Instructables
Picture of Audio Problems
Anyone who has ever used technology knows one thing: IT FAILS.  A LOT.  This is more true in the realm of professional audio than in any computer or circuit I have ever worked with.  In this instructable, I hope to teach you some concepts that will help you run audio with as little problems as possible.  Please note that this instructable only covers VERY BASIC problems you can run into with a sound system.  If there is any problem that you would like me to cover, please leave me a comment or contact me.

You can also see my other instructables on sound:
How Sound Works
The Concept Of Sound Pressure (SPL)

Before we go into how to fix problems there are a few things that I strongly believe about sound that you should know.
1.  You can't program sound.
2.  If it can fail, it will.  If there is no way possible for it to fail... then it sill might.
3.  You should know your equipment better than the back of your hand before attempting to troubleshoot.
With that in mind, let's talk audio!
 
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Step 1: Feedback

Picture of Feedback
Feedback is a howling noise.  It can either be on the high end (very high pitched) or low end (very low pitched).  Feedback is caused when a mic is too loud and is able to "hear itself" in the speaker.  This starts what is called a feedback loop.  Tiny  imperfections in the mic are amplified, and looped over and over again, causing the howling effect.

You can fix feedback by turning the volume on the mic down (the fader on the sound board), turning the gain down (usually the knob at the top), moving the mic behind the speakers, or turning the main fader(s) down.  The preferred way to fix it is to turn the gain down, or the main fader(s).  (The main faders affect your gain structure.)  If you don't know what mic the feedback is coming from, you should use the main fader(s).  To prevent feedback keep your volume and/or gain as low as possible.
I have enjoyed reading all your instructables on sound, I look forward to future 'ibles - I like that they are short and concise.
thegeeke (author)  bricabracwizard2 years ago
I'm glad you enjoyed them! Is there anything specific that you would like me to cover on sound? I'm considering posting a few on some more hands-on topics such as how to run a analog sound board, microphone placement, and things like that, but I am always looking for feedback as to what people are looking for. :)

Thanks again!
Being a 'layman' I'm not sure how to word correctly the things I would be interested in but all you have listed I would definitely like to learn about. Some things that bother me is interference like hum, picking up radio broadcasts, using over 6 radio mics and how to balance sound in a hall and do you have preferred equipment for a travelling show. As you are so familiar with lighting what would be a great configuration for a travelling show, like DMX, spots, colours - ...... well you did ask! Seriously though, I'm sure whatever you write about will be very informative.
thegeeke (author)  bricabracwizard2 years ago
Thanks for the suggestions... I will probably add hum to this instructable, and I will be starting a few more instructables very soon! :) After I do a few more about sound, I will start some on lighting. Thanks again!
S_darnell3 years ago
This was the lightbulb graphic that didi it for me! I recently spent a week in the hospital for a knee replacement. Like any good geek I upgraded all my self-entertainment tech prior since I knew I would be bored silly and also unable to crawl around tweaking my environment during recovery. Imagine my horror when I found my new a/v system had an unalterable lisp when using an a/v feed from a cable box in another part of the house. (we live in saudi Arabia..so every trick in the book was used to get a multi input system..the shack is my friend). Finally I googled up "audio problems" which took me to your tutorial. As soon as I read the clipping section I limped out to look at the volumn setting on the cable box. Sure enough, while I was away someone had turned the volume full up. 2 weeks of frustration solved in an instant! Thank you! Sue
thegeeke (author)  S_darnell3 years ago
I'm glad to hear that it helped! :)