A recent question on Twitter prompted me to write this post about a subtle difference between the Behringer 1204USB mixer and the X1204USB mixer. The number system is confusing since many people think the "X" is an abbreviation for "Xenyx", but it's not. The 1204USB and the X1204USB are very different.
While the X1204USB includes digital effects that the 1204USB does not, the effects are not the most relevant benefit. (We NEVER use effects.) Both mixers include two auxillary sends per channel. Aux sends are typically used to create mix-minux feeds for Skype, Google Voice, Google+ Hangouts, TalkShoe, Paltalk, and other online interactive sites and services. With the aux sends on the 1204, one is pre-fader and one is post-fader. With the X1204, both can be post-fader. Why do you care?
With a pre-fader aux send, the audio from a channel is sent to the aux output even if the channel fader is down. With a post-fader aux send, when the channel fader is down, there is no output from that channel to the aux output. So, if you're using a pre-fader aux send for a Skype mix-minus feed, if you lower your mic fader to cough, the Skype caller will hear the cough. If you're using a post-fader aux send, when you lower the channel fader on the mic, the aux send from that channel is muted, and the caller does not hear you.
This seemingly subtle difference between the 1204USB and the X1204USB totally justifies the cost difference. The pre-fader aux send is usable, but the post-fader aux send is sweet. There are other differences, but you can read about those on the Behringer website.
NOTE: If Behringer made both aux sends on the 1204USB switchable or permanently post-fader, I'd recommend it over the X1204USB.
Via Mike Phillips