Re: Studio mic and external audio chain ?

Jim Szalajeski

I have been around a long time and what I notice is that many HF operators take little care to insure they are not splattering their audio all up and down the band.  You do not need very much compression at all to have a good punch to your signal.  But too much again and the room background noise starts to be picked up. 

The best way to work on your mic gain and compression is to take a second radio and use it to listen to yourself.  Pull the antenna off of it so your not over loading it.  Use a set of headphones and listen to your signal. 

The first step I use is to work on the audio gain.  As you move away from the mic, you should start to notice your voice level go down.  I use a distance of around one foot where my voice drops off significantly. This way the room background noise is not going to be very loud at all.  If You anything like me, I have a number of public safety radios going as well as several ham radios on the local repeaters.  The more you can keep that stuff off your HF radio, the better your signal will sound. 

As for the compression goes, that is a sore issue with many people.  The compressor is designed to keep your audio at about the same level.  If you talk softly or loud, the compressor is like an auto audio gain control.  It tries to keep your voice at the same level all the same. 

Is the compressor starting to sound like an audio gain control?  If you said yes, your right.  So now maybe your stating to see the confusion popping it's head up over how to set the mic audio and set the compression. 

My best comment is to turn off the compression setting and start with the mic gain.  Once you have the mic gain set, then you can turn up the compression just a little.  You really don't need much. 

Now you should be ready to try an on air contact and see what your contact says about how your audio now sounds.  Using a friend that you have regularly talked with is a good place to start.  See what they say about your audio now.  Bet they like it much better.  The other users of the band will like you also because your not being heard to splatter 30 Khz away or more. 

Try it and see how much better your signal sounds. 


On Sunday, October 6, 2019, 1:11:57 AM CDT, Charles & Sandra Cohen via Groups.Io <cpcohen1945@...> wrote:


I haven't played with the IC-7000, but I _have_ played with my Yaesu FT-450, using both a Shure SM58 dynamic mic, and a Behringer C-2 small-diaphragm condenser.

I ran the C-2 through a Behringer VX2496 "vocal chain" (no longer produced) -- preamp / expander / compressor / EQ /.  I ran the Shure SM58 straight into the FT-450.

I set up the VX2496 for "contest audio" -- reduced the bass, put on a heavy "presence peak", used a lot of compression.  Using the C-2 condenser mic (which has flat response down to 50 Hz or so) It sounded much like a contest rig with a Heil HC-4 mic.  

The FT-450 has fairly narrow transmit bandwidth, and a built-in 3-band "transmit equalizer" (with a "low-cut / high boost" setting):

Running the Shure SM58 straight into the FT-450, using the FT-450's built-in TX EQ and compressor, gave almost the same effect, and equal average transmitted power.  That became my standard setup.  

The SM58 is an "industry-standard" mic (in the music industry) for good reasons:

. . . It has decent "pop-and-hiss" rejection (if you want it "pop-proof", put a $5 foam ball on it)

. . . It seems to suit a lot of voices, and you can control bass boost by moving toward, or away from, the mic;

. . . It's physically tough, and lasts forever;

. . . It's not very expensive (around $100 US).

The IC-7000 lets you vary the TX bandwidth and center frequency.  My experience with those controls (using the stock mic) is that you can increase the "low-cut" TX frequency (reducing the bass) without distorting.  But you _should not_ reduce the "high-cut" frequency -- leave it above 3 kHz.

Before you play, read Heil Sound's "All Things ICOM" web page.  You'll find what you need to know about blocking capacitors, and using the "COMP" feature to give enough mic gain to let you use a dynamic mic like the SM58 or Heil PR-781, on the IC-7000.

Have fun --

.    Charles / VA7CPC

PS -- a friend of mine will be trying some outboard audio gear on his Icom rigs, but not an IC-7000.

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