Hertz Cento CBA 250
High Efficiency, High Power Sub-bass From a Compact Enclosure
Hertz released its Cento range of speakers and subwoofers a few years ago. The design concept was devised around a need to provide exciting and energetic sound production predominantly for a young market.
The range has sold well worldwide, and a dramatic shift towards plug-and-play bass solutions has led to the development of an active subwoofer box.
The CBA 250 features a 10″ subwoofer in a rigid box. Also in the box is an amplifier module capable of delivering 250 watts RMS.
The Box
The enclosure in which both the speaker and amplifier module sit is made from braced high-density MDF. The bracing helps with rigidity. At low frequencies, it can be easy for a weak enclosure to dissipate uncontrolled bass, which would detract from performance.
The enclosure is mounted on four resonance-free, removable feet. It can be mounted face down, or the feet may be removed, and the cabinet mounted face up. This will give two very different types of bass. The feet themselves are finished with velcro-style hooks which securely fasten the enclosure to any automotive carpet.
Looking at the connections, a plug-and-play removable power socket allows the subwoofer to be quickly and safely disconnected when additional luggage space is required.
The Speaker
A key objective in the design of the CBA 250 was to make it as energy-efficient as possible. Modern Class D amplifiers will run at astonishingly low impedances, provided they run into a stable and matching load. The 10″ subwoofer pictured above has a nominal impedance of 0.4 ohms, which helps with efficiency. The motor and suspension of the Cento range of subwoofers already facilitate high-efficiency running, but this speaker has been further refined to increase even this.
A wide surround assists with extended excursion, which is desirable when handling powerful low-end transients.
The Amplifier
Perhaps the most amazing feature of this active subwoofer is the amplifier module. By optimising the impedance of the speaker, it was possible to design the powerful amplifier into the smallest space. A large amount of space in most automotive Class D amplifiers is needed for a DC-to-DC convertor. In this product, the module actually runs from the 12 Volt input, which allows the amplifier module to be reduced in size. A heatsink is incorporated into the module, and the overall efficiency of the system means that there is no need for external or forced-air cooling.
The amplifier module is also crammed with features that tune the package for optimum performance. An on-board Butterworth 12dB/octave low pass filter can be adjusted between 50-500Hz, but may be bypassed when connected to an amplifier with built-in DSP. There is also the facility to add an optional wired remote level control (HRC AP). An integral phase adjustment (0 – 180°) is also included.
The module will accept either a high-level or line-level input.
Go to your local FOUR MASTER to learn more and see the product. https://www.fourmasterscaraudio.co.uk/four-masters
