mAirList + Stereo Tool problems

Hello guys,

Ive recently changed from RadioDJ to mAirList Home license. Im using it with Rodecaster Pro 2, and the integration is amazing(multiple channels, fader up start/stop on the players, etc).

  • generic_stereo_tool.dll

The only problem I have is using Stereo Tool with mAirList. I`ve purchased a basic ST license and I tried to install generic_stereo_tool.dll plugin.When I try to configure this plugin I receive a pop-up error like this:

No matter the fact I get that error, the ST configuration screen starts up and I can set there the license and I can choose a preset that I like and it sounds very nice just like that. But everytime I restart mAirList, license and preset that I`ve already set are lost and I have to take all those previous steps one by one to set everything again…
The generic ST plugin is activated in Encoder, on Master tab.

  • dsp_stereo_tool.dll

I went on this forum to read other posts about ST and I found that I can try to use the
dsp_stereo_tool.dll as Winamp plugin. Downloaded it, installed it and started it. I`ve set the license, restarted mAirList and then I try to use that preset that I liked before and … surprise, it sound awful, like having too much volume or something. Both plugins are on the same version of Stereo Tool (10.20), same license, same preset, nothing more.
Volume on Windows is set on 100% on the channel used for encoding and I preffer to let it like that.

  • Conclusion
    Same settings on both plugins, but sound is completely different.

Generic ST plugin sound exactly how I want, but I have to set the license and the preset everytime and it throws error everytime I try to configure it.
DSP ST plugin sounds awful, but it saves the license and presets and doesn`t throw errors.

Sorry, I can`t attach more screenshots for now, due to new users rules.

Would be nice to achieve the same sound on DSP plugin, regarding it has no errors at all, but I need some guidance in this matter.


I can’t offer a straight up solution, but have some information that might help with troubleshooting:
That null pointer issue appeared with the start of the SteroTool 10.x beta in Aug/Sept 2023, which also introduced a major rewrite of the UI. It has been there ever since. The issue with the license key and other ST values getting lost from the mAirList config started exactly at the same time, so I think they may have the same root cause. Something has changed in the ST generic plugin between 9.92 and the first 10 beta that broke the integration.

I personally have since switched to the Winamp version of ST, and I actually like it better, having ST in a separate Window. For me, the sound (levels and quality) are the same, so i’m not sure why it hasn’t been the same for you, sorry.

Have you double checked the “Audio I/O” section on your DSP ST? That page has slight variations between the plugin versions, for example, on my DSP version i see a “Low input level correction” slider that can give up to +32dB of gain, which might cause something like what you’re describing.

Thank you for replying. Unfortunately, the screens look the same, no differences at all. Any preset that I choose, would be causing this noisy, unclear sound.
Triend everything :frowning:

That’s not a “can” option anymore, it’s a MUST to use to prevent errors.

As of 03/2019, we have received that the generic version of Stereo Tool may lead to unexpected crashes of mAirList. Please consider using the Winamp DSP plugin version for the moment (see below).
config:dsp:stereotool [mAirList Wiki]

I’m using StereoTool in the 9.92 version without any problems and no distortions at all. (Didn’t see a need to upgrade yet because I’m used to the GUI). Did you try to use this version?

Just to get to know your setup to sort out: How do you get the signal into the encoder, where the ST is processing the signal right before it is streamed?

Hi, Stefan,

Audio routing using Rodecaster is simple for me. On mAirList, playback is set on the channels provided by rcp2. On Encoder it looks like this:

Then, on Encoder, on Sound processing, I`ve set on Master the Winamp DSP Plugin.

The same setup for both plugins. Generic sounds perfect with any preset out of the box and DSP does not …

I`m gonna try a lower version of ST to see if that sorts the problem out.

INFO: Just tried Stereo Tool DSP 9.92. Works perfect out of the box … :smiley:

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Great! So it seems to be a specific ST problem.

BTW: Did you test this setting that Nils mentioned?

I have another client who is using one of my presets without any hassle in ST 10.x that worked in 9.92 too :wink:

Tested yesterday all the settings Nils mentioned, nothing worked.

Ive just reinstalled ST DSP 10.20 and now its working flawlessly. I don`t know what the problem was, but now it sound so good. :smiling_face_with_three_hearts:

Thank you for assistance, have a great weekend :pray:



First of all, this post is related to the “Generic” Stereo Tool DLL (simply labeled “Stereo Tool” in the mAirList DSP Add menu); not the Winamp DSP version.

Hans van Zutphen (developer of Stereo Tool) and I did some debugging over the last few days, and in fact, it turned out that Stereo Tool 10 did not work anymore in mAirList. Partly because there were functions removed from the DLL which we still required (causing the Access Violation error mentioned in the original code), but there were also some problems in my code leading to other issues like an error message when you clicked Apply in the config, and then Save.

Hans released version 10.21 of the DLL yesterday, and I uploaded mAirList 7.2.6 today. They both should work together very well now. We also fixed some bugs like the GUI not appearing when you open the config for the second time.

Please note that the “Stereo Tool Generic DLL” is now known as "libStereoTool, and can be found under the same name on the Downloads page on

The ZIP archive contains libraries for various operating systems and architectures. The one that we need can be found in the lib\Windows\32 folder, and is now called libStereoTool_32.dll.

mAirList 7.2.6 will detect the DLL under both this new name, as well as under the old name generic_stereo_tool.dll, for those still working with ST 9.xx.

I have also started to work on better configuration management - storing all StereoTool settings as part of the mAirList DSP/encoder configuration, so you don’t need to fiddle with external .sts files anymore. Please expect this to be released in mAirList 7.4.


Thanks for replying,

Tested with the new releases and it works like it should.
Info for other people trying to get the best sound with mAirList and Stereo Tool:if you use Winamp DSP, input that feeds Stereo Tool plugin has to be at 0db maximum. If not, the sound will be distorted. Generic plugin and VST plugin can both handle input that exceeds 0db.

Thanks Torben for all the help :smiley:

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Yes, that’s correct. Both VSTs and libStereoTool (let’s use the new name from now on) are being fed 32bit floating point data, which can exceed 0 dBFS. While Winamp DSP plugins work with 16bit integer data which is clipped as 0 dBFS.