Bookshelf Speakers — Westlake BBSM-4

The BBSM-4 is the smallest monitor in the BBSM range from Westlake Audio, an American company founded in 1971 whose designer and president is Glenn Phoenix. It was conceived as a portable reference for close listening, and Westlake lists project studios, mobile recording, editing suites and broadcast on-air or production rooms as its intended homes. The cabinet is laid out horizontally so that it can sit on a console meter bridge, and the maker states that it works at distances as short as about 45 cm from the listener. The model was already in production by 1992 and remained in the catalogue into the 2000s.

Key specs that matter

Inside the box sits a passive two-way arrangement of two 4 inch bass and midrange drivers and a single 3/4 inch soft fabric dome tweeter, divided by a crossover at 1.5 kHz. Rated response runs from 65 Hz to 20 kHz within plus or minus 3 dB, and sensitivity is quoted as 89 dB at 1 m for a 2.83 V input. Nominal impedance is 4 ohms with a minimum of 2 ohms. Power capacity follows the IEC method, with 80 W short term and 200 W long term. The enclosure measures 20.3 x 38.1 x 25.4 cm and weighs 11.3 kg.

Engineering and use context

The two small woofers flank a central tweeter, and the bass reflex port is placed directly below that tweeter, giving a centrally ported front panel. Each cone is made of doped paper and rides on a roll surround. All three drivers are recessed so their frames sit flush with the baffle surface, but there are no stepped offsets between drivers for time alignment, unlike the later Westlake Lc range. The MDF cabinet carries a black textured utility paint rather than a veneer. Connection is through a heavy duty barrier strip with four terminals, and short link cables are supplied for normal single-cable use.

Pairing

The low minimum impedance means an amplifier must stay stable and deliver current into very low loads, so a solid state design with a real low impedance rating is the logical partner and not a low-output tube amplifier. Because the terminal strip has separate pairs for each driver section, bi-wiring with two runs of cable from a single stereo amplifier is possible once the links are removed. In a desktop or console setting the pair can be driven by a compact studio power amp placed under the desk, with the speakers raised to ear height on the bridge.

Alternatives

For a vertically oriented Westlake stand-mount with a single 4 inch driver and a walnut option, the Lc4.75 is the closest two-way sibling.