how to generate a center-speaker output

[((( atom )))]

hi,

i ordered a new tv in a store yesterday and it has rather good speakers. my hifi is very good and i would like to use the tv as a center-speaker now. i don't have any further surround facilities, so the rest of the signal should be played by my 2 main-speakers. it just botheres me, that when i have guest, somebody always sits to much at the sides, so they don't locate the voices from the tv-position anymore.

my soundcard is a soundblaster live! and i am using the kx dirver and i want to wire the audio-input of my tv.

can anybody set me on the right path of what i'd have to do in order to achieve this? it should work for regular dolby surround as well as for ac3.

bit tricky, eh?

;)

[stargazer]

If I understood correctly, you want to connect center speaker output to audio input on your TV...

You have a center/LFE out on your soundcard (it looks like any other stereo output) - one channel is center and other is LFE, so, just take the center channel and connect it to audio input on your TV. You should use Y cable (stereo jack on one end - two mono chinch on other) or you can manually cut the wire...

I hope i haven't totally misunderstood your post because of my poor english ;)

[edit] If you just want to know how to enable 3.0 output (down mix rear chanels in front), you can do it using Valex's ac3_filter (when watching AC3 divx and even DVD-s, but you should use zoomplayer and build your own dvdgraph that will use a ac3_filter as audio decoder)

HTH :)

[((( atom )))]

ok, that sounds like some startingpoint to investigate. thx.

any idea what to do with 2ch-mp3? afsik one should also be able to generate a center-channel out of that.

greetz

[stargazer]

any idea what to do with 2ch-mp3? afsik one should also be able to generate a center-channel out of that.
Houston, we have a problem! ;)

There's a problem with 2 channel audio - I don't know any software audio decoder that can emulate (in acceptable way) channels form 2-channel audio. It is easy with Dolby Prologic (sorround downmixed) 2-channel audio and hardware decoders (like ones in 5.1 receivers - AFAIK, prologic (2) decoding is a bit tricky :))...

I think your soundcard supports two audio modes: music and movie - you should try play mp3s in movie mode, you could get some sort of center output.

I would use other trick: take + wires from both channels and connect it to center speaker (as if they were + and -), you will get completely different channel.
Or you can take + wires from both channels and connect it together. Then conect it on + input, and minus (both channels use just one) on minus - you will get one mono channel that plays all sound (from both stereo channels).

[edit, again :)] All this is sometimes complicated and surely (no matter which method is used) lowers audio quality, especially if that "2-channel mp3" is a music file. So I prefer playing 2-channel audio on just 2 speakers. I had to point that! ;)

[((( atom )))]

Houston, we have a problem! there are no problems - only solutions!


There's a problem with 2 channel audio - I don't know any software audio decoder that can emulate (in acceptable way) channels form 2-channel audio. It is easy with Dolby Prologic (sorround downmixed) 2-channel audio and hardware decoders (like ones in 5.1 receivers - AFAIK, prologic (2) decoding is a bit tricky )... hmm, so i'll have to further investigate. but i guess if it can be done in hardware - actually a simple process, anyway - software should be capable.


I think your soundcard supports two audio modes: music and movie - you should try play mp3s in movie mode, you could get some sort of center output. i'll have to make some experiments here, since i am using the kx driver and i won't give that up. maybe it even supports i out of the box. finally its weekend and i will have some time to play around. :)


take + wires from both channels and connect it to center speaker (as if they were + and -) ... inverse the phase to be short ;) was that the hole trick to get the center-speaker? i don't really remember anymore how the signals were wrapped into the downmix.. i'll give it a try..


[edit, again ] All this is sometimes complicated and surely (no matter which method is used) lowers audio quality, especially if that "2-channel mp3" is a music file. So I prefer playing 2-channel audio on just 2 speakers. I had to point that! yes, i'd have to kinda build a switch-box. should really be possible in software, though..

i'll let you know the results.. could take a couple of days, though. thanks for your support!

allthebest

[stargazer]

there are no problems - only solutions!
Or: every problem has solution ;)
hmm, so i'll have to further investigate. but i guess if it can be done in hardware - actually a simple process, anyway - software should be capable.
Prologic decoding is a _very_ complicated thing. Many en/transcoding tools support prologic downmix but not prologic decoding. It's the same thing (reversed :)) with mp3 - it is very simple to decode it, but complicated to encode it. I don't say that software decoders don't exist (intervideo and cyberlink audio filters should be capable of prologic decoding), i'm only saying that they don't do it with acceptable results (IMHO, naturaly).
inverse the phase to be short ;) was that the hole trick to get the center-speaker? i don't really remember anymore how the signals were wrapped into the downmix.. i'll give it a try..
No, you will not get center-speaker-like, but completely different channel (not a real channel, but you should give it a try)
i'll let you know the results.. could take a couple of days, though.
I'm waiting :)
thanks for your support!
Hope it helps

[DIggedy]

inverse the phase to be short was that the hole trick to get the center-speaker? i don't really remember anymore how the signals were wrapped into the downmix.. i'll give it a try..

Actually that should give a REAR channel output. Surround information is buried in the stereo track using an inverted phase. The center channel is created by extracting equal signals from both channels.

It would be cheating and not sound as good, but one solution would be to simply feed a mono signal using some cables to your tv. This would keep the center signals focused to the tv, but will also be be sending stereo effects to the tv as well... but it should still sound better than regular stereo.

[((( atom )))]

well, my first test were unlucky.. the kx-driver has a very nice routing-facility, but i didn't find the right filter for the player yet, so all i got was stereo downmixed to dolby surround. also not bad..

@ stargazer: could you send me this filter? i found some links at google, but they were all dead. tell me, if ok, and i'll pm you with my address..

inspired to search on that topic again by digedy i found this site, sich is quite informative:
http://www.ee.washington.edu/conselec/A96/projects/Surround/system.html

i'll go to work now and think about things on my way...

actually it shouldn't be hard at all to extract that center-signal. worst case, i'll grab my soldering-iron ;)

regards

[terriblemonkey]

There is also a way to do similar to dolby decoding with directx plugins and a suitable proggie ie Vegas . I would kill all the stereo information than do a low pass as center channel is mono unlike say the front channel which has some stereo info and rears which are 180 degrees out of phase .or could experiment with the filters in cooledit ,the channel mixer can do some simple out of phase mixing.

[stargazer]

@ ((( atom )))

You can find Valex's ac3_filter here (http://sourceforge.net/projects/ac3filter)

Intervideo/Cyberlink's audio filters are installed with WinDVD/PowerDVD. Also, you can download audiofilters.zip from download section of this site. There is one older version of intervideo audio filter. Newer version you can download from my web folder here (http://free-sb.hinet.hr/stargazer/stvari/filter.rar). You just have to register it with

regsrv32 /s iviaudio.ax

in command prompt.

[((( atom )))]

@stargazer:

thx for the link - very cool tool.

problem is, although it registers fine and zoom player uses it, i get only rrrrrrr-noise when trying to go for anything else than 2channel-output. i read the manual and tried lots of possible combinations, but yet nothing worked out.

i'll surely fight my way through, though, since this tool is the solution for many problems..

[stargazer]

problem is, although it registers fine and zoom player uses it, i get only rrrrrrr-noise when trying to go for anything else than 2channel-output. i read the manual and tried lots of possible combinations, but yet nothing worked out.
You should try changing between waveout and directsound output. Valex's filter "bundle" includes .bat files to change output. It also includes ac3speakers.exe to force speaker configuration wanted.
Or, maybe I don't understand english and your problem is in something else? ;)

i'll surely fight my way through, though, since this tool is the solution for many problems..
I'm sure you will! :)

[((( atom )))]

well, yeah, i tried those .bat files and also the speaker conf, onlny thing i got to work was 2ch-output.. well, it will work out.. also if i find some time i will check out the routing-facilities of my soundcard using the kx-driver. they look promising..

i'll keep reporting, but i guess it will take either till the next weekend or till my new tv comes...

regards

[((( atom )))]

well, i had to fugure something really bad: my shitty live! value is _not_ 5.1-capable! i took for granted, that all live!-models were, but i was mistaken. never knew that. :(

well, i started a thread over at the kx-drivers page and there might be a way to still get my center-out..

the ac3filter works btw, but all i get is 2channel-out or 4channel-out, where the front and rearchannels seem to be the same. didn't bother ro _really_ check it out, because i focussed on the (silent) center-channel..

does maybe anybody here know something about my particular card?

[stargazer]

@((( atom )))

I suggest you to get hands on some solder (is that the right word for thing that you take in your hand, it heats up and then you can connect two wires or something using melt-down tinol wire? ;)) and do some "hardware" downmixing to mono signal (as DIggedy and I suggested before), that will be used as center speaker.

This is a very simple thing to do, and should be more effective then any software "interpolation", emulation,.. (or whatever is the right word) ... you probably noticed my problem with english! :D ;)