Want better sound in your car this year? You don’t need to REPLACE your system. You need to REFINE it.
In 2026, we’re working smarter, not harder, and a crossover is one of the smartest moves you can make for your system. Swapping gear is NOT ALWAYS the answer.
In this guide, we’ll show you how to fine-tune your DS18 setup using two of our most popular crossovers: the XM3 Active Crossover and the PRO-CFX Passive Crossover. You’ll learn exactly how to read your manuals, choose the right crossover points, and get crisp, punchy sound without swapping your entire system.
What is a crossover?
Crossovers are a godsend in the car audio community.
These tools take your full-range audio signal and splits it into parts to ensure all frequencies are directed to the right speaker. Lows go to your subwoofer. Highs go to your tweeters. And your mid-range stays in the loudspeakers.
One bad signal can wreck your audio experience. Even worse, it can damage your speakers. A proper crossover setup doesn’t just make your system sound better, it also keeps it safer. By filtering out the wrong frequencies: you cut distortion, protect your equipment, and get more life out of every component.
Active vs Passive Crossovers: What’s The Difference?
Before you fine-tune anything, think about how your system is built and what kind of crossover setup would benefit you most. Most crossover setups fall into one of two categories:
· These require a power source and ground connection
· Installed between the receiver and amplifier
· They give you full control—crossover points, levels, and sometimes EQ
· Perfect for custom builds with separate amps for different speaker types
· Need more tuning knowledge to work efficiently
Passive Crossovers:
· No power needed.
· Use inductors, capacitors, and resistors to filter frequencies
· Can be component crossovers (between amp and speakers) or in-line (between receiver and amp)
· Simpler to install, but far less flexible
· Come pre-set in component speaker systems for optimal performance
Which One Do You Need?
The one you choose depends completely on what you’re doing with your system.
· If you’re building a system from the ground up or want full control over your sound, an active crossover gives you room to grow.
· If you just want clean audio without extra wiring or tuning, a passive crossover may be all you need.
Either way, the goal is the same: send the right frequencies to the right speakers so you can unlock your system’s full potential.
The Right Tools For The Job: DS18 XM3 and DS18 PRO-CFX
If you’re in the process of dialing in your system, this is #TEAMDS18’s recommendation for the best tools to make it happen.
XM3 – 3-Way Active Crossover with Line Driver
If you want full control over your system, the XM3 is a 3-way active crossover built to get the job done. You get variable filters for front, rear, and sub outputs + adjustable bass boost, input mixing, and a remote level controller for your sub. This is perfect for systems with dedicated amplifiers for each range and running clean, isolated signals to each.
Key Features:
- High-level RCA inputs and outputs (Tiffany-style)
- Low-pass and high-pass filtering from 25Hz up to 20kHz
- Adjustable bass boost (up to 18dB) from 25Hz to 100Hz
- Clip indicators for safe tuning
- 12dB/octave Butterworth slope
- Subwoofer remote level control with clip indicator
Why Use It:
Because you want total control. If your system has power and complexity, the XM3 gives it a fine-tuned edge.
PRO-CFX – 2-Way Passive Crossover
The PRO-CFX is a no-power-needed passive crossover designed for 2-way systems: you average mid-range and tweeter setup. It splits the signal at 3.5kHz, keeping the highs out of your midbass and the lows away from your tweeters. It also includes selectable tweeter attenuation, so your highs remain clean with a simple jumper.
Key Features:
- 2-way split at 3.5kHz (at 4 ohms)
- 12dB/octave slope for clean separation
- Selectable -3dB or -6dB tweeter attenuation
- Screw-down terminals for secure connections
- Clear acrylic housing for easy visual reference
Why Use It:
Because you want simple, effective control in a clean 2-way setup—without extra wiring, tuning, or added electronics.
Which One Should You Use?
- Use the XM3 if you're running separate amps and want complete control over every speaker zone: especially in a 3-way or active setup.
- Use the PRO-CFX if you're working with a 2-way component system and want clean signal separation with easy install.
Both tools will help your system sound the way it should.
Reading Your Manual Like An Installer
Most new guys skip the manual altogether: but, the pros know your manual is a cheat code.
It doesn’t just show you how to wire things or the best way to tune your box for your subs: it’s the KEY to getting the best performance possible.
These are the specifications real installers check first when using a crossover:
Recommended Filter and Range
Your DS18 manual tells you exactly what type of filter to use—and the range it should be set to.
You’ll usually see something like:
- Recommended Low-Pass Filter: 80Hz
- Recommended High-Pass Filter: 120Hz–3.5kHz
These numbers are based on how the speaker was designed to perform. Set your crossover to match those ranges. Go too low or too high, and you’re either wasting output—or pushing your speaker into failure.
Bass Boost & Attenuation
Some active crossovers include extra tuning features like:
- Adjustable bass boost (often listed by range, like 25Hz–100Hz)
- Tweeter attenuation options (-3dB, -6dB)
- Input mixing or sub-level controls
At launch, we may not have exact tuning recommendations for every feature—especially on new products. But we’re always testing, updating, and improving. Check back on the product listing page at DS18.com for the latest manual updates, including recommended settings for your crossover. If we’ve dialed in better ranges, that’s where you’ll find them.
Pre-Tuned Crossovers (The Passive Route)
Some passive crossovers (mostly included with component kits) come pre-set from the factory with fixed crossover points and slopes. If that’s your setup, your job is to understand where those points are and build the rest of your system around them.
The Bottom Line Is …
Your manual tells you everything you need to set your crossover right. The settings aren’t just suggestions—they’re protection. They keep your signal clean, your sound balanced, and your gear safe. However, you should always listen for yourself and tune to your preferred setting.
Step-by-Step Guide to Setting Crossovers
If You’re Using the XM3 (Or Any Active Crossover)
Active crossovers give you control over your entire frequency layout. Here's how to set it up right:
1. Start With Your Speaker Specs
· Grab the manuals or product pages for your subs, mids, tweeters.
· Find the recommended crossover ranges (HPF or LPF) for each speaker.
2. Set the Subwoofer LPF (Low-Pass Filter)
· Turn the LPF knob for the Sub channel to the recommended filter range in your DS18 manual.
· If you like tighter bass, you can go lower (e.g. 63Hz).
· Avoid setting it higher than your other speakers minimum frequency range or you’ll get frequency overlap.
3. Set the High-Pass and Low-Pass for Mids
· On the Front and/or Rear channels:
o The XM3 allows you to set a minimum frequency range and a maximum frequency range.
o Once again use your speakers manuals to find a good range to start with: then listen, and adjust to your liking.
4. Set the High-Pass for Tweeters
· If you’re running tweeters off the Front or Rear channel:
o Make sure you’re not sending any mids or bass to your tweeter—this can damage it.
5. Fine-Tune the Output Levels
· Use the output level knobs for each channel to balance volume across the system.
· Adjust by ear or with an RTA (real-time analyzer) if you’ve got one.
6. (Optional) Adjust Bass Boost
· If using Bass Boost:
o Set the Boost Freq (e.g. 45Hz–60Hz).
o Then add Boost (start small, like +3dB) and adjust based on how it sounds.
o Don’t max it. It can cause distortion or clip the sub.
7. Watch Your Clip Indicators
· Watch the Clip LEDs—if they light up, you’re pushing too hard. Dial it back.
Pro Tip:
Start flat and add slowly. The best systems aren’t always the loudest.
If You’re Using the PRO-CFX (Or Any Passive Crossover)
This one’s much simpler because the hard part is done for you.
1. Check the Built-In Crossover Point
The PRO-CFX splits frequencies at 3.5kHz. That means:
· Your woofer gets everything under 3.5kHz.
· Your tweeter gets everything above 3.5kHz.
No filters to adjust. Just wire it up and go.
2. Choose Your Tweeter Attenuation
If your highs sound too sharp or harsh, use the built-in jumper to reduce tweeter output:
· 0dB = full volume
· -3dB = slightly reduced
· -6dB = more tame
Start at 0dB, then drop it down if needed.
3. Use a Clean Signal
Since the crossover is doing the filtering, make sure your amp or DSP isn’t applying an extra crossover on top. Disable any built-in HPF or LPF from your amp that could conflict with the PRO-CFX.
4. Keep Your Wiring Tight
- Use screw-down terminals and double-check polarity.
- Loose or reversed connections can kill your sound quality.
Pro Tip:
If you're running this with a 2-way component setup, match your amp's RMS to the speaker ratings and let the PRO-CFX handle the split.
Ready for Perfect Audio?
If you’ve been chasing better sound by replacing gear, here’s your sign to start refining.
A properly tuned crossover brings out the full potential of the system you already have. It’s not just LOUDER—it’s smarter. The DS18 difference is real the moment you dial it in. Set your crossover and hear the difference for yourself.
Show us how you set yours:
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Tag us in one of your builds—we might feature your setup on our website! Use #WeLikeItLoud!
