Reporter's Notebook

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Posts Tagged ‘feedback

Better Gear; Better Life

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I posted about a Behringer mixer I bought earlier this year that I thought would meet my needs. When I talked about the smaller Xenyx 502, I was happy with the construction of the box, the clean signal with no noise, and the simplicity. But what I didn’t realize when using an analog mixer (which is slowly going out of fashion it seem in favor of digital mixers), with an analog telephone auto hybrid (digital versions of these are also touted to be better), the problem is feedback. I’m not an engineer, and believe me, I’ve posted to audio websites and harassed engineers in person and over the phone to try to help me thresh this out.

But in a nutshell, the issue is when the audio comes into the auto hybrid, which is a box that turns the telephone signal into something the mixer can hear, and is then fed into the mixer, the 502 didn’t prevent the signal from seeing itself. Somehow, and I don’t know how exactly, the voice coming in collided with the voice going out within the mixer and so, when caller audio passed through the auto hybrid on the way back to the caller’s earpiece, there seemed to be two problems. First, that collision seemed to cause the microphone I’m using to drop so low that the caller couldn’t hear me. Second, because the caller’s incoming audio and the microphone audio were somehow intermingled, when I tried to boost the caller’s audio if it got too low, there would be massive feedback. Likewise if I tried to boost my audio, the microphone was terribly distorted and the audio was garbage. I’m sure part of the problem too was that the 502 allowed me to input my audio only through LINE IN inputs and hear my audio from MAIN OUT outputs.

The Xenyx 802 apparently solves that problem with two different sets of jacks connected by a process. The jacks, FX SEND and STEREO AUX RETURN let me feed the auto hybrid’s input to the former and output the caller’s audio through the latter. The process in-between is something called “Mix Minus”. This, apparently, returns all of the sound the mixer hears to the auto hybrid except the caller audio. These advancements, something the 502 didn’t have, eliminated feedback and separated the microphone and the telephone line. I now have full control over the caller audio and can boost it without feedback. Likewise, I can increase microphone levels if I need to and now, the caller can hear me with no problem.

This problem, as readers of my blog know, has dogged me for months. It now seems solved. I have to say how much I appreciate all of the people who listened to my problems. In the end though, I was the one who understood the uniqueness of the problem and I was the one who had to research how to fix it. That isn’t to say nobody else helped, but it wasn’t their problem and bottom line, they had their own stuff. That’s the thing about fixing problems. In the end, they’re ultimately yours to abandon, live with or solve. Of course, for anybody else with this problem, I’m glad to gallop to the rescue.

Written by Interviewer

September 18, 2013 at 21:36