Can I Add to KEF LSX Speakers? Expansion & Subwoofer Guide

Can I Add to KEF LSX Speakers? The Direct Answer

Yes, you can add to KEF LSX speakers in several ways, primarily by integrating a powered subwoofer to enhance low-end performance or using multi-room protocols like AirPlay 2, Chromecast, or Roon to expand the system into other rooms. While you cannot physically wire additional passive speakers to them or create a wired 5.1 surround sound system using only the LSX hardware, their wireless ecosystem allows for significant expansion through software and network integration.

Quick Summary: Key Takeaways

• Subwoofer Expansion: Use the dedicated Sub Out port to add any powered subwoofer (like the KEF KC62).
• Multi-Room Audio: You can add more speakers to KEF LSX setups by grouping them with other compatible units via the KEF Connect App, Apple AirPlay 2, or Google Home.
• Physical Inputs: Expand your source list by adding turntables (via pre-amp), CD players, or external DACs through the Toslink or Aux ports.
• Home Theater: The LSX II and LSX II LT models allow for easy TV integration via HDMI ARC, whereas the original LSX requires an optical connection.

Can You Add More Speakers to KEF LSX Speakers?

A common question we hear from audiophiles is whether you can simply “chain” another pair of speakers to the KEF LSX. Technically, the KEF LSX is an active, all-in-one system. This means it contains its own amplifiers and crossovers.

You cannot “add” more passive speakers directly to the LSX terminals because there aren’t any. However, you can expand KEF LSX speakers into a whole-home system. By using the KEF Connect app, you can sync multiple KEF wireless sets (like adding a pair of LS50 Wireless II in the living room while the LSX stays in the office).

In our testing, the most seamless way to “add” more sound is through AirPlay 2. If you have an iPhone or Mac, you can select multiple “zones” simultaneously. This effectively lets you add as many speakers as your Wi-Fi network can handle, provided they are AirPlay-compatible.

How to Add a Subwoofer to KEF LSX

The most effective way to add to KEF LSX speakers is by introducing a dedicated subwoofer. While the LSX has impressive bass for its size, its 4.5-inch driver can’t compete with a dedicated sub for sub-bass frequencies (below 50Hz).

Step-by-Step: Connecting Your Subwoofer

1. Locate the Sub Out: On the back of the Primary KEF LSX speaker, find the RCA port labeled SUB.
2. Connect the Cable: Use a high-quality shielded RCA subwoofer cable to connect this port to the LFE or Line In on your subwoofer.
3. Open the KEF Connect App: Navigate to the EQ Settings.
4. Enable Subwoofer Out: Toggle the “Subwoofer Output” to ON.
5. Set the Crossover: We recommend starting with a Crossover Frequency of 80Hz to 100Hz. This allows the LSX to stop struggling with deep bass, resulting in much cleaner mids and highs.

Can You Expand KEF LSX Speakers for Home Theater?

If you are looking to expand KEF LSX speakers into a 5.1 or 7.1 surround sound system, there are limitations. The LSX is designed as a 2.0 or 2.1 stereo system.

However, we have successfully used them as a high-end “Soundbar Replacement.” If you own the LSX II or LSX II LT, you can use the HDMI ARC/eARC port. This allows your TV remote to control the speaker volume directly.

To “add” more to this setup, you are essentially limited to the Sub Out. You cannot currently add wireless rear surround speakers directly to the KEF LSX ecosystem without using a third-party AV receiver that supports “Pre-Outs,” which would defeat the purpose of having a wireless system.

Adding External Sources to the KEF LSX System

When users ask “can i add to kef lsx speakers,” they are often referring to adding new audio sources like vinyl or high-res streamers.

Adding a Turntable

To add a turntable, you must ensure it has a built-in phono pre-amp, or you must buy an external one.

• Connection: Connect the RCA out from the pre-amp to the 3.5mm Aux input on the LSX using an RCA-to-3.5mm adapter.


• Pro Tip: In the KEF Connect App, set the “Default Source” to Aux if you plan on using your turntable frequently.

Adding a Streamer or DAC

While the LSX has an internal DAC, some users prefer the “flavor” of an external unit like a Chord Mojo 2 or a HiFi Rose.

• Connection: Use the Optical (Toslink) input. This is the cleanest way to bypass the internal Wi-Fi streaming if you prefer a wired digital source.

Using the KEF KW1 for Wireless Expansion

If you want to add to KEF LSX speakers without running cables across the floor, the KEF KW1 Wireless Subwoofer Adapter Kit is essential.

We’ve found that the KW1 reduces clutter significantly. It consists of a transmitter that plugs into the Expansion Port (or Sub Out) and a receiver that attaches to a KEF Kube or KC62 subwoofer. This allows you to place the subwoofer anywhere in the room (up to 30 feet away) without losing signal quality.

Can You Add More Speakers to KEF LSX via Google Home?

For Android users, Google Cast (Chromecast built-in) is the primary way to expand KEF LSX speakers.

1. Open the Google Home App.
2. Ensure your LSX and other speakers (like a Nest Audio or another Chromecast-enabled speaker) are on the same network.
3. Create a “Speaker Group.”
4. Add the KEF LSX and your other devices to this group.
5. When you play music via Spotify or Tidal, select the Group Name instead of the individual speaker.

Note: In our experience, multi-brand groups can sometimes have slight latency issues. Use the “Group Delay Correction” setting in the Google Home app to sync them perfectly.

Technical Comparison: LSX vs. LSX II vs. LSX II LT Expansion

Understanding what you can add depends heavily on which version of the hardware you own.

Crucial Note on the LSX II LT: Unlike the other models, the LT version requires a physical USB-C cable to connect the two speakers. You cannot “add” wireless connectivity between the left and right units on this specific model.

Expert Advice: Optimizing Your Expanded Setup

When you add to KEF LSX speakers, the software configuration is just as important as the hardware.

• Phase Correction: When adding a subwoofer, use the Phase Toggle (0° or 180°) on the back of the sub. Listen for which setting produces “tighter” bass at your seating position.
• High-Pass Filter: In the KEF Connect App, enabling the High-Pass Filter is the best thing you can do for the LSX. It prevents the small 4.5″ drivers from trying to move too much air, which significantly reduces distortion at high volumes.
• Room Acoustics: If you add a second set of speakers in another room, try to match the “Sound Profile” in the app so the transition between rooms feels seamless.

Frequently Asked Questions

Can you add more speakers to KEF LSX speakers for surround sound?

No, you cannot use KEF LSX speakers as part of a traditional wireless 5.1 surround sound system. They are designed for stereo (2.0) or 2.1 configurations. To get surround sound, you would need a system like the KEF LS60 or a dedicated AV receiver setup.

Can I add a third-party subwoofer to my KEF LSX?

Yes. Any powered subwoofer with an RCA input can be added to the KEF LSX via the Sub Out port. You do not have to use a KEF-branded subwoofer, though KEF models integrate seamlessly via the app’s EQ presets.

Can you expand KEF LSX speakers to play in different rooms?

Yes, using Apple AirPlay 2, Google Chromecast, or Roon. These protocols allow you to group the LSX with other speakers on your network for a synchronized multi-room audio experience.

Does adding a subwoofer improve the sound of the LSX?

Significantly. By offloading the lowest frequencies to a subwoofer, the LSX internal amplifiers have more “headroom” to power the tweeter and mid-bass driver. This results in a much larger soundstage and clearer vocals.

Can I add a Bluetooth speaker to my KEF LSX?

You cannot “output” Bluetooth from the LSX to another speaker. The Bluetooth on the LSX is an input only, meaning it receives audio from your phone or laptop. To play on multiple speakers, you must use a Wi-Fi-based protocol like AirPlay.