with correctly-positioned sound sources (as with Dolby Digital 5.1), but with a couple of limitations. Firstly, it has no front centre channel, and both rear channels carry the same signal. Secondly, the rear channels do not carry the full frequency range. DPL II was an enhancement that blended some of the front stereo channels into the rear channels so that there is some difference between the rear channels, and an improved frequency range. Sound positioning is too good in that, if a front door-bell sounds behind the camera, I go to answer the front-door.

Any surround sound that is generated artificially by a decoder will purely be a way of spreading the stereo channels into the rear speakers. It will not have any discrete sounds at the rear, and any sounds will certainly not be in the positions that a sound engineer placed them.

It sounds like you need to get a proper Home Cinema Amplifier with the surround sound processors built-in. Your separate decoder or the chaining through the minidisc recorder is obviously not processing the phase data correctly. Have you tried cutting the minidisc recorder out of the loop, and taking the TV stereo output directly into the decoder?

Posted by: MarkE19

I agree with Ian. DPL does get carried via the stereo phono connections. All my TV is view with the sound via my AV amp and always with DPL2 on. I always get the surround, either discreet or matrixed and my only audio connection to the AV system is a phono pair connected to the TiVo.

Mark.

Posted by: AMc

quote:
iankb said - Sound positioning is too good in that, if a front door-bell sounds behind the camera, I go to answer the front-door.

Pavlov's home cinema :D - I can imagine doing that myself but it made me smile to read it.