Production Musings

The Question I Didn’t Think Of

// February 3rd, 2009 // Audio, Thoughts

Last week a friend from another local church asked me for advice for splitting several of their audio signals and asked for my thoughts on the best way to go about this.  After a few more questions, I suggested using a transformer isolated splitter and used the old analogy of splitting a water hose.  If you and I want to wash our cars at the same time but only have one water hose, we could add a simple “Y” split in the hose.  After all, it’s cheap, quick, and easy!  The problem, however, arises when you take the nozzle of one side of the split and begin washing your car.  All goes well for a while, that is, until I take the other nozzle and begin washing mine.  Now we have a water pressure problem!

The same thing happens with audio when we use a simple “Y” splitter.  A transformer isolator solves this problem by isolating both side of the split signal.  Now a FOH tech can adjust his gain structure without affecting the signal going to, say, an audio/video recording tech, monitor tech, etc.

In my friends case, they wanted to split the signal coming to the FOH console to the console and also to their Aviom system.  We settled on the Whirlwind MLTSP1x2 splitter for the job.

A few days pass.

I get a call.  “Drew, it doesn’t seem to be working right.  The band can’t hear the signal.”  Now, they have a wonderful FOH guy named Derrick who spends a great deal of time and energy supporting the band and teaching team at their church.  So, after hanging out with Derrick and looking at the problem this past Saturday afternoon, we both agreed that the splitter was connected correctly (and I’ll add that it was done beautifully).  And then I noticed the problem, and the the error I had made.  They were using the Aviom AN-16/I.

It’s designed for Line Level inputs.  We were sending it Mic level inputs.  Totally different input sensitivities!  What would be nice to have in this case, if the funds were available, would be the Aviom AN-16/I-M Input Module that’s made to receive both Line Level and Mic Level inputs.

So, my friends, be careful before giving advice. In my case, it came down to one question I didn’t ask, “What are we splitting into?” Really, it’s a pretty small issue. I mean it comes down to a difference of only, a volt or so, but that small difference has huge implications when it comes to technical support!