Q: I was programming a new DSP unit and everything was working fine until I compiled the file and now I have no output. The input meters on the front faceplate are still lighting up and I have several places in the signal chain where signal present LEDs indicate that the signal path is intact.

A: The answer to this will vary depending on the equipment manufacturer. Every manufacturer’s DSP will have it’s own unique quirks. What you are most likely experiencing is a built in safety feature where the unit will mute it’s outputs after compiling. Others will mute their outputs in the event of a power failure. I would begin your investigation by opening the window for your outputs to see if they are muted. If the outputs are NOT muted then open each “device” in the signal chain to check for mute switches or virtual connections that were missed. It is easy to overlook incomplete connections especially when working with a system where you are performing a lot of switching, mixing and presets as opposed to simply using the DSP for just dynamics. The reason behind the muted outputs is to prevent costly mistakes after you have made changes to the DSP parameters. Fore example when you meant to enter a +2db gain increase for the horn in your bi-amped cabinet you inadvertently entered +22db. Or if you mistakenly routed low frequency information to your horn with that massive 1000w per channel amp behind it that was intended for your low frequency drivers.