Unless you have seen a product like Harrison Labs' F-MOD 900062, you may not know that there is more than one type of crossover unit. The 900062 is an in-line crossover that is simple to use and even simpler to install. Better yet, it does the job without giving you an opportunity to mess it up.

The F-MOD 900062 looks like an oversized RCA adapter. In fact, that's all it is--a barrel connector with RCA connections on either side, and it plugs right into the line-level cables feeding your amplifier. This is a fixed crossover with a 12dB/octave slope. This model is a low-pass filter, fixed at 100Hz. A variety of other models are available and can be connected together to form the exact signal you wish to pass.

This particular model is used as a filter to remove high frequencies before a subwoofer amplifier. The F-MOD 900062 is a very simple crossover, but sometimes that is all you need.