Quote: “I'm sure my other guitars wouldnt react exactly the same. I feel like it has something to do with the specific pick ups in my 8 string. Or maybe the pickup height?”
Test your other guitars, if they work fine as you think they will, you will know you have thought correctly.
That will then identify the 8 string guitar as the actual problem. No need to look further at the RME equipment, Reaper etc. Focus on fixing the guitar.
Often guitarists think it is a good idea to adjust their pickup height as close to the strings as possible in order to maximise the signal from the guitar. So, I’m wondering if that is the case here?
In point of fact, with particular guitar types and specific types of pickups, adjusting the pickups in such a manner can cause extremely wild sonic anomalies, as the strings are adversely affected by the intensely strong pull of the pickup’s magnets proximity as they vibrate.
https://www.seymourduncan.com/blog/swd/ … strat-itis
If you are muting strings, tightly controlling the degree of string excursion, playing relatively quietly. Then in contrast, playing with completely open or fingered strings, maximising the degree of string excursion in relation to its proximity to the pickup. That is likely to expose the problems striking hard in an extreme manner. But there is an even more extreme condition possible. As muting itself, tightly controlling the string excursion, presses the string down, much closer to the pickup than normal. So hitting the string hard then, causing it to vibrate maximumly when at its very closest to the pickup, is probably what causes the issue.
There are many advantages to backing off pickups so that they are not so close to the strings. It usually results in a better sound, less string to string variation in volume across the pickup, cleaner brighter sound and for rhythm playing, a far better, more even balance from bass to treble for chordal work. Of course, if you are a good player you will want to be able to seamlessly transition from lead to rhythm and involve chordal moments and sections along with octave work into your lead playing too for heightened interest. All that will improve with pickups that are not too close to the strings.
The link below demonstrates the incorporation of such variety of styles that benefit from proper pickup height.
https://www.youtube.com/watch?v=TNjFBUYHVVo
The other thing that occurred to me is that sometimes due to the extreme thinness of the copper wire used in pickups, which are easily damaged. Or because of inadequate wax potting of the pickup in some cases. Or because of poor wiring of the pickups output, involving an intermittent fault.
There may be a defect that exposes itself only under very specific conditions that highlight it, thus escaping normal manufacturing quality control parameters. It’s worth considering that pickups for 8 string guitars are comparatively rare, with manufacturers producing far less of them and production operators far less used to fabricating and handling them. So, it may be a simple issue related to an intermittent fault on a specific pickup or elsewhere in the wiring.
The point is, by a process of trial and error testing you should be able to pinpoint which component on your instrument is actually causing the problem.
Perhaps a guitar tech’s help might be required or someone with electric testing equipment, meters etc. Along with electrical know how.
Maybe a guitar forum if you can find a good one will help you out if you really get stuck. The one linked has many experts.
http://fretsnet.ning.com/forum
Lower your pickups, and by a process of elimination, proceed logically.
You are Johnnylogic aren’t you?