Active Subwoofer Crossover

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I am presenting the Model CR1 “Active Subwoofer Crossover” which I designed as Director of Home Electronics R&D at JL AUDIO headquartered in Miramar, Florida. We are widely known for our high-end home audio subwoofer products and a full range of car and marine audio products.

The CR1 is intended for high-end audio applications in multichannel home theaters and stereo music systems that use one or more subwoofers to augment the low frequency reproduction. The electronic circuitry comprises a unique topography making digital control of precision analog filters possible without any digital zip or hash noises. That is one of the distinguishing factors of this product whereas other manufacturers have moved into cheaper digital audio processing to provide this function. High end audiophiles still reject digitally processed sound as inferior to pure analog. My design preserves the perfection of the analog audio signal and there is no A-to-D and D-to-A conversion needed.

The two chief premises for design of this product were to provide a unique and attractive industrial design (appearance) and render superlative audio performance. It also had to be economically manufacturable and have built-in reliability to provide many years of service. The product also had to be properly defined for suitability and marketability.

Of course, marketability can be enhanced by nice styling but before any work was done with the packaging the functionality was researched to improve upon any competing products. Nine variations were evaluated before I had a handle on the final product definition.
Once a definition was achieved, I set out to design the product. I used CAD systems for solid modeling and PCB layout. The entire assembly was computer modeled. Circuit simulation was used, but most of the analog circuit design was rendered from my own forty years of experience designing high quality audio equipment.

Regarding industrial design, the front panel is an aluminum extrusion that was borrowed from a previous amplifier product (I'll call it the "father") to maintain the family appearances. It was somewhat modified to meet new control space and graphics needs. The father attaches to a cast aluminum chassis but the new product has to be attached to a sheet metal chassis to reduce production tooling cost. A novel adapter was created to allow smooth and seamless attachment of the sheet metal chassis to the panel extrusion.

To further widen the potential market beyond home audio and into professional studio systems and installed sound systems, I put virtually every type of standard audio interface connector on the rear panel so any user could find what they need. Fully professional balanced XLR jacks, semi-pro balanced ¼ inch phone jacks and consumer unbalanced RCA jacks are all present. All can be used simultaneously. Additionally, any balanced jack can be used unbalanced.

The CR1 is presently undergoing production preparations and is expected to be on the market within six months.


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  • Name:
    Donn Werrbach
  • Type of entry:
  • Profession:
  • Number of times previously entering contest:
  • Donn's favorite design and analysis tools:
    SolidWorks, PADS, Electronic Workbench, Excel
  • Donn's hobbies and activities:
    Only Work
  • Donn belongs to these online communities:
  • Donn is inspired by:
    1. To find better solutions to common problems;
    2. To wrap the better solution in an attractive package;
    3. To seek higher value rather than lowest cost;
    4. Gaining recognition for my unique designs.
  • Software used for this entry:
    SolidWorks, PADS-PCB, FilterShop, Electronic Workbench, Adobe Illustrator
  • Patent status: