Sorry to hear about the recent issues you have been experiencing.
Pops and crackles could be attributed to a few different system variables. Here are some general troubleshooting tips you can employ to resolve the issue.
1. Make sure you audio interface has the most current drivers.
2. Set Options/Preferences(OS X) > Audio Setup > Processing > Dropout Protection to Maximum. Read about dropout protection in the Studio One reference manual.
*3. If you are using 5200 RPM hard drives, there will be performance issues on your system. We recommend at least 7200RPM hard drives.
4. If you open the performance monitor in Studio One, you can view the resources that are being used by each of your plug-ins. See if you can find a particular plug-in or set of plug-ins that might be causing the issue.
5. The use of Transform to Rendered Audio(Audio tracks) and Transform To Audio Track(MIDI tracks) also helps to free up system resources on heavier usage tracks. Information on this can be found in the Studio One Reference manual.
6. Employ bussing for audio effects, do this instead of adding plug-ins over and over. For instance, If you have 5 vocal tracks and they are all using the same effect, instead of place that effect 5 times, create an aux bus, and route those tracks to that bus. Here is a video from Home Studio Trainer:
These are just a few examples of troubleshooting steps.
* If you require further assistance tracing down the cause of the performance issues, please submit a ticket to technical support.