How to build world-class studios

August 15, 2013

Photo of WSSM St. Louis by William Mathis of Mathis-Jones Communications and courtesy of the Murray Company, St. Louis.

Great studios aren't just wired, they're built from the ground up. First, size does matter. While other constraints often force studios to be smaller than optimum, it is easier to build and to service equipment in a room that was not previously a closet. Find enough space to have the studio furniture away from two walls and preferably three. This provides good options for reaching the back of equipment racks and for punch block access that does not require you to become intimate with the on-air talent.

For the best sound isolation, use double-wall construction between different studios and staggered-stud construction on outside walls or between studios and the rest of the facility. All studios should have hard ceilings. Even if a suspended ceiling is installed for acoustic purposes, the walls should go up to the building's hard ceiling and be well sealed at the top. Use commercially available sound isolation doors or build copies of them. The same is true for windows. Double- or triple-pane windows should use glass panes of different thicknesses. This provides the maximum efficiency to prevent sound transmission because the panes will resonate at different frequencies. Make sure the glass rests on rubber gaskets, too.

Studio furniture serves as the equipment support structure and must also provide sufficient ventilation and cable access. Photo courtesy of Wheatstone.

Air handling is a vital but often overlooked component of sound isolation. Make sure that the heating, ventilation and air conditioning (HVAC) contractor understands the issues of sound isolation and wind noise. Low-noise registers in a sufficient quantity will ensure low air flow velocity. Sound baffles or multiple bends in the supply ducts will reduce blower noise. Use a minimum of 25 feet and three bends between any blowers and a studio. Each studio also needs its own return register with baffles or multiple bends. Do not use the plenum space above a suspended ceiling as an air return, it will result in sound leakage from studio to studio. I have successfully used pigtails on plenum return systems, which consist of about 20 feet of flex duct snaked with several bends in it in the plenum space. One end is open to the plenum and the other is connected to the return register. This provides excellent sound attenuation while not impeding air flow.

Construction details

Studios should be fairly dead, acoustically speaking, but the best live mic sound is obtained when there is some warmth to the room and instead of being completely anechoic. There are some studio acoustics basics that should be kept in mind.

Different acoustic treatment techniques work better at different frequencies, so use a mix of different types. A suspended ceiling that does not cover the entire room, typically floating about a foot from all the walls, is an excellent bass trap and is unobtrusive. For an aesthetic touch, paint the hard ceiling above the float black or some other dark color. Sound absorption panels are available in different thicknesses and colors to match the decor. Wooden baffle-type sound diffusors, while expensive, are excellent acoustics treatments to prevent slapback echoes on walls behind talent, and they can be quite attractive as well. Another trick that enhances acoustics is to build the studios with non-parallel walls, although this usually takes some serious explaining to management. The offsets don't have to be large; a foot longer on one wall than the opposite wall is enough offset to reduce acoustic standing waves, but odd-shaped rooms take some getting used to. One way we dealt with this in a recent station-cluster project was to build all the studios as wedges around a circle. This worked well acoustically and looked impressive, too.

Maintaining an organized wiring scheme is not difficult (above), but it requires sticking to the original design plan and not taking short cuts, like what was done in the photo below.

I prefer wood floors to carpet because they are more durable if a sufficiently hard material is used. This will put more strain on the rest of the acoustic treatment, especially the ceiling. Use a hard wood, such as oak or Australian cypress, and do not use the pre-finished type. Instead, have it sanded, finished and sealed after installation — this makes for the toughest, spill-resistant floor. Wood floors last much longer when chairs with special wheels intended for wood are used, so make sure the person who specs the studio chairs knows the difference.

Equipment layout

Get the people who will be using the studio involved in the design process of that studio. Draw a set of studio layout sheets for each studio with the proposed rack layouts, equipment placement and console channel assignments generated with input from programming and production staff. Then submit this documentation to the client. Have the client's general manager or program director sign off on the design — literally. Have him sign each sheet. This allows a minimal chance for misunderstanding, and if any last-minute changes are wanted, it's easy to document justification for additional labor charges, if needed.

There is enough prefabricated furniture available for just about everyone's taste and budget, so I don't see much point in having a local carpenter of unproven experience with broadcasting build furniture. Either way, make sure that the cabinets are deep enough for the equipment, that the placement of equipment suits station personnel, that there is sufficient access behind and underneath equipment for servicing and ventilation, and that there are large built-in wiring channels and punch-block areas. Look for quality details like inlaid Formica or other surfacing, and real wood instead of pressboard. Free-standing furniture can be shifted as needed and can be disassembled without ripping it from the walls in the event that the studio must be moved. Generally speaking, built-in furniture cannot be moved. It involves too much hassle, too much damage to the furniture, and too little likelihood that the new room will be the same dimensions as the old one. Free-standing furniture can move relatively easily.

Studio wiring

How many engineers have seen neat and well-documented wiring in new studios? Probably a fair number. How many have seen neat wiring in five-year-old studios? Not many engineers have, because it is almost impossible to build studios, no matter how neat and well-documented, that retain the same level of organization and coherence after several years in the real world of last-minute remotes, unexpected equipment failures and format changes made without notice to the engineering department. It seems almost impossible to stay ahead of the game, but it's not.

Allow enough space in the rack to provide for any future expansion, whether it is adding another station to the facility or accommodating a new format. Clear Channel Hartford rack room by Scott Frances and courtesy of the Lawrence Group Architects, St. Louis.

Expansion will happen. I have never seen a studio or studio facility that didn't need to be expanded within a year or so of its construction. Provide plenty of room for expansion by running extra wire and cable pairs, by allotting additional space for equipment and for wiring blocks, and by providing additional capacity in the entire infrastructure.

Pull more pairs than needed from each rack or cabinet to the wiring block area in each studio and from each studio to the rack room. Order cabinets and racks large and deep enough to accommodate new source equipment, new satellite and remote equipment, and especially new computers. Size generators, UPS units and HVAC equipment to handle additional loads. Save space in the building for future studio areas. Size the rack room to accommodate additional racks, but resist the temptation to let the current wiring expand to fill that available space.

Use only smart wires. Don't wire a studio using anything but AES-3 compatible cable. AES-3 requires a twisted-pair cable impedance of 110Ω while traditional analog twisted-pair is typically 30Ω to 40Ω. Analog wire should not be used to carry an AES signal more than a few feet. Even if your current need is for analog audio only, the AES cable does it no harm, and will be in place when and if your station makes the digital transition, which will become more and more likely as digital equipment prices continue to fall and performance and ease of use rises. The good news is that 110Ω cable is quite common and is available in single pair, multiple pair or snake cable and microphone-tough cable in wire sizes as small as 26 gauge. All Ethernet cable (CAT5, CAT5E and CAT6) cable is rated at 100Ω, which is within the AES-3 audio specification. Ethernet cables are available in 4-, 8-, 12- and even 25-pair configurations, which today are cost-effective compared to traditional individually-shielded, twisted-pair cables. CAT5 is available with overall shields too, although balanced, line-level, low-impedance audio does not usually require shielding.

Multiple-pair, twisted-pair, 110Ω ribbon cables rolled in a tough jacket — and even shielded — are also available. These can be quickly and easily mass terminated to connectors or bulk punch-block connections.

Label the wires clearly. My first experience with heat-shrink labels used white pieces of heat shrink mounted on plastic tabs, like cartridges on an ammo belt, that could be loaded into a modified IBM Selectric typewriter. While they were expensive and time-consuming, the level of professionalism they brought to my wiring generated many positive comments. Today there are improved versions of this that are quicker and cheaper.

Personally, I use sheets of self-laminating laser printer labels that will fit on most cables of less than 1" diameter. I have settled on four fields on each label to indicate where each end of the wire goes, what type of wire it is and the color. The first two fields are for troubleshooting, and the last two are so that my crew doesn't put the label on the wrong wire. Color-coding can be a great tool; just be sure that none of your installers is color-blind.

Various methods exist to create neat and practical labels, some of which are quite advanced and offer bar codes to simplify accessing data. Photo by Don Danko, CBRE CBNT.

Whenever possible, use wiring blocks. Traditional telephone-type 66 blocks are easy to find, offer lots of accessories and can be purchased from stock from several telecom and electronics distributors. Keep in mind that CAT5-rated 66 blocks should be used for AES-3 signals. ADC, AVP, Krone and others make excellent, high-density, high-reliability wiring blocks designed for professional and digital audio.

Keep the wiring blocks neat. Allow enough room to mount all the blocks needed for the current installation and include space for several spares. Because shielding is usually not needed for balanced, line-level analog audio or for AES-3 digital audio, cross-connects on punch or other wiring blocks can be unshielded twisted-pair cable like the phone company uses. Using this type of cable helps keep punch block areas and walls neat and uncluttered. CAT5 cross-connect wire is also available. Not terminating shields increases the density of punch blocks, too. There is almost never any need to carry shields through punch blocks, and the user throws away ⅓ of the block's capacity trying. If using a shielded cable, remember to terminate only one end. I prefer to make a pigtail of all the shields and solder or crimp-connect it to a ground bus bar running near the blocks. Bring the permanent cables in behind the punch blocks, or permanent in one end and cross-connects out the other, so that permanent and cross-connected wiring is as separate as possible.

I have reluctantly decided that wiring channel, such as that made by Panduit, is a mixed blessing at best. Never mount a wire-trough channel upside down. As soon as you remove the cover, all the wires fall out. If you mount it sideways, put a wire-tie anchor inside it every so often, or anchor a Velcro wire-tie instead so the wires can be held up and to the back of the channel, out of the way of the cover. Another drawback is that the first time a cable has to be added in a hurry, the wiring channel covers tend to get removed and then not put back afterwards. Instead, use metal or plastic D-rings. Use the plastic ones that have a little seam that you can thread wires through without having to pass the end through each ring. They also have screw holes to anchor them down. Placing one about every foot and in corners will keep wires organized but not inaccessible — and there are no covers to lose. When appearance is paramount, like running wires that are in public view, opt for the wiring channel.

There is no such thing as too much documentation, a point that cannot be stressed heavily enough. Because I usually work with a crew of several people, I generate lots of documentation. In addition to the layout sheets I mentioned earlier, I generate a wiring and cross-connect list for each wiring block plus a wire running list for each room. That way I have created essentially a complete virtual studio on paper. Once this is done it's easy to go back and verify that the crew actually ran the wires as they were intended. It also serves to verify the documentation. It's easy to create documentation in a spreadsheet, database or forms program. I'm planning to document my next studio project in HTML, complete with hyperlinks for the cross-connects. The advantage is that it can be viewed on any browser and easily modified — with the right passwords.

Good old-fashioned written documentation is not yet obsolete, either. Take a big three-ring binder and use tab separators for each studio and sheet protectors for each page. Mark the revision date or number on each page, so it is obvious which version of a page is out of date. Generate and give the client multiple copies of the documentation and multiple copies of any digitally-stored documents too. Keep copies for yourself. Stations lose paperwork easily during ownership or engineering personnel changes.

Test, test and test again

Before a studio is finished, ring out every wire and every cross-connect, either with an ohmmeter or a cable tester. Test cables for continuity, shorts and polarity. Some wiring blocks will have trouble with AES cable, due to the larger insulation required to make the higher cable impedance, and the engineer may need to punch the occasional wire down twice or take other remedial action.

Jocks and production people can't use features they don't know exist, and who better to show them than the installer himself? Show the program director and the production director everything the studio will do. Make sure they are happy with how it works. This is often the last chance to ensure that the studio's users' needs have been met.

This is an exciting time to be building studios. While the pressures to keep costs down are great, and the flexibility and features desired of a modern studio are many, the tools for accomplishing these goals are plentiful. With proper planning and wiring techniques, the experienced installer can build first-class studios that will also pass the test of time without busting the budget.

Patton is president of Michael Patton and Associates, Baton Rouge, LA. Contact him through