VIAWAVE GRT-145W-8
VIAWAVE GRT-145W-8 — Ribbon Tweeter with Waveguide · Ribbon / Planar Magnetic
95 dB - 8 Ohm - 1,800 – 30,000 Hz - 17 W RMS
Part no.: 42A-CHS-BT-VIA-0004
Documents
VIAWAVE GRT-145W-8 — Ribbon tweeter with waveguide
Waveguide version: higher efficiency at the lower end of the range and controlled dispersion.
95 dB sensitivity · 8 Ω · Frequency range 1.800 – 30.000 Hz
What the SRT technology does
In a classic ribbon tweeter the air gap between ribbon foil and magnet poles is open. Viawave seals it with a U-shaped, heat-resistant polymer film — the patented SRT technology (Sealed Ribbon Tweeter). Two things follow: distortion at the lower end of the range drops markedly, and sensitivity rises by 2 to 3 dB. For a ribbon with only 7 cm² of diaphragm area, 95 dB is an unusual figure.
Technical data
| Nominal impedance | 8 Ω |
|---|---|
| Recommended frequency range | 1.800 – 30.000 Hz |
| Sensitivity (2,83 V / 1 m, 2 – 10 kHz) | 95 dB |
| Power handling, RMS | 17 W |
| Power handling, peak | 40 W |
| Programme power (high-pass 3.000 Hz, 12 dB/oct.) | 150 W |
| Rear chamber resonance | 900 Hz |
| Ribbon dimensions | 14 × 50 × 0.009 mm |
| Ribbon area | 7 cm² |
| Ribbon mass | 0,018 g |
| DC resistance Re | 0,06 Ω |
| Inductance (low frequency) | 7 mH |
| Inductance (high frequency) | 0,034 mH |
| Flux density in the gap | 0,65 T |
| Net weight | 1,43 kg |
Materials
| Ribbon | Aluminium |
|---|---|
| Waveguide | Aluminium |
| Magnets | NdFeB |
| Magnetic circuit | Low-carbon steel |
| Rear chamber | Natural wool |
Use
Der Hersteller gibt einen Hochpass ab 3.000 Hz mit 12 dB/Oktave an. Tiefer trennen geht mit der Waveguide-Version leichter, weil der Wirkungsgrad im unteren Bereich höher liegt. Die Belastbarkeitsangabe von 150 W gilt ausdrücklich nur mit dieser Weiche — ohne Hochpass ist ein Bändchen sofort zerstört.
The manufacturer's datasheet with frequency response, impedance and distortion measurements is available for download above. Part no.: 42A-CHS-BT-VIA-0004
Viawave GRT-145W-8: waveguide ribbon tweeter with 95 dB at 8 Ω for a lower crossover
If you want to integrate a ribbon lower than a flat faceplate allows, the Viawave GRT-145W-8 is the tool. The aluminium waveguide in front of the foil raises efficiency at the lower end of the operating range and controls dispersion; the 95 dB sensitivity (2.83 V/1 m) is therefore quoted for 2 to 10 kHz – exactly where the handover to the midrange takes place. With 8 Ω nominal impedance the driver is the relaxed load for passive crossovers and valve amplifiers.
The foundation is the same as on all Viawave ribbons: SRT technique (Sealed Ribbon Tweeter), meaning an air gap sealed with a U-shaped, heat-resistant polymer film that cuts distortion at the bottom end noticeably and adds 2 to 3 dB of sensitivity. The aluminium ribbon measures 14 × 50 × 0.009 mm at 0.018 g and 7 cm², the NdFeB magnets produce 0.65 T in the gap, and the rear chamber is damped with natural wool. Operating range 1,800 to 30,000 Hz, weight 1.43 kg.
Use and enclosure
The manufacturer's spec: high-pass from 3,000 Hz at 12 dB/octave, at which the 150 W program rating applies. Thanks to the waveguide the way down is shorter than on the version without – the range starts at 1,800 Hz, and the higher efficiency there means the crossover has to boost less. Below the spec you still cross only with a steeper slope: 17 W RMS and 40 W peak are the physical limits of the ribbon, and the rear chamber resonates at 900 Hz. Without a high-pass the driver is destroyed instantly.
In crossover simulation, use the measured impedance: 0.06 Ω ribbon, 7 mH low-frequency and 0.034 mH high-frequency inductance at the transformer. When mounting, mind the directivity – the waveguide defines the coverage angle, and the 50 mm tall ribbon stays narrower vertically than horizontally. Ear height and a short distance to the midrange keep the transition clean.
What to look out for
- 8 Ω via transformer – uncritical for passive crossovers and valve amplifiers
- Aluminium waveguide – controlled dispersion, higher efficiency at the lower end
- High-pass from 3,000 Hz at 12 dB/oct – 150 W program applies only with this filter
- 17 W RMS, 40 W peak, chamber resonance 900 Hz – keep the crossover well clear of it
- 1.43 kg – the waveguide needs room in the baffle
Frequently asked questions
How low can I cross the GRT-145W-8?
The spec is 3,000 Hz at 12 dB/octave. The waveguide makes the range down to 1,800 Hz more usable than on the flat version, but then with a steeper slope – the 17 W RMS rating does not change.
Does the GRT-145W-8 work with a valve amplifier?
Yes. At 8 Ω and 95 dB it is a benign load that needs little power. The high-pass in the passive crossover is mandatory regardless of amplifier type.
What is the difference to the GRT-145-8 without waveguide?
Same ribbon, same SRT technique, same operating range. The GRT-145W-8 brings more level at the lower end and a defined dispersion, but is somewhat heavier and deeper because of the waveguide.
Viawave GRT-145W-8: manufacturer, spellings and classification
Viawave (Viawave Audio) is the maker of the patented SRT ribbon tweeters with sealed air gap. The GRT-145W-8 is a ribbon tweeter, available from 42.audio, Viawave dealer in Germany, with datasheet and full specifications in the driver database.
At 42.audio you get the VIAWAVE GRT-145W-8 with all key data in the driver database. More drivers from this manufacturer: Atlas Viawave.
Specifications
| Allgemein | |
|---|---|
| Manufacturer | VIAWAVE |
| Category | Ribbon Tweeter |
| Series | GRT-145 |
| Impedance (Ω) | 8 |
| Power handling (W) | 17 |
| Sensitivity (dB) | 95 |
| Frequency from (Hz) | 1800 |
| Frequency to (Hz) | 30000 |
| Abmessungen & Korb | |
|---|---|
| Weight (kg) | 1.43 |