The elysia xfilter 500 Series true stereo 4-band EQ delivers exceptional audio quality with flexible tone-shaping control. Its discrete Class A circuitry produces an open, boutique sound with outstanding transient detail and punch, making it ideal for shaping instruments with precision. A unique switchable low-cut filter helps enhance the high end, while versatile mid-peak options allow detailed midrange sculpting. Stepped controls ensure fast, accurate recall, making the xfilter 500 equally at home in recording, mixing, and mastering environments.
With four highly flexible active bands, the xfilter 500 offers serious tonal versatility. The high- and low-shelf bands can be switched into resonant high- and low-cut filters, while two mid-peak bands provide both narrow and wide Q settings. Additional low-cut stages with shielded coils help produce a smooth, polished top end. A passive high-frequency filter adds a gentle resonance peak around 12kHz and begins rolling off at 17kHz, delivering a subtle lift and sheen that’s perfect for mastering applications. This unique circuit is known as “Passive Massage,” and it adds an unmistakable sense of air and brilliance.
Using analog EQ on stereo sources can be challenging when channel components don’t respond identically, often resulting in phase inconsistencies. The xfilter 500 solves this with true stereo operation, allowing both channels to be controlled from a single set of stepped controls. This ensures precise matching between left and right channels — something rarely found in analog EQ designs.
To achieve this level of stereo accuracy, elysia uses computer-selected dual- and quad-layer potentiometers along with custom low-tolerance capacitors. Every potentiometer is individually measured and tested using elysia’s Audio Precision system and proprietary software. Only the most precisely matched components make it into production, delivering boutique-level performance and consistency that set the xfilter 500 apart in professional studio environments.
The elysia xfilter is a true stereo analog equalizer designed for engineers who demand precision, musicality, and flexibility. Built to overcome the channel-matching challenges typical in stereo EQ design, the xfilter uses computer-selected dual- and quad-layer potentiometers along with low-tolerance capacitors to ensure both channels respond identically. The result is a beautifully open and transparent sound that maintains stereo integrity while delivering powerful tone-shaping control.
Very few analog EQs offer genuine stereo linking due to natural component tolerances that cause left and right channels to behave differently. The xfilter solves this by employing carefully selected multi-layer potentiometers and precision components, allowing both channels to track together accurately for stable imaging and phase coherence when processing stereo buses and full mixes.
The outer bands of the xfilter can operate as smooth, musical shelving filters or be switched into high- and low-cut filters with a 12 dB-per-octave slope and added resonance at the cutoff point. This flexibility allows you to tighten low-end response for punch and clarity or add focused high-frequency presence without over-brightening the entire signal.
The two parametric mid bands offer switchable Q settings between wide (Q 0.5) and narrow (Q 1.0), following a proportional Q design for consistently musical results. These carefully chosen bandwidths make it easy to shape tone naturally without the overly surgical behavior often associated with ultra-narrow filters.
A switchable passive LC high-frequency filter adds a gentle resonance peak around 12 kHz and a smooth roll-off beginning near 17 kHz. This circuit introduces a subtle sheen and air to the top end, enhancing clarity without harshness. Known as “Passive Massage,” this feature delivers a polished, mastering-style brilliance with a single switch.
Each potentiometer in the xfilter is individually measured and selected using precision test systems to ensure tight tolerance matching between layers. This meticulous selection process guarantees consistent stereo performance and is a key factor behind the unit’s boutique-level accuracy and reliability.
The xfilter’s four-layer PCB design includes a dedicated ground shield layer positioned close to the audio traces. This significantly reduces susceptibility to hum and electromagnetic interference, preserving signal purity even when filter stages operate at higher impedances at lower frequencies.
The Mastering Edition of the xfilter builds upon the original design with refinements tailored for critical mastering work. It delivers pristine transparency, enhanced precision, and optimized control ranges to help engineers focus on the finest details of a mix while maintaining full musical integrity.
The Mastering Edition features a refined ±5 dB control range across all four bands, allowing for subtle, repeatable tonal adjustments. Combined with stepped potentiometers and clearly defined scales, it offers the accuracy required in professional mastering environments.
With extended headroom up to +27 dBu, the xfilter | Mastering Edition provides ample dynamic space for processing complex program material without distortion. This ensures pristine clarity whether working on delicate acoustic recordings or dense, high-energy mixes.
Available in multiple hardware formats, the xfilter series delivers the same exceptional sound quality regardless of version. Whether used in tracking, mixing, or mastering, it offers consistent performance and musical results across all professional audio applications.
The elysia xfilter and xfilter | Mastering Edition are high-end stereo equalizers built for total sonic control with uncompromising transparency. Featuring fully parametric mid bands, flexible shelving and cutoff filters, and premium analog circuitry, they provide the precision needed for detailed tone shaping while preserving the natural character of your audio. Built with exceptional craftsmanship and reliability, the xfilter series stands as a powerful toolset for engineers seeking professional-grade results in any production environment.
| Number of Channels | 1 (Stereo) |
|---|---|
| High Pass Filter | Yes |
| Low Pass Filter | Yes |
| Number of Bands | 4-band |
| Boost/Cut Range | ±13dB or ±16dB |
| Q Type | Selectable |
| Freq Range High | 700Hz–28kHz |
| Freq Range Hi-Mid | 300Hz–16kHz |
| Freq Range Lo-Mid | 45Hz–2.2kHz |
| Freq Range Low | 20Hz–900Hz |
| Frequency Response | 10Hz–400kHz |
| Manufacturer Part Number | xfilter 500 |
