Crossovers are the only way to get really clean sounding music out of your system because it keeps the right notes on the right speakers. This is so beneficial because it keeps your speakers from trying to play notes or frequencies that they were not meant to play which means they will sound muddled. They also separate the sounds to keep them from interfering with each other. The best thing about them is that they increase the life of your speakers by keeping them from trying to play notes they weren’t designed to play.

They do this by implementing high-pass and low-pass filters that only allow frequencies that are above for a high-pass filter or below for a low-pass filter a certain frequencies. This allows it to send your highs to the tweeters, mids to your speakers and lows to your subwoofers. There are also band-pass filters that only let frequencies in a certain range through.

When looking for a crossover there are few attributes that separate the hi-end models from the ones built into your amplifier. You want to look for a crossover that has a low signal to noise ratio (this affects how clean the sound is after it goes through the crossover) and a high dB/octave cutoff. Having a high cutoff means that it is better at separating the frequencies from each other and will be more accurate.

You also need to know about the three types of crossovers that are available, in-line, passive and active. Passive Crossovers and In-Line Crossovers are very similar except that in-lines are attached before your amplifier and passive units are attached in between the amp and the speaker you are limiting the frequencies to. They both are more inexpensive and easier to install than active units but they generally just separate at a set frequency and do not allow you to adjust the cutoff frequency on the fly to fine tune your sound for optimum performance. The advantage of using a in-line versus a passive unit is that by separating pre-amp your amp doesn’t waste power on frequencies that you are just going to cut out later which makes these ideal if you just need to cut out the mids and highs going to your subwoofer.

Active Crossovers are more expensive than the other types of crossovers but this is because they offer a much greater range of features. The only down side to these types of units is that they are more difficult to install because they require their own power source and are linked to all of your speakers not just the tweeters or the subwoofers. Like in-line crossovers, active units also filter pre-amp for maximum efficiency. Many units also have the ability to control each channel separately so you can keep all of the voices or have them set to a certain volume and have the music playing at a different volume to give you more command over your music. Another really cool feature is that they come in digital and analog form so you can either use knobs with analog or a menu system with digital models. Digital models also let you store presets and have several default options which make it even easier tune your music on the fly and you won’t lose your favorites when you change it for any reason. You can also get active crossovers that have additional sound processing features such as equalizers for even more control.