Purifi’s Debut Tweeter: A Purpose-Built High-Frequency Engine
With the PTT1.3T04-HAG-01 WG104, Purifi Audio finally brings its obsessive engineering approach to the high-frequency range. This 1.3" aluminum dome tweeter has been in development for over two years and is clearly aimed at premium home audio components and serious DIY speaker building projects. The most striking feature is the unusually large 33 mm diaphragm (9.5 cm²) combined with a substantial 1.1 mm linear Xmax, allowing comfortable crossover points at or below 2 kHz—territory where many dome tweeters begin to struggle. The hard anodized aluminum dome is driven by a 33 mm aluminum voice coil with a 3.5 Ω DCR, energized by a neodymium ring magnet motor optimized for very low Magnetic Hysteresis Distortion. A carefully damped, pressure‑equalized rear chamber prevents damage during air shipment while also controlling resonances. Overall sensitivity is a healthy 95 dB (2.83 V/1 m), giving designers plenty of headroom in both passive and active systems.
Waveguide and Coherer: Directivity by Design, Not by Accident
A standout element of this Purifi Audio tweeter is its cast-aluminum, wide-dispersion waveguide with an integrated Coherer phase plug. Rather than treating the faceplate as a cosmetic part, Purifi has co-optimized the waveguide and dome to manage dispersion, loading, and directivity in a controlled, predictable way. The 104 mm waveguide helps maintain a broad listening window while boosting sensitivity and lowering distortion around the crossover region. Measured beamwidth at –6 dB is ±65°, which translates into an impressively wide horizontal coverage for a waveguide-loaded aluminum dome tweeter. The normalized horizontal polar map shows smooth, gradual off-axis roll-off rather than ragged lobing, making it easier for DIY designers to achieve consistent in-room response. For builders targeting high-performance home audio components or nearfield studio monitors, this kind of controlled directivity is key to imaging stability and tonality across the listening area.
Frequency Response and Example Equalization Strategy
Measured on a 15" × 8" baffle, the PTT1.3T04-HAG-01 WG104 delivers an on-axis response within ±2.7 dB from 854 Hz to 19.85 kHz, extending cleanly to 40 kHz. As with many modern waveguide-loaded tweeters, the raw response is not ruler flat: the waveguide’s acoustic loading shapes the magnitude response, and an aluminum breakup mode appears around 26.2 kHz. This is above the audible band for most listeners, but it still matters for designers seeking textbook behavior. Purifi anticipates this and provides an example crossover network that incorporates a parallel LCR equalization circuit to flatten the response when mounted in an infinite baffle. DIY speaker building enthusiasts can use this as a starting point, adapting the topology to their own baffles and crossover frequencies. The takeaway is clear: this driver is designed to be integrated with thoughtful filtering rather than dropped into a design without proper response shaping.
Off-Axis Performance, Consistency, and Distortion Metrics
Off-axis measurements show the aluminum dome tweeter behaving in a well-controlled and predictable manner. Horizontal responses at 0°, 15°, 30°, and 45° maintain similar overall shape, with energy gradually tapering off as angles increase. The 180° CLIO polar plot in 10° steps confirms a smooth directivity transition—good news for anyone tuning room response or targeting a specific power response profile. Sample-to-sample consistency is excellent, with two units matching within roughly 0.5–1 dB from 2 kHz to 20 kHz. Distortion testing at 94 dB SPL (1 m, equivalent) reveals distortion dominated by the second harmonic, while third harmonic components remain very low. Even the second harmonic stays below about 1.2% across most of the working band. For a high-output, low-crossover aluminum dome tweeter, this performance firmly places the PTT1.3T04-HAG-01 WG104 among the most technically refined options available to DIY and OEM designers.
What It Means for DIY Speaker Building and High-End Designs
Taken as a whole, the PTT1.3T04-HAG-01 WG104 encapsulates Purifi Audio’s philosophy: rigorous engineering, verifiable measurements, and application-focused design. The combination of a large 33 mm dome, high sensitivity, generous Xmax, and a carefully engineered waveguide makes this aluminum dome tweeter particularly attractive for 2‑way and 3‑way systems that demand low crossover points without sacrificing headroom or distortion performance. For DIY speaker building enthusiasts, it offers a modern, measurement-backed platform around which to design ambitious home audio components and studio monitors. The detailed data set, example EQ network, and predictable directivity ease the integration burden, letting designers concentrate on crossover voicing and system tuning. Given its measured behavior and build quality, this first Purifi Audio tweeter looks poised to become a reference choice in the premium high-frequency driver space for years to come.