Mono (TV and Movie) Soundtracks -> (upmixed?) Surround Sound

QuadraphonicQuad

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kfbkfb

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I watch/VHS record some of the old TV shows on the OTA digital TV subchannels (MeTV, Antenna TV, COZI-TV etc.).

My default listening setup is 4 Polk T15s fed DPL decoded audio, many of these TV shows have mono soundtracks and DPL does nothing with a mono input.

I was wondering it there's a simple, default upmix process to provide a [fake] stereo input to the DPL decoder to provide some form of surround sound from mono sources (nothing elaborate or that needs several iterations to get acceptable mono - > [fake] stereo)?


Kirk Bayne
 

JediJoker

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I mean, passive mono ➡️ stereo ➡️ surround upmixing is gonna give a pretty crappy result. Can't imagine it being at all immersive or even enjoyable; probably more distracting than anything, as the audio won't track the action on screen.
 

kfbkfb

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True, I was thinking more about a mono -> stereo upmix (with some out of phase content) created so that a matrix decoder (DPL[2], QS Variomatirx, Surround Master etc.) could create a semblance surround sound.

My old Pioneeer SX-2300 stereo receiver has a mono to (fake) stereo function, it's currently part of my DynaQuad system, I'll try a mono source -> fake stereo -> DynaQuad later today.


Kirk Bayne
 

furui_suterioo

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Sometimes a very tiny amount of artificial hall reverb can sound ok with mono going into a decoder, it doesn't send much to the rear channels but expand the sound a little bit. My laptop and phone both have options for this.
 

par4ken

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I don't think that there is an effective way to enhance mono to stereo or to surround. Remember the records released in the seventies from mono recording that were "Electronically Rechanneled to Simulate Stereo", they (mostly) were terrible. I always thought why bother just leave them as mono! I think that all they did was add a bit of phasyness to broaden the image. They were best played with the preamp set to mono.

Mono played through a 5.1 decoder is terrible, sound through the center speaker only. I like my mono played through multiple speakers. I have an oldies DVD-Audio disc that despite being ladled as 5.1 plays mono simultaneously from all speakers and it actually sound excellent.

My only other suggestion would be to add a bit of delay/reverb to the back speakers.

Years ago I played around with a spring type reverb, it sounded rather cool on some music especially with electric guitars, but more of an effect than an enhancement.
 

par4ken

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How does it sound if you just route a mono signal to all 4 speakers? Any frequency cancellation etc?
As I said it sounds good to me. Because room reflections are so randomised I don't think frequency cancellation is that much of an issue. I don't use a subwoofer either just four full range speakers! If you listen via a decoder (with no logic) the sound is more spread around, less focused due to the phase shifting. I do think it sounds best with speakers all in phase but I like my multi speaker mono either way.

As kids we often connected up extra speakers to the AM radio, sometimes out of phase and always thought it sounded rather cool.

With old TV shows and movies I often just use the TV speakers, I don't always bother with surround. Music is a different story.
 
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