I asked CHAT GPT the following... It gave a very nice response I agree is accurate!
Q:
Why does hi end turn lower in a DAW if I turnt the sample rate I mixed it in from 88.2K to 44.1k?
A:
When you reduce the sample rate of a digital audio file from 88.2 kHz to 44.1 kHz, you are essentially cutting the number of samples in half. This means that the higher frequencies that were previously present in the audio signal are now being represented by fewer samples, resulting in a loss of information in the high-frequency range. This loss of information can cause the high-end of the audio to sound duller or less prominent in comparison to the original mix.
Additionally, when you downsample an audio file, there can be issues with aliasing. Aliasing is a phenomenon that occurs when frequencies above the Nyquist frequency (half the sample rate) are not adequately filtered before downsampling. This can result in unwanted artifacts and distortion in the audio signal, which can further affect the high-frequency content.
To minimize the loss of high-end information and prevent aliasing, it is important to properly filter the audio signal before downsampling it to a lower sample rate. Some digital audio workstations (DAWs) include high-quality resampling algorithms that can minimize these issues, but it is still important to be mindful of the potential impact on the high-frequency content of your mix when downsampling.