When words count
Jul 1, 2002 12:00 PM, By Tom Atkins
Whether it's sports, news or general talk, all that jabber presents some interesting challenges to the engineer responsible for maintaining a good and intelligible sound. Some of the more common problems have easily obtainable solutions in the talk radio venue. A station's sound is its signature, and a format based on the most versatile instrument � the human voice � presents its own challenges to maintain the quality sound with a variety of voices.
The first component of the signal chain is the microphone. This single piece of equipment can make the most difference in obtaining a quality sound. One common problem is that the more microphones that are open in a room, the greater the chance for unwanted sound reflections from walls, windows, tables and chairs. When combined, these reflections create a hollow sound that sounds like the program is being produced from the bottom of a well. This problem is amplified by guests that speak softly and sit too far from the mic. Acoustic treatment can help reduce the unwanted reflections, but this approach doesn't eliminate the problem. In reality, a perfect acoustic room is not practical or economically feasible. Education is the first line of defense for poor mic technique. This is accomplished by having a good cardioid mic, flexible mic booms and well-educated talk show hosts and producers.
A directional microphone can reduce the unwanted reflections by attenuating the sounds coming from of-axis sources. While a tight directional pattern can be used, guests that are not comfortable on a microphone may accidentally move outside the mic's pickup area. The trade-off is to install mics with looser patterns for the guests, followed by instruction of basic mic technique.
Producing a talk show from the road is now a simpler task thanks to POTS and ISDN codecs and their associated data channels. Here, the Carey Brothers of On the House and their guest Dom DeLuise use a Comrex Envoy.
One weapon in reducing the well-like sound is an automatic microphone mixer. The Shure FP410 or SCM810 are two examples. These mixers will attenuate microphones not being used and are highly transparent. When set up properly, the hollow sound is minimized if not completely eliminated. The SCM810 also has a microphone mute connection for each input, which is useful as a cough switch. The mixer is initially set and rarely needs adjustment no matter what type of guest speaker you have. There are rare occasions where guests do not have good mic technique at all. However, even in these circumstances, the resulting audio with the automatic mixer is still far superior than without. Models such as the FP410 are ideal for remote talk shows. Because it uses a noise-adaptive threshold, it takes into account constant room noise and only turns on the microphone spoken into and does not randomly turn on channels with room noise. This also reduces feedback on a PA system used at a remote location.
Microphone processing, when used properly, can help achieve a good overall sound. We tend to use one compressor/equalizer combination for all the microphones instead of the traditional one processor per microphone method. A sub-mix of the microphones is passed through the processor. With an automatic mic mixer, the processor can be placed directly on its output. Depending on a station's configuration, it may be possible to route the mics into their own mix bus and process through a patch point or via a return feed. This sounds like a long path for the audio to travel but the results will prove to be satisfactory. When using multiple microphone processors, particularly in a small space, the unused microphones can increase the gain of the unwanted, indirect sound. With multiple open mics, this can quickly result in the hollow sound I mentioned earlier. Setting a gate or expansion threshold on the processor can reduce or eliminate this, but it may need to be set at a level that while high enough to eliminate the hollow effect, it may produce unwanted effects when the mic is in use. Soft-spoken people sound like their syllables are being clipped. This problem is eliminated with one compressor. There are many good processors on the market, and it will depend on the sound you and the station are trying to achieve as to which one will be right for your station.
Go to the phones
On the other side of the talk-radio conversation is the caller. Although your budget will determine what type of telephone hybrid you use, a top-of-the-line one offers digital signal processing, auto nulling, a gain-controlled caller output, caller equalization, and a variable, full-duplex/half-duplex control. The typical talk format spends about 40 minutes per hour talking with callers. This can easily justify the expense of a quality hybrid. The DSP hybrid can achieve superior send-audio rejection, making the caller audio cleaner without the talk show host audio sounding like it has been phase-shifted and flanged. A consistent caller output level is critical in a good-sounding talk show. If you think of all the different types of phones there are and the paths they take to get to the station, it is easy to see why the caller level can vary so much. If anything, the consistent level of audio from the caller will relieve the show's producer from having to adjust the caller audio for every call. Although equalization controls for the caller audio may seem superfluous, it can help if you have especially noisy lines at your station. Don't bother trying to obtain full-fidelity sound from the caller. Plain old telephone service (POTS) lines are capable of 300Hz to 3kHz bandwidth. You can sometimes get a better response, but the typical response is small. The best you can do is make what you are receiving sound better within the constraints of the telephone company's bandwidth. The ability to adjust the hybrid from full-duplex to half-duplex or anywhere in between can help to reduce unwanted noise from callers while the host is speaking. A variable adjustment allows you to adjust the hybrid's ducking response of the caller's audio from none to all the way. It will also help when callers tend to be argumentative and the host needs to maintain control of the show. The host can maintain a level voice and easily override the caller.
Call screening software provides detailed information about the callers and also supplies a quick communications path between host and producer.
For the best results when conferencing multiple phone calls, use separate hybrids. Most automatic nulling hybrids will adapt to two phone lines when they are paralleled as long as the call director issues a re-nulling command to the hybrid when the second line is combined with the first one. Mashing multiple lines together works, but as more lines are added the overall fidelity becomes worse. If multiple calls are taken at the same time, invest in the proper tools and install multiple hybrids.
It should be second nature for people in the communications business to communicate and communicate well. All too often, communication to the talk show host is sacrificed. This is a crucial part of the talk show equation. First, some form of call screener software should be employed. This can be as simple as two computers linked via the RS232 ports running a terminal emulator, to a full-blown network system running commercially written call-screening software. Call Screener for Windows from Condron Broadcast Engineering and Assistant Producer from Telos Systems are two call-screener programs. The software communicates with the call director to show which lines are on hold, which lines are on-air and which lines are inactive at the moment. Most software packages are made to run on a computer network so the information entered into the system is immediately available to the talk show host. The networking can also be accessed from a remote broadcast using dial-up networking.
The host position should have clear sight lines to the guests, call screener display and the show producer.
The second most important item in communicating with the talk show host is IFB. Simple IFB systems can be constructed using a relay that when activated by the producer, interrupts the audio in one ear of the host's headphones. Commercial studio intercom systems are available. Many audio routers have the ability to function as intercom/IFB systems as well. In our configuration, the producer can talk to the host whether he is in the studio or on a remote. During a remote, the producer sees no operational change once the remote site dials in to the IFB through a POTS line. Another benefit of using an intercom system is that it is based on a cross-point switcher and any one of the 32 intercom stations can talk directly with the host. The newsroom can now alert the host of late-breaking items without leaving the room.
Talk radio is a format with a uniqueness that is all its own. The timely delivery of information is vital, and the communications between show staff, listeners and the host are crucial. Out of the 40 or so minutes of talk each hour, any silence can be deafening. Then it is up to the technical staff to provide the tools so the conversation can continue effortlessly and without interruption. Hopefully these tips and techniques will keep your talk station from experiencing silence for some time to come.
Tom Atkins is director of engineering for Entercom Communications, Buffalo, NY.
Seven steps to better-sounding talk shows
- By doubling the distance from the source to mic you reduce the audio level by one-half.
Keep this in mind when positioning mics and speakers to avoid unwanted sound pickup and comb-filtering effects.
- Avoid giving guests headphones.
Headphones tend to make guests speak more softly and focus on the sound of the voices instead of focusing on what is being said.
- Install a telephone speaker in the talk studio.
The speaker's level can be set to introduce minimal bleed into the open microphones, but still provide a suitable level for guests to hear the callers.
- Provide a separate headphone feed for the host and guests.
If the guests are given headphones, do not provide the same feed that the host receives. The host headphones can be supplied with communications from the show producer without distracting the guests.
- Maintain clean site lines.
If guests are made to feel comfortable, they will speak more freely and openly. Visual clutter from too many mic booms, monitors and other equipment makes them feel closed in.
- Instruct everyone about proper mic technique.
Experienced hosts should already know this, but a refresher usually helps. Don't inundate guests with too much information; give just enough to keep them on mic.
- Solve acoustic problems acoustically.
Mic placement and technique are the first step in good sound. Avoid the trap of installing more electronics to overcome an acoustic problem. For example, instead of filtering the air conditioner rumble it should be eliminated at the source.