Stereo Tool

Has anybody noticed a strange fluctuating gain reduction being shown by the advanced clipper metering (with composite clipper on) when just the pilot tone is present?

Cobalt was still not updated, although I do have a slightly newer version that I can have ready sometime tomorrow.

Also, the entire generic and web preset sections are, in my opinion, excessively cluttered with presets that were initially designed for FM broadcasting that, in some cases, do not sound all that good when moved into the other preset areas, especially as "generic". This is not a jab at any of those preset makers, as I'm sure they're great for FM, but I'm relatively sure that the presets are not tested as a generic to see how they sound.

Phrased differently, none of my presets were "upscaled" to FM. If someone submits a FM preset, and only an FM preset, I'm of the opinion that it should not be "downscaled" to the other areas. If the person wants a preset in the other areas, they should make one specifically for web or generic.

Further, some presets in the generic section are popping up with FM warnings.

Preset importing needs review. In fact, I had proposed a review board, to remove some of the burden off of you. If you don't want to let go of the reigns any, please at least check into discrepancies with the various sections.

Thanks...

Adjusted settings a bit and added non-oversampled Stokemask filter (less accurate!):

Stand alone: http://www.stereotool.com/download/ster ... 21-002.exe
Winamp DSP: http://www.stereotool.com/download/dsp_ ... 21-002.exe
VST: http://www.stereotool.com/download/vst_ ... 21-002.dll

Note: Eldoradofm is going to do a spectrum analyzer check of this filter (thanks!!!) which will tell us if this thing is really compliant. He already did some measurements yesterday which at leasts showed that the method used is correct, but it might need some small adjustments.

@Brian: I'll check the FM warnings. About a review board: When browsing through the presets forum you can see that in many cases there are no or very few responses to a preset. So I'm not too sure that that would work, unless some people are really going to try out any preset that's being posted.

After seeing measurements done by Eldoradofm I know now that my other method - since today, methods - of measuring it are inaccurate.

MpxTool has differences of more than 10 dB in its display compared to a real spectrum analyzer.
The Pira analyzer shows peaks nearly hitting the Stokkemask lines even if I broadcast silence (even without stereo pilot and RDS).

This might mean that the Stokkemask filter actually works for SSB mode, I don't know that yet. First I need to calibrate it for DSB mode... Waiting for a new video from Eldoradofm, that will tell me whether the latest version is compliant or not.

Does this mean that the Pira Analyzer is accurate or inaccurate?

It is actually VERY accurate - just not the RF/Stokkemask part. And it could even be that it's caused by other stations at too close frequencies (there are nearly no free frequencies to be found here, and since I don't have a license I'm using minimal power on my transmitter).

I just received my Pira analyzer yesterday and I must say I'm pleasantly surprised by how accurate the peak level measurement is. I have used some other (far more expensive) analyzers that some radio stations that I visited had, and the Pira is far more accurate than those. (As in: I send out a 60 kHz tone at 75 kHz modulation. Now, I don't know how accurate the sound card and transmitter are, but I calibrated it to be at 75 kHz modulation for a 1000 Hz tone. The Pira reports 72 kHz, some other devices reported values between 20 and 30!!!). 72 could very well be perfectly accurate, I've tested this with the built-in sound card of my laptop, not with a Marian card or anything like that. 25 is definitely NOT accurate (and surprisingly, those other devices show the correct RDS level, so they compensate for HF loss there. But not in peak level measurement). So, with high enough Loudness setting and the composite clipper, with the build-in sound card of my laptop, I see peak levels at 74 kHz (70% of all values are there), 75 kHz (5%) and 76 kHz (0%, sometimes a single value is measured here).

Looks like the Pira is also perfectly suitable for adjusting the bass tilt. I'll have to do more tests when I get my sound card back (probably 2 days from now).

Can confirm that. We once compared it to the measurements that the Regulation Authority has done with their very expensive Rohde & Schwarz-Analyzers, and the results from the pira were exactly the same!

Interesting about the Pira analyzer. I guess you have the P175 (boxed version with USB connector)
A lot of measuring possibilities in one small box. Great, thanks for the tip!

It would be a volunteer position. Basically, whoever volunteered would be assigned a section suitable for them. The example I used before was using myself. I could volunteer for web and generic, but not FM.

As for the lack of commentary, I think that's partially fueled by some instances where comments have been offered and the person making the preset got offended and fired back a retort. I recall a particular incident where a certain person said that those providing criticism were "jealous". That kind of thing needs to be handled via moderators.

Beyond that, many presets posted are for FM, and depending on whether or not the person is a competitor in a market, the feedback may not be offered. Also, there are people, like myself, who are not broadcasters and should not really be commenting on whether or not a particular FM preset sounds good, as we don't have the equipment to properly test the preset end-to-end.