"you don't even know how to string the thing properly, nor even connect the string to a stick "

It seems that you misread my post above. I didn't offer a description of how to "string the thing properly, nor even connect the string to a stick" because I've seen enough players and playing styles to know that seldom are two ever exactly alike. Hence, why I said what I did.

"Keep in mind that this is just a starting place to work from and your actual measurements may vary to work best with your purposes and individual approach to playing."

The reason that I've touted my friend's approach is because I've heard plenty of others and nothing that I've heard has been even close to his. Period. By that, I'm not saying that other one string bass players were bad. Nothing could be farther from the truth. I've seen some wild and freaky thumpers that were absolutely astonishing in their efforts. I haven't seen them all and in all likelihood, I won't get that opportunity. I'm merely saying that even via their best efforts on a variety of different types and approaches to one string bass builds, none has been able to equal what my friend could do with his. If and when I do hear one better, you can bet that I'll be happy to post about it.

Now, please understand, that this is just my opinion. Hey, the next guy might think that he sucks and that I'm a tone deaf mutant. We all have our own ideas regarding what we like and why.

I understand what you're getting at, regarding the use of something that might be more costly than what you're willing to invest in for such a project. I can imagine that new drum heads might be pricey items to purchase. I wouldn't go that route. As for me, I seldom purchase new items and prefer to shop at garage sales, junk stores and swap meets. I've had an old bass drum in the basement for years that I've been threatening to turn into a drum bass. At the moment, I have lots of other more pressing projects but I'll get around to it.

I don't know how many drum heads that my friend might have gone through in his experimentation to create what he did. Being curious about that aspect of his concept, I did asked him how he managed to keep the tugging on his string from pulling through the head and he explained how he managed that part to me. I will restate that because of the sensitivity of the plastic drum head, there is no need to apply even a fraction of the pressure needed to play an average steel tub bass. So, I never saw him lose a head at any time when we played together. Back then, he primarily played in an acoustic jug band configuration.

Hey, speaking of digital dreams, my friend, who plays spoons, managed to attach a pickup to one of his spoons and pumped it into a digital effect processor and looper. I liked the way he could alter the sound to make his spoons sound like anything within the sound bank from birds chirping to you name it. A wah pedal became a tonal shifter so he could play melodies as well. I've been wanting to take some of my pursuits into that same realm. The best of luck to you in your digital designs.