[tekstyle]

hello guys. I did a search and found nothing related. my computer's rear speakers have an audio delay of a few milliseconds. Is there any software I can use that lets me adjust my individual channels' delay? I want to delay the fronts just as much as the rear so I can have them play sound in sync.

I have a Realtek AC97 audio driver at the moment.

 

[error401]

Quote:

Originally Posted by tekstyle /img/forum/go_quote.gif hello guys. I did a search and found nothing related. my computer's rear speakers have an audio delay of a few milliseconds. Is there any software I can use that lets me adjust my individual channels' delay? I want to delay the fronts just as much as the rear so I can have them play sound in sync. I have a Realtek AC97 audio driver at the moment.

Nothing I'm aware of OS-wide, at least on Windows, however there are solutions for some specific applications. The ffdshow audio decoder, for example (DirectShow decoder support MP3, AC3 and others) has a delay module that does this.

 

[picklgreen]

There should be a way to setup the 4 speakers so all 4 play the same sound with no sound delay. In my sound drivers its just called "4 channel stereo". There is no delay at all with the rear speakers.

 

[error401]

Quote:

Originally Posted by picklgreen /img/forum/go_quote.gif There should be a way to setup the 4 speakers so all 4 play the same sound with no sound delay. In my sound drivers its just called "4 channel stereo". There is no delay at all with the rear speakers.

I took his question to mean that he wants to set up time-compensation for the distance from the drivers. My deck in my car can do such a trick and it works quite well, improves soundstage quite a lot in the sub-optimal environment the system is in...

 

[picklgreen]

Ok well than that makes no sense. He said he has a time delay on the rear speakers. Now he says he wants a delay on the fronts that are equal to the delay in the rear. So now all 4 speakers have a few millisesond delay EQUAL to each other! This means there is no time compenstation what so ever, just an overall delay in the sound from all the speakers. Your car deck is not doing the same thing. It is setting a delay of different amounts to the front and rear speakers to simulate a bigger room. This is the same thing home receievers do to simulate surround sound. I guess this guy likes the idea of while playing a game he shoots or something and doesnt hear it until the other guy has already shot him!?!

 

[error401]

Quote:

Originally Posted by picklgreen /img/forum/go_quote.gif Ok well than that makes no sense. He said he has a time delay on the rear speakers. Now he says he wants a delay on the fronts that are equal to the delay in the rear. So now all 4 speakers have a few millisesond delay EQ

It does make some sense if you try to get the output of all the speakers in phase at your listening position. There's no substitute for proper speaker placement, but there are a lot of situations where you can't really do that. I suspect that he's got his rear speakers a fair distance further away from the listening spot than the fronts and is trying to compensate for the different time it takes for the sound to get to him, causing phase issues. By choosing the furthest speaker as a reference and applying an appropriate delay to the other 3 he should be able to improve the spatial resolution and phase characteristics with, since it's all in the digital domain, no real downside.

How to do it with a computer, I have no idea, however. My car stereo has it built-in as I said. If you wanted to get really into the nasty I suppose you could use a SPDIF receiver IC feeding a uC or some shift registers or something to create the delay, and then into the DAC - but that seems overkill...

 

[picklgreen]

If all 4 speakers are set to the EXACT same time delay like he is describing than this will provide NO time delay to make the room sound bigger or whatever like your car stereo is doing! In order to do what you are describing you have to have the rear speakers set at a time delay in reference to the main speakers. There are a ton of white papers available on the web if you want more details on how this works.

 

[tekstyle]

Quote:

Originally Posted by picklgreen /img/forum/go_quote.gif Ill say it again...if all 4 speakers are set to the EXACT same time delay like he is describing than this will provide NO time delay to make the room sound bigger or whatever like your car stereo is doing! In order to do what you are describing you have to have the rear speakers set at a time delay in reference to the main speakers. There are a ton of white papers available on the web if you want more details on how this works.

error401 is right. my rear speakers are a few msec delayed compared to my front speakers. in order to have them output sound in sync, i want to delay the front speakers by just as much as the rear ones to compensate for my slow rear speakers. therefore, the result should be all 4 of my speakers outputting sound as one.

 

[tekstyle]

Quote:

Originally Posted by error401 /img/forum/go_quote.gif Nothing I'm aware of OS-wide, at least on Windows, however there are solutions for some specific applications. The ffdshow audio decoder, for example (DirectShow decoder support MP3, AC3 and others) has a delay module that does this.

i found the ffdshow video decoder. but i can't find the audio decoder. not even on their official site. is it the same thing?



updated:
nevermind, i just downloaded a screwed up version of the program. i got another one that has it. thanks hehehee. now to the test

updated again:

i have no idea how to get this thing to work. I have installed it and then played with the delay settings. I have messed with the codec > decoder, but it seems like ffdshow is not doing anything to my audio experience. I sense no change. what am i doing wrong?

 

[error401]

Quote:

Originally Posted by tekstyle /img/forum/go_quote.gif i found the ffdshow video decoder. but i can't find the audio decoder. not even on their official site. is it the same thing? updated: nevermind, i just downloaded a screwed up version of the program. i got another one that has it. thanks hehehee. now to the test updated again: i have no idea how to get this thing to work. I have installed it and then played with the delay settings. I have messed with the codec > decoder, but it seems like ffdshow is not doing anything to my audio experience. I sense no change. what am i doing wrong?

I'm not sure. The codec may not be getting used to decode your audio, and that's my suspicion - I don't think it will have any effect in most programs since they have their own MP3 decoders - perhaps even WiMP doesn't use DirectShow filters for MP3. Further, you will have to enable MP3 decoding in the ffdshow control panel If the codec is being used, you should see an icon in your task tray.

You're most likely to get it to work with AC3 audio, as on a DVD, because Windows doesn't include a decoder for this type of audio and the decoder in ffdshow is enabled by default.