Stereo Tool

And that is now strange......
Hope you measured with "FM transmitter calibrtion" OFF ?

No! If you are still seeing an RDS signal after turning it off, either your sound card is very despot (it could be a harmonic of the 19 lBs carrier) , or your transmitter is adding it. I would start with the transmitter..

The way things are programmed, the phase between pilot and RDS cannot suddenly move.

Given your post in another thread, is it possible that your transmitter is adding an out of phase RDS signal?

Hans, He has already said... Now i am out of ideas, checked with other soundcard, and still same....

Only thing i can now tell is ... If it's not something in StereoTool .. then your previous stereo coder was contrary phase shifted then exciter and then you have 0 degrees when you measure.

Yes I did.

Hans, maybe you should combine the two threads I've started, since we are talking on both of them for the same problem.

I've done the same tests with my AEV stereogenerator/rds. I've disabled L+R to check that the transmitter is ok, and yes the TX is clean.

I've also tried 3 DIY cables coming out of the card to the STL. Same thing. A fellow tech guy told me about 75Ohm cables and the bad specs of simple-solder one connectors. His advice is to use 75ohm digital video cable. I've run across the follwing site. Maybe I'll try the crimped ones and try to find that expensive "true 75ohm" connectors.

http://store.a2zcable.com/75vica.html

Maybe I'm getting phase diff. because of the non-matching cable connected to my STL. I suppose hardware stereo coders have a real 75ohm out and STLs wait for a 75ohm cable to give them MPX.

You guys make your tests by directly connecting your cards to the TX? No one uses an STL or something between to carry the MPX to the transmitter?

i merged topics.

@Bojcha: Thanks!


Lef, just to check: Your stereo separation is good now, right? And if you turn RDS off, you still see a signal at 57 kHz?

There's no way Stereo Tool can generate a 57 kHz harmonic (which you see if you turn RDS off), because:
- The audio processing itself is done at around 44.1/48 kHz.
- The pilot tone is just a single sinusoid.
- The stereo signal is made by multiplying a twice-as-fast running sinusoid (locked to the pilot) with the L-R signal
- The RDS signal is made by multiplying a three-times-as-fast running sinusoid (locked to the pilot) with the RDS data signal.

Now it's theoretically possible that the lock between the pilot and RDS sinusoids should not be at 0 degrees - if that's indeed the case there would be a constant offset. But... You say that the offset is moving. And I really cannot explain that at all. Unless the transmitter is doing something, or the soundcard has a varying phase drift (which would be very strange).

If the waveform itself is flattened or clipped, the 1st harmonic of the 19 kHz pilot tone would be at 57 kHz though - so maybe something like that is happening. Could you lower the output level of Stereo Tool (volume slider for 'Direct Sound Card Output' or "FM Output").

Lef, could you try what happens if you start and stop Stereo Tool a few times? Using the same preset. Just to see if the phase difference changes or is constant.

Ok, I think I'm getting crazy. So I've even installed 2 ferrites on both ends of the cable going into the STL.
Same results.

I'm posting screenshots of my analyzer in case you see something I can't see. RDS is enabled on ST.


And here's a screenshot with RDS set to off. There is still something on 57khz.


When I lower my sound out to 0.200 (normally at 0.700) there is still something on 57. The 19k pilot of course is lowered now.


The strange thing happens when I lower the input too much (ST shows activity on input at the first green level)
Update. Phase diff. appears at -52 deg again, after 2 songs played.


I'm sharing my preset as well.

[Common]
CPU usage - Quality (new style)=0.200000003
Latency (samples)=4096
Pre amplifier=10.079999924
Post amplifier=1
Extra loudness=2.200000048
Extra loudness - Very deep bass relative clipping level=0
Extra loudness - De-esser limit=65536
Extra loudness - Punchy=-0.149999976
Extra loudness - Max Punch peak=0.800000012
Extra loudness - Deep bass protection - Enabled=1
Extra loudness - Deep bass protection - Difference=0
Extra loudness - Deep bass protection - Value=0.636619747
Extra loudness - Forcibly remove DC component caused by Loudness=0
Extra loudness - Reflection strength=0.100000001
Extra loudness - Allow more distortion=0
Extra loudness - Highs burst strength=1
Extra loudness - New Bass Protection - Very deep bass filter frequency 1=150
Extra loudness - New Bass Protection - Very deep bass filter frequency 2=350
Extra loudness - New Bass Protection - Clip very deep bass at=0.899999976
Extra loudness - New Bass Protection - BassMid filter frequency 1=350
Extra loudness - New Bass Protection - BassMid filter frequency 2=750
Extra loudness - New Bass Protection - Clip BassMid at=1
Extra loudness - Voice vibrations - Highs feedback strength=1
Extra loudness - Voice vibrations - Never reduce bass below=0.400000006
Extra loudness - Voice vibrations - Multiply measured vibration level by=0.899999976
Extra loudness - Voice vibrations - Ignore vibration levels below=0.5
Extra loudness - Voice vibrations - Reduce sensitivity for non-constant sounds strength=1
Extra loudness - New Bass Protection - Strict clipping=1
Extra loudness - New Bass Protection - Strict clipping - More strict=0
Extra loudness - New Bass Protection - Strict clipping frequency 1=250
Extra loudness - New Bass Protection - Strict clipping frequency 2=350
Extra loudness - New Bass Protection - Strict clipping - Clip bass at=0.899999976
Extra loudness - New Bass Protection - Strict clipping - Clip Punched bass at=0.949999988
Extra loudness - New Bass Protection - Strict clipping - Never dynamically raise bass level above=1
Extra loudness - Dirty Bass=0
Bass protection - Enabled=1
Bass protection - Two steps=1
Bass protection - Clip level=140
Bass protection - Deep bass boost=60.049999237
Bass protection - Raise clip level if highs get above=110.180000305
Bass protection - Maximum clip level raise=35.88999939
Hard limit output=1
[FM Hiss]
Enabled=0
Difference=0
FM median pos=25
FM measure max multiplier=2
FM reduce=150
FM delay=2.5
FM delay median=7.5
[Noise Gate]
Enabled=1
Difference=0
Noise level=1
Relative noise gate level - Band 1=1
Relative noise gate level - Band 2=1
Relative noise gate level - Band 3=1
Relative noise gate level - Band 4=1
Relative noise gate level - Band 5=1
Relative noise gate level - Band 6=1.247190952
Relative noise gate level - Band 7=1.777777672
[Singleband Compressor]
Enabled=1
Difference=0
Maximum volume=1
Attack speed=0.00009539
Decay speed=0.01706367
Above Top Limiter=0
AGC RMS style Enabled=0
AGC RMS style Target RMS level=25000
AGC RMS style Remove remaining peaks above=1.5
[Pre Compressor]
Enabled=1
Maximum volume - Band 1=45760
Attack speed - Band 1=0.000004457
Attack speed - Band 3=0.000002096
Decay speed - Band 1=0.000249943
Decay speed - Band 3=0.00026822
Dual band=1
Third band=0
Relative expected volume of highs=0.649999976
Relative maximum volume of highs=3
Relative maximum volume of very highs=0.330000013
Remove remaining peaks above (relative to maximum volume)=1.299999952
Maximum expected dynamics strength for smoothing=1
Enable smoothing=0
Smoothing time=10
Gating level=512
Use ITU-BS.1770=0
Channel separation=0.300000012
Gating based on volume before Pre Amp=1
Lock bass to band 2 strength=0.5
[Multiband Compressor]
Enabled=1
Difference=0
Delay enabled=0
Maximum volume - Band -1=5370
Maximum volume - Band 0=6250
Maximum volume - Band 1=6740
Maximum volume - Band 2=6940
Maximum volume - Band 3=6840
Maximum volume - Band 4=6300
Maximum volume - Band 5=5670
Maximum volume - Band 6=4980
Maximum volume - Band 7=3710
Maximum volume - Band 8=1560
Attack speeds linked=0
Attack speed - Band -1=0.000032212
Attack speed - Band 0=0.000032212
Attack speed - Band 1=0.000032212
Attack speed - Band 2=0.000032212
Attack speed - Band 3=0.000034489
Attack speed - Band 4=0.000034489
Attack speed - Band 5=0.000072158
Attack speed - Band 6=0.000096324
Attack speed - Band 7=0.000132422
Attack speed - Band 8=0.000132422
Decay speeds linked=0
Decay speed - Band -1=0.000836979
Decay speed - Band 0=0.000836979
Decay speed - Band 1=0.0010933
Decay speed - Band 2=0.0010933
Decay speed - Band 3=0.0010933
Decay speed - Band 4=0.0010933
Decay speed - Band 5=0.0010933
Decay speed - Band 6=0.0010933
Decay speed - Band 7=0.001244719
Decay speed - Band 8=0.001414664
Above Top Limiter=0.519999981
Clipping enabled=1
Postprocessing enabled=1
Flat frequency response enabled=1
Relative clip position - Band -1=1.89855051
Relative clip position - Band 0=2.278688431
Relative clip position - Band 1=2.225806475
Relative clip position - Band 2=2.174603224
Relative clip position - Band 3=2.03030324
Relative clip position - Band 4=1.985074759
Relative clip position - Band 5=1.941176653
Relative clip position - Band 6=1.739726067
Relative clip position - Band 7=1.631578922
Relative clip position - Band 8=1.597402573
Final limiter value=1
Final limiter decay speed=0.000700178
Final limiter clipping=2.508771658
Channel separation steepness protection enabled=1
Channel separation steepness (maximum artifact strength)=0.300000012
Equalizer enabled=0
Equalize before multiband-compression=0
Equalizer position - Band -1=1
Equalizer position - Band 0=1
Equalizer position - Band 1=1
Equalizer position - Band 2=1
Equalizer position - Band 3=1
Equalizer position - Band 4=1
Equalizer position - Band 5=1
Equalizer position - Band 6=1
Equalizer position - Band 7=1
Equalizer position - Band 8=1
Center frequency - Band -1=43.06640625
Center frequency - Band 0=86.1328125
Center frequency - Band 1=172.265625
Center frequency - Band 2=344.53125
Center frequency - Band 3=689.0625
Center frequency - Band 4=1378.125
Center frequency - Band 5=2756.25
Center frequency - Band 6=5512.5
Center frequency - Band 7=10000
Center frequency - Band 8=15000
[Stereo]
Enabled=3
Stereo AZIMUTH Enabled=1
Stereo Image Enabled=0
Stereo Boost Enabled=1
Stereo Boost Excessive Reverb Protection Enabled=0
Delay enabled=0
Difference=0
Center bass=0
AZIMUTH limit=60.000003815
AZIMUTH change speed=0.200000003
Image phase amplifier=1
Image phase amplifier maximum angle=180
Image phase amplifier maximum separation strength=100
Image width amplifier=1
Extra phase shift=0
Mono or stereo only=0
Stereo Boost strength=12
Stereo Boost maximum amplification=2.170000076
Stereo Boost multiplier=1
Stereo Boost - Never reduce below original level=1
[Channel Delay]
Enabled=0
Left Delay=0
[Output Filter]
Enabled=1
Lowpass filter=16500
Highpass filter=32
Highpass filter linearity=Auto
[Bass Boost]
Enabled=0
Strength=1
Start lowpass frequency of input filter=0
End lowpass frequency of input filter=120
Start lowpass frequency of output filter=120
End lowpass frequency of output filter=250
Clip level=1.5
Clip level is relative to estimated maximum level=1
Preserve louder peaks=1
Difference=0
[Phase Rotator]
Enabled=0
Start frequency=700
Start speed=1400
Number of rotations=4
Smoothness=0.980000019
Low latency look back samples=112
Low latency look ahead samples=20
[Final Limiter]
Enabled=1
Difference=0
Pre-amp=1
Pre-limiter enabled=1
Pre-limiter relative volume=1.850000024
Reduced CPU processing=0
[FM Transmitter]
Enabled=1
Pre-emphasize=1
Pre-emphasis time=50
Output is pre-emphasized=1
Stereo encoder enabled=1
RDS encoder enabled=1
Pilot signal volume=8
RDS signal volume=4
FM overdrive volume=1.010699987
RDS PS text=-DEEJAY-/89.6/
RDS RadioText text=10:89.6 IOANNINA DEEJAY
RDS PTY=10
RDS PI=4233
RDS Alternative frequency 1=0
RDS Alternative frequency 2=0
RDS Alternative frequency 3=0
RDS Alternative frequency 4=0
RDS Alternative frequency 5=0
RDS Alternative frequency 6=0
RDS Alternative frequency 7=0
RDS Alternative frequency 8=0
RDS Alternative frequency 9=0
RDS Alternative frequency 10=0
RDS Alternative frequency 11=0
RDS Alternative frequency 12=0
RDS Alternative frequency 13=0
RDS Alternative frequency 14=0
RDS Alternative frequency 15=0
RDS Alternative frequency 16=0
RDS Alternative frequency 17=0
RDS Alternative frequency 18=0
RDS Alternative frequency 19=0
RDS Alternative frequency 20=0
RDS Alternative frequency 21=0
RDS Alternative frequency 22=0
RDS Alternative frequency 23=0
RDS Alternative frequency 24=0
RDS Alternative frequency 25=0
RDS TP=0
RDS TA=0
RDS Music=1
RDS Artificial Head=0
RDS Compressed=0
RDS Dynamic PTY=0
RDS RadioText Enabled=1
RDS ClockTime Enabled=1
FM Transmitter Calibration Enabled=0
MPX Oversampling mode=Always
FM Transmitter Calibration - Volume 20 Hz=1
FM Transmitter Calibration - Volume 40 Hz=1
FM Transmitter Calibration - Volume 80 Hz=1
FM Transmitter Calibration - Volume 160 Hz=1
FM Transmitter Calibration - Volume 320 Hz=1
FM Transmitter Calibration - Volume 640 Hz=1
FM Transmitter Calibration - Volume 1280 Hz=1
FM Transmitter Calibration - Volume 2560 Hz=1
FM Transmitter Calibration - Volume 5120 Hz=1
FM Transmitter Calibration - Volume 10240 Hz=1
FM Transmitter Calibration - Volume 19000 Hz=1
FM Transmitter Calibration - Volume 23000 Hz=1
FM Transmitter Calibration - Volume 28000 Hz=1
FM Transmitter Calibration - Volume 33000 Hz=1
FM Transmitter Calibration - Volume 38000 Hz=1
FM Transmitter Calibration - Volume 43000 Hz=1
FM Transmitter Calibration - Volume 48000 Hz=1
FM Transmitter Calibration - Volume 53000 Hz=1
FM Transmitter Calibration - Volume 57000 Hz=1
FM Transmitter Calibration - Phase shift 20 Hz=0
FM Transmitter Calibration - Phase shift 40 Hz=0
FM Transmitter Calibration - Phase shift 80 Hz=0
FM Transmitter Calibration - Phase shift 160 Hz=0
FM Transmitter Calibration - Phase shift 320 Hz=0
FM Transmitter Calibration - Phase shift 640 Hz=0
FM Transmitter Calibration - Phase shift 1280 Hz=0
FM Transmitter Calibration - Phase shift 2560 Hz=0
FM Transmitter Calibration - Phase shift 5120 Hz=0
FM Transmitter Calibration - Phase shift 10240 Hz=0
FM Transmitter Calibration - Phase shift 19000 Hz=0
FM Transmitter Calibration - Phase shift 23000 Hz=0
FM Transmitter Calibration - Phase shift 28000 Hz=0
FM Transmitter Calibration - Phase shift 33000 Hz=0
FM Transmitter Calibration - Phase shift 38000 Hz=0
FM Transmitter Calibration - Phase shift 43000 Hz=0
FM Transmitter Calibration - Phase shift 48000 Hz=0
FM Transmitter Calibration - Phase shift 53000 Hz=0
FM Transmitter Calibration - Phase shift 57000 Hz=0
[Lossy compression output optimization]
Enabled=0
Spike Protation pre-emphasis time=15
[Direct soundcard access]
Enabled=1
Device ID=Line 1 (Virtual Audio Cable)
Volume=0.939999998
Buffer size=0.049999997
Send to Winamp=Nothing
ASIO Override channel 1=0
ASIO Override channel 2=1
[Low latency output]
Enabled=0
Device ID=Microsoft Sound Mapper
Volume=1
Buffer size=0.180999994
ASIO Override channel 1=-1
ASIO Override channel 2=-1
[ASIO]
ASIO Enabled=0
Sound card=
[Soundcard - Normal output]
Enabled=1
Device ID=Speakers (2- CMI8738/C3DX PCI A
Volume=1
Buffer size=0.268295079
ASIO Override channel 1=-1
ASIO Override channel 2=-1
[Soundcard - Input]
Device ID=Microsoft Sound Mapper
Sample rate=192000
Buffer size=0
ASIO Override channel 1=2
ASIO Override channel 2=3

Ok, now I'm really confused. Lef, please tell me if I'm interpreting things correctly here:

1. The graph on the left top is the MPX waveform
2. What is the graph on the right top?
3. The graph at the left bottom shows the frequency content of the signal. It looks VERY messy by the way - compare it to the MPX output window in Stereo Tool and you can see that that looks much cleaned - bad FM reception?
4. The graph on the bottom right shows the strength of the pilot and RDS signal, and the phase difference between the two.

Now in #4 some weird things happen:
a. When you turn RDS off the RDS signal is NOT gone
b. When you lower the Stereo Tool output level, the pilot drops, but the RDS signal does not (it actually seems to go up a bit!)
c. Sometimes the phase difference is not reported, in other cases it varies wildly (upto -81 degrees).

To check 'b': Please check what happens to the RDS signal when you turn the Stereo Tool output down COMPLETELY - or close it down.
W.r.t. 'c': Could it be that you're just seeing reception noise here? And what happens if you *increase* the RDS output level in Stereo Tool (so it gets much louder than the noise).

Are you *really really really* sure that there's no other source that's generating an RDS signal?

1. MPX oscilloscope
2. Audio oscilloscope
3. the reception is 5/5 on the analyzer, so it's reading perfectly
4. correct

a. yes it's not, there is still something there
b. correct. it was supposed to drop too, but it doesn't
c. yes

Screenshot of analyzer with ST not running at all.


Pilot volume at 0% and RDS volume is at full level, 9%


And I'll post a screenshot using my AEV coder too, later this weekend.

Please do check my preset to see if something is overdone.