SonaVyx vs REW

SonaVyx vs Room EQ Wizard: Two Philosophies for Audio Measurement

Room EQ Wizard (REW) has been the go-to free audio measurement tool for audiophiles, home theater enthusiasts, studio builders, and professional acoustic consultants since its initial release in 2006. Developed by John Mulcahy, REW has earned its reputation through an extraordinary depth of features — from basic SPL metering to advanced room simulation, multi-sub optimization, and automatic EQ filter generation — all provided completely free of charge. The software has an active community forum with thousands of members who share measurement techniques, troubleshooting advice, and room treatment strategies. Any honest comparison must start with this acknowledgment: REW is one of the most generous contributions to the audio measurement community, and it has enabled thousands of people to improve their listening environments who otherwise would not have had access to measurement tools.

REW's Strengths: Depth and Comprehensiveness

REW excels in areas where depth of analysis matters. Its cumulative spectral decay (waterfall) plots reveal frequency-dependent decay behavior that identifies room modes, resonances, and decay anomalies that a simple RT60 number cannot capture. The room simulator predicts modal behavior based on room dimensions, helping users understand which standing waves are causing problems before they even take a measurement. REW's EQ filter generation is arguably its most powerful feature: after measuring your room, the software automatically calculates a set of parametric EQ filters that, when applied to your playback chain, flatten the room's frequency response at the listening position. These filters can be exported directly to miniDSP processors, Dirac Live, Roon, and other DSP platforms. The multi-sub optimizer calculates optimal placement, delay, level, and polarity for multiple subwoofers to achieve the smoothest bass response — a capability that home theater builders particularly value. REW also supports all major measurement microphones through calibration file import, enabling Class 1 accuracy when paired with appropriate hardware.

SonaVyx's Approach: Accessibility, AI, and Mobility

SonaVyx approaches audio measurement from the perspective of accessibility and intelligence. Where REW requires downloading and installing a Java application, configuring audio device drivers, and navigating a feature-rich but complex interface, SonaVyx runs in any modern web browser with zero installation. Open the URL, grant microphone permission, and start measuring. This browser-first architecture means SonaVyx works on smartphones, tablets, laptops, and desktops without any platform-specific considerations. For users who are intimidated by REW's extensive feature set — and there are many, judging by the forum posts from newcomers struggling with setup — SonaVyx provides a guided workflow that captures measurements and delivers actionable results without requiring deep knowledge of acoustic measurement theory.

AI Diagnostics: What Your Data Means

The fundamental difference between SonaVyx and REW lies in what happens after the measurement. REW provides extraordinarily detailed data visualization — waterfall plots, spectrograms, group delay curves, minimum phase extraction, excess group delay calculation — but interpreting this data requires significant knowledge and experience. Understanding what a 15 dB peak at 63 Hz means for your listening experience, whether it is caused by a room mode or a boundary reinforcement effect, and what the most effective treatment strategy would be — these are questions that REW leaves to the user. SonaVyx's AI diagnostic engine, powered by Claude, analyzes the measurement data and provides specific, contextualized answers. It identifies the likely cause of each anomaly, recommends treatment approaches ranked by effectiveness and cost, and predicts the expected improvement from each intervention. For experienced acousticians, this serves as a second opinion. For newcomers, it bridges the knowledge gap between collecting data and knowing what to do with it.

Multi-Device Measurement: No Audio Interface Required

REW requires an audio interface to capture microphone signals, which adds $100-$500 to the setup cost and introduces complexity around driver configuration, sample rate matching, and latency management. SonaVyx uses the smartphone's built-in microphone directly, and its multi-device WebSocket architecture enables two-phone measurement without any audio interface at all. This is particularly significant for dual-channel measurements (transfer function, coherence) where the reference and measurement signals traditionally must arrive at the same device. With SonaVyx, one phone generates or captures the reference signal while another captures the measurement at a different location — connected wirelessly rather than through cables. For room acoustic measurements where you need to capture from multiple positions, this mobility is transformative.

Professional Use Cases Beyond Room Correction

While REW focuses primarily on room acoustic measurement and correction, SonaVyx addresses a broader range of professional audio measurement scenarios. Sound insulation testing per ISO 16283, noise dose monitoring for occupational health compliance, speech intelligibility (STI) measurement per IEC 60268-16, and environmental noise assessment per ISO 1996 are all capabilities that SonaVyx provides but REW does not. The professional PDF report generator creates branded, standards-compliant documentation for client delivery — essential for consultants and integrators who need to document their work formally. These capabilities make SonaVyx a more complete platform for audio professionals who work across multiple domains, while REW remains the deeper tool for the specific domain of room acoustic measurement and correction.

When to Use Each Tool

Choose REW if you are focused on room acoustic correction, need EQ filter generation for miniDSP or Dirac Live, want the deepest possible analysis tools (waterfall, spectrogram, room simulation, multi-sub optimization), prefer a mature application with extensive community support, or need to work offline without an internet connection. Choose SonaVyx if you want measurement tools that work on your phone without installing anything, value AI-powered diagnostics that tell you what to do (not just what the data looks like), need multi-device measurement without an audio interface, require professional-grade reports for clients, or work across multiple measurement domains (live sound, building acoustics, environmental noise). Both tools can coexist in your workflow: use REW for detailed room correction and EQ generation at your studio or home theater, and use SonaVyx for on-site measurements, quick checks, and AI-assisted analysis whenever you need a measurement tool and only have your phone.