Stereo Tool

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.

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.

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.

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.

before all you should tell.. what transmitter you use? Cable, and how long cable?

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.

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).

@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.

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 ?

Yes, I can try with AC883.

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