Key takeaways
- A built in subwoofer typically reaches 60 to 90 Hz, while a separate subwoofer routinely extends down to 25 to 35 Hz.
- A separate subwoofer can be placed for the best room gain, often a front corner, while a built in unit is stuck wherever the bar itself sits.
- Skipping a separate subwoofer saves roughly 100 to 300 USD and removes a pairing step, at the direct cost of bass extension.
- Deep bass under 40 Hz travels through shared walls and timber floors far more readily than the gentler output of a built in woofer.
- A separate subwoofer can be swapped or upgraded later. A built in one is permanent for the life of the bar.
A soundbar with its subwoofer built into the same cabinet trades bass extension for a single box under the TV. A model that ships with, or accepts, a separate wireless subwoofer trades that simplicity for real low end, at the cost of a second box somewhere else in the room.
A customer in a one bedroom flat asked me last year why his all in one bar, a compact model with side firing woofers built into the cabinet, sounded thinner during action films than his brother’s setup a few streets away. The brother owned a Samsung HW-Q990D with its separate wireless subwoofer sitting in the corner. Same size television, same size living room, genuinely different bass output.
The choice comes down to four things: how deep the bass actually reaches, where the subwoofer can physically sit, what a separate box adds to the price and the setup, and what happens once shared walls and neighbours are part of the picture.
How deep the bass actually reaches either way
A built in subwoofer, sharing a cabinet with the main drivers, is limited by the cabinet volume available inside a slim bar. Most reach down to somewhere between 60 and 90 Hz before running out of headroom, enough for dialogue and most television but thin under a war film’s artillery or a racing game’s engine note.
A separate subwoofer, something like the SVS SB-1000 Pro or the wireless unit bundled with the Samsung HW-Q990D, has an enclosure measured in tens of litres rather than a few, and a driver built to travel further in and out. That combination routinely reaches 25 to 35 Hz, the range where an explosion stops being heard and starts being felt in the chest. That point one in a 5.1 designation, covered in channel counts explained, refers to this exact subwoofer channel regardless of whether it lives inside the bar or in a separate box, a convention Dolby documents in its own surround format guides.
The Sonos Arc Ultra is a useful middle case. Its own cabinet houses larger drivers than most bars manage, reaching further into the bass than a typical built in woofer, but it still depends on a separate Sonos Sub for the deepest output serious action content asks for. Whether that gap actually matters depends heavily on what you watch.
A genuinely built in design like the compact end of the Klipsch Flexus range keeps everything in one slim cabinet by design, trading the deepest bass for a shelf that never gets any wider or gains a second box, which is precisely the trade this whole comparison is about.
Where the subwoofer can physically go in the room
A built in subwoofer has no placement decision to make. It sits exactly where the bar sits, under or in front of the television, which is rarely the acoustically ideal spot but is also one less thing to think about during setup.
A separate subwoofer can be moved to wherever the room actually reinforces bass best, often a front corner, which can add several dB of low end for free through room gain alone. That flexibility is also where problems start: a subwoofer shoved against a wall purely to hide the cable can sound boomy in one specific frequency range rather than genuinely deeper, a trade off examined in fixing boomy bass in a small room.
Cable routing is a real constraint too, not an afterthought. A wireless subwoofer still needs a mains power outlet, and moving it more than about 8 to 10 metres from the bar on the shared 2.4 GHz link some models use can introduce dropouts, so the ideal acoustic spot and the ideal electrical spot are not always the same corner.
What a separate box adds to the price and the setup
A built in subwoofer model saves roughly 100 to 300 USD compared with an equivalent bar sold with a separate unit, since there is no second cabinet, driver, amplifier, or wireless radio to manufacture. Setup is also faster: one box to unpack, one power cable, no pairing step at all.
A separate subwoofer adds that cost back, plus a pairing step that usually completes within 30 seconds once both units are powered on, and a second mains outlet somewhere in the room. Driver size within that separate unit then becomes its own decision, typically 6 to 10 inches depending on room size and budget, though buyers rarely see which output measurement method, following standards published by the Consumer Technology Association, was used to reach the number on any given box.
If a separate subwoofer is being added to an existing bar rather than bought as a bundle, confirm the bar actually supports a third party or later generation sub before ordering. Pairing compatibility is rarely universal even within the same manufacturer’s own product range.
Vibration, shared walls, and what neighbours notice
A built in subwoofer, limited in both output and how low it reaches, is gentler on shared walls almost by accident. Its bass simply does not extend far enough into the range that travels most readily through a timber floor or a party wall.
A separate subwoofer capable of real output below 40 Hz can become a genuine neighbour complaint in a building with shared structure, particularly a timber framed apartment rather than solid concrete construction. Rattles and vibration are the more immediate symptom indoors, while low frequency transmission through the structure is what the people next door actually notice.
An isolation pad under a separate subwoofer, decoupling its vibration from the floor, recovers a meaningful amount of that impact without touching the volume dial at all. It is a cheap fix that most owners never think to try before assuming the subwoofer itself is the problem.
A simple test settles most disputes before they become an argument with the flat downstairs. Press a flat hand against the shared wall itself during a loud scene. If you can feel a distinct pulse in time with the bass rather than a general hum, the level or the crossover point needs adjusting regardless of which type of subwoofer is installed.
Whether the subwoofer can be swapped or upgraded later
A built in subwoofer is permanent. When the bar eventually fails or feels dated, the subwoofer goes with it, since there is no way to separate one from the other. There is also no upgrade path if your taste or your room changes and you decide you want deeper bass than the cabinet was ever built to provide.
A separate subwoofer can usually be replaced or upgraded independently, provided the new unit pairs with the existing bar, and can be added later even to a bar that originally shipped without one at all.
That reversibility is the real argument for buying the version without a built in subwoofer whenever the budget allows it, even if a dedicated sub is not added on day one. The option stays open. Built in bass, once you own it, is the whole and final answer.
Built in or separate, matched to the room
A small bedroom, a studio flat with close neighbours, or a household mostly watching dialogue heavy shows: the built in subwoofer version is genuinely enough, and the money saved is better spent elsewhere in the system.
A living room over about 20 square metres, a household that watches action films or plays games at real volume, or anyone who wants the option to upgrade bass later without replacing the whole bar: pay for the separate subwoofer, whether bundled as with the Samsung HW-Q990D or added afterward like an SVS SB-1000 Pro.
Either way, confirm you actually need the extra bass at all before paying for it twice over, once in the box price and again in the space it takes up in a room that might not have much to spare.
Questions readers ask about this
Almost never on the same model. A subwoofer built into the cabinet is not designed to be disabled or supplemented, unlike bars sold with a separate wireless sub that often let you add a second unit later. Check the specific model's manual for a subwoofer output or pairing mode before assuming an addition is possible.
Not meaningfully. Both use similar driver technology, and lifespan depends more on how hard the driver is pushed relative to its size than on which cabinet it sits in. A small built in woofer driven near its limit regularly may show fatigue sooner than a larger separate subwoofer running comfortably within its range.
Generally yes. A home office rarely needs bass below about 60 Hz for typical video calls, music, or the occasional film during a break, and a built in subwoofer covers that range without adding a second box to an already crowded desk. Save the separate subwoofer budget for a room where you actually watch action content.
Not directly. Dialogue clarity comes mostly from the centre channel drivers, not the subwoofer, whichever type is used. A separate subwoofer can help indirectly by taking low frequency effects off the main cabinet, freeing it to focus on the midrange where speech lives, but it will not change how clear dialogue itself sounds.
Some bars allow it, but the more common result is phase cancellation, a dip in bass where the two subwoofers partially cancel each other at certain frequencies rather than adding together. Most manufacturers let you disable the built in unit once a separate subwoofer is paired, which avoids the problem entirely.
About the author
Rahul Gupta
Rahul Gupta has spent nearly a decade quietly wiring living rooms, testing soundbars in every awkward apartment layout imaginable, and untangling the kind of HDMI handshake problems that make people give up on Atmos altogether. He writes here about what actually works when you get the boxes home—not what the spec sheet promises. If a piece of gear on this site earns a recommendation, it earned it in a real room with real furniture, not a lab.
