How to Connect a Crossover to an Amplifier

Many audio enthusiasts go the extra mile to ensure that they get the most out of their sound equipment. For them, the quality of sound should always be on a cinema-level of crispiness. In time, they’ve learned some tricks as to how to feed this niche. For example, they often add both a crossover and an amplifier to their setup.

On some occasions, even using two amplifiers at once is not taboo. The crossover sends high-frequency audio into one amplifier and low-frequency audio into the other. That process is otherwise known as bi-amping. For the pairing to work, the amplifiers will connect to different speakers or speaker component inputs. The tweeter, the part of a speaker that emits loud frequencies, will connect to one amplifier, and the second will connect to a woofer.

how to connect a crossover to an amplifier
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Suppose you’ve just purchased your crossover system and intend to give it a chance for the first time. But before you can do so, you’ll need to learn how to connect the crossover to the amplifier. If done correctly, it can result in excellent audio quality.

Read on to get the details about amplifiers and crossovers. Also, take a look at some useful tips and tricks.

Understanding the Function of an Amplifier

understanding the function of an amplifier
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An amplifier is an electronic device that amplifies the low voltage signals from any source system to a high voltage signal. So, the original sound receives a boost and comes out much stronger. As a result, you can hear each cord clearly.

This process is a bit more nuanced than it seems, though. An amplifier’s function does not necessarily mean they make the sounds louder. It also brings out all the fine details in sound that you may not get if you are using a speaker by itself.

How It Works

The amplifier will be the connection between the crossover and the speaker in this context. The sound coming from the crossover goes into the amplifier. The amplifier, in turn, enhances the sound before sending it to the respective drive (tweeters, woofers, subwoofers) in the speaker.

Most amplifiers in the market have a built-in high-pass and low-pass filter, which the crossover system utilizes. However, these filters in the amplifier are often inaccurate; that’s why audio enthusiasts prefer a separate electronic crossover.

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Understanding the Function of a Crossover

understanding the function of a crossover
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A crossover system is an essential component in this setup. It’s in charge of filtering the emitted sounds. Then, it ‘groups’ them up into different frequency ranges, such as high, mid, and low. Next, the crossover sends the output to an amplifier. Finally, this path ends up with the drivers or otherwise known as the speakers.

How It Works

This device takes input signals, filters them, and divides them into three outputs. These outputs are of various frequency bands – a high-range, mid-range, and low-range frequency.

The different bands then connect to the various drivers of your sound system. Among these are the tweeters, woofers, and subwoofers. The crossover ensures that each drive gets the exact frequency they are meant to play.

For clarity, we can illustrate this process in a more relatable way. Imagine the crossover as a ‘sound inspector’ whose only job is to direct the frequencies. The device will lead the high frequencies to the tweeters, mid frequencies to woofers, and low range frequencies to subwoofers for that task. So, it’s much like traffic police.

Needless to say, a crossover’s role may prove vital. Without it, our system would often put out an incoherent mess. Sounds would completely mix up and ruin the signal. For one, the low and mid-range frequencies would clash in the woofers. On the other hand, the tweeters would waste energy playing notes from the mid-range frequency. Also, many frequencies will simply get lost in the void. So, we owe a sincere “thank you” note to our tech gurus.

Connecting Crossovers to Amplifiers

In this section, we’ll get more technical about connecting your active crossover with the amplifier.

First of all, remember that green and yellow color markings represent ‘the earth’, the blue color markings indicate ‘neutral’, and brown color markings mean ‘life’. However, these are dependent on the brand of a particular crossover system. So, if your crossover and amplifiers are not from the same manufacturer, this may not apply. Hence, the colors on the amplifier may even not correspond to the color markings on your crossover.

But, this is not a cause for an alarm. For such cases, look for an ‘E’ symbol on one of the amplifier’s terminals. ‘E’ means ’earth’; thus, you’ll know it is compatible with the green and yellow colors on your crossover.

The color blue on your crossover means the same as the black terminal on the amplifier. Usually, you can spot them by the “N” symbol. Lastly, the brown wire of your crossovers pairs with the red terminal on the amplifier. Also, look for an “L” symbol.

Sometimes the alternative colors for the ‘life’ wires are red instead of brown. Similarly, the substitute color for the usually blue neutral wires is white. Then, for the ‘earth’ wires, you can find them in yellow or green color.

Precautions to Keep in Mind

You should never expose these devices to dripping or splashing fluids. So, on no account should you rest an object filled with liquid on top of the equipment. This precaution is crucial to prevent any accidents from occurring.

Also, use a dry material whenever it’s time to clean this electronic device from dirt or dust. Furthermore, do not place the equipment so that its vent openings get blocked. Always make sure that your equipment’s vent openings face toward an open space.

Also, never install the crossover equipment near any device that produces heat. Examples to avoid include radiators, stoves, or any other heat-generating device. Even putting it next to another such amplifier is a bad idea.

Lastly, keep an eye on the weather, too. If a lightning storm starts raging outside, be quick to detach the equipment from the power source.

How to Connect Crossover to an Amplifier Using Passive and Active Crossover Units

how to connect crossover to an amplifier using passive and active crossover units
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You often see these audio combinations in home theaters, studios, during live acts, etc., but how does one set it up? Well, you could either work with a passive or active crossover. Your preference and budget are the main factors regarding that choice. Whatever your pick, though, we’ll explain both methods below.

Connecting With a Passive Crossover

Your crossover is placed and wired between the amplifier and the speaker for this setup. So, the first thing you want to do is unplug your speakers from any other power source. Next, connect your amplifier’s output using speaker wires or RCA connectors to your crossover’s input. You can do this by plugging the speaker wires, the +ve and -ve terminals of the amplifier, into the crossover inputs.

Remember the color codes mentioned earlier? Use red wires for +ve terminals and black for the -ve terminals. Then, tighten the terminals using a screwdriver or a hex key, depending on the amplifier and crossover unit.

Afterward, all that remains is to pair the crossover to your speaker. Start by connecting your speaker wires from the crossover output for woofers. Lastly, tweeters go to your speaker’s woofer and tweeter.

The following markings are dependent on the brand of the crossover unit you choose to use. However, the signs on the woofer are usually marked as “W+” and “W-”. For tweeters, look for the “T+” and “T-” signs.

In the end, test the connection by playing some tunes. If everything’s fine, then you should hear a significantly clearer sound. Otherwise, retrace your steps.

Pros of Passive Crossover

Passive crossovers are easy to set up since they require no power and ground connection. Also, they do not require any frequency setting. That’s because the passive crossover functions at a particular frequency for a specific speaker.

Cons of Passive crossover

That automatic frequency-finder can be a bad thing, too. It means that you can’t change it easily. In other words, for a different frequency, you’ll need a new crossover system. The passive crossover has a frequency for that speaker, and that’s it. Secondly, this crossover consumes a lot of energy and is vulnerable to noise.

Connecting With an Active Crossover

connecting with an active crossover
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This crossover setup is between the receiver and the amplifier. As before, disconnect your speakers from their current power source at the start.

Since active crossover units are larger in size than passive ones, you’ll need to mount them properly. Find the perfect space that will allow you easy access. Optimally, you’ll be able to quickly make adjustments on the unit’s switch (or knob). However, do not mount your crossover directly on any metallic rack. Doing this will only negatively affect the audio quality.

Using the right cables, connect your crossover to your receiver. Next, the wires that come out of the receiver will need to go into the crossover’s input terminal.

Follow that by connecting the crossover to the amplifier. Connect each output of the crossover unit into its respective terminal in the amplifier.

If you choose not to work with a subwoofer, set your crossover to two-way mode. Once you accomplish that, send the high-frequency to the tweeter amplifier and low-frequency to the woofer. Check your user’s manual to apply the settings correctly if you are unsure.

If you are working with a subwoofer, there are several ways to connect it to your system. Whichever approach you take, make sure you set your crossover so that only the mid-frequency go into woofers. You do not want the low-frequency signals interfering there.

For a subwoofer without power, the first approach uses more cables to make the connection. Set the crossover to three-way mode if there’s a separate speaker component (woofer and tweeter). The two-way option is the way to go if you are just sending bass into the subwoofer.

The second approach is to connect the cable from the subwoofer’s output terminal of your receiver. Newer models of receivers have their crossover settings. Hence, there might be no need for an external crossover if you are using those. Also, some subwoofers have a built-in crossover and may not require you to get it at all. However, they will not provide you with the maximum sound quality as an external crossover would.

So, if crystal clear audio is a must to you, try another route. For example, combine your external crossover with a subwoofer with a built-in crossover. But you can’t use more than one crossover at a time. So, in this case, you will need to shut off the built-in crossover by turning it to its maximum rotation. That will effectively remove it from the circuit.

Pros of an Active Crossover

This crossover has knobs or switches for adjusting the frequencies. This property makes the crossover suitable for any speaker, unlike the passive crossover.

Also, with an active crossover, there is no need to stress over the strength of the amplifier. An active crossover processes the signal before it goes into the amplifier, thus doing much of the heavy lifting.

Cons of an Active Crossover

Setting the crossover to the right frequency can be difficult. It requires a good understanding and experience to know the right frequency to cross your speakers to. If you set your frequency to low, you stand a chance of damaging your tweeter. And if you put it too high, you’ll experience distortion from the mid-range frequencies.

However, there is a solution to this, which involves getting an active crossover with a digital sound processor (DSP).

Connecting Your Crossover to Power

Some amplifiers have a terminal for sending power to the crossover. Then, plug the crossover into a power outlet when setting up your home or studio equipment. For a vehicle, plug it into your car battery which will supply 12 volts to power up the crossover.

Once the crossover is in use, you can tune and test the system to see how the audio holds up. For that, turn everything down with the knob: both the crossover and amplifier gain to the end. Start testing by playing your favorite songs. Then, while the music is playing, slowly turn up your crossover’s input gain. Do this until you get comfortable with the sound coming from the speakers.

Set the crossover’s output until all frequencies find their place. After this, raise up the amplifier’s gain until right before the sound distorts. Continue readjusting your frequencies until you find the right combination.

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Connecting an Active Crossover With Two Amplifiers

connecting active crossover with two amplifiers
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When using two amplifiers for your connection, the system is called a bi-amp system. However, the setup is quite similar to the conventional method we’ve covered above. The crossover placement is between the sound source and the amplifier. Assuming that the sound source is a mixer, it creates the sound signal. Then the crossover separates the sound signals into different frequencies. These frequencies go to their respective amplifiers, which in turn go to the speakers or speaker components. In other words, the tweeter, woofers, and subwoofers.

Using your shielded connection cable, connect to the mixer’s primary output. Depending on your system, the output is either balanced (low impedance) or unbalanced (high impedance) and needs a quarter-inch or XLR connector.

Connect the other end of the shielded connection cable from the mixer’s output to the crossover’s input port. The second shielded cable connects the crossover’s output high-frequency terminal with the other end of the amplifier’s input. This connection will power the high-frequency horn speaker.

Next, use the third shielded cable for your crossover’s low-frequency terminal. Pair with the amplifier’s input. This powers up the low-frequency bass speaker.

Plug the first speaker cable into your high-frequency amplifier’s speaker output port. The other end of the speaker’s cable should go into the frequency horn input port.

Lastly, the second speaker cable should lead to the low-frequency speaker output port. The other end, just like the first speaker cable, will go to the low-frequency bass speaker input jack.

Frequently Asked Questions

Q1.   Why should I adjust my crossover frequency?

If you are playing music and notice some distortions or extra noise, your next step is to adjust your frequency settings. By fine-tuning these settings, you might get a much clearer signal.

Q2.   Are active crossovers worth it?

Well, that depends on the purpose you are using the crossover for. So, the answer varies whether it’s for professional purposes or personal use. However, an active crossover system will allow you to get the most out of your audio system.

Q3.   What distinguishes active crossovers from passive?

The main difference between these two is that active crossover needs power.  The passive crossover doesn’t, but it comes with specific caveats.

Q4.   How do I know which speaker is right for my amplifier?

When trying to find the right speaker that matches your amplifiers, you should consider three main factors. The first is the power ratings of the two devices. Next comes their impedance. Lastly, check the sensitivity ratings of the speaker.


Evidently, there are several ways to utilize crossovers and amplifiers. Knowing how to tinker with that combination is a good way to stay resourceful. Also, it might save you time and money in searching for new equipment. Instead, you could make the most out of your current devices. By correctly fixing them up, you can unlock their full potential. In turn, those same devices will produce a much better sound. The result will be comparable to a professional-level sound system. Afterward, you’ll get to enjoy your favorite tunes in a whole new way. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to