Description
Overview
The Master Series M1 tweeter is a high stroke, low distortion multilayer fabric dome 25mm tweeter. This tweeter features exceptionally high stroke to allow lower crossover points without compression.
The M1 tweeter features a split-gap design which provides ±1.6mm of linear excursion, approximately 5 to 6 times that of most other tweeters. The result is a wider operational bandwidth – as low at 1500 Hz – and distortion reduced by up to a factor of 4.
The M1 use a specially developed dome material. The dome’s fabric is a lamination of silk, polyester, and cotton and treated with a proprietary compound to unify the layers but allow each to provide their own unique benefits. Silk adds the stretch/pull basic mechanical strength; polyester provides rigidity of shape; cotton provides improved damping.
The M1 does not use a rear chamber to lower its resonance; instead, a larger roll surround provides a lower resonance of the driver. This design allows for higher stroke as well, for full-range output down to 1500 Hz. And by removing the rear chamber, resonances from that chamber are eliminated. The elimination of the rear chamber results in an 11.7mm (15/32”) mounting depth for freedom of positioning.
The M1 comes with a chemically etched steel grille featuring an anti-resonant hole-pattern with size of opening optimized for dispersion. The grille is mounted to the main tweeter with a friction-fit gasket ensuring vibration-free operation and eliminating visible screws.
Crossover Frequency and power handling
The M1 Tweeter is a wideband, high stroke tweeter. This gives it quite a bit of flexibility in operation. The following table summarizes general guidelines. As noted above, this is not a hard-and-fast set of limits, and the final installation needs to be considered when setting actual crossover values and gains.
| Power | 6dB/Oct | 12dB/Oct | 18dB/Oct | 24dB/Oct |
| 50W | 2000 Hz | 1750 Hz | 1500 Hz | 1200 Hz |
| 100W | 2800 Hz | 2200 Hz | 2000 Hz | 1800 Hz |
| 200W | 4500 Hz | 3500 Hz | 2600 Hz | 2350 Hz |
| 400W | Not Recommended | Not Recommended | Not Recommended | 4000 Hz |
Not that with lower power applications, these frequencies may be adjusted down; with higher power, you may need to adjust the frequencies up. Again, the actual implementation of the entire system needs to be considered when installing these products.
Thiele Small Parameters
| Impedance | 4 Ohms |
| Nominal SPL | 89 dB @ 1W, 1m (92 dB @ 2.83Vrms, 1m) |
| Resonant Frequency | 1500 Hz ±10% |
| THD @ 100 dB, 4th order high pass @ 1500 Hz | Less than 1%, 1 meter |
| Max power handling | 400W, 4th order high pass @ 4000 Hz |
