I, too, am getting crackling noises in my recordings. I record 2-hour orchestra concerts, using 6 mics. I record into a Windows laptop (Core i5, 8gb RAM, 100% solid-state drive). For hardware, I am using either my FireStudio Project box or my Presonus StudioLive 16.4.2 mixer, connecting them to the laptop via firewire. For recording software, I have used either Studio One v18.104.22.168191, Studio One v2, or Capture 22.214.171.124798. I do keep my software open the entire 2 hours. I don't close the program or reboot the laptop at all during the 2-hours. What I DO do is periodically click "save" between songs. So, that means there are multiple WAV files for each track, i.e., Track 1(2).wav, Track 1(3).wav, etc. In two different concerts now, about an hour into the concert, a crackling sound starts. It is louder when the music is louder. The crackling is on all 6 of my recorded tracks. I am not anywhere near clipping. In my last 4 concerts, I used a different combination of mixer vs FireStudio, and Studio One vs Capture.
The only pattern I see is that the crackling is there when I have clicked "save" a number of times during the concert. For example, in one concert, I clicked save 9 times: the first 6 WAV files were fine, the last 3 WAV files had crackling. Another concert, I clicked save 8 times: the first 7 WAV files were fine, the last WAV file had crackling. Another concert, I had only TWO saves, and both WAV files were fine. In a 4th concert, I had 4 saves, and all 4 WAV files were fine. All 4 concerts were 2 hours long. How can I prevent the crackling?? I don't notice it until the music starts, and then it's too late. I have not tried shutting down and rebooting during intermission. Do you have any suggestions? Thanks.
P.S. This is an addendum, after matthewgorman replied below (sorry; I can't figure out how to add a new comment after someone has clicked on -answer- to my question). I also have a backup recording. It is a field recorder that is plugged in directly to the main-outs of the FireStudio Project box or the tape-outs of my mixer. The backup recording also has the crackling sounds. Since the backup recording does not go through the firewire connection, can I eliminate the firewire as the cause?