GhettoMixer v1
February 14th, 2006 @ 8:29 by NormMonkey
From the electronics department:
If you haven’t read Office Love, then you don’t know that once upon a time I had an office and now I’m in a cubicle pit.
Let me tell you a little bit about my job. I do technical support, which means I talk on the phone a lot. If you’ve ever spent any time talking on a regular handset while trying to use a computer, you know it sucks (if this is you, listen (read?) closely: there’s a better way. Stop punishing yourself).
Marketroids and executives will use speakerphone for this because they don’t mind offending people by putting them on speakerphone, where all those other noises (like typing on a keyboard and scrolling the mouse) are just as annoying to the listener as the talker is. They also have offices, so there’s no yahoos around them also talking on the phone or yelling at each other to mess things up.
I have a phone headset instead. Handsfree operation yet not annoying like speakerphone. It’s a one-earpad (left ear) headset with a boom mic sticking out. It plugs into a little base unit that has volume control and mute buttons and stuff. These things are great for offices or even quiet cubicles.
However, I work in the cubicle pit. I’m surrounded by sales guys who talk on the phone all day. If that isn’t enough, they’re walking back and forth behind and around me, having conversations off to the side, and all the other guys who have offices are yelling across at each other because they can’t be bothered to get up and walk over to actually see each other.
In this sort of environment, the single-earpad headset is no good. One ear is completely un-blocked, and the small earpad on the left ear don’t do much, either. So, when the Powers That Be threw me in the pit, I had to come up with a solution. For awhile, I brought in my good music headphones. These are the sort of headphones that actually sit right over your ear and surround it, blocking external noise. I would wear these overtop of my single-earpad headset. I adjusted the balance on my MP3 player to 10%-Left to offset the imbalance from the earpad. This worked, but it was uncomfortable for any length of time. A better solution was required.
Meet the Ghetto Mixer, v1. GhettoMixer is designed to mix stereo music from a source like an MP3 player or a radio, plus telephone audio, into one headset. I ordered some parts from Digikey, and ordered a computer headset from TigerDirect. The computer headset has big ear-covering external-noise-blocking pads, and a boom mic. Then I got out the soldering iron and built that thing you see above.
GhettoMixer v1 works great for me. Much better than I expected, really (I expected total failure plus sparks and fire). Now I can talk on the phone, listen to music, and drown out all external noises.
GhettoMixer v1 is not ideal, though. The audio from the telephone is only in one ear, not both. I can’t enclose it in a metal box because some grounds are not shared. There’s also a “bug” where when you take the phone off-hook to begin a call, the MP3 audio in the left ear dims. I think this is a feature, though, since you’d want the music to be softer so you can hear the telephone better.
Anyways, I’ve got plans to make GhettoMixer v2. This version will have full isolation and op-amps with volume controls to tweak everything proppa. Telephone audio will be in both ears while still maintaining the stereoness of the MP3 stereo signal.
