Aurus is a two-way system with a 6.5" Peerless CC-line woofer and a 1" Peerless soft-dome tweeter. The tweeter is mounted at the back of the baffle in an exponential horn with machine-screws and nuts in the cast concrete. The woofer is mounted in the same way at the front of the baffle. The baffle is designed for low diffraction-effects and a nice look, and care is taken to handle the time-delay between the driver elements. The exponential horn works as an acoustic transformer and the benefitof using it in the design is that, when you compensate for amplification of the horn in the filter, you also lower the distortion.The use of the horn loading also allows you to place the treble driver in the correct time-delay plane. The enclosure is made of 19 mm MDF finished in an ash veneer.
The vent is 68 mm in diameter and ends in the bottom of the enlosure. This makes the vent resonances less noticeable. The vent is tuned to about 44 Hz.
The woofer is acoustically damped; that is, you put the damping material at the back of the driver basket. This is a damping method that is not commonly used, but it is recommended by, for example, Doctor R.H. Small. Adding this type of damping allows you to adjust the driver-parameters.
The filter in my speaker system includes a CFAC-inductor in series with the woofer and MIT-capacitor in series with the treble. The other elements in the filter are polypropylene capacitors and non-inductive resistors. The crossover frequency is roughly 1800 Hz with a 6 dB slope on the treble and 12 db slope on the woofer. The filter construction is computer-optimized using the CALSOD software package and fine-tuned by listening. The filter is hard-wired at theloudspeaker terminals. The terminals that are provided support bi-wiring. The loudspeaker's outside dimensions are: W = 24 cm, H = 42 cm and D = about 28 cm.
I´ve also constructed a stand with three legs that goes well with the loudspeaker design. This stand rests on three brass cones and is made of rectangular steel tubes that are supposed to be filled with sand or lead. The height of the stand is 65 cm including Sonic Design damping feet which I use between the stand and the loudspeaker to minimize vibrations in the enclosure.
All in all, this is a loudspeaker that is capable of drawing the most out of recorded material. It has got an ability to clearly reproduce a very wide dynamic range, from the softest micro-details to the very loudest crescendos.