I've tried with onboard Realtek AC883. Same thing.
I've changed the preset I was working on to the one uploaded on this forum"Omnia 6". Phase diff. is now -70 deg
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| M-Audio 192 on Win7 vs WinXP https://forums.stereotool.com/viewtopic.php?t=3737 |
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| Author: | hvz [ Wed Jun 22, 2011 11:21 pm ] |
| Post subject: | Re: FM calibration. How to?! |
Quote: Okay, I'll install latest BETA and run on Win XP. I'll troubleshoot a little bit using the Pira75 analyzer and will get back here with the update.
It might be depending on where you live, but the Stereo Tool output should contain *NO* spikes bigger than about 0.5% at all - anything above that comes from the sound card, cables or transmitter.The 75khz modulation is indeed really ok, giving a few spikes of modulation at 80-82KHz which is legaly acceptable, as far as I know. I should add to this though that most sound cards cannot handle a DC offset (or extremely low frequencies), and Stereo Tool can generate extremely low frequencies due to clipping asymmetries. To at least reduce this effect, you can enable "Forcibly remove DC component caused by Loudness (reduces quality!)" in the Loudness window. It won't be completely gone though. |
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| Author: | lef [ Wed Jun 22, 2011 11:28 pm ] |
| Post subject: | Re: M-Audio 192 on Win7 vs WinXP |
Another update. I'm really positive that ST running on M-Audio's 32bit drivers (WinXPSP3) is having a better output. Dunno how to explain, but I can hear and feel that the processing is really working. That's a personal opinion though, I don't want to force anybody downgrade to XP. Personally, I'll stick to the 32bit drivers. |
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| Author: | lef [ Wed Jun 22, 2011 11:32 pm ] |
| Post subject: | Re: FM calibration. How to?! |
About the separation test you wrote a few posts before, I made the following test: I've disabled one channel from my mixing console and I've tried to listen on a good quality tuner what's happening on that. I could barely hear the music, but not total silence. I'll try tomorrow your way, by disabling it from the ST interface. |
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| Author: | Bojcha [ Wed Jun 22, 2011 11:42 pm ] |
| Post subject: | Re: FM calibration. How to?! |
before all you should tell.. what transmitter you use? Cable, and how long cable? |
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| Author: | hvz [ Thu Jun 23, 2011 12:26 am ] |
| Post subject: | Re: FM calibration. How to?! |
I just measured the frequency content below 3 Hz, with highpass filter set to 30 Hz, and in a 10 minute recording (8 different tracks) the loudest spike I found was less than 1/20th of the input level (less than 5%, so could cause spikes upto 78.75 kHz). (Below 10 Hz, it's 6-7%). Oddly, it doesn't seem to matter much whether "Forcibly remove DC component caused by Loudness (reduces quality!)" is on or off - on is slightly better, but probably not worth the quality loss. |
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| Author: | hvz [ Thu Jun 23, 2011 12:29 am ] |
| Post subject: | Re: FM calibration. How to?! |
Quote: About the separation test you wrote a few posts before, I made the following test: I've disabled one channel from my mixing console and I've tried to listen on a good quality tuner what's happening on that. I could barely hear the music, but not total silence. I'll try tomorrow your way, by disabling it from the ST interface.
Then you definitely do NOT have a 60 degree phase shift in the stereo signal. (You reported poor stereo separation, right?)I would expect the RDS signal to be ok too - a 60 degree angle is quite a lot. Unless there's a bug in my RDS encoder (which is always possible, but has not been reported by anyone else so far). |
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| Author: | lef [ Thu Jun 23, 2011 2:42 am ] |
| Post subject: | Re: FM calibration. How to?! |
@Bojcha It is a custom made EXC and a Linear AMP after that, made though by a professional. There is a STL that carries the signal up to the TX site. No doubts that the transmitter or the STL causes something, since my previous results on the pira75 and my AEV stereo generator/RDS coder (AEV Stargate) were with 0 deg (or max 1-2 deg) phase difference between the 19khz pilot and the 57khz RDS signal. The cable coming out of the soundcard to the STL is about 5m, mono. Connectors are good, made by me, double and triple checked. @hvz The thing I'm reporting is a rather big phase difference between 19 and 57khz. I believe that maybe it has to do with M-Audio 192 and ST. Can't give any other explanation. Is there any chance that a bad setting all over the software (loudness, limiter, you name it) could cause a signal of around 57khz to be present, as a harmonic result? I know that it is weird and impossible, but I'm just asking. |
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| Author: | Bojcha [ Thu Jun 23, 2011 3:09 am ] |
| Post subject: | Re: FM calibration. How to?! |
My guess is that M-audio is problem then.... I belive that Phase output on ST is good. I said 'belive' because here no way to check it. Can you get any other soundcard with 192kHz output.. atleast Onboard Realtek ? |
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| Author: | lef [ Thu Jun 23, 2011 6:10 am ] |
| Post subject: | Re: FM calibration. How to?! |
Yes, I can try with AC883. |
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| Author: | lef [ Thu Jun 23, 2011 1:46 pm ] |
| Post subject: | Re: FM calibration. How to?! |
I've tried with onboard Realtek AC883. Same thing. I've changed the preset I was working on to the one uploaded on this forum"Omnia 6". Phase diff. is now -70 deg
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