Crank It Up

LED vu meterMost every audio mixer has at least one set of level meters, similar to the one shown at the left. It shows the level of the audio leaving the mixer (going to a recorder or PA system). Many will also have “clip” or “overload” or “peak” lights at key inputs (shown on the right).cliplit

These meters aren’t just an entertaining display to look at. They are a very important part of your mixer’s operation and setup. Going through the steps is not difficult. But if you don’t set up the mixer correctly, you may have noisy audio, and other problems.

Let me explain…

The “clip” indicators are usually seen on MIC inputs. The typical setup procedure is to adjust the input gain trim control (near the mic connector) while speaking into the mic. When the “clip” indicator lights, reduce the gain setting just a bit, until the “clip” no longer lights. (A dynamic mic may not clip even with the gain at maximum. This is not unusual… dynamic mics need a lot of gain.) Now the gain on that channel is properly set for that mic. Repeat for all mics. Once set, the gain trimmer control will not need to be re-adjusted while the same mic is connected.

The input level must be correct for each mixer channel. The MIC channels have individual gain controls. The LINE LEVEL channels may have a switch to select between high and low levels. But most depend on the source device — CD player, etc — to have its own output level control.
UNITYHave another look at the LEVEL controls at the bottom of the mixer. Each one has a “default” position (or UNITY GAIN), usually marked with a line or some graphic to indicate the favored position. Depending on the manufacturer, the unity gain position may be 1/2 to 3/4 of the travel of the control.

When all of the input levels have been properly set, mixing becomes much simpler.

Try it… set all the LEVEL controls at their unity gain spot. (Do the same for the mixer’s MAIN OUT level control.) Then speak into the mics one at a time, and play audio from the other devices. The mixer’s main output meters should show activity lighting up all of the green, and bouncing up into the yellow. (This is the time to make adjustments to the output controls of the LINE LEVEL devices.) Now, simply starting with the level controls at their UNITY setting will give a reasonable mix. Only minor adjustments may be needed depending on the audio sources. (You may need to adjust the MAIN OUT level up or down a bit to get the ideal meter activity. That’s OK… you’ll only do it once.)

What is shown on the meter is what is being sent to your recording device, through the USB connection (if available), and to remote callers that may be connected via hybrid or codec.

A quick glance at the meters every now and then will let you know that everything is running along smoothly.

Many users will turn the knobs just enough to hear something in their headphones, and call it “good enough”. But that level is usually too low to even show up on the meters. Noisy recordings and poor interaction with 2-way conversations (phone or codec) will result.

Light those lights! (except the red ones) Crank it up!


So Many Cables

mic cable smallGood cables are critical to good sound. The cables are responsible for transporting the sound energy from one device to another, often over fairly long distances.

Be sure to use a cable that’s appropriate for the task. I don’t mean that you should buy cables that make exaggerated claims about their superiority due to the amount of “pixie dust per cubic centimeter”.

Most any well-made cable will deliver professional-quality audio. The differences are mostly in the mechanical construction of the cable:

- A cable that will be dragged across the floor, or be stepped on frequently, should have a rugged outer surface and strong connectors to survive the abuse. See ProCo’s EXM and Hosa’s CMK series.

- A cable that will simply be connected to a desktop mixer, and may not be touched again for many months, does not need to be overly elaborate. SMM and CSS are popular examples.

- Long microphone cables may pick up electrical noise along their length. A cable with “quad” wiring is more immune to electrical noise. The AQ “Ameriquad” line is excellent.

- Cables for lapel mics, or headworn mics, should be as small, flexible, and durable as possible. Mogami makes several lines of bulk cable for this purpose. (Mogami bulk cables are not shown on our website, but are available… just ask.)

Don’t buy pixie dust. Buy good engineering.


Who Ya Gonna Call?

smallmixerThe low-cost mixers used for recording music have so many knobs and buttons, most any of them should work for radio, right?

Well… no. It’s not just the number of controls that matter. It’s more about the suitability of those controls.

For example:
– Many general-purpose mixers don’t have powerful enough microphone preamps to work properly with the dynamic mics that we prefer in radio.
– In radio, we generally prefer to have no EQ controls on the mixer. EQ should be “baked in” during production. The on-air person should not have the opportunity to “mess it up”.
– Some small mixers have compressors on every mic channel. That’s nice, but those compressors are better suited for singing… not speaking. They generally don’t sound right on the radio.
– The reverbs, echos, and other “effects” don’t add any benefit to a radio presentation.
– While some general-purpose mixers can be set up to work with a telephone interface, mis-adjustment is easy.
– The mixer’s built-in USB connection commonly directs computer playback only to the monitor speakers and headphones. But for broadcast use, we need to route the sound into an input channel. Only a few mixers can be configured that way.
– The announcer often needs to hear the sound from an assistant (whether on the phone or on a mic) only in his headphone, without that assistant’s voice going on the air. Many small mixers can’t do this.

From these few examples, you can see that, even though a low-cost mixer may have a lot of controls, most of them are not appropriate for broadcast. And mis-adjusting them can cause headaches. Better to use a mixer that’s made specifically for broadcast.

A music dealer may not understand all the non-typical things we need to have in place to make a radio broadcast happen. It’s best to talk to someone that’s been there, and knows what capabilities you need to have available.

Most of the salespeople at BSW have spent many years (or decades) in broadcast, either in front of the mic or behind the equipment racks. We know what needs to be done, and we know what gear it will take to make it happen.

We know which mics to use, which mixers work well with them, which ones do USB right, and how to route signals from most anywhere to most anywhere else.

(We know a few other things, too.)

Give us a call. We’ll help identify which items will get your program working just the way you want it to.



Make ‘em go “WOW!”

WOW burstTo create “WOW”, you need to keep the audio quality at its best all the way through your station, with no shortcuts.

That is, don’t play mp3 files or anything that’s been overly processed. Play only uncompressed linear audio direct from the CD. If you use a satellite music service, be sure the audio is high quality. (You would be surprised at the “garbage” some stations are re-transmitting.) Don’t take a low-quality internet stream from your program provider, either.

When you record audio to your PC or portable recorder, use .wav or .PCM (linear file with absolutely no data compression). Back when hard disk space was expensive, it made some sense to record compressed .mp3 files. But these days data storage space is cheap. Don’t record as .mp3 or any other compressed data format. (You won’t get “WOW” if you are playing .mp3 audio… trust me.)

Be consistent with the microphones in your studio. For example, if you use RE20 in the on-air studio, use the same model in the Production Room too. This maintains a consistency to the “flavor” of the station voices, no matter where they are doing their work.

Use mic processors (286S, 528E, M1 are among the most popular). Don’t rely on the program processor to manage the mic sound… it needs to be optimized for the overall audio program. Process the mics separately and individually, and make sure all the mic processors are adjusted to sound the same. Ideally, the listener should never hear the voice distorting, going loud and soft, or so “boomy” as to be unclear. When properly adjusted, the sound from the mics should be consistently loud, without that “gritty” sound so common on over-processed stations.

The telephone hybrid you use can make a significant difference, especially if phone calls are central to your program. Several models have automatic caller leveling, which keeps the caller’s voice consistently loud. And the HX1 has its own multi-band processor built in, which optimizes the highs and lows (yes, it adds a bit of “WOW” even to a phone call.) Very impressive sound, and easy to use.

Another part of “WOW” is the program processing.  It used to be that you could be “loud” or “clean”, but not both at the same time.  With the latest digital processing techniques, multi-band compression and multi-band limiting, it’s much easier to maintain competitive loudness, while still having a “relaxed and open” feeling to the audio. The more bands of compression, and the more bands of limiting you use, the less damage will be done to the sound. A popular mid-priced unit is Wheatstone VP-8IP. The 4 bands of AGC and 8 bands of limiting allow it to sound unusually clean, clear and “open” while being louder than anything else in its price range. For those of you engaged in all-out loudness wars, some of the $10K+ units go up to 31 bands of limiting.

And don’t forget the most important part… your on-air talent needs to project “WOW” every time the mic is on. And the programming, whether it’s music or talk, needs to be so much more interesting than the competitors, that listeners would turn to your station even if the other “WOW” components weren’t there. But once you’ve hooked them, the high-quality presentation and high-quality sound will keep them stuck to your place.



Keep Your Remote Broadcasts Sounding Their Best

com_accesstie_commanderg3fieldBroadband IP codecs from leading manufacturers like Comrex and Tieline, have made wireless remote broadcasts much easier and more reliable.

The most common method of using wireless IP to manage a remote broadcast is to use a rack-mounted codec at the station, and a portable codec (often with a built-in mixer) at the remote location. The remote codec has circuitry inside that makes it behave like a regular  “smartphone”, complete with its own SIM card and phone number. The codec uses this circuitry to make a broadband internet connection, which then links to the codec back at the station.

Apps exist that allow you to use an ordinary smartphone, and make the same broadband IP connection to a Comrex or Tieline codec. Tieline offers their REPORT-IT software. Comrex mentions (but does not sell) several apps.

Using these apps, any smartphone can be used to do a quick “drop-in” news report, using the phone’s built-in mic. The sound will be significantly better than an ordinary cell call, but the phone’s mic is not fully “broadcast quality”. You wouldn’t want to do a long remote, or a ball game, with just the phone’s mic.

tieline_micadapter_1To address this situation, Tieline developed the MIC-ADAPTER, which allows connection of a professional mic and headphone. But it works only with iphone 4 and 4S.

I hear you ask “why can’t I just get an adapter cable, and connect a regular handheld reporter’s mic, and headphones to my phone?” Good question. Here’s the answer:
– most handheld “reporter’s mics” are dynamic, which requires much more preamp gain than is provided by the phone. It won’t be nearly loud enough. And by the time the guys back at the station turn up the volume enough to hear you, the background noise will be offensive.

OK, so why not use a handheld condensor mic?
– if the condensor requires phantom power to operate (most do), it will need between 12 and 48 volts, which the phone can’t supply.

A few condensor mics are available that have their own internal battery supply. Those would work, except for the usual reasons we don’t use condensor mics for field reporting:
– easy to overload when yelling your way through a sports broadcast.
– if used in wet weather, the mic can fail completely (until dried out for several hours.)

I have been testing several headsets, looking for one that will give professional results when connected directly to a smartphone or ipad. All those tested thus far have severely limited frequency response on the microphone elements. Little or no fullness to the lower registers of the voice. The search goes on…

So, as it stands right now, for a full remote broadcast, use a remote codec system made for this purpose. For occasional quick reports, a smartphone’s internal mic will do OK.

[ -- DEAD AIR -- ]

please stand byIn broadcasting, silence is NOT golden. If your signal is not working… for any reason… the listener will just click on to the next station. And it may be a challenge to bring them back to your place once the problem is fixed.

You need a plan to keep your audio running, no matter what.

If the failure is a headphone, microphone or music player, you likely have another one (maybe in your remote interview kit) that you can substitute temporarily. But what do you plan to do when the dreaded “I spilled coffee into the mixing board” call comes in? Or, even worse… “the link to the transmitter is down.”

Any station that intends to offer “live” program material every day really needs a fully-capable spare studio to move into if anything happens to take the “main room” out of service. The spare studio will be used most of the time as a production room, where interviews and spots are constructed and edited. It may have a slightly less-complex mixer, but there should be enough capability to get the basics done… put a live phone call on the air, have enough mics and headphone capability for a live guest or two. In some cases, your remote broadcast kit may be capable enough. (You can do a lot with a JK RemoteMix , a smartphone, and a couple of headset mics.)

For the transmitter site, consider a silence detector that will switch to a continuously-playing loop of one full broadcast day, including sponsors. If the main audio goes down, the replacement audio will have the same messages at the same times for the same sponsors. If the sponsor’s message got through, the pain is less.

Be creative! Keep those listeners tuned to your station… not somewhere else.

Control Yourself… and that other guy, too.

528EFront_300Microphone processing is one of those things that most broadcasters know about, but it seems mysterious to those new to the industry.

When we say “mic processing”, we don’t mean that it will change the voice to suddenly sound like Darth Vader. We are concerned with controlling the overall level of the voice, minimizing background noises, and a few other things.

In the course of an ordinary conversation, your voice may go from very quiet (almost a whisper) to extremely loud (when you get really excited about the point you are making). The problem is, the person listening to your program is not usually able to deal with the full range between soft and loud. The listener is usually in a car or office, with other distracting noises around them. In order to hear you at all, your voice needs to be maintained at a consistent level, and not allowed to drop very far from that level.

The mic processor’s job is to ensure that, when you are speaking loudly, your voice does not exceed the level that the equipment is designed to pass. This prevents a distorted sound. At the same time, the processor brings the quieter parts up to the same level as the loud parts, so when you speak softly, your words are still heard clearly.

The action I just described is compression. But a mic processor does more than merely compression.

When you stop speaking, or take a breath, the background noise of the studio would be clearly heard. A mic processor has a “downward expander” system that effectively reduces the background noise during even brief pauses.

It’s this combination of compression and downward expansion that creates the “bigger than life” sound of a polished radio program. Most mic processors have additional functions that add to the “finished” sound of the voice talent…

Some people have unusually loud “sss” sounds. An ordinary compressor over-reacts to a strong “sss” sound by reducing the level of the voice farther than needed, to the point that the next few words may be too soft to hear. A mic processor treats “sss” sounds separately, with a system called a “de-esser”. It specifically watches for overly loud “sss” sounds, and holds them to a normal level, so the main compressor  circuit can more effectively control the overall sound.

Equalization changes the tonal balance of the voice, by altering the amount of high or low frequencies that are heard. Some mic processors have elaborate equalization sections, while others are more basic. It’s in this section that many users go too far, and cause more harm to the sound than if EQ had not been used at all. If EQ is called for, the amount of adjustment should be minimal for the best results.

Consider this: the microphone you selected for your studio was chosen because of its sound characteristics. You may have heard another one that sounded almost the same, but this one sounded “just right”. If the mic was carefully determined to be “just right”, then why are you anxious to change its sound by altering the equalization settings on the mic processor?

The final process found in many units is the “symmetry control” or “phase scrambler.” On certain (mostly male) voices, a slight increase in loudness can be gained by engaging this process. If the talent is listening to his “processed” voice, the “phase scrambled” effect may be undesirable, and he may elect to not use it. This process is most often used in traditional over-the-air broadcasting. It has little benefit on a non-transmitted format.

So, using a mic processor will ensure that your talent is heard at a consistent level, whether he is shouting or whispering. And the room’s background noise will be reduced.

It’s the first “upgrade” to consider for your new studio.

The most popular mic processors are: Symetrix 528E, dbx 286S, Vorsis M-1, AirTools 2X,  and Aphex Channel.


Get every new post delivered to your Inbox.