Which subwoofers to choose for an interactive sound installation

Hello everyone,

For my graduation project, I am working on an interactive sound installation, and am now looking for the right speakers. Maybe someone of you could help me out with some questions I am facing? That would be pretty amazing . 

The installation I am planning is being activated by around two to five people using pulse sensors. The sensors are set up as midi controllers in Ableton Live and the signal translated into sound. As the idea is that people can hear and feel their own and other people's heart rhythms, I would like to work with low frequencies to achieve a chest pounding effect (around 60-80Hz). I already figured that subwoofers might be the best solution, as they focus on low frequencies and display them in the best way possible, compared to mid-range speakers. But researching into subs I found myself in a jungle of possibilities, in terms of technology, design and price.

Another problem I am facing is the question: how many subs do I need, which size and how do I need to place them? My first idea was to have a sub for each sensor, so that the installation starts with displaying everyone's rhythm individually and after that, merging all sounds on all subs, creating an immersive soundscape. But I guess it is quite tricky to position them in a way that they do not interfere each other, right? Or is this something I could adjust by changing their angels a little, so they do not directly face each other? Or is it even possible to have subs that just end at some point, so they kind of don't touch each other?

Also, I will probably have my exam presentation in an open space like an industrial hall or something like that. Therefore, even though I will be limited to a space of 6 to 9 square meters, I will need to consider the space around and its acoustics that I do not know yet. I also have the possibility to build a little room around it or use acoustic panels. Researching the size of the driver and space I will need, I figured, with an 12-inch subwoofer, I reach 1.25 cubic feet. This feels like nothing to me, but might also solve the problem of interference? But is this the same with all kinds of subwoofers? I think especially if I use several speakers they shouldn't be too big but strong enough to create the tangible feeling in the body. Would 5 x 12-inch speakers, placed 2,50 apart from each other, be enough? 

Looking at the possibilities to access speakers, buying, renting and building them could all be an option for me. Even though I am still not so happy with the idea of rental. By looking into different opportunities of speakers especially in the DIY area, I found the direct sub, the scoop, the folded horn and the tapped horn. As I understood might folded horn and tapped horn be the best in quality as they have more space to amplify the vibration, but are also more difficult to build and probably more expensive. A guy from a music store recommended me to rent two direct 18 inch subs and 5 mid-range top speakers, while someone from Thomann Music recommended me to get five of these active 8inch subs  which are unfortunately a bit too expensive for me, especially without knowing if they would work as I want them to.

So that's more or less what I have now. It would be amazing if someone could help me out .

THANKS a lot. Best, Laura  

Hoi Laura, Ik zie dat je uit Nederland komt, deze kost is taai genoeg in het Nederlands, laat staan in het Engels. Dus als je verder wilt praten in het Nederlands stuur me een mailtje (questionsaboutcubo at gmail dot com).