July 1, 2018 at 12:35 pm #4097
I had been trying to cobble up a piezo disc contact mic for a wooden tap dance floor, and honestly, wasn’t having much luck. Then I came across the Zeppelin Design Labs site and things changed for the better. I have zero sound design knowledge, but a tiny bit of electronics experience. I ordered the Cortado kit, and Brach helped me with a fake phantom power circuit that uses a 24Vdc power supply that I had. The website instructions are superb (kudos to you guys, best photo op-sheets I have ever seen!!). It powered up just like it was supposed to and no problem setting the bias.
Getting the mic to pic up the floor vibrations took some thinking, and there will be improvements to it. The idea is to have a little pocket sized (ok, maybe small back pack size) floor contact mic, pre-amp, amp, and speaker all in one package that can be used wherever there is a reasonably resonant dance floor. It seems like the mic needs to be separate from the rest of the stuff to avoid feed back, etc.
What is showing in the first pic is the whole proto assembly, which is a lot bulkier and clunky than the finished item will be. The Cortado piezo is under the can and metal weight, you can see the Cortado pre-amp, fake phantom power adapter, 24vdc bench top power supply, home made amp with LM386 IC, and a little speaker in a box.
Here is the Cortado pre-amp and the piezo disc is hidden under a tuna can with a one pound metal weight on top of it.
This is what seems to be working as far as reasonable coupling to the floor vibrations, at the present time. Just taping the piezo to the floor didn’t do much, so I had to experiment. There is a piece of soft foam rubber inside the tuna can. Then there is a small piece of aluminum rod, about 3/8″ in dia. x about 3/8″ long, and then the piezo disc is held in place on top of all that with a piece of tape. The stuff is lightly squished into the can so that when the can is inverted and the piezo is placed against the floor, there is about 1/8 to 1/4″ of compression on the foam in the can so that the piezo can vibrate, but the heavy metal weight on top of the can holds everything else still.
It’s working and I hope to get a video of it in action soon!
Lloyd-ssJuly 2, 2018 at 8:20 am #4104
That”s great to hear that everything is working well for you. Let me know if you have any more questions.