Speaker cable looks simple — two conductors, two ends, connect amplifier to speaker. In practice the choice of gauge and core count has a direct effect on how much power actually reaches the speaker, and getting it wrong on longer runs or with low-impedance speakers produces audible results: reduced bass control, power loss, and in some cases amplifier stress. For AV installers running cable through walls and ceilings, the decision also involves jacket specification — what is appropriate for concealed installation in an occupied building.

This guide explains what the gauge numbers mean, when to step up from 16AWG to 14AWG, when 4-core cable makes more sense than 2-core, and which DTECH cable suits which application.

What AWG means and why it matters

AWG stands for American Wire Gauge — a standardised system for specifying conductor diameter. The counterintuitive part of the system is that a lower number means a thicker wire. 14AWG is thicker than 16AWG. Thicker wire has lower electrical resistance, which matters in speaker cable because the amplifier and speaker form a circuit, and any resistance in the cable is in series with the speaker’s own impedance.

The practical effect is power loss. Every metre of cable has a measurable resistance — 16AWG copper runs at approximately 13.2 ohms per 1,000 metres per conductor, 14AWG at approximately 8.28 ohms per 1,000 metres. Over short runs that resistance is negligible. Over longer runs — 10, 15, 20 metres — it starts to represent a meaningful fraction of the speaker’s impedance, and power that the amplifier is delivering never reaches the driver. The widely accepted guideline is to keep total cable resistance below 5% of the speaker’s nominal impedance. For an 8-ohm speaker that means keeping total loop resistance under 0.4 ohms. For a 4-ohm speaker the threshold is 0.2 ohms — half as much headroom, which means either a shorter run or a thicker cable.

The other effect of cable resistance is on damping factor — the amplifier’s ability to control the movement of the speaker cone. High damping factor is particularly important for bass reproduction. A cable with too much resistance for the run length degrades damping factor and results in looser, less controlled low frequencies. This is most noticeable on subwoofers and full-range floor-standing speakers driven at higher levels.

16AWG speaker cable

16AWG is the standard specification for most installed AV work. It is flexible enough to route through walls and ceiling voids without difficulty, terminates cleanly into spring and screw terminals, and its resistance characteristics are adequate for the majority of in-room and short-run installations with standard 8-ohm speakers.

As a practical guide for 16AWG with 8-ohm speakers:

• Runs up to around 15 metres — well within the 5% resistance threshold
• Background music systems, ceiling speakers, surround sound satellites
• Standard home cinema and commercial background audio installations

DTECH’s 2x16AWG internal speaker cable has an LSZH jacket and is colour-coded pink — making it immediately identifiable in a multi-cable installation alongside data and AV cabling. The pink jacket is the install-grade standard colour for internal speaker cable, allowing quick visual identification during and after installation without needing to trace or label every run.

For runs that pass through external walls, underground ducts, or between buildings, DTECH’s 2x16AWG internal/external speaker cable adds a weatherproof mylar wrap beneath the UV-stabilised LSZH black outer jacket. The mylar layer — an aluminium-polyester laminate — acts as a moisture barrier, preventing water ingress into the cable construction during and after installation, while the UV-stabilised outer jacket resists degradation from prolonged sunlight exposure. Together they make the cable suitable for routes that transition between inside and outside environments without requiring a cable join or additional protection at the transition point.

14AWG speaker cable

14AWG has approximately 63% of the resistance per metre of 16AWG. That difference is academic on short runs but becomes significant on longer ones, or where the speaker load is lower impedance.

14AWG is the correct specification when:

• Runs exceed 15 metres to 8-ohm speakers
• Speakers are 4-ohm or dual-voice-coil designs with lower nominal impedance
• High-power amplification is in use and full power delivery to the speaker matters
• Subwoofers or full-range floor-standing speakers where bass damping factor is audible
• Commercial installations with longer cable runs to remote speakers

DTECH’s 2x14AWG internal speaker cable uses an orange LSZH jacket — the install-grade colour for 14AWG speaker cable, providing immediate visual differentiation from 16AWG pink cable in the same installation. If a project uses both gauges for different speaker positions, the colour coding removes any ambiguity at termination.

4-core speaker cable

4-core speaker cable contains four conductors rather than two. It has two primary applications in installed AV work, both of which are about installation efficiency rather than any electrical advantage over 2-core.

The first is running two speakers from a single cable pull. A 4-core cable run from the amplifier rack to a central point in a room can split at that point to feed two separate speakers — left and right satellites in a rear surround position, for example, or two ceiling speakers at the back of a multi-speaker zone. One pull through the wall or ceiling void instead of two. On complex installations with many speaker positions, the time and containment savings are significant. The four conductors are paired at each end — cores 1 and 2 to one speaker, cores 3 and 4 to the other — and must be correctly colour-matched throughout.

The second application is bi-wiring, where both pairs of conductors run to the same speaker but connect to separate high-frequency and low-frequency input terminals on speakers that support it. This is less common in installed commercial work but relevant for high-end residential and hi-fi installations.

DTECH’s 4x16AWG internal speaker cable in pink covers internal-only installations. The 4x16AWG internal/external speaker cable in black adds the same weatherproof mylar wrap and UV-stabilised jacket as the 2-core external variant — giving the same environmental protection for installations where a 4-core run needs to pass outside.

LSZH jackets for installed speaker cable

All DTECH install-grade speaker cables carry LSZH (Low Smoke Zero Halogen) jackets. For speaker cable permanently installed inside walls, ceiling voids, and floor ducts in occupied buildings, this is the correct specification. Standard PVC speaker cable releases toxic hydrogen chloride gas and dense black smoke when it burns. LSZH compound produces no halogen gases and significantly less smoke, maintaining visibility and reducing toxicity in a fire.

For AV installers working on commercial projects, schools, healthcare facilities, and any building where fire safety specifications apply, LSZH-jacketed speaker cable is the appropriate default. The colour coding — pink for internal 16AWG, orange for internal 14AWG, black for internal/external variants — is consistent across the DTECH range and makes mixed-gauge installations straightforward to manage.

Which cable for which application

View our install-grade speaker cable range: Install-grade speaker cable

Frequently asked questions

Does speaker cable gauge actually affect sound quality?

On short runs it makes no audible difference — the resistance of a few metres of 16AWG cable is so small relative to the speaker’s impedance that no measurement instrument or human ear would detect it. The difference becomes audible on longer runs where cable resistance begins to represent a meaningful percentage of speaker impedance, particularly in the bass frequencies where amplifier damping factor affects cone control. For installed work, specifying correctly by run length and impedance means the system performs as designed rather than leaving potential performance unrealised in the walls.

Can I use 4-core cable to run two speakers from one amplifier channel?

Yes — this is one of the primary practical applications of 4-core in installed work. Pairs 1+2 and 3+4 carry independent signals to two separate speakers. The important consideration is impedance: if both speakers are connected to the same amplifier channel in parallel, the combined load is half the individual speaker impedance. Two 8-ohm speakers in parallel present a 4-ohm load to the amplifier. Most modern amplifiers are stable into 4 ohms, but this should be confirmed against the amplifier specification before wiring.

Why does install-grade speaker cable have a different colour jacket from standard speaker cable?

Colour coding in installed AV work allows quick identification of cable type and gauge without having to trace or test every run. Pink for internal 16AWG and orange for internal 14AWG are the standard install-grade colours used across the industry. On a multi-room installation where both gauges are used for different speaker positions, the colour coding eliminates termination errors at commissioning and makes future identification straightforward for anyone working on the system later.

What is the maximum run length for 16AWG speaker cable?

For 8-ohm speakers, 16AWG is reliable to around 15 metres while keeping cable resistance well within the 5% of speaker impedance guideline. For 4-ohm speakers, the threshold is around 7–8 metres before resistance becomes a meaningful factor. Beyond these distances, stepping up to 14AWG restores the headroom. These are practical guidelines rather than hard limits — the system will still function beyond them, but performance is measurably better within them.

What does the mylar wrap on the external cables do?

The mylar wrap is an aluminium-polyester laminate applied beneath the outer LSZH jacket on DTECH’s internal/external speaker cables. Its primary function is as a moisture barrier — it prevents water from penetrating into the cable construction during installation in damp conditions and over the life of the installation. It also adds a degree of mechanical protection to the conductor insulation. The UV-stabilised LSZH outer jacket then protects the mylar layer itself from degradation due to sunlight exposure, making the combination appropriate for permanently installed external routes without additional conduit or protection.

Do I need LSZH speaker cable for a home installation?

For domestic installations in privately owned homes, LSZH is not a regulatory requirement in the same way it is for commercial buildings. It is however the correct specification for any cable permanently installed inside wall or ceiling voids — particularly in flats, houses in multiple occupation, and any dwelling where building regulations require attention to fire spread. For commercial, retail, hospitality, healthcare, and education installations, LSZH is the appropriate standard for all permanently installed cabling including speaker cable.

Summary

16AWG covers the majority of installed speaker cable work — it is the right specification for standard 8-ohm speakers on runs up to around 15 metres. 14AWG is the correct step up for longer runs, lower-impedance speakers, and high-power applications where the additional resistance of thinner wire would cost measurable performance. 4-core cable is a practical installation efficiency tool, allowing two speaker feeds to be run in a single cable pull rather than two.

All DTECH install-grade speaker cables carry LSZH jackets and follow consistent colour coding — pink for internal 16AWG, orange for internal 14AWG, black for internal/external variants. The internal/external cables add a weatherproof mylar moisture barrier beneath the UV-stabilised outer jacket, making them suitable for any route that passes outside without additional protection at the transition.

If you need help specifying the right speaker cable for your installation, get in touch with the DTECH team — we supply install-grade AV and data cabling to installers and IT teams across the UK, Europe, and the Middle East.