Daisy Chaining Jackboxes
For AV professionals, the term “daisy-chaining” usually refers to connecting a string of speakers (one or more) to a master speaker in order to project sound to larger audiences. The same concept of stringing consecutive jackboxes together can also be used in a classroom and library for learning centers.
Like the wireless PA version of daisy-chaining, a jackbox provides a simple way of routing audio to a number of headphone-wearing listeners (jackboxes have between 4 and 10 outlets and are available in mono or stereo versions with a choice of 3.5mm, 1/4″ and even USB plugs). But what if the size of the group who’ll be listening exceeds the number of outlets on the jackbox? A simple and cost-effective solution is to plug in a secondary jackbox so you’re daisy-chaining from the first one. This would almost double the number of potential listeners (since the second jackbox plugs into the first one, the number of listeners will be one less than double the amount if you’re using two jackboxes).
Is there a limit to how many jackboxes can be strung together? There are functional and practical limits. Functionally, since the audio is traveling through (non-powered) jackboxes, there will be an eventual degradation of the signal power, so two should be a working limit although three might be possible. If you have a couple of available jackboxes, you could hook them up to listen for when the signal begins to erode.
Practically though, since most classes have between twenty and forty students, chances are good that if you have at least twenty students listening to the same audio through headphones (connected to two 10-position jackboxes), it might make more sense to disconnect the jackboxes and play the audio out loud for everyone’s benefit.
Read an earlier blog about jackboxes.
