Coupling an external speaker with FED3

[Maria Shujah]

Hello everyone, 

My behaviour task involves the mice to distinguish between various acoustic features of different sounds. For this purpose, I require a high resolution and high quality speaker. The in-built FED3 speaker might not suffice for this purpose. Therefore, I am planning to attach an external speaker via the BNC output in the FED3. I was wondering if anyone here has had an experience with that, especially with programming the FED3 software to trigger the external speaker? 

Thanks for the help! 

[Lex Kravitz]

Hi Mariya,

Thanks for the question!  The FED3 has a small internal piezo beeper (this one) does a decent job with tones and frequency sweeps but cannot reproduce high quality audio.  FED3 also has an external connection to a 12-bit true analog output, meaning you can generate complex audio signals directly on the FED3 and play them back on a high quality external speaker.  In theory you could play back .wav files stored on the SD card, although I've never tried that.  

I recorded a video to demo some frequency sweeps using the internal speaker and the external audio output.  Demo code is here as well.  If you decide to do something like this we can add functions into the FED3 library which would simplify adding frequency sweeps into a task with FED3. 

Video link: https://www.youtube.com/watch?v=pAmaJOZ0MGE

Best,

-Lex