I AM the system administrator. Who do I call?
SPDIF KeepAlive for Home Theatre PC
After building a new Home Theatre PC I’ve discovered that the onboard IDT audio has a problem with the SPDIF output, or at least my Sony receiver has a problem with it! Every time a sound is played it causes the SPDIF input on the receiver to initialise which takes about 500 milliseconds, after the sound has finished the SPDIF goes back to sleep. As a result the first 500ms is lost off every sound that is played; not really a problem if you’re watching a movie but for applications that have little blips as you navigate around these sounds tend to get missed altogether; such is the case in MediaPortal the HTPC application I use.
My old motherboard with Nforce sound didn’t have this problem the SPDIF remained “active” all the time.
After much searching I did find a few other people with the same problem but no solution so I’ve written a small .NET application called SPDIFKeepAlive. It does just that. It sits in the system tray and continuously plays a silent wave file to keep SPDIF port active.
Hope this is helpful for others, leave comments for bugs / feature requests etc
Version History
Version 1.0
- Initial release
Version 1.1
- Added new output options
Version 1.2 (Current Version)
- Fixed auto play on startup
- Added auto-restart option
(.Net 2.0 Required)
| This entry was posted by RhysGoodwin on May 10, 2008 at 3:20 pm, and is filed under HTPC, Windows Desktop. Follow any responses to this post through RSS 2.0. You can leave a response or trackback from your own site. |


about 8 months ago
I have been looking for exactly this for 2 days! . I havent tried it on yet but I am sure it will work in Win7. Thanks again.!! This will save me a lot of troubles about my HTPC optical connection sleep problem!
about 8 months ago
Unfortunately this program stops working when you start XBMC and play a movie.
((
about 1 year ago
Thank you!
about 1 year ago
Thanks for this! Also thanks to Marcus for the tip, that works perfectly!
It was a bit worse than described on my Xonar DX and Logitch Z-680′s in that it would pop or crackle each time the optical stream started up again… Yikes
about 1 year ago
Juats wanted to say thank you! I was just about to code the same thing when I found your tool. Don’t have to do that now
about 1 year ago
Thank you, this saved me much frustration. However I found my receiver would still go to sleep at even the tiniest interval of silence with all of the settings except for “Test Tone”. The solution for me was to create a 20KHz wav file and use it as a custom file. Apparently my receiver has a lower end limit but not a higher end one. Thought this might help someone.
about 2 years ago
“Yeah sorry about this, I was meant to fix this ages ago. I’ll get to it soon. I’ll make sure it starts playing as soon as it starts. That’s how it used to work but I broke it in the last version!”
Any update? Program would then be perfect
about 2 years ago
In Vista and above, you can have the audible tone running but set the mixer to reduce the volume output specifically by this program to zero. You won’t hear anything but the connection is still kept alive, and you can check on it anytime but raising the program’s volume output.
Rhys – thanks btw for this excellent tool.
about 2 years ago
Could the executable capture the parameters of output options so that the inaudible tone starts automatically at Windows start up?
about 2 years ago
Yeah sorry about this, I was meant to fix this ages ago. I’ll get to it soon. I’ll make sure it starts playing as soon as it starts. That’s how it used to work but I broke it in the last version!
about 2 years ago
Well only thing with 1.1 is that it wont auto start when then the startup menu.
On the previous ones I would place it to start with windows. This one starts but you have to open it and then click start to get it going.
If you could make a option to start what ever sound you choose when lauched I think it would be perfect!
about 2 years ago
Hmmm…Yeah good point. I’ll sort that out soon.
about 2 years ago
Ok I’ve updated and finally fixed the startup problem!
Version 1.2 now available
about 2 years ago
Downloading new version! Just reinstalled windows Glad I could find this website again.
THANK YOU
about 2 years ago
New version tested and it’s perfect now (for my ears at least ;D). I couldn’t hear the inaudible tone and any sound I play on my computer now is heard on the HT’s speakers without any delay. Thank you.
about 2 years ago
Ok new version (1.1) available now. New inaudible tone and option to select a custom wav file
about 2 years ago
That’s the same version I was trying. I’ve noticed the 3 options: test, inaudible and silence. Obviosly, only the first 2 keep the output busy. But I can listen to both tones, even the high frequency of the inaudible one. I know it’s not common for humans to listen to frequencies above 16 KHz, but unfortunately that’s my case. I remember once when I made a step motor drive to use in a device and followed the component’s datasheet recommendation to use a frequency of 20 KHz, which would be inaudible for humans. The funny thing is that I was the only one who could listen to the high pitch buzz the machine emitted.
about 2 years ago
Okey, I’ll put up a new version soon with a new audio file. Maybe an option to specify your own .wav file so you can experiment.
about 2 years ago
That’s exactly what I was looking for. However, I think I might have a canine ancestor, as I’m able to hear the inaudible tone. That happened to me before with other high frequency sounds people usually couldn’t hear. What frequency did you use? 20 KHz? Is it possible to use a higher one (and maybe also a lower volume)? Thanks in advance.
about 2 years ago
Hi, Can you try the test version, it has some options for output type. If it’s still not working I’ll dig the code out and have a look
about 2 years ago
Thank you for the 64bit update. Now working great in vista x64 sp1 with .dot net 3.5!
Keep up the great work.
Now if I could only find vista 64 bit drivers for the ps3 sixaxis controller id be set to use vista full time.