How to Add a Subwoofer to a Stereo Amplifier
A home theater receiver redirects bass to the subwoofer. A stereo amplifier almost never does — which changes what you connect, and what you set the crossover to.
Disclosure: we earn a commission if you buy through the links on this page, at no extra cost to you. It does not influence what we pick — our criteria are published and reproducible, so you can check our work. How we pick · Full disclosure
These picks are spec-and-price analyses, not listening tests. We have not heard this gear and we do not pretend to have: every figure below is sourced to the manufacturer and linked, and every price is live or not shown at all. Here are the rules we followed.
Quick picks
Ranked on the published criteria in How We Pick. Prices are live as of August 31, 2026. Tap any row for the full write-up.
- 9.0
- 7.0
- 6.6$359.00View on Amazon
$399.0010% off
- 6.0$209.00View on Amazon
$249.0016% off
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 |  SVS SB-1000 Pro The only subwoofer here whose manufacturer publishes both a continuous power rating and the measurement condition behind its frequency response — 20–270 Hz ± 3 dB at 2 m ground plane — which is what makes its numbers comparable to anything. | Best overall | 9.0 | |
| 2 |  BIC America F12 An old design that does the two things this bracket usually gets wrong: it publishes a continuous power rating next to the peak one, and it takes speaker-level inputs from an amplifier with no subwoofer output. | Best for older amplifiers | 7.0 | |
| 3 |  Polk Monitor XT12 A braced, ported 12-inch with line, LFE and binding-post inputs and a published 80–160 Hz crossover — and a manufacturer specification table that lists no amplifier power and no frequency response at all. | Best connectivity | 6.6 | $359.00View on Amazon $399.0010% off |
| 4 |  Polk Audio PSW10 The cheapest way into a real .1 channel, and the one where Polk's own page argues with itself — the marketing says 35 Hz, the specification table says the −3 dB point is 40 Hz. | Best for a small room | 6.0 | $209.00View on Amazon $249.0016% off |
An AV receiver has bass management: tell it your speakers are “small” and it takes everything below the crossover away from them and sends it to the subwoofer. A stereo integrated amplifier almost never does this. Your main speakers keep running full range, and the subwoofer is added underneath rather than swapped in.
That single difference changes how you connect it and what you set the crossover to. It is also almost never mentioned, which is why so many stereo-plus-sub systems end up with a hump in the upper bass.
Route 1: your amplifier has a subwoofer output
The cleanest option when it exists. A single RCA from the amplifier’s sub out to the subwoofer’s line input, and the subwoofer’s own low-pass filter does the rest.
Which of the amplifiers we cover have one, and what they publish about it:
| Amplifier | Subwoofer output | What is published about it |
|---|---|---|
| Marantz PM6007 | Yes | 2.8 V (200 mV input, volume at maximum) |
| Denon PMA-600NE | Yes — pre-out | 1 V / 100 Hz |
| Yamaha A-S501 | Yes | No level or filter figure published |
| Yamaha A-S301 | Yes | No level or filter figure published |
| WiiM Amp | Yes | User-adjustable 30–250 Hz crossover, with auto cable detection |
| Cambridge Audio AXA35 | Not published | Four RCA inputs, one phono, one front aux — no sub out listed |
| Fosi Audio V3 | No | RCA line inputs only |
Two of these rows are more interesting than they look.
Denon publishes “1 V / 100 Hz”for the PMA-600NE’s subwoofer pre-out. That second figure is a filter: Denon is telling you the output is low-passed at 100 Hz. It does not mean the main speakers are high-passed — they still run full range — but it does mean the amplifier has already limited what reaches the subwoofer.
The WiiM Amp is the outlier, publishing a user-adjustable 30–250 Hz crossover on its subwoofer output. That is bass management of a sort, in a stereo-shaped box, and it is unusual at this level.
Route 2: speaker-level inputs on the subwoofer
If your amplifier has no sub output — and plenty do not — the subwoofer can take a feed from the speaker terminals instead. Its internal circuitry attenuates that down to line level. The main speakers stay connected in parallel and are unaffected.
This only works if the subwoofer has the input, and half the subwoofers we cover do not.
| Subwoofer | Speaker-level input | Published detail |
|---|---|---|
| BIC America F12 | Yes | High-level inputs plus line-level LFE, with automatic signal sensing |
| Polk Monitor XT12 | Yes | Left/right 5-way binding posts, plus line level and LFE |
| Polk Audio PSW10 | Yes | Two pairs of gold-plated spring terminals, plus stereo line level |
| SVS SB-1000 Pro | Yes | Speaker-level stereo input at 1 kΩ, alongside RCA in/out at 16 kΩ |
| Klipsch R-120SW | No | Line level / LFE RCA jacks only |
| ELAC Debut 2.0 SUB3010 | No | Two RCA inputs (L, R/LFE) only |
If your amplifier is an older integrated with no subwoofer output, the Klipsch and the ELAC simply will not connect to it. That is a compatibility fact from the spec sheet, and it is the single most common reason a subwoofer purchase goes wrong. It is why the BIC F12 is our pick for older amplifiers.
Route 3: split the line-level signal before the amplifier
If your source has two outputs, or your DAC has a preamp mode, you can feed the amplifier and the subwoofer in parallel from the source side. Several of the DACs we cover publish a preamp mode that makes this workable — the Topping E30 II, the FiiO K11, the FiiO K7 in speaker mode.
The drawback is that the subwoofer level no longer follows the amplifier’s volume control unless the split happens after a variable output. Get that wrong and the subwoofer plays at a fixed level while everything else moves. Check whether the output you are splitting is fixed or variable first.
The setting almost everyone gets wrong
On a home theater receiver the standard advice is to set the crossover to 80 Hz, because the receiver simultaneously high-passes the main speakers at 80 Hz. Bass goes to one place or the other.
On a stereo amplifier there is no high-pass. Your main speakers still play everything they can. So if you set the subwoofer’s low-pass at 80 Hz and your speakers are flat to 44 Hz, both are producing output across that whole overlap — and where two sources produce the same content, the level rises.
Set the subwoofer's low-pass near the main speaker's published low-frequency limit — not at 80 Hz by default
Inputs
- ELAC Debut 2.0 B6.2 published response: 44 Hz – 35 kHz (no tolerance published) (ELAC spec page)
- Klipsch R-51M published response: 62 Hz – 21 kHz ± 3 dB (Klipsch spec sheet (PDF))
- Klipsch R-41M published response: 68 Hz – 21 kHz ± 3 dB (Klipsch spec sheet (PDF))
- Micca RB42 published response: 50 Hz – 20 kHz, stated as “typical in-room” (Micca spec page)
Result
With ELAC B6.2 mains: low-pass near 45–50 Hz, overlap ≈ 5 Hz wide
With Klipsch R-41M mains: low-pass near 65–70 Hz, overlap ≈ 5 Hz wide
Setting 80 Hz with ELAC B6.2 mains: both sources active across 44–80 Hz — an overlap 36 Hz wide
In the overlap band the subwoofer and the main speakers are reproducing the same content into the same room. Where they arrive in phase the level adds; where they arrive out of phase it subtracts. Either way it is not flat, and the wider you make that band the more of the audible bass it covers.
These are published anechoic-style figures and your room will not deliver them — boundary gain typically extends real in-room bass below the published number. Treat this as the starting point, then adjust by ear or by measurement. Note too that Klipsch publishes no low-pass crossover range at all for the R-120SW and BIC publishes none for the F12, so on those two you are turning a dial with no published scale.
Phase, and the one control worth actually experimenting with
A subwoofer sits somewhere different in the room from the main speakers, so its output arrives at your seat at a different time. The phase control compensates for that.
Most subwoofers we cover offer a 0/180° switch — Klipsch publishes it on the R-120SW, Polk on the Monitor XT12. SVS publishes continuous phase adjustment through its app on the SB-1000 Pro, along with three parametric EQ bands per preset and room-gain compensation.
The test takes a minute: play something with sustained bass, sit in your listening seat, and flip the switch. One position will be noticeably fuller than the other. That is the right one. There is no theoretically correct answer independent of your room, which is exactly why the control exists.
Position it before you tune it
Where the subwoofer sits changes its in-room response far more than any control on its back panel. The crawl method — put the subwoofer on your seat, play repetitive bass, and crawl the floor to find where it sounds most even — is described step by step in the home theater setup guide and works identically for a stereo system.
And if the problem you are trying to solve is boominess rather than absence, a subwoofer will make it worse. Uneven bass in a small room is a room-mode problem; corner traps address it and a second bass source does not.
The order of operations
- Check what your amplifier publishes: subwoofer output, or nothing.
- If nothing, buy a subwoofer with speaker-level inputs — and check that line specifically, because two of the six we cover do not have them.
- Position by the crawl before adjusting anything.
- Set the low-pass near your main speakers’ published low-frequency limit, not at 80 Hz out of habit.
- Set level so you notice the subwoofer only when it stops.
- Flip the phase switch and keep whichever position sounds fuller.
Every pick in detail
Every specification below links to the manufacturer document we read it from. Where a manufacturer does not publish a figure, we say so rather than estimating it.
SVS SB-1000 Pro
Best overallPrice as of August 31, 2026. #ad
The only subwoofer here whose manufacturer publishes both a continuous power rating and the measurement condition behind its frequency response — 20–270 Hz ± 3 dB at 2 m ground plane — which is what makes its numbers comparable to anything.
- extension
- 9/10
- published data
- 10/10
- room control
- 10/10
- value for money
- 6/10
- build quality
- 9/10
| Specification | Published value | Source |
|---|---|---|
| Frequency response | 20–270 Hz ± 3 dB, measured 2 m ground plane away from reflective structures (quasi-anechoic). SVS is the only manufacturer in this group that publishes the measurement condition. | SVS product page |
| Amplifier power | 325 W RMS continuous (820+ W peak dynamic), Sledge STA-325D class D | SVS product page |
| Driver | 12 in long-throw, 13.3 mm Xmax / 26.9 mm Xmech, 1.5 in voice coil | SVS product page |
| Enclosure type | Sealed, extra-thick MDF front baffle with internal bracing | SVS product page |
| Inputs | Unbalanced stereo RCA in/out (16 kΩ) plus speaker-level stereo input (1 kΩ); 3–12 V AC/DC trigger | SVS product page |
| DSP / app | 50 MHz Analog Devices DSP; Bluetooth app for iOS/Android with 3 nameable presets, 3 parametric EQ bands per preset, adjustable low pass, phase, polarity and room-gain compensation | SVS product page |
| Dimensions (with grille) | 13.5 in H × 13 in W × 14.76 in D (342 × 330 × 375 mm) | SVS product page |
| Weight | 26 lb (11.9 kg) unboxed with grille | SVS product page |
Pros
- 325 W RMS continuous is a continuous rating, not a peak figure dressed as one
- 20–270 Hz ± 3 dB published WITH its measurement condition — nobody else here does that
- App DSP with three parametric EQ bands per preset and room-gain compensation, which is real control over the one band room correction handles worst
- Speaker-level inputs as well as RCA, so an integrated amp with no sub output can still drive it
- Sealed 13-inch cabinet — it fits where a ported 12 will not
Cons
- The most expensive pick here
- Sealed alignment trades raw output near tuning for a gentler roll-off — a ported box of the same size will play louder at 30 Hz
- The app is the interface for the good features; the front panel alone is not
- One of these in a large open-plan room will run out before a bigger ported sub does
Skip it if your room is large and open-plan and output matters more to you than measured accuracy. A ported 12 costs less and moves more air down low.
BIC America F12
Best for older amplifiersPrice as of August 31, 2026. #ad
An old design that does the two things this bracket usually gets wrong: it publishes a continuous power rating next to the peak one, and it takes speaker-level inputs from an amplifier with no subwoofer output.
- extension
- 6/10
- published data
- 6/10
- room control
- 3/10
- value for money
- 8/10
- build quality
- 6/10
| Specification | Published value | Source |
|---|---|---|
| Frequency response | 25 Hz – 200 Hz. No ± dB tolerance is published, so treat the 25 Hz as a claim rather than a comparable spec. | BIC America product page |
| Amplifier power | 475 W dynamic peak / 150 W RMS continuous, BASH design. Both figures are BIC's; only the second is a continuous rating. | BIC America product page |
| Driver | 12 in injection-molded long-throw woofer, front-firing | BIC America product page |
| Enclosure type | Vented, with BIC's patented “Venturi” vent | BIC America product page |
| Sensitivity | 90 dB | BIC America product page |
| Inputs | High-level (speaker-level) inputs plus line-level LFE, with automatic signal sensing | BIC America product page |
| Dimensions | 17 in H × 14.75 in W × 17.25 in D | BIC America product page |
| Weight | 42 lb | BIC America product page |
| Low-pass crossover range | Not published | — |
Pros
- 475 W peak AND 150 W RMS continuous both published — the split most listings hide
- High-level (speaker-level) inputs, so it connects to a vintage integrated or a receiver with no sub out
- Automatic signal sensing, so it powers itself up
- 12-inch driver and a published 90 dB sensitivity
Cons
- The 25 Hz – 200 Hz response is published without any ± dB tolerance, so the 25 Hz is a claim rather than a comparable measurement
- BIC does not publish the low-pass crossover range at all
- 42 lb — the heaviest subwoofer here
- A long-running design; the cabinet and finish show it next to the Polk and ELAC
Skip it if you want published data you can check. BIC gives you a continuous power figure and then no tolerance on the frequency response, which is half a spec sheet.
Polk Monitor XT12
Best connectivityA braced, ported 12-inch with line, LFE and binding-post inputs and a published 80–160 Hz crossover — and a manufacturer specification table that lists no amplifier power and no frequency response at all.
- extension
- 5/10
- published data
- 2/10
- room control
- 4/10
- value for money
- 7/10
- build quality
- 8/10
| Specification | Published value | Source |
|---|---|---|
| Amplifier power | Not published | — |
| Frequency response | Not published | — |
| Manufacturer's bass claim | Polk's feature bullet says “smooth low frequency extension down to 24 Hz”. It appears nowhere in the specification table, carries no ± dB tolerance and no measurement condition — so it is a claim, not a spec. | Polk Monitor XT12 info sheet (PDF) |
| Amplifier type | Class A/B | Polk product page |
| Low-pass crossover | 80 Hz – 160 Hz, continuously variable, plus LFE | Polk product page |
| Phase adjustment | 0/180 | Polk product page |
| Driver | 12 in bi-laminate paper cone with foam surround | Polk product page |
| Enclosure type | Bass reflex (ported), braced MDF | Polk product page |
| Inputs | Line level, LFE (single RCA) and speaker level via left/right 5-way binding posts | Polk product page |
| Dimensions | 16 in W × 16.4 in H × 17.9 in D (407 × 418 × 456 mm) | Polk product page |
| Weight | 39 lb (17.7 kg) | Polk product page |
Pros
- Line level, LFE and 5-way binding posts — the most complete input set here alongside the SVS
- Low-pass crossover published as 80–160 Hz continuously variable, with 0/180 phase
- Braced low-resonance MDF cabinet with a removable grille
- A 12-inch driver in a ported box — the alignment that moves the most air for the money
Cons
- Polk's specification table publishes NO amplifier wattage and NO frequency response — the “down to 24 Hz” is a marketing bullet with no tolerance and no measurement condition
- 39 lb and 17.9 inches deep
- No DSP, no app, no room EQ — volume, crossover, phase and nothing else
- Nothing published that lets you compare it against the SVS or the Klipsch on paper
Skip it if you want to check the claim before you buy. There is no published response spec here to check it against.
Polk Audio PSW10
Best for a small roomThe cheapest way into a real .1 channel, and the one where Polk's own page argues with itself — the marketing says 35 Hz, the specification table says the −3 dB point is 40 Hz.
- extension
- 3/10
- published data
- 7/10
- room control
- 3/10
- value for money
- 8/10
- build quality
- 5/10
| Specification | Published value | Source |
|---|---|---|
| Frequency response (−3 dB) | 40 Hz → 160 Hz. Polk's own marketing copy on the same page says “down to 35 Hz”; the specification table says 40 Hz. We publish the table. | Polk product page |
| Amplifier power | 100 W peak, class D. Polk publishes no continuous rating for this model — the 100 W is a peak figure. | Polk product page |
| Amplifier bandwidth / distortion | 40 Hz – 200 Hz, < 1% distortion | Polk product page |
| Driver | 10 in Dynamic Balance polymer composite cone | Polk product page |
| Enclosure type | Vented via front-panel flared port | Polk product page |
| Inputs | Stereo line level (2 × RCA) plus speaker level (2 pairs of gold-plated spring terminals) | Polk product page |
| Dimensions | 14.375 in H × 14 in W × 16.125 in D (36.5 × 35.6 × 41 cm) | Polk product page |
| Weight | 26 lb (11.8 kg) | Polk product page |
Pros
- Polk publishes proper −3 dB limits (40 Hz → 160 Hz), which most sub makers at this price do not
- Line level AND speaker level inputs, so it works with almost anything
- 26 lb and the smallest 10-inch box here — it disappears in an apartment
- Amplifier bandwidth and distortion (< 1%) are published
Cons
- 40 Hz is a genuinely limited bottom end for film — the LFE track goes an octave below that
- Polk's own marketing on the same page claims 35 Hz against its own spec table's 40 Hz
- 100 W is a PEAK figure; Polk publishes no continuous rating for this model
- No DSP, no app, no room correction
Skip it if your room is bigger than a bedroom or you watch action films at volume. This is the entry point, and it is honest about being one.
Frequently asked questions
Can I connect a subwoofer to a stereo amplifier without a sub output?
Yes, if the subwoofer has speaker-level (high-level) inputs. The BIC America F12, Polk Monitor XT12, Polk PSW10 and SVS SB-1000 Pro all publish them. The Klipsch R-120SW and ELAC SUB3010 publish line-level RCA inputs only, so neither will connect to an amplifier with no subwoofer output.
What crossover should I set on a subwoofer with a stereo amp?
Not 80 Hz by default. That figure assumes a receiver is high-passing your main speakers, which a stereo amplifier does not do. Start near your speakers’ published low-frequency limit instead — around 45–50 Hz with ELAC Debut B6.2, around 65–70 Hz with Klipsch R-41M — so the two sources overlap as little as possible.
Does a stereo amplifier have bass management?
Almost never. An AV receiver set to “small” removes bass from the main speakers and sends it to the subwoofer; a stereo integrated leaves the mains running full range and adds the subwoofer underneath. The WiiM Amp is a partial exception, publishing a user-adjustable 30–250 Hz crossover on its subwoofer output.
Should the subwoofer phase switch be 0 or 180?
Whichever sounds fuller from your listening seat, and there is no way to know in advance because it depends on where the subwoofer sits relative to your speakers and your chair. Play sustained bass, flip the switch, keep the louder setting. SVS publishes continuous phase adjustment via its app on the SB-1000 Pro rather than a two-position switch.
Read next
The Best Subwoofers for a Home Theater
Six subwoofers ranked on continuous power and published response, including two that publish neither.
Preamp vs Power Amp
Voltage versus current, what damping factor tells you in ohms, and the pre-out spec that decides whether you can ever split them later.
Home Theater Setup: The Complete Guide
The complete setup, built on Dolby's published layout angles rather than on vibes — plus what to do when your room disagrees.
Ported vs Sealed Speakers
What a port buys in efficiency and extension, what it costs in placement and roll-off, and how the sealed and ported subwoofers we cover actually compare.
The Best Integrated Amplifiers Under $1,000
Six amps under $1,000, and the dynamic-power trap that overstates the popular pick by roughly 2x.
The Best Bass Traps
Ranked on published 125 Hz absorption rather than NRC — and only one maker publishes it for a corner trap.
Sources
Every specification on this page was read from one of these documents. If one of them has changed, or we have made an error, tell us — corrections are logged and dated per our editorial policy.
- Marantz PM6007 — subwoofer output specification
- Denon PMA-600NE — subwoofer pre-out (1 V / 100 Hz)
- Yamaha A-S501 — subwoofer output
- WiiM Amp — subwoofer output with 30–250 Hz crossover
- BIC America F12 — high-level and line-level inputs
- Polk Monitor XT12 — inputs and crossover range
- Polk PSW10 — inputs and published response
- SVS SB-1000 Pro — inputs, DSP and app control
- Klipsch R-120SW — inputs (spec sheet, PDF)
- ELAC Debut 2.0 SUB3010 — inputs and crossover
- ELAC Debut 2.0 B6.2 — frequency response
- Klipsch R-41M — frequency response (spec sheet, PDF)