What the PTT1.3T Tweeter Is and Why It Matters
Purifi Audio’s PTT1.3T04-HAG-01 WG104 is a 1.3-inch aluminum dome tweeter with an integrated 104mm waveguide, designed as a premium home audio transducer offering controlled dispersion, low distortion, and unusually high linear excursion to support low crossover points in high-performance loudspeakers. As Purifi’s first proprietary tweeter, it signals the company’s move beyond amplifier modules and woofers into a full transducer ecosystem for high-end speaker builders. The hard anodized aluminum dome measures 33mm in diameter, coupled to a wide-dispersion cast-aluminum waveguide and a damped rear chamber. A 33mm aluminum voice coil in a neodymium ring magnet motor delivers 1.1mm Xmax and a rated sensitivity of 95dB at 2.83V/1m, positioning this aluminum dome tweeter as a serious option for premium speaker components in both DIY and OEM designs.
Inside the Hardware: Dome, Motor, and Rear Chamber
The PTT1.3T04-HAG-01 WG104 is built around a 33mm hard anodized aluminum dome with a diaphragm area of 9.5cm², which is large for a home audio tweeter and central to its high output potential. The aluminum dome is driven by a 3.5Ω DCR voice coil wound with aluminum wire, 1.8mm in height and working in a 4mm gap to achieve 1.1mm Xmax. According to Voice Coil’s Test Bench, this excursion means “this device will be able to be crossed over comfortably at least as low in frequency as 2kHz.” A neodymium ring magnet motor with very low Magnetic Hysteresis Distortion supports clean high-level operation, while a damped and pressure-equalized rear chamber controls resonance and prevents damage during air shipment. Gold-plated lockable Faston tabs round out the package for straightforward integration into premium speaker components.
Waveguide Design and Directivity Control
What sets this aluminum dome tweeter apart is its 104mm cast-aluminum waveguide, co-optimized with an integrated Coherer phase plug to manage dispersion and loading. The large waveguide helps maintain a wide and predictable beam width; Purifi specifies a -6dB beam width of about ±65°, and the horizontal directivity map normalized to the listening window shows controlled off-axis roll-off without ragged lobing. This waveguide design is especially appealing for high-end audio transducers in living rooms and studios where consistent coverage matters more than on-axis flatness alone. By shaping the wavefront at the source, the WG104 waveguide makes it easier to match directivity with larger midwoofers, improving power response through the crossover. For DIY speaker builders and OEMs, that translates into smoother in-room sound with less trial-and-error in cabinet geometry or baffle shaping.
Frequency Response, EQ Needs, and Harmonic Distortion
Tweeter measurement data from Voice Coil reveals a detailed picture of how the waveguide shapes performance. On-axis, the PTT1.3T measures within ±2.7dB from 854Hz to 19.85kHz, with the aluminum breakup mode appearing around 26.2kHz and useful response extending to 40kHz. As with many waveguide designs, the raw response is not ruler-flat; Purifi provides an example crossover including a parallel LCR EQ network to flatten the waveguide-induced contour when mounted on an infinite baffle. Off-axis, normalized curves out to 45° and a 180° polar plot confirm smooth directivity, supporting crossovers near 2kHz. Distortion measurements at 94dB/1m show second harmonic as the dominant component, with very low third harmonic and second harmonic content below about 1.2% across most of the operating range, aligning with Purifi’s reputation for low-distortion high-end audio transducers.
Implications for High-End Builders and Purifi’s Future
For designers of premium speaker components, the PTT1.3T04-HAG-01 WG104 offers several practical advantages: high sensitivity, controlled directivity, and enough Xmax to cross over near 2kHz without strain. The tightly matched sample-to-sample response, within roughly 0.5–1dB between 2kHz and 20kHz, makes it suitable for stereo and multi-channel systems where imaging depends on close tolerances. DIY builders gain a high-performance aluminum dome tweeter with predictable behavior, while OEM manufacturers get a modern waveguide design that can anchor an entire product line. Perhaps most importantly, this driver marks Purifi Audio’s expansion from amplifier and low-frequency modules into the full bandwidth of transducer design. If their earlier woofers are any indication, the PTT1.3T suggests that future Purifi tweeters and midranges could form a coherent, low-distortion toolkit for the next generation of high-end loudspeakers.