Chapter 4 SCA PROGRAM STUDIO FACILITIES (Oops, There Goes The Budget!) I am not going to attempt to design acoustically controlled studio rooms for you (because it would require more space and perhaps more expertise than I have available) nor am I going to present you with a "shopping list" of the equipment and other hardware you should purchase. What I will attempt to provide to you is an understanding of the needs and considerations in establishing adequate facilities. Armed with such awareness you will be prepared to consider your design approaches with a better chance of success and with a reasonable expenditure of that limited budget of yours. "Program studio facilities" covers the whole spectrum of the rooms used, the equipment needed, and the system techniques employed. Of course, the equipment is a function of the techniques, but fortunately for "Radio Talking Book" uses, there are some most desirable methods that should be employed which can reduce this discussion to "the most likely" cases. Before anything else can occur, you will need some rooms, which means you must have a building. What kind of building? Well, it really can be anything. Many radio stations operate out of houses converted to studios and offices. Several stations have invested millions in specially constructed buildings. You will probably fall somewhere between these. If you seek to rent space then you must always remember that your primary objective is to record and/or broadcast sounds! Eliminating background ambient sounds in the typical, quiet, residential living room environment is difficult; but eliminating such noises in a factory building which is located next to a bus route (or railroad) is close to Impossible! (Without a great deal of budget expenditure, that is.) So try to seek buildings which are located away from the "beat of the city". Avoid locations which are down the street or around the corner from fire and police stations or hospitals. (Those are "great" conveniences when you're on fire, being burglarized, or sick - but those sirens sure are loud!) If the building you are considering has other tenants then examine their activities, and the likelihood of their moving and being replaced by a less desirable "neighbor". I can relate a little (unhappy) tale about this. In our building we existed in total harmony with a company who rented the floor above our studios. They were really nice people conducting a thriving accounting type of business. Eventually they grew to where they decided it would be more cost effective to print their own forms. Additionally, they reasoned, they could also contract printing services to help defray that equipment investment. Business was good and they got bigger yet. One day I came to our studios to be greeted by a loud and nonstop - "thump; thump; thump" sound. (Our building is constructed of solid concrete, including each floor which is about 14" thick of concrete!) They had installed a large hydralic paper shear that impacted with sufficient force to vibrate through the concrete mass of the building. The lesson here is not that solid concrete buildings are bad, to the contrary, they are very desirable. The lesson is that future changes could occur that can disrupt your world! "Murphy's Law" (If anything can go wrong - it will.) dictates that you plan ahead for the most improbable of events to occur. Our "thumping" problem? Oh, as I said earlier, they really were nice people - so we reached a "gentleman's" agreement that they would avoid using their noisy machines during our most critical "live mike" times. That almost worked, but with some frustration felt by us both at times. Eventually they became big enough to move on to what I suspect were bigger and better facilities, and then we leased that space! Basements are often "nice". In a basement location there is no one (of consequence) beneath you making noises. The walls also are below grade and mute sound transmittal into your studio spaces. Now, all you have to worry about is activities on the floor above you and the "racket" of furnace blowers, etc., down there with you. (I'm avoiding comment on "dungeon effect" from not seeing the sunlight by your staff! Install bright lights and pretty scenic pictures?) Wherever you decide to locate, if you let the considerations of internal and external sounds guide you, you will make a "sound" choice! What is a "studio" room? (Note: A "recording booth" is merely a very small studio.) Studios, in the broadcast/recording world, are rooms which are acoustically treated so that desired sounds may be captured and undesired sounds excluded. Now, that definition is a bit too simplistic since the function of a good studio is also to control and thus perhaps enhance desired sounds. So a studio room should be thought of as being a box of space of which all six sides of the cubic space are acoustically considered and treated. There are basically two concerns to address. The first one is to prevent external sounds from penetrating the barrier (walls, etc.) and reaching the inside of the studio room! To achieve this, dense materials are usually employed. Solid walls of brick are nice, but single walls are usually inadequate. Double brick walls with a gap of space between them is a good technique. The idea is to make the walls, floor, ceiling, so solid and rigid (stiff!) that they cannot be readily set into vibration unless you hit them with a sledgehammer. Next, any vibrations (don't forget, sounds ### simply mechanical vibrations!!) which occur on the external wall surface, if it is strong enough to vibrate the wall, must not be mechanically coupled (passed) into the inner walls surface. This is why two walls, separated by an air gap of space, are the preferred construction technique. (Note: If you build "brick" walls from concrete blocks, do not forget to fill the openings inside the bricks with sand or mortar as the wall is constructed!) If bricks or blocks are too heavy for your budget, or the floor you want to put them on, use stud-wall construction but utilize "staggered stud" technique. What this means is you use twice as many studs, with the outside wall on one set, and the inside wall on the other set. This prevents vibrations on the outer wall from being directly connected to the inside wall surface, as it would be if it could pass through a single and common stud. This staggered stud method is what is almost always used in ceilings. (It's awfully hard to build ceilings out of bricks!) Don't forget, use multiple walls and ceilings with air gaps between them! Cover them with several layers of dense material such as plywood (or lead)! Good studios should never be built with windows in them! No, I'm not really a "nut", it is simply a fact that windows, especially large ones, are acoustically incompatible. Unfortunately, we all like windows, and they make it so much easier to see what's going on in the adjacent areas, such as the "control room" studio. So, I guess we're "damned" to have them, unless you're willing to consider a rather extensive closed circuit TV video system too. Windows also must be constructed as "double-wall" devices. The outer glass must be mounted in a resilient frame on the outer wall. The inner glass is mounted on the inner wall in the same manner. The glass should be not less than 3/8ths of an inch thick. Both panes of glass must not be mounted in a common frame, or parallel to each other, rather the inner glass should slope so as to reflect sounds up toward the ceiling. The outer glass should likewise slope to reflect sounds up toward the ceiling, however, if the "outer" wall is not also the inner wall of an adjacent studio, that glass could be mounted vertically. Studio doors, like the walls, floor and ceilings, must be massive and dense. Two inch thick solid wood is an absolute minimum. Two doors, one on the outer wall and one on the inner wall are great, but most of us don't do it. Doors, like windows, must be mounted in frames which include resilient material between them and the walls. Doors should use special latch hardware also. Conventional door latches will not pull the door into the resilient sealing gasket which must surround the door, and also conventional latches make metallic noises, which are undesirable, when opening or closing the door while a "live mike" is in use. Instead, special wedge type of hardware is sold for this application. Also special hinge hardware is available and is usually required because of the weight of these doors as well as the high forces which can be produced by the wedge latch forcing the door into the sealing gasket. All wiring runs, heating, air conditioning and ventilation, etc., into the room must be sound treated. Labyrinth type baffled routes which are lined with sound absorbing materials must be employed. Be cautious that sounds cannot pass down the route with the wires, nor can it penetrate through it's walls and then into your studio room. Many otherwise good studios have been "messed up" because a common airconditioning duct was routed above the rooms and connected directly into each room. What this did, of course, was to couple the sounds from one room to the other. Think of sound as being a liquid and close up every leak and opening into the room to keep it "bone dry". Regarding ventillation - it is very important!! Studios quickly get very warm and uncomfortable if this is not carefully considered. A frequent mistake is that often it is not realized that an air-conditioning system cannot force air into a tightly sealed room. Therefore, your air-conditioning system must provide both an air supply and an air exhaust system -- (located on opposite sides of the room, please). An additional consideration is that the air flow in and out of the room (they must be equal, of course) must be of high volume but very low velocity! High speed air "whistles" -- slow up the blowers but use BIG ones!! Don't forget to use air baffles ("mufflers") following the blowers! The blower noises should not reach the rooms, just the air! Now that we have conceived a sound isolated space for our studios, let's turn our attention to the inside of the room. This is the second of the two concerns I stated that we must address. Since the first concern was to prevent external sounds from getting into the studio room, the second is controlling those sounds which you produce inside the room. The first consideration is the size and shape of the room. Studio rooms should never have any two surfaces (walls, floor, ceilings) parallel to each other! I fully realize that most studio rooms do not adhere to this rule -- but that doesn't diminish the fact that they should! Parallel walls will allow sounds to reflect back and forth between them with the minimum of absorption and enables a "resonance" effect (a strong reinforcement of a specific sound pitch) to occur. This "resonance" always occurs between any two parallel surfaces, and is like the tuning of a pipe organ tube (or the liquid level in a coke bottle) to produce a certain tone. Therefore, it stands to reason that if a room must have parallel walls then at the very least the distance between different surfaces of the room should not be the same. If they were all the same (the room were a perfect cube) a very strong "boomy" effect would occur. If the dimensions are dissimilar, the room will exhibit three different tones of reinforcement, but they will be less strong and be spread out over the acoustic range. On the other hand, non-parallel surfaces prevent sound reflections from returning directly to the source of their origin, but force them to strike several absorbent surfaces before they do return. There are preferred dimension ratios for a studio room. Basically, the "magic number" for determining this height to width to length ratio is to make the ratio proportional to the cube root of two (2) or multiples. For example, use the ratio of 1:1.15:1.6 for small rooms; use 1:1.25:3.2 for longer rooms; use 1:1.6:2.5 for "average" sized rooms; etc. (Hint, set the ceiling height to be "1" since it usually is easier to adjust the wall locations than the ceilings.) Now we could engage in a very lively debate over how "lively" a studio room should be! Generally we do not desire a studio to be completely "dead" (sometimes called "dry") and totally without reverberation. How much reverberation, and it's delay and decay characteristics, is an extensive subject of it's own. Fortunately (Well, I guess it's fortunate) most of us are not going to be able to construct studios good enough to be too concerned about this. If you are - then you would also be consulting an acoustics studio design engineer and he will advise you further. Most of us will try to make our rooms as "dead" as possible, and they will become adequate but not quite too much. The problem with an overly "dead" room is that sound volume levels tend to be low, which necessitates close-in microphone placements, and voices and music also tend to sound "disinteresting". On the other hand, excessively "lively" rooms sound like echo chambers and getting good "presence" of the subject you want to have "on-mike" is difficult. Therefore, it is best not to use flat, hard, wall surfaces (too reverberent) nor is it best to cover all wall surfaces with thick sound absorbing materials (too "dead"). Generally it is best to cover at least half of the surfaces with sound absorbing materials. Four to six inches thick of building wall insulation fiberglass is fairly inexpensive and quite effective. Of course, commercial acoustic products can be purchased, such as "Sonex" (manufactured by Illbruck Co., 3800 Washington Ave. N., Minneapolis, MN 55412), and is excellent for these uses. Incidently, it is best to mount such sound absorbing materials a few inches (or more) away from the hard wall surface. This allows sound to be absorbed twice, first as it passes through the material and then again after it reflects off of the wall and repasses through it. Another comment is that so called "acoustic ceiling tiles" are not worth much when it comes to studio design considerations. They are far more cosmetic than acoustic. Also cosmetic are those big windows! They really reflect sounds, so keep them tilted to send the sound into an absorbent ceiling. To summarize this subject; make solid, multilayered, walls; pay attention to openings into the room so as to keep sounds out; use correct room size ratios; avoid parallel surfaces; install plenty of absorbent surface covering; and use good microphone techniques (more on that in Chapter 5). Now that we have a building in a good location and know how to construct "decent" studio rooms in our building, we have to decide how big and elaborate our broadcasting facility should be. At a bare minimum, you must have one studio room to be dedicated as a Master Control Room, and one studio for live use such as newspaper reading or general live interview type recording activities. Most operations will find it very desirable to include one more studio room for simultaneous auxiliary recording, etc. So I would recommend a minimum of three studio rooms, one of which is the Master Control/Announcer operating point. (Master Control should be able to view operations in all other "production" studios.) The Master Control studio must be large enough to contain the main control console, probably a couple of phono turntables, two or more broadcast cartridge (not cassette) machines, an operators desk/working space, and about three standard size 19-inch equipment racks to hold your tape decks, audio processing equipment, control logic, etc. (Don't forget you'll need a reliable independent source of adequate electrical power and, probably, telephone lines to this room.) We probably need a room at least 8.5 by 11 feet, and larger would be better. If you,re limited to two production studios it is generally convenient to have one smaller studio, perhaps about the size of the control room, and another which is perhaps twice as large. This gives the most flexibility for a given amount of available space. It generally is a good idea, in the two studio arrangement, to locate Master Control between the other two studios for both acoustic isolation and for better control room visibility of the production operations. If you have more space and money than do most of us, by all means, build more and/or bigger studios. However, most operations will not usually require more than two production studios. This leads me to the subject of recording booths. Recall that I mentioned earlier that these were really just very small studios. Everything we've discussed about studios in general still applies! We do, however, tend to be less careful about room dimensions in recording booths. Since we usually use "headband" microphones or else "closetalked" microphones in these booths, we can get away with more "cheating on theory". Recording booths can be purchased as "pre-fab" units. These are often intended to be used as auditory testing chambers. There are several advantages to buying such commercial enclosures, such as the ventilation and wiring problems have already been solved for you. On the other hand, they tend to be fairly expensive. You may be able to do nearly as well acoustically and spend less of your budget by constructing your own, especially if this is part of a larger studio construction contract. Of course, constructing your own recording booths gives you more flexibility in size and location arrangement. (If you or your volunteer support resources are "crafty" you can save a lot of money by "rolling your own" studios and recording booths. Just don't try to save money by skimping on the basic design criteria or it will come back to haunt you eventually.) How many booths will you need? This is hard to predict since it depends on how you operate your service and how many "on-air" hours you contem- plate. Needless to say, you probably will always require two more than whatever amount you have. I doubt if most "Radio Talking Book" services can get by very well with less than six booths, many of us wish we had at least twice that number. You will discover that scheduling volunteers in to record becomes quite a juggling act. Most of them are available at the same times during the day, or close enough so that they would overlap each other's time slot. What this means is that you will always have vacant booths while waiting for the next arrival. By the way, don't forget that you will require microphones and tape recorders for each one of those booths. This certainly has a budget impact as the number of recording booths increases! A recording booth should have a comfortable (well, not too comfortable) chair and desk surface. If the reader also operates the tape recorder then it either should be remotely controlled and outside of the booth, (It could be controlled by another person out there too, of course, if you prefer to use two people instead of one for each recording) or else it must be mounted on a separate equipment desk/shelf from the operators desk. Preferably, the microphone should be a headset type. (Such as a Beyer DT-109, etc.) Avoid the use of florescent lighting in studios and recording booths. Although florescents have many good features, they create problems that you don't need. For example, they tend to get dim with time; they have a nasty habit of buzzing mechanically; they can create a lot of electrical "hash" noise in audio equipment. Incandescent bulbs do none of these things. They do, of course, create more heat than florescents, but if you did your homework on the ventilation system correctly, it doesn't matter. Also incandescents can be easily installed as "track lighting" which gives nice flexibility in moving the light to where you want it. In addition, most of us agree that reading is much less eye straining and tiring under incandescent lighting than florescents, since florescents have a 120Hz strobe-like flicker that is not visually apparent but is subconsciously burdensome. (Yes - I know you will find lots of studios with florescent lights in them, not everybody understands or are willing to do things right.) Unfortunately, florescents make "good looking" installations and cost less to operate for a given amount of illumination, but I'm hoping your standards are skewed toward technical performance and not strictly fiscal or aesthetic satisfaction. At this point I want to shift toward equipment discussions, as there isn't too much more in general comments that I can pass on about the rooms themselves. Some have suggested that studio equipment should be a separate chapter, in fact I was one of them! However, I've come to realize that this subject is extensive only if you attempt to compare products and list them with their pro's and con's. I do not believe that would be a wise course to follow. One reason for this is that I would have to try to judge if we should consider the use of less costly "consumer entertainment" equipment or just professional grade recording/broadcasting equipment. To consider all of both, or either, would turn this project into an encyclopedia; and I'm really not that thrilled about writing. The second reason is that quite candidly, I don't claim to be that much of an expert on all the hardware that is available! And a third reason is that by the time you read this, any lists I were to present to you would most likely no longer be current. So my general advice to you on the selection of specific equipment products is that you look around your community at radio stations and recording companies. See what's in use. Ask questions of the operators and engineers about what characteristics they love, and what they hate. Make your own lists and notes of comments. Talk to sales reps. for the various brands. (They love to talk to you!) Get prices and decide what you need and can afford. (It ain't gonna' be cheap! But then, nothing good is.) You are, or are about to become, a radio broadcaster! It's time to start thinking like one, if you haven't already. My next gem of free advice is that a broadcaster should find someone who knows about technical equipment and systems and get him on the staff. You will need to select a lot of hardware, and after you get it you have to hook it all up correctly. Then it has to be calibrated and operated correctly. Finally, it will require ongoing maintenance. Whatever you pay him it won't be enough. (But of course, I may be a little bit biased!) You will need a Master Control console (called "the board" by most operators). All of your program sources such as microphones, tape decks, cart decks, phonos, etc. are connected into this. At this control console the desired program source is selected, volume controlled, and routed on to be broadcast, recorded, monitored, etc. These consoles are generally defined by how many sources are able to be connected into it and also by how many destinations it can deliver a source out to. Thus, a "16 by 4" console would have 16 inputs and 4 outputs. Standard program signals used by these consoles is generally +4Dbm or +8Dbm, 600 ohm balanced lines. In essence, what this means is that two wires are used to carry the signal, not a single shielded wire such as is common in consumer "Hi-Fi" equipment. The "Dbm" rating means that the nominal (RMS) voltage of the signals is 1.23 volts or 1.95 volts when correctly connected to a 600 ohm destination. Why am I telling you this somewhat extraneous information? Because I've frequently discovered that there is a great deal of confusion and misunderstanding about signal levels and their metering by most non- technical personnel, and by many technical persons as well. Therefore, since control consoles generally use "VU" meters, I believe it is appropriate to discuss this subject in a bit more depth. The ubiquitous VU (volume unit) meter is actually a rather poor indicator of program volume. However, it is a long established standard that, unlike in Europe, continues to persist in this country. The VU meter was designed to be rather slow (about 1/3rd of a second) in it's reaction to changes in volume. This was so it would tend to show the operator the psychological effects of loudness rather than the actual absolute values of the signals whose loudness was being observed. What this means in practice is that the actual signal levels can be, and are, much greater than what the meter displays. If you wish to display the actual instantaneous values you must use a "peak meter" or an oscilloscope. (Note: peak meters have various values of attack response time, decay time, and overshoot too!) So why do I care, you ask? Because in tape recording or broadcasting, there is an absolute ceiling that you must not exceed either because of FCC rules or because of severe distortion effects, or both. So how do you "live with" a VU meter then? First I would encourage you to back them up with proper peak meters! But, lacking that, you should understand that the standardized VU meter will read 0VU with about 0.775 volts RMS of signal applied to it. This is equivalent to the voltage level which exists when one milliwatt (lmw) of electrical power is being consumed by a resistance of 600 ohms. This amount of electrical power is defined to be 0Dbm (zero decibels above lmw in 600 ohms). But a VU meter's resistance is 3900 ohm, which is too low a value to properly connect across the 600 ohm resistor it is measuring. Therefore, the VU meter is required to have a 3600 ohm resistor added in series with it's connections. Thus the VU meter's 3900 ohms plus the resistor's 3600 ohms presents a total of 7500 ohms to the 600 ohm resistor to be measured, and this is "O.K." since a 10 to 1 ratio is generally considered acceptable. Adding the resistor to the VU meter also makes it's mechanical ballistics (rise and fall times) correct for the standard. But the VU meter now requires 1.23 volts RMS to indicate 0VU. This is an increase of 4 decibels, so we now state that the meters 0VU reading equals +4Dbm. If we wish to, we could, and sometimes do (especially for feeding telephone lines), make the VU meters 0VU indication equal to +8Dbm. Now that you know that a standardized VU meter reads +4Dbm at 0VU, you should also know that the actual program signals which can shove the meter up to display that value will be typically about twice that voltage level. (Remember, those VU meters are slow and don't move fast enough to show those large signal peaks.) Therefore, when your program signals show an average of about 0VU on your consoles VU meter which is calibrated to be equal to +4Dbm, the actual levels of the program signals will be approximately 6Db (twice as much) more, or actually equal to +lODbm. Another way of saying this is that your VU meters must lead the program signal levels by being made to be 6Db too sensitive. Therefore, to correctly calibrate the system, a signal level of +lODbm must be used as the 100% volume if the system uses standardized VU meters which read 0VU at +4Dbm. Note that under this test calibration condition the VU meter will be reading fully off it's scale to the right. Now I recommend you reread these past few sentences until they begin to make some sense to you. You see, too often I've seen operators adjust a tones volume to give 0VU indication on the console meter and then adjust their transmitter to be at 100% modulation. This certainly appears to be correct, especially since most VU meters also say "100%" at the 0VU point on their scales. However, if program material is then used and volume adjusted so as to indicate 0VU on that console meter, the actual transmitter modulation would be about two times too much, or 200%, which is also stated as being 6Db excessive. That is, this over modulation will surely occur unless you are also employing some automatic volume control audio processing systems following your console. If you are, you are doing things right -- if not, then run, don't walk, to the nearest equipment sales representative and get some quickly! We will discuss this subject next, but before we leave consoles, let me finish by mentioning that you will probably require at least two more inputs and outputs than whatever you have. There are ways to practically minimize the console channels required, but I would feel very limited if I had less than about four "microphone" inputs and eight "line level" inputs, with five or six line outputs. Most of us in Radio Talking Book operations use the console simultaneously for on-air broadcasting and "in-house" recording production which requires multichannel facilities. But, let me caution you that many console channels also means many "bucks". It may be less costly to have two simpler control consoles which can be cross-connected, with one primarily as "on-air" and the other as the auxiliary control and production operations. For Radio Talking Book purposes you require signal routing flexibility, not fancy equalization features. Put your money into multichannel flexibility and reliability. (You can't afford equipment failures, especially if you own only one piece!) Now, back to automatic volume level audio processing equipment. Yes, you must have this stuff! Your listeners depend on it, and so does your relationship with the FM broadcast stations main channel operations! Oh, how I wish they were even half as careful with the main channel modulation as we insist on being on the SCA's. What this equipment does is assure that your broadcast volume is kept loud and yet never exceeds the maximum legal values. It is impossible for a human operator to achieve this degree of manual control, plus he would have to be at the control console every minute you are broadcasting. Even if he was "glued" to the console, he couldn't anticipate the volume differences as they occur between persons, different tapes programs, etc. Even if he were a "God-like" operator and could anticipate correctly, and decipher that sluggish VU meter, he couldn't enhance the effective loudness of your broadcast -- but an "auto-level" controller can! Auto level controllers are technically known as "Compressors" and "Expanders". Compressors basically prevent an increase in output volume upon an increase at it's input. Expanders, on the other hand, produce larger volume increases at their outputs than occurs at their input. We are most interested in using compressors in Radio Talking Book operations. In actuality, a good auto-level controller operates as an expander upon low volume inputs and then functions as a compressor once the input volume reaches "reasonable" and greater values. By very careful design of the response time characteristics, and the degree of volume control adj#stment, an auto-level controller actually makes the average program volume louder than normal in addition to maintaining constant volume upon variations of the program sources. This increase in "loudness" is highly desirable, in fact it is necessary, when broadcasting on an SCA channel whose effective signal to noise performance is seldom much better than 35Db! If an auto-level controller reacts too quickly to correct volume changes it will exhibit a bad sound characteristic which is appropriately termed "breathing" or "pumping". To counter these effects, rather exotic design concepts are employed, plus two completely separate control units are usually used. The first auto-level controller somewhat slowly adjusts for major volume level errors. The second unit rapidly corrects the output of the first unit. The second unit generally also includes what is termed "peak limiting". Peak limiting is a feature which assures that no matter what happens during other control actions, the absolute maximum peak volume level will never exceed a preset value. This is highly important to guarantee that our signals volume never causes us to exceed 100% modulation of the SCA, which is #6KHz peak deviation of the 67KHz SCA carrier. This second, peak limiter, unit should be installed at the SCA generator's location, not in your studio control room. Many of these peak limiters also contain audio bandlimit filters and pre-emphasis circuits. If so, the bandlimit filter usually found inside the SCA generator should be discarded. Likewise the pre-emphasis in the SCA generator should be removed. By using the pre-emphasis and filter (5KHz) in the peak limiter, much cleaner and more accurate transmission occurs. (An alternative, and a very good one, is to use the Modulation Associates brand "Sidekick" SCA generator which employs excellent modulation level control internally!!) In this area I will mention specific auto-level control equipment. The CBS "Automax" and "Volumax" and the Collins "Auto-level" and "Auto-limiter" units are nearly as ubiquitous as VU meters. Fortunately they are not quite as imprecise, but they're close to it. (At least partially because more than half of them are improperly adjusted.) On the other hand, Moseley Associates, Inc. sells the model TGR-340 "Audio Gain Rider" and the model TFL-280 "Audio Limiter". These companion units are excellent controllers, especially for speech type program materials. Oh yes, you can also misadjust these controllers, but they are very effective and forgiving of even adjustment errors. This isn't meant to sound like a commercial message, but merely it is an acknowledgement of a good design effort. Fact is most of the "good" brand names are effective units. Purchase what you can afford and are pleased with - but, do purchase these units. Your broadcasts cannot become effective until you do. Other equipment you probably will want in your control room are broadcast type cartridges. These are "endless" loops of tape which come in various lengths of several seconds to many minutes of program time. They are used for "spot announcements" such as program introductions, station I.D.'s, community activity messages, etc. We generally find the 70 second lengths to be the most useful. Carts, as they are called, cue themselves ready for the next replay, and can contain messages of any length up to the maximum time available for that cartridge. You will need at least one record/play cartridge unit, and probably one or more play only units in addition to several dozen cartridges. I like Fidelipac brand cartridges, and I believe that the only cartridge equipment worth considering to purchase is made by ITC (International Tapetronics Corp.). But some people like Fords and some folks prefer Chevs? --- so evaluate the market and make the most of your budget and good local advice. Of course your control room will need tape decks. Some people have considered using cassettes, a practice which I would tend to discourage. There are way too many problems and editing limitations with cassettes. Unless you are willing to purchase nothing but $4,000.00 each Nakamichi decks, and even then, I believe you are asking for production and quality control headaches. Among open-reel tape decks there are many good choices, none of which are inexpensive. A modestly priced machine which has probably the best tape handling performance of any tape recorder I've ever measured is the Techniques RS1520US. This is a professional grade transport that provides all the "bells and whistles" and correct features you require at about $2,000.00 each. Buy professional grade machines. These are going to be the "workhorse" of your operation and they have to give you service as well as serviceability. Plan on having not less than three machines, in the control room. You require one to be "on-air", one ready to play next, and one available for simultaneous recording and/or a standby spare. Actually, four or five machines is preferred, but you can "make it" with as little as three (not counting your recording booths, of course). Once again, buy professional grade machines. Don't be fooled by good looking openreel tape decks that sell for less than $1000.00 each. They will appear to perform well and might look nice, but they will not stand up to the abuse they will receive. Within two years you will probably be out shopping for replacements. We have, for many years, pretimed our master tape reels to a length which represents 58 minutes at 3.75 ips. Thus programs are recorded to fill the reel length and we know the time is correct for an hours broadcast plus a two minute station I.D./announcement time on the hour. Believe me, this is the only timing technique which actually works in practice. The pretiming is done using Lyric precision tape measuring devices. (Don't try to do this on a tape recorder, the speed errors are too great! I shouldn't have to say this, but I will! These tape decks you select, like all the rest of your stations audio equipment, must feature 600 ohm balanced line inputs and outputs! You must include monitoring speakers and a "decent quality" amplifier to drive them. Don't forget to include such monitoring in all of your studio rooms. Any good "Hi-Fi" hardware will serve well for this function. Don't forget that you must automatically mute the speaker in the studio whenever the microphones in that studio are turned on, or you will get a "feedback" squeal! You should also consider an intercom system between the master control room and the other studios. (Some of these features may be included in the control console.) Remote control of tape recorders, cartridge machines, and phono turn tables is required. Be sure to consider how the main control operator can control these equipment without having to leave the operating console and running across the room. An "off-the-air" receiver must be included in the master control room. The only way you're sure you're broadcasting is to actually listen to it. Include a main power control panel which "unlatches" upon a loss of electrical power. Often when power failures occur the restoration of electricity is preceeded by overvoltage surges which can quickly destroy your expensive equipment. The power control panel forces an operator to re-power everything after the big surges have stopped. In other words, a short time after the lights come back on in the building and everything appears to have returned to normal, the operator then, and only then, pushes the master "go" switch and restores power to all station equipment. There are several miscellaneous "niceties" we could go on with, such as patch bay jackfields, telephones, etc. But we have attempted to keep this subject to the primary concepts. About all that hasn't been mentioned about equipment needed so far is microphones. But that's the topic of the next chapter, so I hope you still have some budget left, because you'll need a few more dollars. The big expenses are behind you now if you've done a good construction job using the correct approach. I will end this chapter with some more of my free advice, which comes not from wise foresight, it comes from experienced hindsight! Do it well and correctly the first time. You will be so busy keeping it going, you will NEVER get enough time to go back and REDO IT the right way!