Author Archives: Andy Kos

Custom Crossover Design

We’re not like your typical webshop, that’s just full of random products and meaningless specifications – our range of products is backed up with extensive technical knowledge and many years of experience in the industry. One of the areas we specialise in is custom crossover design. Our test lab is kitted out with prototype cabinets and extensive testing and measuring equipment – and with a huge range of transducers at our disposal, we can fine tune passive crossovers for virtually any combination of devices.

Over the last few years, we have been developing a range of crossovers designed to work with selection of popular transducers. Recently we had to opportunity to put together a custom specification for a customer who was looking to upgrade some existing small speakers with an 8″ woofer and 1″ tweeter. He wanted to increase power handling and performance, and was looking for a premium solution that required the minimum of EQ. This meant a complete rebuild, new woofer, new tweeter and new crossover.

You can read about the design process here: https://speakerwizard.co.uk/designing-a-2-way-crossover-example-project/

If you want to skip to the details, we selected a B&C 8NDL51, B&C DE12TC and B&C ME15 horn flare, all premium components which offered improved sound quality and higher power handling than the original components.


Here are the measurements of the finished design, the red plot is on axis, and subsequent measurements are at 10 degree intervals. Measurements were taken in a standard room with a little dampening material, so will show room reflections.


The B&C 8CX21XLF Revolutionizes Small Sound System Installations

In the world of sound system installations for bars, clubs, and restaurants, the B&C 8CX21 has long been a trusted go-to choice. Revered for its remarkable sound quality and competitive price point, it has won over countless speaker designers and audio enthusiasts. However, one limitation often posed a challenge: the 8CX21’s bass response tended to taper off around 90-100Hz, requiring the addition of a separate subwoofer to fill in the lower frequencies.

Responding to valuable feedback from customers and a growing demand for more comprehensive bass capabilities, B&C Speakers undertook the task of creating a custom version of the 8CX21. The result of this venture is the B&C 8CX21XLF – a transducer designed to deliver an extended bass response without the need for an additional subwoofer in small installations.

Key Tech Specs Comparison:

  • 8CX21XLF: Fs – 53Hz, Xmax – 6.3mm, MMs – 31.6g
  • 8CX21: Fs – 74Hz, Xmax – 5mm, MMs – 21g

The pivotal change in the 8CX21XLF lies in the incorporation of a rubber edge surround on the cone, and a heavier cone, which lowers the woofer’s resonant frequency from 74Hz to 53Hz. This alteration leads to a significant extension of bass response, reaching down to 50-60Hz. As a result, the 8CX21XLF becomes a game-changer for audio engineers and installers, as it effectively eliminates the need for a separate subwoofer in small-scale installations.

It’s important to note that this enhancement comes with a balanced trade-off. Although the 8CX21XLF’s resonant frequency improvement makes it a superior choice for applications where extended bass response is crucial, it slightly reduces the overall efficiency of the woofer. Consequently, there is a decrease in sensitivity and mid-range output compared to the original 8CX21.

Despite the trade-off, the 8CX21XLF’s ability to handle deeper bass frequencies opens new doors for more straightforward and cost-effective installations. Audio enthusiasts can now enjoy an immersive, bass-rich experience without compromising on sound quality. The 8CX21XLF is quickly becoming the transducer of choice for small installers looking to elevate their audio experience and push the boundaries of sound system design.

In conclusion, the B&C 8CX21XLF introduces a paradigm shift in sound system installations with its extended bass response capabilities. The result of dedicated customer-driven innovation, this custom co-axial transducer is setting a new standard in the world of professional audio. By addressing the need for comprehensive bass performance, the 8CX21XLF delivers unmatched audio clarity and a seamless integration that promises to revolutionize sound system design for years to come. Audio professionals and enthusiasts can embrace the potential of a simplified, yet powerful audio experience with the B&C 8CX21XLF.

Ready to buy? Available from our webshop on Blue Aran