Stereo Tool

Hello All,

'Long time reader, first time poster.

I wanted to make a preset that tries to sound like Cornelius's CGSmooth preset.

Like all the other presets, this assumes that input audio is regularly hitting the top of the metre, I say 0dBFS however I suspect the input is float so it's not like one is clipping when the levels are set correctly.

This handles most types of material pretty well, and is designed to be fairly transparent. The highs are controlled, so this isn't particularly bright but it's not as muffled as a cassette tape either.

Leveling is pretty good, with only occasional significantly audible volume reductions on problem tracks. Sometimes quieter portions get brought up, but no worse than most processing.

I test it with track with VERY quiet intros, such as Alpha and Pulstar by Vangelis (1976), as well as track that go from like -20dB RMS to -7 in a fraction of a second. (Such as Darkness by Peter Gabriel, 2002., and a few others that are not at all mainstream). The goal was to minimize audible gain reduction in instances like that.

I also tested it on classical. Quiet portions are brought up just a tad, but the effect is pretty subtle!

The default settings for the web / DAB version allow headroom for lossy codecs, though the clipping is not as strict. The FM version uses the strict clipping.

In both versions, the declipper is "cranked" to use more CPU, but also to better reduce distortion. Natural Dynamics is pretty much at the default.

I would say this is suitable for Public Radio, despite not being flat.

Cheers!

Here is an update -- Brought the highs up just slightly, to sound more like the preset I was trying to emulate.

Cheers!

Nice & smooth. I'm liking this.

I'll post a tweaked version that's a bit louder, though I suppose that was NOT the point of this preset.

What's interesting though is that it's only a matter of increasing the clipper drive. There is a point in which is sounds nearly identical to the original, should artificially louder audio be the desire of the user.

Personally I think -8 LKFS is really quite overkill for FM, but that seems to be the ballpark people are aiming for...

I mean obviously -23 is probably low... still. Haha.

I am going to build a "New York" style preset using this as the base, since the AGC leveling works so well. I figure using a rough target of the LKFS reading Breakaway gives off with the 0/6, 50, 50, 50, default sliders should be a good comparison. Though I must point out that I am not equipped to do FM testing with these other than MPX tool.

EDIT -- Maybe not. It's worth a shot experimenting, however it looks like there are a lot of other presets that do the same thing.

Precisely! As far as I know the new EBU standard -23 LUFS reffered more to digital media rather than analog. Correct me if I am wrong. Furtheremore, I think that one overlooked reason for using more than -23 LUFS is that this standard is OK, but only for quiet environments. And therefore not suitable for some applications (try to listen to this in your car!).

Recently I tested other preset (that was probably Unveil by Bojcha) it peaked at -8, -9 and -10 LUFS on average and sounded quite open. LUFS measurement is more like guidance for the whole program material (even though short-term measurements were mentioned as well in presentations I've seen somewhere).

That would make sense that it is more targeted towards digital media.

-23 is indeed probably too low for a car. Classical music would have soft passages as low as that, but I doubt anyone would be trying to aim for an average level that low.

I was reading a few papers talking about digital media, and how -16 seems to be the sweet spot for portable devices. In this case the presets I built occasionally hit -8 but they do not sustain at at that level constantly.

If anyone is interested in hearing what this sounds like on a real stream...

I have it feeding a 256kbps mp3 and ~24kbps AAC+ encoder.

Note that in order to comply with the license, *ONLY* the free portions of Stereo Tool are in use. Therefore there is no advanced clipper, declipper or natural dynamics.

Both streams use the single-band compressor / limiter and simple clipper to catch stray peaks.

The high frequencies are less attenuated than the original preset I posted here, but the sound is pretty similar.

http://199.195.194.140:8001/ - m3u is on the page, mp3 256kbps.
http://199.195.194.140:8099/ - m3u is on the page, aac+ ~24kbps.

The source is a playout system tied into an old Wheatstone D-16 console, then an Airtools delay. Then over long XLR cabling into an ANCIENT Audioscience ASI4300 PCI Card on an old Optiplex 330 running Windows 7 32-bit.

Cheers!



PS - Attached is the modified free-only preset version that I am using.
Levels are around around -10 to -13 LKFS, with headroom for lossy encoding. It can be pushed louder, obviously at the expense of distortion depending upon how you do it. I am hitting the simple clipper very lightly, for that reason!

My friend, this is smooth. All I did to adjust it was set up mono processing because that allows me to play stereo tracks in AM radio style, stereo tracks processed that way in Stereo Tool are much better sounding than just doing a regular fold-down. I have the DAB-free version, and am wondering if the DAB version has enough of a difference in it to justify registering the program.

Either way, your efforts are truly appreciated.

Thanks!

The DAB free version can work quite well, however having the declipper and natural dynamics really can do wonders for a lot of material. For others, the effect is more subtle, since it's not program adaptive.

Here is a the same 75us FM preset, but I take some of the energy off the clipper by using the single band section. The result is a subtle loudness increase but not so much density.