Alesis QS8.1 and unwanted extra midi effects

Flanging can also happen if you are mixing the internal Alesis sound with a pianoteq instrument. Differences in tuning and/or spectrum can sound as flanging or introduce phase cancellations. If you have standard or pro, the pianoteq instrument can be adjusted to the Alesis tuning note by note to reduce or eliminate the unwanted effect.

We would need a bit more information about your setup. Are you using the stand-alone version of pianoteq, or as a plugin in other software? What OS are you using?

For the stand-alone version, Pianoteq has an option "Listen to all MIDI inputs" in the "devices" setup window which is enabled by default. (File -> Audio/MIDI setup -> Devices) Try turning it off, and make sure only the keyboard you want to play (alesis, casio, ...) is checked.

That's weird... you don't see your keyboard in the same little box as in "listen to all MIDI inputs" when it's plugged in? It should be there, and that's the one you should activate (obviously).

I'm pretty sure it is Presonus AudioBox USB as mentioned in the topmost message.

Right, you have to look at the Presonus AudioBox in the list then... and check there is only one instance?

Added: you may not read everything I wrote, because I did not got exactly what you describe from the first glance, pay attention to what I write about MIDI monitor and the very last two sentences.

Since you still could not solve your problem my strongest advice is to find a person in your area who can come and fix it all. I clearly understand that different people have a very different areas of experience and if somebody lack some technical approach to stuff it's totally ok. If you still want to try to solve it by yourself the best way of thinking is to see a chain of events which are hardware, software, etc. and you have a mistake somewhere in the chain. Try to separate the links and test them to debug the chain. Is your master keyboard ok? Download another virtual synth, some demo, try to play it. Download some MIDI file and load it to Pianoteq to play by itself internally. Does it sound right when you play with a mouse on a Pianoteq virtual keyboard? Play audio demos from Pianoteq website. Play just some piano music from YouTube, does it play well? Choose another type of drivers, not ASIO, try WDM, or whatever you have in your hardware list, etc. Try extremely large/small audio buffer settings. Finally you'll be able to narrow your search and locate a problematic spot. Maybe you have a broken audio interface or some other hardware failure which could only be replaced or repaired.

Since you mentioned 'flanging' effect it just means that somehow audio plays the same twice (or more) with a short delay. Maybe your keyboard double send the MIDI signal, or maybe it appears later in audio domain. It should be possible to locate 'where' it actually happens. (!) Ok, to check if your keyboard transmit MIDI right just go to Pianoteq > Options > Midi page then play a single note on your keyboard and check in the MIDI monitor window that a single 'note on' event received with velocity information also and then when you release the key the 'note off' event also received - it is a normal behaviour. If it is ok then your keyboard is ok, look further in the audio domain.

Also note that there is no such thing as 'MIDI sound' - MIDI is not a sound, it is just a controller data that contains the information about simple events - what key is pressed and velocity and then that a key is released. Based on this data software and hardware then actually generate the 'sound'.

You know, it's easily possible that it is a window or some bookshelf in your room resonates and generates this effect. It's extremely hard to guess from where I am.

...Pianoteq > Options > Midi tab - in the very bottom 'Notes Channel' switch from 'Any' to 1.

...Check the Alesis manual (google it) and find how to reset everything to factory settings.

Three more things you could look into:

Have you made absolutely sure you disabled the audio output from the Alesis when you use it with Pianoteq? If not, unpluck all audio output cables from the keyboard so only the MIDI out remains. You should also be able to test this by playing a short sequence on the keyboard and then afterwards just replaying the midi in Pianoteq - if it sounds as clean as the demo, i.e. the effect is gone during replay, then you have your cause...

Do you have anything plugged into the MIDI IN or MIDI THRU connectors on the keyboard? If so, unplug these, too, to make sure the keyboard is not being fed back its own MIDI signal creating a MIDI loop of some sort.

Failing that, consider uploading the MIDI sequence you recorded (to the "Other files" section of this forum) so others can take a look at what might be the problem with the data sent by your keyboard. (You might also go to the Options>MIDI screen in Pianoteq, hit a single key once on your keyboard and post a screenshot of what appears in the MIDI monitoring window to give us a first idea of whether there are any irregularities there.)

Hope this helps,
Dan