AudioQuest Forest Coaxial Digital Audio Cable (3m Single)

AudioQuest Forest — Digital Coaxial Audio Cable

The Forest is the second tier in AudioQuest's digital coaxial cable range, above the entry-level Pearl and below the Cinnamon. The digital coax lineup follows the same naming convention and silver-plating hierarchy as AudioQuest's HDMI and other digital cable ranges: Pearl (solid Long-Grain Copper), Forest (0.5% silver-plated LGC), Cinnamon (1.25% silver), Carbon (5% silver), Coffee, and Diamond (100% solid Perfect-Surface Silver). This is a 75-ohm single RCA-to-RCA S/PDIF cable designed to carry digital audio between a CD player, transport, streamer, or other digital source and an external DAC. It is not a stereo analogue interconnect — it carries a single digital data stream, with the DAC at the receiving end performing the conversion to analogue audio.

Why Silver Plating Matters More on Digital Than Analogue

AudioQuest's rationale for silver-plating the conductor of a digital coaxial cable is rooted in a specific electrical property: the skin effect. At the high frequencies used by digital audio signals (S/PDIF operates in the megahertz range), electrical current travels almost exclusively on the outer surface of the conductor rather than through its full cross-section. This means the surface material of the conductor disproportionately defines the cable's performance. By applying a 0.5% silver plating to the outside of a solid Long-Grain Copper conductor, AudioQuest places a higher-purity, higher-conductivity metal exactly where it matters most. The result is performance that approaches that of a solid silver cable — silver being the highest-conductivity metal available — at a price point much closer to copper. This is what makes the Forest a particularly cost-effective entry point into silver-conductor digital cables.

The conductor itself is solid rather than stranded. In any cable, electrical and magnetic interactions between the individual strands in a stranded conductor create distortion. In a digital cable, this strand-interaction distortion manifests as jitter — timing errors in the digital data stream that compromise the DAC's ability to accurately reconstruct the analogue waveform. Solid conductors eliminate strand interaction entirely, which is why AudioQuest uses them across every tier of their digital range.

Hard-Cell Foam Insulation and Impedance Consistency

Where AudioQuest's analogue interconnects (like the Evergreen) use foamed polyethylene insulation, the Forest digital coax uses Hard-Cell Foam — a related but functionally distinct material. Like foamed PE, Hard-Cell Foam is nitrogen-injected to create air pockets, and since air absorbs almost no energy, the dielectric effect on the signal is minimised. The critical difference is in the name: the foam is deliberately "hard" — stiff enough to lock the conductor into a consistent geometric relationship along the full length of the cable. This stiffness is essential in a digital coaxial cable because the characteristic impedance (75 ohms for S/PDIF) must remain consistent from end to end. Any variation in the spacing between the central conductor and the surrounding shield will cause localised impedance mismatches, creating signal reflections that degrade data integrity and introduce jitter. Hard-Cell Foam prevents the conductor from shifting or flexing within the cable, maintaining that consistent 75-ohm impedance along the entire run.

Shielding and Noise-Dissipation

The shield on a coaxial digital cable has a dual role that makes it more critical than the shield on a typical analogue interconnect. It functions both as a conventional electromagnetic shield (blocking external interference) and as the signal return path — the ground conductor through which the return current flows. Because the shield directly participates in the signal circuit, its metal quality and fabrication affect sound quality in a way that goes beyond simple noise rejection. AudioQuest uses foil plus tinned braid for 100% shield coverage on the Forest.

The Metal-Layer Noise-Dissipation System (NDS) addresses the same ground-plane contamination problem found across AudioQuest's cable range: conventional shields capture radio-frequency interference effectively, but then drain that captured energy directly to the equipment's ground plane, modulating the ground reference and introducing distortion into the signal. The NDS absorbs and reflects most of this captured RFI before it reaches the ground-connected layer, preventing the shield's noise-rejection function from undermining the signal quality it is supposed to protect. All internal conductors are direction-controlled — oriented during manufacture to direct RF noise propagation in the optimal direction.

Terminations and Build

The Forest uses cold-welded, gold-plated RCA terminations. Cold welding bonds the conductor to the plug using several tonnes of pressure rather than solder, avoiding the introduction of a dissimilar metal at the junction (solder is a relatively poor conductor) and the heat damage that soldering inflicts on the copper's crystal structure at the termination point. The ground shells are stamped rather than machined, allowing the metal to be selected for its low-distortion properties rather than its machinability. The cable carries a green-on-black aesthetic consistent with the Forest name across AudioQuest's product lines.

When to Use Digital Coax vs Optical vs USB

Many DACs offer multiple digital inputs — coaxial S/PDIF, optical (Toslink), USB, and sometimes AES/EBU. Digital coaxial has long been regarded as the preferred connection for dedicated CD transports and legacy digital sources because it supports higher sample rates than optical Toslink (up to 24-bit/192kHz vs optical's practical limit of 24-bit/96kHz on most equipment) and uses a purely electrical connection with no optical-to-electrical conversion at each end. USB has largely overtaken coaxial for computer-based and streaming sources, but coaxial remains the standard for connecting standalone CD players and transports to external DACs, and many audiophiles prefer its simplicity and consistent performance characteristics. The Forest is available in four lengths: 0.75m, 1.5m, 3m, and 5m.

Specifications