Crossovers are an integral part of any stereo or home theatre system that sounds great. Unfortunately, understanding how they work and accurately setting crossover frequency for various speakers can be confusing.
To set crossover frequency for speakers, you need to know the exact speaker type first. If you know the type of speaker you have, you can then work with its recommended crossover range. For subwoofers, for example, the recommended crossover frequency is 80 Hz.
Read my article “Does Lower Hz Means More Bass? Bass & Frequency Link Explained” for some handy background knowledge which will help in understanding the subject better.
Also read my guide on Subwoofer Crossover Settings
The rest of the article will take a deep dive into crossover frequency and what it’s all about. Watch out for the recommended crossover frequency for other types of speakers apart from subwoofers.
What is Crossover Frequency
A crossover is an electronic or electrical system designed to split the sounds from a musical source and then providing the best output for a specific speaker. Most speaker systems that sound great come with at least one type of crossover built-in.
Crossover frequency, on the other hand, refers to the sound frequency point, after which specific sounds will be reduced, or effectively blocked. The crossover frequency is used as the reference point at which a speaker’s output—or input to an amplifier—is cut by 3 decibels (-3dB).
So, a crossover filters out the range of sound you’d like to prevent from reaching a certain speaker, but the filtering will only start at a specified crossover frequency.
What Are the Types of Crossovers?
Crossovers are divided into passive (speaker) and active (electronic) crossovers. With passive crossovers, you don’t need power to block sounds.
Active crossovers, on the other hand, require power, as well as ground connections, but they ensure you have better flexibility when it comes to controlling the finer details of your sound output. Below is a closer look at both of them.
1. Active Crossovers
With an active crossover, each sound driver gets its own channel amplification. By giving the subwoofer, woofer, and tweeter, their own channels, the available power, and dynamic range—from softest to loudest—is greatly increased. This gives you better control of the whole audio spectrum as well as your system’s tonal response.
An active crossover is typically wired between the receiver and amplifier, cutting out any unnecessary frequencies and ensuring that the amp doesn’t waste energy on boosting them. This ensures that the amp can focus solely on delivering the frequencies you’d like to hear from a specific speaker.
Active crossovers also come with volume controls on the channels, allowing you to maintain the sound balance from all the drivers. Some designs of active crossovers come with other sound-processing features like equalization, allowing you to further tweak the sound generated until you are satisfied.
The downside to active crossovers, however, is that they require +12V, ground, and turn on connections to run. This makes them more challenging to install and set up.
If you can spare a little time, however, you should be able to deal with this challenge. The advantages far outweigh the setup difficulty, which is why most people that take their music seriously go for systems that have active crossovers. It is the perfect way to keep your speakers belting out crisp and clear sounds of all frequencies.
2. Passive Crossovers
Passive crossovers don’t need a connection to a power source to work. There are two variants of these types of crossovers: in-line crossovers and component crossovers. The latter sits in the middle of the amplifier and the speakers while the former fits between the amp and the receiver.
3. Passive Component Crossovers
These crossovers fit into the signal path beyond the amplifier. They feature a small network of capacitors and coils and are installed near the speakers. Speaker systems with component crossovers are designed to deliver the best performance possible out of the box with little or no external tweaks. They are also simple to install and set up.
With a passive component crossover, a full-range signal first leaves the amplifier, and then it gets to the crossover, where the signal is separated into two parts.
The high notes are sent to the tweeter, while the mid and low notes go to the woofer. In most passive component crossover systems, you can reduce the tweeter sound a bit when you think it is too loud for the woofer.
A passive component crossover will waste power because it is filtering a signal that has been amplified already. The unwanted sounds are released as heat.
Additionally, you need to consider the fact that speakers don’t maintain fixed impedance as they play sounds. This can change the crossover point or frequency response of a passive component crossover. This can cause some inconsistencies with the sound definition.
4. In-Line Crossovers
While component crossovers operate on speaker-level signals mostly, in-line crossovers connect before the amplifier. These crossovers have a cylindrical appearance, with RCA connectors at both ends. They plug directly into your amplifier’s inputs.
In-line crossovers solve the problem of energy wastage where the amplifier processes signal you won’t need. This means you don’t have to worry about scenarios like high frequencies being processed by a subwoofer amp.
By installing an in-line crossover system, you can improve the sounds of your system a great deal, especially if you have a component speaker system.
You should know, however, that in-line crossovers generally come set to a specific frequency and can’t be adjusted. Additionally, in-line crossovers interact differently with different amplifiers. This means that the crossover points can be unpredictably affected.
Which Crossover Types Are the Best?
Now that you’ve seen all the possible crossover types, you are probably wondering which one of them to go with. Your decision should come down to just how seriously you’d like to take your sound setup. If you plan on regularly upgrading or expanding your system in the future, you won’t go wrong with a separate outboard crossover.
Relying on the crossovers that have been built into the amplifier and receiver isn’t a great idea in this scenario. This is because although they work well enough, you won’t have the same level of control that will be provided by an external or outboard unit.
Additionally, you won’t have to worry about losing the crossover after you upgrade your amp.
What Is a Crossover Slope?
A crossover slope refers to the depth of a crossover’s filtering capacity. It’s basically how steep a crossover’s filtering can go beyond the crossover frequency boundary. As is the case with a crossover frequency, slopes are also determined in decibels.
With crossover slopes, bigger is better. A larger steepness or greater slope means that the crossover is very effective in filtering out a specific sound frequency before sending it out from a speaker system.
What Is a Good Crossover Frequency?
A good crossover frequency is a range at which the crossover is able to filter the unwanted sounds perfectly. It’s hard to settle on a unified crossover frequency for every speaker because a lot of factors come into play when setting one. However, there are common frequency ranges that will work well in many cases.
- For subwoofers: the recommended crossover frequency is 80 Hz (low pass). This a good low-pass frequency that ensures the subwoofer bass is prioritized without including any midrange sounds. It is best for low-end bass.
- For main speakers: the recommended crossover frequency is 56-60 Hz (high pass). At this frequency, low-end bass, which can cause distortion, is filtered out. This crossover is the perfect middle ground between midrange bass capability and full-range sounds.
- For tweeters and 2-way speakers: the recommended crossover frequency is 3.5 kHz (high pass, or high/low pass). Anything below this range for these speakers will lead to suboptimal performances.
- For midrange speakers and woofers: the recommended crossover frequency is 1-3.5 kHz (low pass). Most woofers and midrange speakers don’t deliver quality sounds above this range. This is why they have to be augmented with tweeters to avoid poor treble delivery.
- For 3-way speakers: the recommended crossover frequency is 500 Hz and 3.5 kHz. The midrange drivers in a 3-way system most likely won’t deliver quality sounds below 500 Hz or 250 Hz.
How to Determine Speaker Crossover Frequency
You’ve seen some recommended ranges to work with for your speaker crossover. To determine the speaker’s crossover frequency, you, first of all, need to understand the type of speaker you are dealing with.
If you can distinguish between 2-way and 3-way speakers, or woofers and subwoofers, you can apply the recommended crossover frequencies to them.
For a more specific setting, however, here’s what you should do.
Look at your speaker’s specification sheet only to find the details for the frequency response. It will look like “32-10,000Hz” or other numbers within that range.
Go to your receiver’s setup menu with the remote to find the part of the menu that highlights the size of your speaker and crossover point. The process of finding this menu will vary from one product to the other, so you may have to use your product manual.
While in the receiver’s menu, look at the speaker’s specification sheet, and take note of the lowest frequency. In most 2/3-way speakers, it will be 30, 40, or 55 Hz, but on subwoofers, it could be as low as 20 Hz.
Pay attention to the options that are available in your receiver’s crossover adjustment menu. Now, multiply the lowest value on your speaker’s specification sheet by two.
This means that if the value is 30 Hz, the crossover point in your receiver’s menu should be 80 Hz. This is expected with a standard 12db/octave high-pass crossover found in most receivers.
The high-pass crossover point is the frequency at which your bookshelf speaker gives way to the subwoofer (assuming you have such a configuration, for example). The low-pass crossover point is the range where the subwoofer will begin to taper off to avoid playing a lot of mid-range sounds.
The result of this is that there’ll be a flat response from the crossover point down to when the speakers naturally start to roll-off.
The “roll-off” point is typically below the speaker’s designated lowest frequency, at which point it will stop to produce any sound. This means that a speaker with the lowest frequency rating of 40 Hz will have its roll-off around 32 Hz.
How Can You Set the Phase and Crossover Frequency on a Subwoofer?
To set the phase and crossover frequency on a subwoofer, here’s what you have to do.
How to Set the Phase
The first thing you need to do at this point is to set all your speakers in a way that they’ll be facing the same directions. With this approach, you can better judge the quality of the sound.
It’s possible that you’ll end up with subwoofers that are not in sync with each other phase-wise. When this happens, the bass quality of each speaker will end up canceling each other out, causing poor quality sound overall.
If you have RCA cords on your speakers, you can’t switch the wires. In this situation, the best thing to do is to set up a phase switch. You can do this by setting up your speakers in a way that you can still listen to them without fully installing them in the entertainment case or the wall.
Once you’ve done this, listen to the quality of the sound. If you are not impressed with the bass, you can turn the phase to 0 or 180 to get the quality you are looking for.
How to Set the Crossover
As you’ve seen above, failing to set the crossover frequency means that the subwoofer may not be able to solely focus on delivering low-frequency notes or deep bass.
If you bought an integrated system with an EQ feature, the crossover might have been set automatically on your subwoofer and the rest of your speakers. If this isn’t the case for you, you can set the crossover manually. Here’s how to do it:
- Find the low-end of the subwoofer’s frequency range either from your user manual or from the manufacturer’s website.
- Set the crossover point 10 Hz higher than this range for the best result (or go with the recommended 80 Hz).
- Listen for a smooth transition between your subwoofer and the rest of the speakers ensuring that the sound is crisp.
- If you hear a bass bump at the crossover frequency, adjust the subwoofer volume to match the sound from the other speakers in your lineup closely.
Some Examples of Outboard Crossovers You Can Buy
Some of the best outboard active crossovers you can find in the market today include:
Planet Audio EC20B 3-Way (Amazon link)
The Planet Audio EC20B 3-Way crossover offers three filter circuits for a wide range of setup options. Its variable low-pass range is 32 Hz to 250 Hz, while the high-pass range is 40 Hz to 400 Hz. It also has a bass generator with a frequency response of 10 Hz to 20 kHz.
Additionally, it offers remote and independent front, rear level, and subwoofer controls.
Behringer Super-X Pro CX2310 (Amazon link)
The Behringer Super-X Pro CX2310 is a professional stereo 2-way/mono 3-way crossover famous for its Linkwitz-Riley filters and 24dB/octave. It provides a flat summed amplitude response, which ensures zero phase difference.
There’s also an additional subwoofer output with independent frequency control. The individual output gain controls and mute switches give you more flexibility with setting up your system.
XV-6-V15 6-Way (Amazon link)
The XV-6-V15 6-Way offers a continuously variable crossover frequency with separate inputs for your speakers and subwoofers. It comes with a multiplier switch and delivers non-fade low pass output, as well as front and rear high pass outputs. The bass boost feature will also help deliver seamless and air-tight bass from your subwoofer.
SoundStorm SX310 (Amazon link)
The SoundStorm SX310 is a feature-packed crossover. It has a parallel input system, and a selectable crossover slope. The bass boost function allows you to tune the center frequency to deliver the hardest bass with little to no distortion.
Is your subwoofer’s position causing cancellation as a result of overlapping sound waves? The Sound Storm SX310’s phase shift selector is designed to deal with all “out of phase” issues.
With the system’s independent channel output level controls, you can improve the spatiality of your sound setup easily. The three-year warranty offered by the brand is one of the most generous in the industry.
Should You Install a Crossover Frequency on Your Own?
If you have a perfect understanding of all the concepts that’s been discussed in this article, you can most certainly complete the installation of an external active crossover frequency. The user manual from any of the systems you purchase should guide you.
On the other hand, if it all sounds too technical for you, you are better off sticking with built-in crossovers or at least automatic variants. If an active crossover frequency can improve the quality of your sound setup, however, you should invite a professional sound engineer to complete the process for you.
Crossover frequency sounds like technical stuff that should remain in the background. For most people, this is true. For audiophiles, however, every bit of improvement that can improve the overall sound counts.
What better way to improve the sound than ensuring that all your speakers are only delivering the exact frequencies they were made for? With the guide above, you can set crossover frequency for all the speakers in any audio system.