However, Qtractor allows you to import audios in 48000, even if the audio engine is working in 44100.
In options > audio > conversion type, set them to "sync best".
Test to see if the conversion is unnoticeable and does not produce artifacts or background noise.
In any case, according to my experience, the best option is always to convert them with specialized software and have a 44100 version of those audios.
Maybe someone else can shed some light on this matter.
However, Qtractor allows you to import audios in 48000, even if the audio engine is working in 44100.
In options > audio > conversion type, set them to "sync best".
Test to see if the conversion is unnoticeable and does not produce artifacts or background noise.
In any case, according to my experience, the best option is always to convert them with specialized software and have a 44100 version of those audios.
Maybe someone else can shed some light on this matter.