The design of our 1961 speakers are built around a 28mm synthetic soft dome with custom-designed, matching waveguide. The design of this tweeter was made on the 1723 series, and most of its design principles are trickled down to the 1961 series. The soft dome itself is very light weight, totally pistonic to ultra-high frequencies, optimally damped, produced to exceedingly tight tolerances and specifically chosen for its sweet sound character and consistent frequency response. We are basically utilizing the same tweeter as in the 1723 series, but instead of a neodymium magnet assembly we have opted for a less expensive ferrite magnet assembly that still makes the tweeter sound exquisite.
The role of the waveguide is to take an already excellent tweeter and provide refinements to the tweeter’s performance. The size and shape, although appearing rather simple, is in fact the result of painstaking modeling, testing and refinement. In precisely controlling directivity across the tweeter’s frequency range, we are able to broaden top end dispersion, which the tweeter naturally wants to beam straight ahead and focus frequencies at the bottom end of the tweeters range, which naturally want to spread out in all directions. This provides a more consistent polar response across the tweeters entire range and provided a close match to the dispersion pattern of the mid-bass driver it works with, simplifying crossover design.
Design
Everything about this tweeter except for the diaphragm is completely ground up modelled, designed and tooled. The motor of this tweeter is a powerhouse, all bespoke designs for Arendal Sound and extensive FEA modelling and optimization through Comsol. As per usual we use Klippel analysis to review all driver designs.
The end result is a high performance, high power handling tweeter with very good bandwidth, low distortion and high efficiency.
- High temp polyimide CCAW wire.
- Underhung voice coil design.
- Ultra-low viscosity Ferrofl uid contributes to voice coil cooling and ensures the best possible transient response.
- Large aluminum heatsink/shorting ring lowers distortion and prevents thermal compression.
- Multiple vents for increased airflow and balanced compliance.
Waveguide assembly
The waveguide is specifi cally designed for the new 1961 tweeter and its new speaker applications. It’s a constant directivity, custom-designed and tooled waveguide in ABS plastic material, thick and sturdy to avoid any resonance. To put that final touch of feel and looks to the waveguide assembly, we have designed and tooled an NBR rubber ring that fits smoothly to the end of the waveguide shape covering screw holes and showing off a subtly integrated Arendal Sound logo.
The waveguide serves several purposes, augmenting tweeter performance to a level that no fl at baffle e mounted single dome solution could reproduce:
- Increased efficiency by controlling lower frequency dispersion – Typically a 6dB gain.
- Very low distortion due to increase in bottom end efficiency.
- Precise Polar Response control (constant directivity).
- Low crossover frequency (approx. 1 octave lower than without the waveguide).
- Excellent directivity transition from mid/woofer to tweeter.
Air flow venting
The air chambers, venting and damping materials found behind the dome and surround are optimized to create a very well-controlled impedance, void of secondary resonance spikes that typically result in electrical phase shifts that present an awkward load for amplifiers and further smear the sound, adding a harsh character
