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by Poul Kirk* Elan Audio’s “MERLIN” Broadcast Quality Mixer . . . ideal for training or semi-pro applications Australian company Elan Audio has released a studio mixer with broadcast-quality specs, designed for applications such as school/college media training or even community radio station production. Elan have put together a comprehensive guide to the equipment and techniques required for this growing special-interest area. M edia Training is becoming a very important part of general education, as it helps students develop valuable skills in self-expression and the ability to present these to an audience. Many schools and colleges are now installing quite sophisticated media centres to assist with this training. Indeed, some schools and colleges, especially those which have courses in the field, have studios and equipment which allows very professional video and audio production. The presentation skills acquired by students from a Media Training Course will be extremely valuable and useful in a wide variety of future careers, whether that be as a professional radio journalist or presenter, or to simply call in these skills in sales and marketing, corporate management, or even 94  Silicon Chip choose a career where public speaking is essential – such as a politician! Engineering” – somewhat outside the scope of what we are describing here. Audio and video editing vs. music recording The radio broadcast training studio As the saying goes, there are different strokes for different folks. Here we are most interested in the equipment and techniques used for sound recording and more specifically, recording of interviews, audio editing and radio-type presentation. Video recording and editing requires a different set of equipment (although the audio component might share some of the equipment we are looking at here). Recording of music, whether groups or soloists, is yet another specialised area which requires yet another type of equipment and skills. In fact, music recording is best described as “Audio The audio mixer or audio control panel is the central and most important piece of equipment in a radio broadcast studio, whether it is used for professional or community broadcasting or for Media Training Broadcast (on-air) mixers are highly developed and specialised units which at first glance, seem rather simple and basic when compared to, say, a stage or PA (public address) mixer. These usually feature a multitude of control knobs and switches but in fact lack the essential standard features of on-air mixers, making these unsuitable for use in siliconchip.com.au A typical “Merlin” application: a community radio station studio. Typically, dollars are short and so is equipment – but with the equipment shown here (and detailed in this feature) a community radio station can mix it with the big boys! radio broadcasting. Broadcast on-air mixers are designed to be easy to operate, have very good audio performance and benign overload characteristics able to handle accidental excessive audio levels. In fact, they are quite complex devices. Let’s have a look at some of the essential features on on-air mixers: • Silent channel on-off and cue switching • Selectable monitor facility • Automatic monitor mute with microphone on • On-air light relay contacts closing with microphone on • Accurate and easy-to-read audio level metering • Overload and phase fault indicators • Cue loudspeaker and cue level metering • Announcers headphone output with split cue function • Guests headphone output • Manual monitor “dim” or mute • Phase check switches And that’s just the mixer! In a typical siliconchip.com.au small radio broadcast training studio, you will also find: • At least two broadcast quality microphones • A microphone boom arm for presenter’s microphone • A microphone table stand (for guest microphone) • Microphone pop guards (desirable) • Two pairs of good quality headphones • A high quality monitor system (amplifier and loudspeakers) • Two commercial CD players • Audio “spot delivery” equipment That’s the bare bones training studio. Desirable additional equipment might include: • Audio recording equipment • Audio processor • On-Air light Equipment details The Elan Audio “MERLIN” is designed specifically for use as a Media Training Mixer and is the ideal choice for a basic high school or college media training studio or for use in a community radio station, where it can also be used for basic production and outside broadcasts With full broadcast performance specifications, this mixer operates exactly like a full-sized radio broadcast station “on-air” mixer, making the transition from a training studio to a radio station broadcast studio very easy for the student. As a bonus, it’s as easy to set up as a typical hifi system. Broadcast-quality microphones There is no point training with, or broadcasting with, “toy” microphones. The quality of microphones must be acceptable for radio broadcasting and ideally (though not absolutely essential) the presenter and guest microphones should be identical. • Cheapest acceptable types are the AKG D770 II and D880 M types of dynamic microphones. Considerably better (but more expensive) is the AKG C1000 S Electret Condenser Microphone. October 2006  95 advantages, particularly that of being fragile and difficult to handle. Fortunately, it is a vanishing format; unfortunately it is still used by a number of community broadcasters. The rear panel of the “Merlin” mixer is easy to understand, even for the novice trainee. Flash Card Players, such as the EDIROL-R1, and the more Microphone boom arm suggest the following setup for guaranteed professional Marantz PMD 660 or rackAn articulated boom arm is required for good results. mounting PMD 570 can be used in place of the presenter’s microphone to allow easy • Altec Lansing AL-MX 5021 Active Speaker Mini Disk and are less fragile and easier to adjustment and keep the area in front of the System consisting of one subwoofer and handle or manage. mixer clear. A second boom arm for the guest two satellite speakers Although all Flash Card recorders feature microphone would be nice but most choose • Elan Audio RMA-01 monitor amplifier a built-In microphone (or two in the case of a table-mount stand. and one pair of Energy Connoisseur C3 the Edirol), a high-quality external micro• Suitable types include the K&M 23850, bookshelf speakers phone (or in some cases two), will produce and K&M 23855 Table Mounting Flange • Elan Audio RMA-01 monitor amplifier, much better results. Not only that, a radio Athena ASP-4000 subwoofer and 2 W-15 station’s ID or “flag” can be mounted on the Microphone pop guards satellite speakers microphone and if the interviewee is also beMicrophone pop guards are much more ing filmed, offers the chance for totally free Commercial CD Players effective in preventing the troublesome station publicity (it’s very hard for TV stations popping sounds caused by inexperienced We recommend that only commercial or to edit out moving microphone flags!). presenters pronouncing “plosive” words professional CD players be considered. DVD A commercial CD Player can, of course, than “foam rubber socks”. They’re also players can play CD’s but are virtually unmanalso be used for “spot” delivery with the more hygienic than socks which can and ageable, suffering from a very long loading required material burnt onto a CD. do become a health hazard. In fact, socks time and are practically impossible to cue to Best, most convenient and the most comare better used for wind noise reduction in the start of a track. In addition, the audio quality monly used method these days, is a standoutside broadcasts – and most presenters from most is not particularly good. alone personal computer or, as is common these days carry their own, just in case! Moderately-priced hifi CD players are for virtually all commercial broadcasters, a Experienced presenters, trained in correct becoming difficult to obtain. Audio quality is networked, computer-based audio delivery microphone technique, should be able to use generally good but they are also difficult to cue system, loaded with suitable software and of a microphone not fitted with a pop guard or to the start of a track and will run into the next course the required audio material. foam rubber sock. “Microphone technique track if not stopped. Many “hifi” CD players The stand-alone PC together with the 101” should always include a lesson on NOT cannot handle MP3 discs – an essential ele“MERLIN” Mixer, can also be used to problowing into the microphone to check if it ment in both training or community studios duce and edit “spots” which in itself gives is working! as many adverts, promos, stings and other valuable training. For training purposes, we suggest student audio may be supplied in MP3 format. The PC can also be used to deliver rebe taught to use microphones without pop The difference between hifi-type and comcorded music tracks but for the purposes of guards or socks. mercial CD Players is that the latter will autoMedia Training, this is just too easy and not matically cue to the start of a selected track, likely to help the student develop broadcast Quality Headphones start on command and stop at the end of a presentation skills! Two pairs of medium quality headphones track. They also offer excellent sound quality Hum and noise should be available for use in the studio. and a number of other practical features inOnce again, for health and personal reacluding wired remote control start and certain Hum and other electrical noise problems sons, presenters usually supply their own practical programming features. are often experienced when connecting PCs headphones. In this case, they need to be • The DENON DN-C615 entry-level commerto audio mixers. Good wiring techniques, checked for suitability for the system and, cial CD player plays MP3 as well as CDs paying particular attention to earth loops, more importantly, the correct connectors! and is a perfect match to the “MERLIN” are essential. Even then, sometimes “heavy • Cheapest acceptable type are the AKG Mixer. duty” help is needed. K44. • Similarly, the DENON DN-C635 intermediElan Audio has developed a hum reducer, ate-level commercial CD Player plays MP3 the MIM-01, designed to connect between High quality monitor system and has a spin-dial track selector the PC and the “MERLIN” Mixer to eradicate The importance of a high quality monitor or substantially reduce this problem. Audio “spot delivery” equipment system cannot be overstated. It allows stuDesirable Additional Equipment dents to accurately judge the audio quality All commercial and community radio of the project being worked on. broadcasting involves the delivery to air of A recording of the output from the mixer is It is virtually impossible to accurately pre-recorded “spots” such as messages, necessary to allow both the teacher and stujudge audio quality using ordinary “comcommercials and sponsorship announcedent to critically evaluate the quality of student puter-type” speakers and even the best ments. This should be simulated and form performance, presentation, and progress. headphones available can be misleading if part of the training. Several delivery options A cassette deck is usually satisfactory used for quality monitoring. exist: Mini Disk, Flash Card Player, CD Player for this, provided the recording is to be Good quality hifi equipment may be suitand Personal Computer are the main ones. used purely for evaluation or examination able if the budget is restricted. Otherwise, we Mini Disk suffers from a number of dispurposes. Compact audio cassettes are 96  Silicon Chip siliconchip.com.au cheap enough to keep as permanent records. However, if the recording is to be used for public presentation or radio broadcasting, a professional “Flash Card Recorder” such as the Edirol R-1 or Marantz PMD-660, or indeed a personal computer (student’s own laptop?), is a better choice. Professional flash card recorders operated at 44.1kHz, 16-bit linear sampling, (the same as standard CD-quality recordings). These recordings can be transferred to the “spot” delivery PC via USB for editing and cleanup, and then burnt to CD for possible later broadcast or auditioning and examining by the media teacher. given to the student without the benefit of an Audio Processor so they get the feel for the “raw product”. “raw” program, is a very practical method, as only one PC will be required in the training studio. On the Air Thoughts about PCs Standard practice in radio broadcasting, is to have an on-air light, mounted outside the studio door (and often inside as well), arranged to turn on whenever a Microphone is switched on. The Elan Audio AAL-01 On-Air Light operates from a safe 12V DC from the “MERLIN” Mixer which activates when a microphone is turned on Interviews Editing and signal cleanup Virtually all audio editing these days is done on a personal computer loaded with suitable software – see below for examples. Interviews may be done in “stereo” using one microphone for the interviewer and one for the interviewee, This allows the level of the two voices to be adjusted or balanced and converted to mono in the editing process, in which unwanted words, pauses and mistakes can be removed. Basic audio “spots” including background music and effects can be produced easily, using the “MERLIN” Mixer and edited on the PC. Complete radio programs intended for eventual later broadcasting, complete with announcements, music and “spots” can be produced on the “MERLIN”, recorded on a PC or flash card recorder and then edited on the PC to take out minor mistakes. During editing, the student can also make time corrections to make the program the exact duration specified by the lecturer and finally “burn” this to CD for later broadcast or archiving Using a flash card recorder to record the A modern PC provided with a USB port, sound card and CD burner, loaded with suitable software is an absolute necessity for media training as well as for simulated and live broadcasting. A notebook/laptop PC has the features needed and is most convenient. A few applications are suggested here: • Transfer of recorded field interviews and other from flash card recorder to the PC using USB. • Live recording in the studio, interviews and voiceover segments for use in “spots”. • Recording of basic music and songs. • Editing of interviews and other recorded material. • Creating “spots” by combining voice, music and effects by editing. • Compressing or “ripping” edited and other recorded material to MP3 or other compressed format. • Storage of recorded audio material including “spots” and music tracks for later playback. • Playback of stored “spots” during training. • Playback of stored “spots” and music tracks during live broadcasting. • Transfer from recorder and editing of recorded programs for later broadcasting. • Burning recorded material to CD for archiving or later broadcasting. SC Editing and cleanup may be undesirable for program material recorded for examination but is very practical, even essential, for material recorded for later broadcasting An Audio Processor is an automatic level controller, normally connected between a broadcast studio and a transmission system to prevent over-modulation; or between an audio mixer and recording equipment to keep audio levels from becoming excessive.This often causes overload of the recording equipment resulting in audible distortion. Audio Processors range from basic and inexpensive units to very complex and expensive Digital Multi-band systems. There are many different makes and types of Audio Processors on the market, most of which are specialised for different applications, such as recording or for AM, FM or TV broadcasting, webcasting etc An advanced Audio Processor is very forgiving and will help the presenter maintain correct recording or modulation levels, probably making things a little too easy for the student. We suggest initial training be Audio Editing * Principal, Elan Audio For more information, visit Elan Audio’s website – www.elan.com.au, or call them on (08) 9277 3500. Elan Audio are located at 2 Steel St, South Guildford, WA 6055. A few useful software programs: Audacity: http://audacity.sourceforge.net/ Available free from the Internet; audio recording and editing software package, easy to use, works well. Alto MP3 Ripper: http://www.yuansoft.com/ Available for US $ 29.95c from the Internet, probably the best wave to MP3 converter or “ripper”. MP3 Gain: http://mp3gain.sourceforge.net/ Available free from the internet, the best audio level normalizer we have come across. Windows Media Player: http://www.microsoft.com/windows/windowsmedia/default.mspx Normally part of Microsoft Windows operating system, upgrades available free from the Internet, useful as a very basic “spot” playback utility (not particularly good but it works!). DirEttore: http://www.mixtime.com/ Basic version available free from the internet, basic broadcast automation package, very useful for “spot” and music track playback, looks good on PC monitor screen, works rather well. Please note, It is OK to use DirEttore during training for playback of “spots” but not recommended for playback of music tracks as this makes presentation too easy! It is OK to use for music tracks during live broadcast. siliconchip.com.au October 2006  97