If I may interfere in this subject, I also think that the MP3's are not easy to find.

I know it takes a lot of time and work to build a shop and the Mindplace website does look already nice and is quite clear. So this comment is really not intended to diminish your hard work.
It took me some time to realise that what you call "Media" are actually some MP3 files. I can't speak for others, but for me, it wasn't obvious. I find that "MP3", "Music" or "Audio" are terms easier to identify.

Maybe you could try the organize the menu's differently? And have for exemple on the Home page different links to the "About Us", "Contact Us", "Support", "Product comparison", "Meditation Challenge" and "Blog" sections/pages. Which would free some space to have on the main horizontal bar : "Home", "Light Sound" (with all the AVS machines including the "Refurbished"), "Biofeedback", "Accessories" (including Ganzframes, parts, environmental lighting system) and "MP3" (maybe divided into "AudioStrobe" and "SpectraStrobe"). So the "Shop" section wouldn't exist anymore.

It's not easy to predict how customers will react to a specific website layout. The best way to know what is best to improve your conversion rate is to test.
I think the tools in Shopify and Google Analytics allow you to track what visitors do. If you were to decide to change how your sections are displayed, you could monitor during a few months if you got more "add to cart" than with the former layout for the same period of time the year before (so it wouldn't be affected by seasonal events), and if not, you could just go back to how it is now, or decide to try something else.