The most common question everyone has is which one to go for passive crossover or active crossover? The crossovers plays a very important role in the audio system as they limit the frequencies of the music to reach the speakers which they are not designed to play and protect them from damaging.

What does a crossover do? Why you need crossover?

The Passive Crossover or Active Crossover are the two types of crossovers which are used to play speakers with the amplifier. If you have a physical independent crossover that is a passive crossover and if you do not have any physical crossover between speakers and amplifier then it is called as active crossover where the amplifier or DSP will work as a crossover.

The crossover is wired between the amplifier to the speakers and it is tuned to 20Hz to 20000Hz and divides it up to the frequencies which the mids and the highs suppose to play. This is known as a Passive Crossover. The advantage of having a passive crossover is they limit the frequencies which the speakers or tweeters does not suppose to play. Another advantage of the passive crossovers is it has more imaging and the clarity. The disadvantage of the passive crossovers is you cannot take enough output from it from the stock radio directly, you will need to have a  aftermarket amplifier installed to power the component speakers.

PASSIVE CROSSOVER

The best example to explain the passive crossovers are the component speakers which has a crossover which is connected to the speakers and the tweeters. The coaxial speakers and component speakers are considered to be the full range speakers but the coaxial speakers does not called as a passive setup for audio as the coaxial speakers does not have any kind of crossover to drive the speaker, it only have a capacitor installed for the tweeter to limit the low frequencies to reach tweeter so that it do not get blown. The component speakers which can either 3 way or 2 way it has a crossover in between the connection of amplifier to the speakers and tweeters which handles everything. Active setups does not have any kind of crossovers to divide frequencies to the drivers, all the work is done directly by the amplifier or a DSP if you are using a it in your install.

Advantage of passive crossover is if you have only 2 channels available on the amplifier and you want to install the component speaker set, you can connect it easily to that 2 channels of the amplifier. If in such case you have to install one pair of mid and 1 pair of tweeters to an amplifier and you are going active you will need at least 4 channels for installing them, Which means running passive requires less channels and more speakers installed. Running passive keeps tweeters protection which means if accidentally you send the bass signal to the tweeter the crossover will filter it out and protect the tweeter. But if the tweeter is directly connected to amplifier and we are using a crossover on a Digital signal processor or on amplifier itself and that crossover fails we no longer have protection like a passive crossover in line.

Disadvantage of passive crossovers is that they eat up some amount of amplifier power. It is still good to use these if you have plenty of amplifier power. Another disadvantage of passive crossover is we get less tuning flexibility. If you are using a DSP for time alignment process and you having a component speaker installed, the DSP will treat each side as a single speaker not the mid and tweeter individually. Another disadvantage of running passive is sometimes tweeters might be too loud, But the good premium crossovers does comes with the adjustment tweeter controls which will reduce the amount of sensitivity of the tweeters. If you are installing a component speaker set in your car you will need to install the crossover additional in compared to speakers and tweeters and will require more wiring as the wire coming from the amplifier will reach the crossover installation place then the speakers and tweeters wire will route to the crossover which will make the installation lengthy process. 

ACTIVE SETUP

If you are planning to go active you should check the impedance of the speakers and tweeters before installing them to the amplifier will be unstable if the speakers will be wired in wrong ohm loads. Do not connect the speaker and tweeter directly to the head unit of the car and hope that you are playing active setup directly to the radio of the car. The head unit of the car will not able to work as a crossover like an amplifier and can even damage the tweeters. 

The active setup has tuning flexibility which a passive crossover does not have which means you can adjust the levels of the tweeters and the midrange according to you. If you are tuning your speakers in active setup you can tune your crossovers and sensitivity individually which is not possible in passive crossovers. The advantage of having active setup is the speaker and tweeters are directly connected to the amplifier which means no loss of amplifier power anywhere and will result in more output. Active setups generally sound louder than passive setups and are more refined and clear.

The disadvantage of going active is you need separate individual channels at amplifier for each speaker and tweeter, you cannot install everything together on each channel. Disadvantage of active setup is by mistake if the crossover fails on the amplifier or the digital signal processor it will blow the tweeter very easily by sending lower frequencies to the tweeter.