Selecting AV & Control Cables: From RS-232 Wire to Cat 7 for High-Performance Systems

In commercial AV projects, signal paths tell the real story of system performance. Processors, amplifiers, displays, microphones, and control touchpanels all depend on the right cable between them. When a system drops commands, introduces hum, or struggles with bandwidth, the root cause often lives in the layer that people do not see: the cabling.

This is how to think about selecting AV and control cables, from legacy serial links to modern Cat 7 based networks. The focus remains on commercial environments that rely on platforms such as Crestron, Axlink, and AMX systems, offering universal control, along with lighting, shading, and building management interfaces.

Why Cable Choice Matters in Modern AV Systems

Modern commercial AV systems serve as both IP networks and control systems, as well as audio transport platforms. A single rack may host DSPs, matrix switchers, control processors, amplifiers, and network switches, each with its own cabling expectations. Selecting the wrong pro av cable can limit system capability even before the first device powers up.

Control signals require predictable behavior over extended periods. Audio paths need low noise, stable impedance, and consistent shielding. High-bandwidth video and data traffic place heavy demands on twisted-pair performance. When approaching a project, view cable selection as one of the primary tools for managing all three aspects simultaneously.

Control Cables: Understanding RS-232 and RS-485

For many years, RS-232 wire and cable formed the backbone of device control. RS-232 uses single-ended signaling, point-to-point, and works well over shorter distances where noise remains manageable. Many displays, switchers, and legacy processors still feature a DB9 connector and require a 9 pin serial cable for direct communication.

RS485 takes a different approach. It utilizes differential signaling over a balanced pair, which provides better noise immunity and enables longer distances. In large conference centers, campuses, and hospitality projects, RS485 often connects remote equipment rooms or distributed devices back to a central processor. When specifiers compare RS-232 and RS485 for AV control systems, they often consider cable length, environmental noise levels, and the number of devices on a segment.

In both cases, the control cable selection needs to support the signaling method. Balanced twisted pairs with appropriate impedance help RS485 maintain its advantages. For RS-232, shielded multi conductor constructions protect single ended signals from interference. Platforms such as Crestron and AMX systems benefit when their processors and endpoints communicate over cabling that matches the electrical behavior those protocols expect.

For a deeper dive into the role of these cables in automation and AV, this blog adds helpful background.

Mic Line and Digital Media Cables: Preserving Audio and Signal Quality

Audio transport adds another layer of complexity. A dedicated mic line wire or cable needs to protect low-level signals from hum, RF interference, and crosstalk. Balanced microphone lines rely on twisted pairs and shielding to reject common-mode noise. When a specifier selects wire for audio control and transport, they pay close attention to shielding type, conductor size, and capacitance per foot.

As systems add networked audio, video, and control, digital media cable wire supports higher bandwidth signals that may ride on copper as either baseband or IP. That might include audio over IP feeds, control channels, and various proprietary transports that expect category style cabling. Matching the cable construction to those expectations plays a major role in how clearly a system passes audio and control data across long runs.

Category Cables in AV: From Cat 6 to Cat 7

Twisted pair category cabling now accounts for a significant share of AV traffic. Category 6 cable supports gigabit networking and many AV over IP platforms in commercial systems. When installations introduce higher data rates, more simultaneous streams, or longer runs near strong sources of interference, specifiers often look toward Cat 7 cables for additional margin. Cat 7 offers higher bandwidth ratings and extensive shielding, which help maintain signal integrity in noisy spaces.

Certain projects require runs that pass through challenging environments or transition points within buildings. In such cases, a Category 6 outdoor cable or other specialized construction may be specified for segments that face more aggressive conditions, while still supporting the same network and control traffic as interior links.

Patch panels, racks, and field enclosures then rely on high-quality patch cables to interface devices cleanly with the permanent link. Those patch cords should match or exceed the category rating of the installed cabling so they do not become the weak link in the channel, particularly when carrying AV over IP or control traffic for critical systems.

Specialized Cables for System Integration

Beyond category cabling and dedicated control lines, AV systems depend on a mix of specialized products tailored to specific roles. Serial control for legacy devices still uses 9 pin serial cable assemblies in many commercial installations, often running between a modern control processor and older projectors or displays. These connections may not carry high-bandwidth data, but they do require solid shielding and reliable terminations to ensure commands arrive consistently.

Video transport also influences cable choices. An in-wall HDMI cable, rated for commercial use, supports fixed connections between source devices and displays while remaining hidden in conduits or behind architectural finishes. That cable must be able to handle the expected data rates for the resolution and refresh requirements of the project and meet any flame or building code classifications that apply to its pathway.

Power and data now share conductors in many networked AV devices through POE (power over ethernet). That places additional current on category cabling, which makes conductor size, bundle behavior, and temperature performance key considerations. High-quality pro AV cable for PoE applications balances insertion loss, DC resistance, and temperature rise while still supporting the full data rate.

From Axlink to Modern Control Platforms

Control architectures have evolved, but cabling fundamentals remain important. Earlier systems, such as Axlink from AMX and other proprietary buses from manufacturers like Crestron, still depend on reliable low voltage control cable to move instructions between processors, keypads, and interface modules. Even when those links sit beside modern Ethernet-based control networks, they still require appropriate copper, shielding, and topology to perform as intended.

The introduction of AMX systems universal control and comparable platforms from other vendors extended this concept into more flexible architectures that can mix serial, IP, and proprietary control transports. In each case, careful selection of control cable types helps maintain consistent timing, reliable command delivery, and predictable behavior across the entire ecosystem.

Simplifying Procurement and System Design

One of the biggest advantages in AV design comes from a portfolio that consistently covers all these needs. When mic line wire or cable, RS-232 wire and cable, RS485 control cable, category products, and specialty assemblies share similar quality and documentation, system designers spend less time reconciling mismatched specifications.

A broad assortment of pro AV cable options supports small conference rooms, large auditoriums, and campus-wide distribution systems with the same underlying principles. The focus remains on signal type, protocol, bandwidth, and environmental conditions, rather than chasing one-off solutions every time a new device enters the design.

For teams who want a central reference, this AV Resource Center is a great place to start.

Smarter Cabling Decisions for Better AV Performance

High-performance AV and control systems depend on more than the latest processor or display. The path between devices matters just as much. By understanding the role of mic line wire or cable for audio, RS-232 wire and cable and RS485 for control, Cat 7 cables and category 6 outdoor cable for data and PoE, and specialized options such as in-wall HDMI cable and 9 pin serial cable, project teams can match each circuit to the right construction.

When specifiers treat cabling as an integral part of system design, they create a foundation for stable, predictable performance in demanding commercial environments. Those decisions support everything from reliable Crestron and AMX systems to universal control, clean audio, responsive touchpanels, and dependable networked AV transports. For readers who want support aligning cable choices with specific project requirements, check out our AV resource center or contact us for additional help.