Buckman

I have questions regarding a sculpture I am making-

To keep it simple, let's say the sculpture is simply a rectangle, ~4'x8'. What I would like to do is set up eight motion sensors (one in each corner and one in the middle of each side) that when triggered activate a corresponding tape player with a tape loop inside to play on a central speaker unit. So the goal is simplest terms is for people to walk around the installation triggering a musical note and with enough people organize a composition or a chord.

Each motion sensor would have its own respective tape player, but I don't have the funds to supply eight seperate speakers. I also don't have much money to spend on PIRs, however, ebay has a bunch of PIR home security sensors for around $5. This project is most likely going to be crude, so I'm not overly worried about how sloppy it may turn out.

What I imagine is to have the tape players always on, always running their loops, and a way for their respective sensors to allow the sound to play through the speaker. The gaps I need filled-

1) Is it sensible to use the PIR sensors I'm finding on ebay? (Aleph XP-40, Ademco 998)

2)short of buying eight speakers, is there a way to hook up all eight tape players to a central speaker unit?

3) If I am making this overly complicated, might you know of a better way to accomplish the task?

To keep it simple, let's say the sculpture is simply a rectangle, ~4'x8'.  What I would like to do is set up eight motion sensors (one in each corner and one in the middle of each side) that when triggered activate a corresponding tape player with a tape loop inside to play on a central speaker unit. So the goal is simplest terms is for people to walk around the installation triggering a musical note and with enough people organize a composition or a chord.

Each motion sensor would have its own respective tape player, but I don't have the funds to supply eight seperate speakers.  I also don't have much money to spend on PIRs, however, ebay has a bunch of PIR home security sensors for around $5.  This project is most likely going to be crude, so I'm not overly worried about how sloppy it may turn out.  

What I imagine is to have the tape players always on, always running their loops, and a way for their respective sensors to allow the sound to play through the speaker.  The gaps I need filled-

1)  Is it sensible to use the PIR sensors I'm finding on ebay? (Aleph XP-40, Ademco 998)

3)  If I am making this overly complicated, might you know of a better way to accomplish the task?


art-installation

You could detect motion with one camera placed high enough. The captured video feed could be split in different zones each triggering its own loop.

Zach Poff's app does just that with a camera (only six zones though):

https://cycling74.com/project/project71-video-trigger/

Camera is going to be the cheap way, easy hardware setup and should work well too, have used PIR's for this sort of thing and painted over the lenses to restrict their view, but not cheap and a bit of electronics to do and you'd probably need a microcontroller like Arduino. Could look at pressure pads too?

2. A mixer? Sure you can find a cheapo 8 channel mixer easy enough.

I would also vote for a camera. There are cheap cameras even with infrared lighting, which could work in a darker area. I'd mix in the computer, no external mixer required...

Technically this is all doable, but needs some experience and tweaking for the details. Your idea with the sensors is much more complicated, as they typically can't differentiate between left and right and are active on a bigger angle and thus would overlap. But this depends much on the size of your rectangle...

Artistically the challenge is much higher. Such installations can get boring within seconds. I'd suggest to use more than eight "tapes" or varying processing to create some diversity and keep the participant curious...

I would also vote for a camera. There are cheap cameras even with infrared lighting, which could work in a darker area. I'd mix in the computer, no external mixer required...
Technically this is all doable, but needs some experience and tweaking for the details. Your idea with the sensors is much more complicated, as they typically can't differentiate between left and right and are active on a bigger angle and thus would overlap. But this depends much on the size of your rectangle...
Artistically the challenge is much higher. Such installations can get boring within seconds. I'd suggest to use more than eight "tapes" or varying processing to create some diversity and keep the participant curious...

Art Installation