[Eye of Horus]

Originally posted by pelmen
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.

Starting with 6 mono wavs recorded separately would be ideal. But we're using stereo and need to extract as much as possible from only 2 channels !
I don't think we can get the same results, but with music we can get close !

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.

I do think there is some software that can analyse surround sounds, but I am not sure. I found that the C3 analyser is the most promising, but I could only find a Chinese (or Japanese ?) site, and..... no english translation there. But seeing the screenshots for stereo, it makes me feel this could be the ideal analyse software !
OTOH what would you exactly do with such software ?
I mean : as you say with a single mono the spot is in the middle, but this doesn't represent the ideal situation for the listener.
Music can be loud sometimes in a song from one speaker only and than with the same benchmarking you're thinking of, that spot won't be in the middle. And that doesn't indicate the mix is wrong then !!

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.

Aha ! Yes , this way makes sense !
Can you upload that track to alt.binaries.sounds ?
It would be very interesting to use as test sound for the new bidules we're developing (Kempfand and me).
They are already very nice and give more separation than the things I tried till now, but such a track would be very helpful to finetune even further !

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 never heard of it, but perhaps some googling can help ?
I will do a search online too and let you know if I could find anything.....

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

I wish that too !! :-)
I am not the writer of the bidules made ! I am more the guy with the (sometimes very weird) ideas behind bidules and I try to translate every technobabble into a useable guide. Some of the techniques used to get the results are too difficult for me to understand. The outcome however is for me the only thing important !!

thx

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

ALWAYS smiling :-)

kind regards,

EoH