Wow. Having a mixer makes all the difference in the world for our little radio stations.
Up until last week I was doing all of my audio via a computer. All music, shows, commercials, PSAs, promos, weather reports, etc, were all recorded, stored and played as computer audio WAVE or MP3 files. All audio was sent to my transmitter via the soundcard's line out.
This week I purchased a Behringer 10 channel mixer to add to my station. Within minutes I had the ability to grab the mic and go live. After a trip to Radio Shack to grab a handful of cables and audio connectors, I had connected a variety of inputs. Microphone, PC, MP3 player, and even a telephone. Yes, now with a telephone that has a headphone jack style headset connector I am able to wire things up so that I can make telephone calls with the phone audio going through the mixer. The caller can hear what is playing or being spoken through the mic and whatever they say goes on the air. I have full control over their level and EQ. Using the mixer's FX send, I am able to separate the phone's input and output signals so there is no echo caused by sending the callers signal back down the phone.
Wow. Having a mixer makes all the difference in the world for our little radio stations.
Up until last week I was doing all of my audio via a computer. All music, shows, commercials, PSAs, promos, weather reports, etc, were all recorded, stored and played as computer audio WAVE or MP3 files. All audio was sent to my transmitter via the soundcard's line out.
This week I purchased a Behringer 10 channel mixer to add to my station. Within minutes I had the ability to grab the mic and go live. After a trip to Radio Shack to grab a handful of cables and audio connectors, I had connected a variety of inputs. Microphone, PC, MP3 player, and even a telephone. Yes, now with a telephone that has a headphone jack style headset connector I am able to wire things up so that I can make telephone calls with the phone audio going through the mixer. The caller can hear what is playing or being spoken through the mic and whatever they say goes on the air. I have full control over their level and EQ. Using the mixer's FX send, I am able to separate the phone's input and output signals so there is no echo caused by sending the callers signal back down the phone.
One cool thing I can do with the phone connection is to be able to listen to a program while far away from my coverage area via my cellphone. I rebroadcast some live netstreams, and if, for example, I need to go to the grocery store where I can't hear my signal but I dont want to miss the show, I can dial up my cellphone, turn down the input level on the mixer, mute off the cellphone, plug in a headset and listen to the program via cellphone as if it's a portable radio
Another plus is that I can now easily and cleanly netstream the audio by taking it off the mixer and then back into another soundcard. This gives me a much cleaner sound than taking the sound off the air from a monitor radio.
This mixer is available in 4, 8, 10, and 12 channel models. My 10 channel mixer was only $60 at Musician's Friend. It fits well on my small desk and has super quiet, easy to use controls.
For any internet or Part 15 broadcaster who wants to take his or her studio to the next level, I can't recommend enough the addition of a quality mixer.
Regards,
Scott
Robin Valley Community Radio, Omaha, NE
[email protected]
http://robinvalley.org/
When putting together my station, matching levels from the automation to processor to transmitter and combining stereo into mono for AM became a small challenge.
The first challenge, getting the best quality audio out of the computer, was accomplished by experimenting with audio processor plugin settings in the software. Once these settings were discovered, and set for the desired sound (including EQ), the soundcard output was set for the optimum level (best signal to noise ratio) of the "on air" mixer; a Mackie VLZ 1402 Pro with a Broadcast Tools CC IIA studio controller. This give me total control over the studio monitor, studio on-air light and the host and guest microphones.
Next, combining left and right channels to produce a monoaural signal that is not distorted or out of phase to feed the Innovonics 222 final processor, Trango microwave and AM1000 transmitters. This is accomplished with a passive network of 22k resistors in a small p-box. The output on the mixer is used to provide the proper audio level needed by the audio chain to the AM transmitters.
The FM transmitter is fed by an independent output (virtual DA) on the mixer dedicated to the FM transmitter. The internet live audio stream is fed by one of the sound buses in the automation computer. The automation computer uses Spacial Audio SAM3/mp3pro, the Music1 programming scheduler streamed to a variety of server platforms for broadcasting.
At times, my stations use as many as three mixers for the purpose of level matching and audio distibution control. They range from a little Radio Shack job to a Behringer UB 1002 6-channel mixer to the Mackie on-air mixer/control system already mentioned.
This kind of flexibility helps the station product be as flexible as the "big boys" and with equal or better quality. One caveat: to set up a system like this takes some test equipment, patience and a really good ear.
Marshall Johnson, Sr.
Rhema Radio - The Word In Worship
http://www.rhemaradio.org
Scott,
Could you please provide details as to the specific equipment and configuration you use for your on-air phone system? Maybe a diagram or schematic would help me understand how you accomplished the mix-minus function.
Anyway, It really intrigues me how you do it without a phone hybrid.
Marshall Johnson, Sr.
Rhema Radio - The Word In Worship
http://www.rhemaradio.org
Scott,
Could you please provide details as to the specific equipment and configuration you use for your on-air phone system? Maybe a diagram or schematic would help me understand how you accomplished the mix-minus function.
Hi Marshall:
Here's my equipment:
- BEHRINGER UB1002 EURORACK MIXER - $60 at Amazon.com
- Durabrand PH3235 - $10 at Walmart
The Durabrand telephone is special because it uses a common 1/4 in. 3-conductor TRS headphone jack for it's headset. A common headphone to RCA cable makes it easy to connect this cheap phone to the mixer.
After a long delay, I've created a block diagram showing the basic idea behind this mixer-to-phone setup.
What makes this work is that I use the mixer to feed all of the audio, minus the output of the phone, back to the phone. This prevents echo and feedback.
Different mixers will do this different ways, but the Behringer has a knob on each channel for "FX Send". Then there's a master FX send that governs the total output to FX. I turn up each channel for everything I want to send back to the phone. The output of the FX send goes to the phone. I don't send the normal audio destined for the air to the phone.
Anyone trying this should test it out well in advance of going on the air. It's quite possible to create configurations where the caller can't hear what listeners on the air hear, and cases where the listeners don't hear what the caller hears.
I'm sure there are other ways to do this with multiple callers and also perhaps a way to chat with the listener using the mic without listeners hearing.
I can take some photos of my mixer and phone if anyone is interested.
Regards,
Scott
Scott,
Thank you for the time you spent putting the diagram and everything together. It all makes perfect sense. I have the exact mixer you do for talk studio production. I'll get a phone and get 'er done.
Marshall Johnson, Sr.
Rhema Radio - The Word In Worship
http://www.rhemaradio.org
One other thing I should mention is that I heard a loud hum when I first made this configuration. I installed the Radio Shack ground loop isolator between the phone and the mixer and that seems to have alleviated the hum.
Regards,
Scott
Robin Valley Community Radio
Omaha, Nebraska
AM 1690
http://robinvalley.org/
Scott,
Thank you again for the great input info. I just did a search on the ground loop isolator. When going from unbalanced to balanced audio all the time with some of the audio gear we all use, this little device could end up being a real life saver. Thank you again.
BTW, for anyone wondering what the Radio Shack product number is: 270-054.
Marshall Johnson, Sr.
Rhema Radio - The Word In Worship
http://www.rhemaradio.org