Naudio mixing samples in real time

Question

So im making a little app, some kind of synth. My idea is to use short samples (3-5 seconds) each of this samples will be a note (C, C#, D, D#, ...). The way i want it to work in that when a user presses a key on the keyboard the corresponding note will play. I have tried a few things like on every key press initilizing a new WaveFileReader and playing it wtih an IWaveProvider, but this doesnt work to well becouse it fills my RAM very quickly.

The closest i have got is with creating a mixer and then feeding it streams, this seems to work but i dont know if this is good practise (also because when i get this done i plan to add multiple channeles that will play in the background).

some test code of the working example

public void wProvider( IWavePlayer pro)
    {
        IWavePlayer pr = pro;

        WaveStream wstr = WaveFormatConversionStream.CreatePcmStream(wave);
        WaveStream wstr2 = WaveFormatConversionStream.CreatePcmStream(wave2);

        var mixer = new WaveMixerStream32();

        var strC32 = new WaveChannel32(wstr);

        mixer.AddInputStream(strC32);

        strC32 = new WaveChannel32(wstr2);

        mixer.AddInputStream(strC32);

        pr.Init(mixer);

        pr.Play();
    }

So my most recent idea is to have a channel for each key and all the channels conected to one mixer. Then when the key is pressed the coresponedent sample wil be played on the distinct cahnnel.

I want some kind of "listener" that listens for incoming strems and adds them together and then delivers them to the output. Is there a simple way of doing it? Did i choose a wrong approach?

Also is it wrong to have multiple mixers? (one for notes played by the user and one for all the olther saples playid in the background) I found alot of anwsers on how to concatenate samples and save them on the disk but none on how to add samples and play them in real time...