HTPC 'Hiss' Noise

[THRobinson]

I recently switched to Openelec from Win7 with KODI, and changed a few pieces of hardware so can't say for certain if hardware or software causing the issues.

Basically, from the main screen of KODI I have a high pitched hiss. I still have it if streaming. If I play a video file locally stored, it goes away, even if I click pause, the sound is gone.

OpenElec/Kodi is running off a 32GB SSD drive, which is new (use to be a 250GB HDD) and I also swapped out the GTX650TI card for a fanless GT710. Also replaced the CPU fan for something quieter. Wanted a quiet HTPC, but after switching to a new case, it was pretty loud. Sound carried a lot more.

So, not sure if the software making the hiss? I don't think the GPU/HDMI else why would I get hiss from streaming not from stored files?

I do have 2x3TB HDDs with TV/Movies on them, and it's when I play from there that I no longer have the hiss.

Could the sound be from the cheap SSD drive? fans? software?

 

[ricdiculus]

Ok. first things first. is it more of a hiss(think sound like a breeze, but quieter) or more like a high pitched whining sound(like an old fashioned camera flash, or coil whine)?

 

[THRobinson]

More the camera flash... or like the old CRT tv's... sometimes you'd get that sssssssssss noise, very high pitch, borderline where only dog's can hear it.

I'm wondering if maybe some sort of feedback from a component is coming through the speakers or something.

Like I said, on the main screen its there and streaming... but when I switch to playing a stored file on one of the two HDDs, noise goes away instantly. Even if I pause (so no audio playing) the sssssss noise is gone. Close the file, and instantly that high pitch noise is back.

 

[ricdiculus]

I cant help but wonder if the video card is changing resolution or possibly some other setting when switching between locally stored media and the UI/streaming media. I know it sounds wierd, but this started when you changed video cards, right? the fact that it only does it under certain conditions makes me think its not a hard fault, like wiring or connector problem. Makes me wonder if the new card isn't leaking a little electrical noise under certain operating conditions. Don't think your fan would cause it. The conditions when it's changing doesn't match what the fan should be doing, doesn't seem like. So, maybe software? Seems unlikely to me, but I guess Iv'e seen stranger things. Did you need to reroute any cabling different from before? The noise your'e describing is definantly electrical radiation of some kind from one of your components. Thing is, it doesn't do it all the time. So what's changing? CPU, the same as before. PSU, same. Ram, same. MB (audio chipset/codec), same. 32G SSD, is that SATA, or did you convert to PCI-E? That might explain it, your using a section of the MB that you weren't before maybe? I dunno, this one is tricky.

 

[THRobinson]

Well... I did a big switch all at once, which is a problem for narrowing things down.

I had a computer (mid-tower) and wanted something that would sit on the shelf and look like it belonged to the TV instead of sitting next to it. Grabbed a Silverstone Grandia case... looks nice, but don't buy one... horrible layout, thin, sound escapes like crazy.

So, decided the PSU was old and very noisy (which I later fixed for an Arcade Cabinet build) and the CPU fan was loud, plus a GTX650 for playing MP4's was overkill and had 2 fans so... basically bought a CPU fan, PSU, fanless GPU and replaced the case fans with a pair of 120mm silent fans. I also replacd the 250GB HDD with a cheap 32GB SSD SATA drive... one of the KingDian ones off NewEgg. Was on for $20CAD, then lost in the mail so got a refund, was told if ever shows up to keep it, few weeks later showed up so... cheap brand and free.

At that time I also switched to OpenElec since the PC was only used for KODI, I didn't think I needed to waste resources with running Win7x64.

My assumption is also electrical noise bleeding through somewhere...

Was going to mess with it last night, but of course, no noise issue. Seems to be an issue most of the time but ever so often, it's quiet.

Other issues I've had, and also hard to determine if GPU, Software or TV... be watching something where the scene is at night and can barely see any detail at all. Discovered this weekend that if I go into the TV menu and just click around, I don't have to enable/disable anything, then the TV switches to be brighter and I can see all the details again. Never had that issue before either.

I kinda regret "upgrading" the system.

 

[ricdiculus]

Sorry to hear about the case I run a LC16M case my self and its built like a tank. and dead silent with noctua fans and looks like a piece of pro audio gear with its VFD display. In my rig I use the optical out and let my pre-amp handle the D/A conversion with its high end converters. absolutley dead silent, no background noise what so ever, even if it's turned up wide open. I wish I knew what to tell you about the noise issue your having, cause that can drive you crazy. A different PSU could also be a source, but due to it's intermittent nature, it's gonna be hard to track it down. Good luck too ya man

 

[THRobinson]

Finally know what it is.

"Send low volume noise"

Some sort of setting in the newer KODI program that's supposed to be inaudible and keeps the amp alive, but obviously, very much audible. Downside is, disabling is worse. When flipping through the menus the audio is constantly cutting in/out making that sort of static "ppp" noise... like tapping a microphone with your finger.

Hopefully someone on the KODI site has a 3rd option, because this wasn't an issue in version 16 or older, just version 17 that it's now running.