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VIZIO M-Series 5.1.2 Immersive Sound Bar

VIZIO M-Series 5.1.2 Immersive Sound Bar

By VIZIO · Soundbars · Desk & Streaming Setup

  • 5.1.2 audio channels
  • 40" (1016 mm) sound bar
  • 11 high-performance speakers
  • 6" wireless subwoofer
  • 45Hz bass extension

Price not listed

New
Used, refurbished, open-box

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Problems, parts and running costs

Summary

A 2021 5.1.2 soundbar system with a wireless subwoofer and two rear satellites that wire to the sub, plus two up-firing height drivers. Check the box contents before you buy used: many listings at $85–$92 are the bar alone, with no sub, rears or remote.

Strengths

  • Eleven real drivers, a six-inch sub, two up-firing drivers and two rear speakers give movies an actual surround image.
  • RTINGS praised bass, soundstage and dialogue, and found high usable loudness with little bar compression.
  • A dedicated center channel and dialogue enhancement keep voices intelligible at low volume.
  • Manual tuning covers height, center, surrounds, sub, bass, treble and EQ presets.
  • HDMI IN plus eARC gives more source paths than bars that only connect to the TV.

Weaknesses

  • Rear satellites connect to the sub by two cables, so the system is not wireless and the sub must sit where those leads reach.
  • No Wi-Fi, AirPlay, Chromecast, mobile app control or automatic room calibration.
  • Rear satellites can cut out and need a sub power cycle; one owner traced it to a shorted satellite cable.
  • Atmos and HDMI sources can drop out or fall out of sync depending on TV, source and codec.
  • Bass can overwhelm dialogue and sound muddy on some tracks; sub placement matters.
  • Up-firing height is limited by ceiling height and reflectivity and does not match discrete ceiling speakers.

Verified specifications

ModelM512a-H6, released May 2021; 5.1.2 system with 11 drivers.
Driversmain bar three full-range drivers (2.19 × 2.81 in), three 0.79-inch tweeters, two 3-inch up-firing height drivers; each satellite one 1.61 × 2.22-inch full-range driver; subwoofer one six-inch driver.
Frequency response45 Hz–20 kHz; published 103 dB measured with pink noise at 1 m, C-weighted.
Bar dimensions40.00 × 2.68 × 4.07 in, 8.47 lb. Subwoofer: 8.30 × 9.92 × 11.69 in, 11.53 lb.
Inputs1 HDMI IN, 1 HDMI OUT (eARC), 1 optical (TOSLINK), 1 analog 3.5 mm AUX IN, 1 3.5 mm AUX Voice Assistant input, Bluetooth 5.0, 1 USB for WAV/MP3 playback.
Audio formatsDolby Atmos, DTS:X, DTS Virtual:X, plus standard Dolby/DTS surround.
In the boxmain bar, powered wireless sub, two satellites, two satellite audio cables, two AC power cables, HDMI cable, LCD remote with two AAA batteries, two pairs of wall brackets, wall template, four mount screws, four cable ties, quick-start guide.
ControlsMovie, Music, Game and Direct EQ presets; individual center, treble, bass, subwoofer, height and surround levels; lip-sync AV delay; night/TruVolume.
Electrical100–240 V, 50/60 Hz. No batteries in the bar or sub; remote uses two AAA alkaline cells.
Firmware2.1.0.4 in the 2022 update family; exact latest 2026 version unconfirmed.
Warrantyone-year limited for noncommercial US/Canada use from original purchase; 90 days commercial.
Full research notes and sources

Rear speakers and cable faults

Both rear channels wire to the powered subwoofer: blue for left, gray for right. The bar-to-sub link is wireless, but the rears are not. That arrangement puts the sub near the seating area, which can boost perceived bass. Several owners report both rears going silent while the sub keeps playing, sometimes after a loud passage; a July 2024 owner isolated it to one satellite cable, replaced it, and restored both channels, with a February 2025 reply confirming the fix. A September 2024 report and a March 2026 comment describe the same pattern without a confirmed diagnosis. Test each rear channel separately and inspect the RCA-style leads before blaming the amplifier. A replacement blue left satellite cable (part 1018-0000675) is listed at $19.99 by Vizparts, with M512a-H6 compatibility stated; the matching gray right cable (1018-0000676) is also listed at $19.99, but its direct page was not accessible during verification.

HDMI, Atmos and gaming

The bar has one HDMI IN and one HDMI OUT with eARC, plus optical, analog AUX and Bluetooth. Atmos and DTS:X play over the supported path, but the format you get depends on the TV, source and input: streaming Atmos usually needs eARC or ARC with Dolby Digital Plus, and TrueHD from Blu-ray needs an appropriate eARC or direct HDMI path. RTINGS confirms HDMI passthrough, but the 2021 documents do not establish HDMI 2.1, 4K120, VRR or ALLM. For a high-refresh console, connect the console directly to the TV and send audio back over eARC, then test. Owners also report lip-sync delay and unintended switching between ARC and HDMI IN on PS5 setups, with mixed results after firmware updates.

Bass and room tuning

The six-inch sub can be overpowering up close, and Tom’s Guide found it muddy on some tracks even at reduced levels. Moving the sub toward the front of the room helped in that review but required longer satellite cables. RTINGS notes rear satellite distortion at high volume. The up-firing drivers depend on a flat, reflective ceiling and centered seating; sloped or absorbent ceilings reduce the height effect. There is no microphone or app calibration, so tuning is manual with the LCD remote.

Treat completeness as the first filter. A $91.90 eBay listing was the bar and power cord only, and a sold $85.33 listing was also bar only; neither is a 5.1.2 system. A separate used subwoofer listed at $85 carries no proof it will pair with a different bar. Best Buy showed the M512a-H6 at a $424.99 clearance reference price and listed it unavailable, with a $499.99 comparison price. A certified-refurbished eBay listing asked $329 with free shipping and two-year Allstate coverage but was out of stock. A used bar-plus-sub set asked $295 plus $37.40–$59.02 shipping in September 2026. A third-party feed surfaced $349.99 tagged in stock, but the exact page could not be validated. New alternatives: Insignia NS-SB512 at $179.99 on a recent promotion (open-box good at $162.99), VIZIO SV510X-0806 5.1 at $149, and Hisense AX5125H with a last visible clearance price of $262.99 that was unavailable. For a complete, tested M512a-H6 with matching sub, rears, cables and remote, $100–$150 locally is strong value, $150–$200 delivered is plausible, $200–$250 should be conditional on testing and return policy, and above $250 is hard to justify against new 5.1.2 sets.

Running costs

There are no filters, pods or subscriptions. The remote takes two AAA batteries. Electricity is unknown: the manual gives 100–240 V but no measured wattage. As an illustration only, a combined 30 W average for 3 hours a day plus 3 W standby would cost about $11.17 a year at $0.20 per kWh. Replacement parts are condition-based: the LCD remote is $19.99 from Vizparts, and a shorted satellite cable is about $19.99 to replace.

Warranty and support

The manual’s warranty is one year limited for noncommercial US/Canada use from original purchase, 90 days for commercial use. It applies to the original buyer of a new unit from an authorized retailer; clearance, recertified and unauthorized-seller units are excluded. VIZIO may repair, replace or refund, and may use new or recertified parts. Because the M512a-H6 launched in May 2021, most 2026 units have no remaining manufacturer term. Service requires preauthorization before shipping in, and the owner may pay outbound freight. Firmware 2.1.0.4 is documented, but at least one July 2025 owner reported “subwoofer not found” after updating, with support stating rollback is unavailable; treat firmware updates as a risk, not a fix-all. No audited support turnaround or repair success rate has been published.

Which model this is

This page covers the M512a-H6, a 2021 40-inch 5.1.2 system with 11 drivers. Do not confuse it with the M51a-H6 (5.1 without physical height drivers), M51ax-J6, M512E-K6, or the newer Elevate SE SL512X-0806; VIZIO’s old M512a-H6 product URL now redirects to that Elevate SE page, so its app control and auto-rotating height drivers do not apply here.

Sources

Manufacturer:

Independent reviews:

Owner reports:

Parts and stores:

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