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Review conditions. The loudspeakers were placed on Acoustic Revive RST-38 anti-vibration platforms next to my Harbeth M40.1 which I moved aside. To counteract the movement of the M40.1 woofers I shorted out their terminals. The tweeter of the Howard S3 ended up at the same height as the Harbeth midrange, i.e. a little higher than my ears. The loudspeakers were turned inwards such that their axes crossed behind my head. The tweeters were positioned on the inside. The top grille was in place, the front one removed. I used the supplied jumpers.
Description. The Howard S3 from Castle’s Classic Series is the biggest speaker from the company. This is a floorstanding 3-driver model in a 2.5-way configuration. Two mid/woofers of 150mm diameter mate to a 28mm soft dome tweeter with coated diaphragm loaded into a short broad waveguide to control directivity. The former two use a woven carbon fiber diaphragm with a phase plug and cast basket. Their voice coil is made from copper-coated aluminium. Custom-made for this driver are specially shaped pole pieces to increase dynamics. Two drivers mount to the front baffle, with the tweeter below the midwoofer and shifted away from the central vertical axis.
The frontal mid/woofer loads into a quarter-wave labyrinth. The second mid/woofer fires up from the top. Together they create a "twin-pipe quarter wave" with the mouth at the plinth, between cabinet walls and base. Each line is tuned to a different frequency. This is done with an MDF divider that runs the entire length of the enclosure to form two sections, one front one back. Toward the rear sits another panel this time placed at an angle to form a folded line for the top driver. This section is barely damped.
The forward-facing mid/woofer loads into a small sub-chamber which is heavily damped and open to the remainder from beneath. The overall enclosure is 18mm MDF reinforced by cross braces and the internal divider. The veneer is beautiful natural issue. My loaner came in ‘ancient oak’. The box is supported on large spikes with integral swivel protectors.
The crossover mounts to a removable plate on the back. The manufacturer explains that the connections are point to point and that the caps are ICW issue The internal cabling is CasWire made by Castle. I spotted large and very large polypropylene capacitors with the Castle logo on them, an air coil for the tweeter and two very big core coils on transformer frames for the main drivers. All elements of this assembly are made in the Chinese IAG factory. The company also specified WBT terminals which look very good and come in biwire configuration with nicely cabled spade-terminated jumpers made from the internal hookup wiring. These jumpers are worth noting as they transcend the usual massive gold-plated awful sounding metal jumpers.
Technical data (according to manufacturer):
Frequency response: 35Hz-20kHz
Nominal impedance: 8Ω
Efficiency: 90dB/1W/1m
Amplifier power: 25-175W
Dimensions (HxWxD): 1000 x 210 x 335mm
Weight: 26kg