VCD in Dolby Surround?

[flaninacupboard]

i've seen a -lot- of televisions which have this feature of inverting one channel. seen it called everything from wide stereo (ancient Rank front projection TV, god i loved that TV) to Hyper Sound (cheapass JVC thing my girlfriend has) to Space Sound *TM* on the Sony set downstairs. you often see it on cheap cd players as well. even worse, there's a Nine Inch Nails EP called "Broken" which is mastered this way on purpose. makes me laugh, the back of the cd says "WARNING!! -NOT- FOR USE IN MONO CD PLAYERS!!" i wonder what my pro logic2 amp would make of it......

[JDI]

Ya , it's a way to try and implement sound depth in two speaker system.
Of course for Prologic2 Amp it is a waste of time. I had a Zenith DVD player that had virtual surround and it added some depth to 2 speakers , it's ok if you dont have 4 - 5 speakers , then again maybe I am wrong , as you have listened to these features for some time. In comparision to prologic amp, it's a far cry.



Simple question:

In regards to making a sort of dolby surround.

L = (C + S)
R = (C - S)

reduce by 3db and do low pass , range of surround channel is:

100 - 7000hz (surround channel)

As suggested to do low pass on (C + S) & (C - S)

I read that it is the surround channel that has this 100 - 7000hz range.
Why do I apply this same filter to the C channel as well?

Should I not just apply the low pass to the S channel or am I missing something. Even though both C channels from L and R are directed to Center channel then range is still 100 - 7000hz , is it necessary to filter the C channel?

Thanks.

JJ

[flaninacupboard]

don't get me wrong, i know it's terrible. i've never used the wide stereo options and i never will. being a sad hifi man i care about things like sound staging and depth of field, both of which wide stereo kills. my remark about the NIN ep in a pro logic amp was satirical, i know it wouldn't do anything, except sound crap.

[JDI]

Simple question:

In regards to making a sort of dolby surround.

L = (C + S)
R = (C - S)

reduce by 3db and do low pass , range of surround channel is:

100 - 7000hz (surround channel)

As suggested to do low pass on (C + S) & (C - S)

I read that it is the surround channel that has this 100 - 7000hz range.
Why do I apply this same filter to the C channel as well?

Should I not just apply the low pass to the S channel or am I missing something. Even though both C channels from L and R are directed to Center channel then range is still 100 - 7000hz , is it necessary to filter the C channel?


Also:

As I read the specs for Dolby Surround , There is a low-pass on the Surround channel along with a -3db reduction ...as well there seems to be Dolby B-type noise reduction or a High Frequency boost of 5db applied to the Surround channel. How may I add this filter using Goldwave or Cool Edit? There must be a way but I am not sure if that's all that's done to the channel. Spec is modified Dolby B-type noise reduction and a further look brought me to the High frequency boost of 5db , is that all there is to it?


Thanks.

JJ

[vitualis]

I read that it is the surround channel that has this 100 - 7000hz range. Why do I apply this same filter to the C channel as well?

Because you are supposed to...

Should I not just apply the low pass to the S channel or am I missing something. Even though both C channels from L and R are directed to Center channel then range is still 100 - 7000hz , is it necessary to filter the C channel?

Yes, otherwise you get "leakage" of signals from the "centre" channel into the L and R channel --> noise.

As I read the specs for Dolby Surround , There is a low-pass on the Surround channel along with a -3db reduction ...as well there seems to be Dolby B-type noise reduction or a High Frequency boost of 5db applied to the Surround channel. How may I add this filter using Goldwave or Cool Edit?

Don't know...

That's why Dolby Surround encoders are expensive machines made by Dolby...

Regards.

[kwag]

Inverting a single channel of a stereo sound will produce a simulated surround-sound effect.

Whoever decided to write that was pulling everybody's leg
If you invert a channel, you're changing the phase by 180 degrees. Effectively cancelling left and right channel. That would be if the signals reach exactly the same point at the same power level and opposite phases. In reality, this is not achieved (reflected paths, etc.,) so the effect you are hearing is audio levels cancelling each other when out of phase and increasing level when they sum each other (in phase). So that has nothing to do with surround or even a pseudo surround effect. 8)

-kwag

[JDI]

Thanks for all the info.


As for Dolby B-type noise reduction.
This was used solely for cassette tapes and VHS.



JJ

[flaninacupboard]

Kwag, you're correct, it's nothing like surround sound, but nonetheless it crops up time and time again on TV sets as a "pseudo surround" feature.
i'm not saying it's right or effective (it's not) just saying it's there...

[JDI]

I have a basic question regarding DD5.1 wav files for Audio CD.

If I have true AC3 file with 6 channels I may downmix it to Dolby

Surround using Besweet. I know it's maybe not necessary for use with

decoder but can be done.

I can't seem to downmix DD 5.1 wav , I have tested an ac3 and downmixed

it and I heard the sound from my 2 speakers.

So , is there a way to downmix DD 5.1 wav ,,,not AC3 to Dolby Surround?

SoftEncode has 3 option when saving files.

1. Dolby Digital (AC3)
2. Dolby Digital (Wave) I presume for 5.1 Audio CD's.
3. Microsoft wave - a multi-channel wav file , without the Dolby Digital

- I,m guessing analoge.

When I save as Microsoft wav it wont play if there were more than 2 input

channels of course.

Option 1 and 2 give me noise , which is normal without a decoder I take

it.

Any ideas would be appreciated.

Thanks

JJ

[kwag]

So , is there a way to downmix DD 5.1 wav ,,,not AC3 to Dolby Surround?

Have you tried HeadAC3he ?

[JDI]

Ok thanks.

I have a question that I am sure someone can answer.

I am considering getting 5.1 DD output.
Which is better ,,, a sound card capable of 5.1 output or a seperate external Dolby decoder?

Would the sound card offer me more control and felxibility over this?
What about cost? Is one way generally cheaper than the other?

JJ