Doom9's Forum - View Single Post - GUIDE: Stereo to 5-Channel Surround

pelmen · 28th May 2004, 13:00

EoH,

by "proper 5.1" i basically meant what a professionally produced 5.1 track can sound like. like what you'd expect on a good special effects movie with things audibly moving clearly throughout the room. so while atm we may be able to take a 2.0 copy of say the battle sequence from Master and Commander it might sound "big" when we turn it into 5.1 but it is still a long way from the original 5.1 soundtrack.

i guess there's no such thing as a "surround sound benchmarking" system or something. something that could analyse a 5.1 track and show you a visual "spread" of the soundstage...maybe something like a colourspace graph. it could look at how much each channel has in common at any given instant and graph it over time. so when you put a single mono track into all 6 channels it would show you a dot in the middle of the room because each channel is identical. something along those lines anyway i was hoping might exist, it might be a way of helping to benchmark bidules and fine tune them? or am i just fantasising? would also help people like myself who dont have a very good surround setup nor a good "ear". Also being able to use an app to test a file i'd probably trust more anyway since the audigy spits everything i play out to 5.1 channels anyway so its hard to tell if i'm hearing the results of the upmixing or the audigy's own processing.

so far i've been using a channel seperation dolby surround track for my testing. it is a voice speaking each channel in turn (left, centre, right, surround) followed by a few seconds of (pink? white?) noise. then i load up each of the 6 mono wavs at the end and "measure" the height of the noise sections for each channel mentioned by the audio. from that i can see how much cross channel leaking there is easily. since i can't subjectively trust my hearing for small differences between techniques i tend to use this one track as my benchmark to compare a new bidule layout to what i've used already and go from there. its probably the best testing method i'm going to be able to use.

does anyone know if there are prologic channel seperation tests available free online in a two channel format? my dolby surround test cd rips to a 2 channel wav and that wav clearly plays in each designated speaker as the original cd does. from memory prologic should be the same, just it gives more channels but i dont have a prologic test cd but something like that i'd have thought would be available free online to help developers.

i've been having a lot of fun playing around and exploring this process anyway since i recently got a dvd burner. i originally stumbled across this thread, it was not even something i'd considered possible but its certainly given me some inspiration to put a bit of extra effort into my vhs to dvd conversion so i end up with something that will last a long time to come. can't wait to see what new tricks people come up with! jsut wish i understood it all

thx

btw.. SMILE!!! its the weekend!!!

28th May 2004, 13:00	#495 \| Link
pelmen Registered User Join Date: May 2004 Posts: 30	EoH, by "proper 5.1" i basically meant what a professionally produced 5.1 track can sound like. like what you'd expect on a good special effects movie with things audibly moving clearly throughout the room. so while atm we may be able to take a 2.0 copy of say the battle sequence from Master and Commander it might sound "big" when we turn it into 5.1 but it is still a long way from the original 5.1 soundtrack. i guess there's no such thing as a "surround sound benchmarking" system or something. something that could analyse a 5.1 track and show you a visual "spread" of the soundstage...maybe something like a colourspace graph. it could look at how much each channel has in common at any given instant and graph it over time. so when you put a single mono track into all 6 channels it would show you a dot in the middle of the room because each channel is identical. something along those lines anyway i was hoping might exist, it might be a way of helping to benchmark bidules and fine tune them? or am i just fantasising? would also help people like myself who dont have a very good surround setup nor a good "ear". Also being able to use an app to test a file i'd probably trust more anyway since the audigy spits everything i play out to 5.1 channels anyway so its hard to tell if i'm hearing the results of the upmixing or the audigy's own processing. so far i've been using a channel seperation dolby surround track for my testing. it is a voice speaking each channel in turn (left, centre, right, surround) followed by a few seconds of (pink? white?) noise. then i load up each of the 6 mono wavs at the end and "measure" the height of the noise sections for each channel mentioned by the audio. from that i can see how much cross channel leaking there is easily. since i can't subjectively trust my hearing for small differences between techniques i tend to use this one track as my benchmark to compare a new bidule layout to what i've used already and go from there. its probably the best testing method i'm going to be able to use. does anyone know if there are prologic channel seperation tests available free online in a two channel format? my dolby surround test cd rips to a 2 channel wav and that wav clearly plays in each designated speaker as the original cd does. from memory prologic should be the same, just it gives more channels but i dont have a prologic test cd but something like that i'd have thought would be available free online to help developers. i've been having a lot of fun playing around and exploring this process anyway since i recently got a dvd burner. i originally stumbled across this thread, it was not even something i'd considered possible but its certainly given me some inspiration to put a bit of extra effort into my vhs to dvd conversion so i end up with something that will last a long time to come. can't wait to see what new tricks people come up with! jsut wish i understood it all thx btw.. SMILE!!! its the weekend!!!