Dolby pro logic vs true 5.1

[Carbsandcaps]

I’ve got an older pioneer elite vsx-99 that I fell in love with. I tried to get the ac3 to work through a few hdmi to coaxial adapters with no luck. There’s no toslink input. There’s no individual inputs for each channel. I’ve come to the conclusion that since there’s no true ac-3 converters out there because it’s such an outdated technology, im stuck with 2 channel. I’m coming from a marantz sr 6008 so I had good surround sound but the receiver just didn’t do it for me.

The receiver has Dolby pro logic and simulated surround. My question being how close is pro logic to true 5.1 surround sound?

 

[Retro_Pete]

I’ve got an older pioneer elite vsx-99 that I fell in love with. I tried to get the ac3 to work through a few hdmi to coaxial adapters with no luck. There’s no toslink input. There’s no individual inputs for each channel. I’ve come to the conclusion that since there’s no true ac-3 converters out there because it’s such an outdated technology, im stuck with 2 channel. I’m coming from a marantz sr 6008 so I had good surround sound but the receiver just didn’t do it for me.

The receiver has Dolby pro logic and simulated surround. My question being how close is pro logic to true 5.1 surround sound?

Dolby Pro Logic is taking out of phase signals and sends it to the respective speakers. It is not "proper" surround and when compared to true DTS or Dolby Digital there should be no doubt that the digital encoded sound is superior.

 

[a_retent]

I’ve come to the conclusion that since there’s no true ac-3 converters out there because it’s such an outdated technology, im stuck with 2 channel.

Dolby Pro Logic was 1980's tech so it's not any newer than ac-3. It would be my guess that your assumption of "stuck with 2 channel" from that receiver is correct. I used to sell Lexicon cp-1 Dolby PL units which were the unit to have to control multiple source units and amplifiers. I stopped using HT all together sometime around 2000-2001 and never really missed it, but that's me.
I would think if surround sound is your goal then you'll need to pony up for a newer unit.
Just my $.05 (inflation).

 

[twiiii]

original Dolby pro logic was all analog so won't work with a digital source. The best you can do is send an analog stereo from your DVD player to the unit and let it do its analog thing. You might be surprised. Ten if there are 2 versions of a Dolby digital processor there must be 12 different steps up the ladder to an ATMOS processor. Yuk.

 

[twiiii]

Thats why I have separates, so I can keep the amps and only buy a more advanced processor occasionally. I bought my MX 151 in early 2017 for 66% off. Such a deal. maybe I will do the same when my Pioneer 1080P Elite plasma quits and I go to a Sony 4K advanced OLED display. Or maybe I will just feed the video to the display and continue to use my 7.2 processor as Dolby Digital is back ward compatible in sound . I have done something similar with older Dolby processors.

 

[Carbsandcaps]

I would love to just used a 5.1 decoder and run seperate inputs to each channel but there’s no descrete channel inputs. I’ve looked at the schematics in an attempt to install individual inputs but not sure if it’s worth it. I’ve tried 3 different hdmi to supposed ac-3 adapters and get nothing out of the receiver.

 

[Carbsandcaps]

original Dolby pro logic was all analog so won't work with a digital source. The best you can do is send an analog stereo from your DVD player to the unit and let it do its analog thing. You might be surprised. Ten if there are 2 versions of a Dolby digital processor there must be 12 different steps up the ladder to an ATMOS processor. Yuk.

Right now I’m just using an hdmi to 2 channel and have Dolby pro logic and simulated surround on. It doesn’t sound terrible but it’s certainly not like newer 5.1

 

[Carbsandcaps]

Well after 5 pages of ac3 demodulation, ad, dsp, ect schematics this is the analog output of the ac3 system. It then feeds into the tone and volume controls. I’ve got plenty of video in rca jacks that I’m not using or make a seperate rca board that I could hook these up to then use an hdmi demodulator that has 5 discrete outputs. Not much to lose I’ll try not to cut too much I’ll probably just make a new jumper to hook into the board. I’ll make another post when I get around to getting into it. I’m not giving up on this vsx-99!

 

[katana1100]

Dolby surround is simply matrix a third channel into the existing stereo, extract it out for surround.
Prologic simply takes identical info in both fronts and steers to a different channel -that’s now the center. I have a few surround mics made by Vive, each has three little mics, actually sounds better than the pseudo 5.1 my camcorder has.