How To Connect Two Wireless Subwoofers To One Soundbar
By Robert Jones · 2020-11-01
Thinking of adding a second wireless subwoofer to your soundbar but unsure how? It's a common hurdle, but I'll show you the reliable ways to get that extra bass integrated for a much smoother sound.
Right, you've got a soundbar, maybe a cracking bit of kit like a Sonos Arc or a Samsung Q990C, and you're thinking, "One sub? That ain't gonna cut it for my living room." Or perhaps you've just picked up a second wireless subwoofer and you're wondering how on earth to get both of them talking nicely to your soundbar. It's a common enough puzzle, especially with all the different brands and their own little quirks these days. I've seen plenty of folks scratching their heads over this in my workshop, so let's sort it out.  *How To Connect Two Wireless Subwoofers To One Soundbar — tested in the SpeakersMag workshop.* **Quick Verdict: Connecting two wireless subs to one soundbar is often tricky, sometimes impossible directly, but usually achievable with clever placement or an external processor.** ### Why Two Subwoofers? It's Not Just About More Bass, Mate Now, before we get stuck into the "how," let's talk about the "why." A lot of people think adding a second subwoofer is just about shaking the foundations more. And yeah, it can do that. But honestly, the real benefit isn't just sheer volume; it's about *better* bass. More even bass. Less boomy, more controlled, and smoother bass across your whole listening area. See, bass frequencies are a tricky bunch. They propagate as really long waves, and when those waves bounce off walls, furniture, and even you, they create all sorts of cancellations and reinforcements. You get these "dead spots" where the bass just disappears, and "hot spots" where it's far too loud and boomy. Drives me absolutely crackers. One sub, no matter how good, will always have this issue to some extent. Throw a second sub into the mix, especially if you position it smartly, and you can significantly smooth out that bass response. The two subs work together, filling in each other's nulls and making the bass sound far more consistent. It's not just about making the neighbours complain more; it's about making the bass sound right, no matter where you're sitting on the sofa. I've had countless customers come in with complaints about muddy bass, or "it sounds great in my mate's house, but in mine, it's just not right." More often than not, it's room acoustics messing with a single sub. Two subs can often be a far simpler and more effective solution than trying to treat an entire room with bass traps, which, let's be honest, most of us don't want plastered all over our living rooms. ### The Wireless Conundrum: Soundbars and Subwoofers Playing Nice (or Not) This is where things get a bit fiddly, especially with wireless gear. When you buy a soundbar system with a wireless subwoofer, that sub is usually designed to pair exclusively with *that specific soundbar*. It's a proprietary handshake, a bit like trying to get an Apple charger to work with a Samsung phone. They just don't speak the same language. Most soundbars are only set up to connect to one dedicated wireless subwoofer from their own brand. They simply don't have the internal electronics or the software to manage a second, independent wireless bass unit. Think of it like a single lane road – only one car can pass at a time. This is where most people hit a wall. I've had a few punters bring in their shiny new second sub, expecting it to just "connect" like magic. Then they look at me with puppy-dog eyes when I tell them it's not quite that simple. For instance, if you've got a Samsung Q-series soundbar, it'll pair beautifully with its bundled wireless sub. Trying to add a second *different* Samsung wireless sub (or, heaven forbid, a JBL one) often ends in frustration. The soundbar simply won't see it. Some higher-end soundbar systems *do* support multiple wireless subwoofers, but these are pretty rare and usually sold as a specific "2.2" or "5.2.2" package from the get-go. For example, some Nakamichi soundbar systems are designed with two subs in mind, but they are often wired or use a dedicated hub. **Who it's for:** * Anyone unhappy with uneven bass in their home cinema setup. * Those looking to smooth out frequency response rather than just increase volume. * Users with larger rooms where a single sub struggles to fill the space. * People willing to get a bit technical or invest in an external processor. **Who should skip it:** * Folks with small rooms where one decent sub already performs well. * Those on a very tight budget, as adding a second sub can get pricey. * Anyone expecting a simple "plug and play" solution for non-matching wireless subs. * If your primary goal is just ear-splitting bass, a bigger single sub might be a simpler answer. ### Option 1: The "Lucky Break" – Soundbars That Support Two Wireless Subs Natively Let's start with the ideal, albeit uncommon, scenario. A handful of soundbars out there are actually designed to work with two wireless subwoofers from the off. These are usually systems where the manufacturer sells specific "add-on" subs, or the initial package already includes two. Take the Nakamichi Shockwafe range, for instance. They often come with two wireless subwoofers in their premium packages. The soundbar unit itself acts as the central hub, sending signals to both subs simultaneously. There's no real trick here; you just follow their instructions for pairing, and it usually works a treat. It's an integrated system, designed to handle it from the ground up. Another example might be certain high-end Klipsch or Sennheiser systems, where they explicitly state compatibility with two specific wireless subs. In these cases, the pairing process is usually straightforward: power on the sub, put the soundbar in pairing mode, and they find each other. Sometimes there's a button on the back of the sub, other times it's all done through the soundbar's remote or an app. **Pros of this approach:** * Designed to work together, so reliability is usually high. * Often simpler setup, as the system is integrated. * Optimised for balanced sound within the manufacturer's ecosystem. **Cons of this approach:** * Rare for most popular soundbars. * Limits you to specific subwoofers from the same brand. * Can be an expensive upfront cost if buying a whole new system. If you're lucky enough to have one of these systems, you're golden. Just crack open the manual, follow the pairing steps, and enjoy the improved bass. For the rest of us, it's a bit more work. ### Option 2: The Wired Workaround – When Wireless Just Won't Play Ball So, your soundbar only talks to one wireless sub? Don't despair. You might be able to incorporate a second *wired* subwoofer. This means you'll need a soundbar with a dedicated Subwoofer Output (sometimes labelled LFE Out or just Sub Out). Most decent soundbars will have one of these, even if they come with a wireless sub. It's usually an RCA jack. Now, here's the catch: that single Sub Out on your soundbar is, well, *single*. It sends out one signal. To get that signal to two wired subwoofers, you'll need an RCA Y-splitter cable. You plug the single end into your soundbar's Sub Out, and the two split ends then go into the LFE input (or Line In) of each of your *active* subwoofers. **What you'll need:** 1. **Soundbar with a Subwoofer Output:** Essential. Check the back of your soundbar. It's usually a single RCA port. 2. **Two Active Subwoofers:** Crucially, these need to be active (powered) subwoofers. Passive subs need an external amplifier, which complicates things much more. Most standalone subs you buy today are active. 3. **RCA Y-Splitter Cable:** A simple, inexpensive cable that takes one RCA input and splits it into two RCA outputs. 4. **Two RCA Subwoofer Cables:** To run from the splitter to each subwoofer. **Setup Process:** 1. Connect the single end of the RCA Y-splitter to the Subwoofer Output on your soundbar. 2. Connect one of the split ends of the Y-splitter to the LFE/Line In of your first active subwoofer using an RCA subwoofer cable. 3. Connect the other split end of the Y-splitter to the LFE/Line In of your second active subwoofer using another RCA subwoofer cable. 4. Power on everything and start playing some bass-heavy content. 5. Crucially, you'll need to spend some time adjusting the gain (volume) and crossover frequency on *each* subwoofer individually. You want them to blend seamlessly, not overpower each other. I've set up countless systems this way. It's robust, reliable, and generally gives excellent results. The key is to match the subs as closely as possible in terms of output and phase, and to spend a good hour or so tweaking their individual settings. You might even want to try a bass sweep test tone to listen for dead spots in your room. **Pros of this approach:** * Very reliable connection, no wireless dropouts. * Often allows you to use different brands of subwoofers. * Opens up a wider range of subwoofers, including some cracking value passive options if you have an amp. * Relatively inexpensive if you already have the subwoofers. **Cons of this approach:** * You'll have cables running across your room, which isn't always pretty. * Requires active subwoofers (or an extra amplifier for passive ones). * More manual adjustment needed for crossover and gain on each sub. * Might not work if your soundbar *only* has a proprietary wireless sub output and no general LFE out. ### Option 3: External Processors and Advanced Setups (For the Keen Beans) Alright, for those of you who want to get a bit more serious, or if the above options just aren't cutting it, you can look into external bass management processors. These bits of kit are usually found in dedicated home cinema receiver setups, but you can get standalone versions. A simple approach might be a dedicated subwoofer preamp or line-level splitter with gain control. You'd run the single LFE out from your soundbar into this unit, and then it would have multiple outputs to feed your subwoofers. The advantage here is that you often get individual level control for each sub, making balancing them much easier. For the truly committed, something like a miniDSP unit could be considered. These are digital signal processors that allow you to apply all sorts of magic to your audio, including precise equalisation, delay, and phase control for multiple subwoofers. You'd route your soundbar's LFE output (or even its pre-outs, if it has them) into the miniDSP, and then out to your subwoofers. This allows for incredibly fine-tuned bass response, even correcting for room modes. But make no mistake, this isn't a plug-and-play solution; it requires a fair bit of technical know-how and measurement gear. I've used miniDSPs in my own setup to iron out some nasty room issues. The difference can be night and day, turning boomy, undefined bass into something tight, articulate, and truly impactful. But it's not for the faint of heart, and you'll need a measurement microphone like a UMIK-1 and software like Room EQ Wizard (REW) to get it right. **Pros of this approach:** * Unparalleled control over bass response. * Can correct for room acoustics and integrate multiple subs perfectly. * Can be used with virtually any sub/soundbar combination (with appropriate connections). * Future-proof for further system upgrades. **Cons of this approach:** * Significantly more expensive than other options. * Requires technical knowledge and patience for setup and calibration. * Adds more components and cables to your system. * Might be overkill for a casual soundbar setup. ### Placement, Placement, Placement: Where to Put the Bass Box(es) No matter how you connect them, proper placement of your subwoofers is absolutely critical. Two poorly placed subs can sound worse than one well-placed one. My golden rule: don't just dump them where they "fit." With two subs, you're aiming for that smoother bass response. Here are a few common strategies I recommend: * **Opposite Corners:** This is often a cracking starting point. Placing subs in diagonally opposite corners of the room can help energise the room more evenly and minimise standing waves. I've seen this work wonders in many rectangular living rooms. * **Mid-Wall Placement:** Sometimes, placing them roughly halfway along opposite walls (e.g., front and back, or left and right) can also be very effective. This helps to distribute the bass energy more uniformly. * **Front Stage:** Placing both subs at the front of the room, near your soundbar, can help create a more cohesive front soundstage. This is often good if you want the bass to feel like it's coming from the screen. * **Subwoofer Crawl:** This is my favourite method for finding the best spot for a single sub, and it works for two too, albeit with more effort. Put one sub in your primary listening position (where your head usually is). Play some bass-heavy music. Then, crawl around the room on your hands and knees, listening to where the bass sounds the smoothest, most integrated, and least boomy. That's where your sub should go. Repeat for the second sub, trying to find two spots that complement each other. Remember, small adjustments can make a huge difference. Move them a foot forward or back, rotate them, try different corners. It's a bit of an art, not a science, and it requires patience. Don't be afraid to experiment. I've spent entire afternoons just shuffling subs around a room, and the results are always worth it. ### Crucial Settings and Calibration Tips Once everything's hooked up and roughly in place, it's time for the fine-tuning. This is where you turn a decent bass setup into a fantastic one. #### 1. Crossover Frequency This is vital. Your soundbar, if it has a Sub Out, will typically have some internal bass management that sends frequencies below a certain point (e.g., 80Hz or 100Hz) to the subwoofer. If you're using the soundbar's LFE output, you usually set the crossover on your subwoofers to their highest setting, often "LFE" or "Bypass." This lets the soundbar handle the crossover. If your soundbar *doesn't* manage the crossover for its LFE out (less common, but possible), or if you're using an external processor, you'll need to set the crossover on your subs. A good starting point is 80Hz. This means the subs handle everything below 80Hz, and your soundbar handles everything above. This is the THX recommended standard and generally works well with most speakers. #### 2. Gain (Volume) Control Each subwoofer will have a gain knob. Start with it about a quarter to a third of the way up. You want the subwoofers to blend seamlessly with the soundbar, not dominate it. Play some familiar music or movie scenes. Gradually increase the gain on each sub until the bass feels present, impactful, and balanced, but not boomy or overwhelming. Don't be tempted to just crank them up to max; that's how you get muddy, uncontrolled bass. #### 3. Phase Control Some subwoofers have a phase switch (0° or 180°) or even a continuously variable phase knob. This controls whether the subwoofer's output is in sync with the main speakers (soundbar). Incorrect phase can lead to bass cancellation, making your bass sound weak or thin. Try both 0° and 180° settings on each sub (one at a time, then both together) while playing bass-heavy music. Listen for the strongest, most impactful bass at your listening position. If your subs are far apart, you might find different settings work best for each. If you're using an external processor like a miniDSP, you can achieve far more precise phase alignment. #### 4. Room Correction (if available) Some higher-end soundbars (and especially AV receivers) have built-in room correction software (like Audyssey, Dirac Live, or proprietary systems). If your soundbar has this, use it! It will often take measurements from your listening position and automatically adjust levels, crossovers, and even some basic equalisation for your subwoofers (and main channels). Run it *after* you've manually set your subs roughly in place and adjusted their gain and phase. It can make a huge difference. ### Common Pitfalls to Avoid * **Mixing Wireless and Wired Inputs:** Most subwoofers will either accept a wireless signal *or* a wired LFE input, not both simultaneously from different sources. If you're using the soundbar's wireless connection for one sub, don't expect to then plug a wired connection into that same sub from a different source. * **Overlapping Frequencies:** If your soundbar's speakers are full-range and your subwoofers' crossovers are set too high, you can get a lot of overlap. This leads to muddy, undefined bass. Ensure a clean hand-off between your soundbar and subs. * **Ignoring Room Acoustics:** I cannot stress this enough. Your room is the biggest component in your sound system. Glass, bare walls, open-plan spaces – they all play havoc with bass. While two subs help, they can't fix everything. Think about soft furnishings, curtains, and rugs to help tame reflections. * **Buying Incompatible Subs:** Before you spend your hard-earned cash on a second sub, do your research! Check your soundbar's manual or the manufacturer's website to see if it supports multiple subs, or at least has a dedicated LFE output. ### Comparing Approaches for Multi-Sub Setup | Feature | Native Wireless (System) | Wired (Y-Splitter) | External Processor (e.g., miniDSP) | | :------------------ | :-------------------------------- | :-------------------------------- | :------------------------------------ | | **Complexity** | Low (plug & play if supported) | Medium (cabling, manual tweaks) | High (technical knowledge, calibration)| | **Cost** | High (usually premium systems) | Low-Medium (cables, sub cost) | High (processor, mic, software, time)| | **Performance** | Very Good (optimised) | Good (reliable, flexible) | Excellent (custom-tuned, room-corrected)| | **Flexibility** | Low (brand-locked) | Medium (mix & match wired subs) | High (any sub, precise control) | | **Cable Management**| Minimal | High (cables needed) | High (more components, more cables) | | **Wireless Subs** | Yes (specific system) | No (requires wired subs) | Possible (if processor supports wireless, rare)| | **Who it's for** | Convenience & integration focus | Value-conscious, reliable bass | Enthusiasts, critical listeners | ### FAQ: Getting Two Subs to Work with Your Soundbar **Q: Can I connect any two wireless subwoofers to my soundbar?** A: Almost certainly not, mate. Most soundbars are designed to pair with one specific wireless sub from their own brand, using proprietary tech. Trying to connect a second, different wireless sub usually won't work. You're better off looking at wired solutions if your soundbar has an LFE out. **Q: My soundbar only came with one wireless sub. Can I just buy another one from the same brand and add it?** A: It depends entirely on the soundbar model. Some very few high-end systems (like certain Nakamichi models) are designed for this, but the vast majority aren't. Check your soundbar's manual. If it doesn't explicitly state support for a second wireless sub, assume it won't work wirelessly. **Q: What if my soundbar doesn't have an LFE/Sub Out port? Am I out of luck for a second sub?** A: If your soundbar *only* supports a single proprietary wireless sub and has no physical LFE output, then adding a second *independent* subwoofer (wired or wireless) becomes extremely difficult, bordering on impossible without some very niche and complex workarounds that I wouldn't recommend for most home users. You'd essentially need to tap into the soundbar's audio signal before it goes wireless, which is a massive faff. **Q: How do I know if my two subwoofers are in phase with each other and the soundbar?** A: The simplest way without special equipment is to use your ears. Play some music with a strong, consistent bass line. Try switching the phase on one subwoofer (e.g., from 0° to 180°). Listen for which setting produces the loudest, most defined, and punchiest bass at your listening spot. Repeat for the second sub, then try both together. You're aiming for maximum output and clarity. If you can, use a sound level meter app on your phone (take it with a pinch of salt, but it can give you a rough idea) or, even better, a dedicated SPL meter. ### Final Word So there you have it. Getting two wireless subwoofers hooked up to a single soundbar isn't always as straightforward as "plug and play," but it's certainly not impossible for most decent soundbar systems. The key is understanding your soundbar's capabilities and being prepared to go a bit more old-school with cables if its wireless tech is limited to just one bass bin. Adding a second sub, when done right, really can transform your home cinema experience. It's not just about turning up the bass; it's about creating a more immersive, evenly distributed, and accurate low-frequency foundation for your movies and music. Give it a go, take your time with placement and calibration, and you'll be rewarded with a sound that truly fills the room. It's a journey, but a worthwhile one for any serious home cinema enthusiast. Just don't forget the brew when you're doing all that crawling around, eh?