Joe was on the right track, I would expand on the "rider technique" a lot. So much of the amount of pop you are getting as to line control. Line control is really everything in wakeboarding. Line control mixed with a proper edging technique leads to a good pop. I am sure everyone has heard of a "progressive edge." What the progressive edge is really helping the rider to is gain speed at the wake and generate energy or load the line. This energy is being stored in the rider and the line and is released at the top of the wake, that energy really helps dictate the amount of pop you're are able to generate. I like to run riders through what I call the "edge/pop Drill" What I the rider do is take a cut out from the wake heelside 15-20 feet. Then take a nice mellow progressive edge into the wake, with the goal of generating enough speed to clear the wake. Doing it over and over again until they are edging correctly and clearing both wakes. Then we have them take a shorter cut out and repeat the drill until they can take a super small approach at the wake and clear both wakes. With enough practice and proper technique you can/should be able to clear the wake with a 5-10 foot approach.* Doing this over and over is building muscle memory, and you learn that line control is everything.
Derik also brings up a good point about body position at the wake, a large amount of tricks in wakeboarding can be done with a seated position at the wake, as if the rider is sitting in a chair, think backrolls, glide tricks, hs fs off axis spins. On the other hand there are tons of tricks that require the rider to stand tall, backside spins, tantrums, hs flat spins, etc.
Hope this helps and makes sense.