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Vizio V Series V51-H6 vs Vizio M Series M21d-H8R
Side-by-Side Comparison
Products
Vizio V Series V51-H6
Vizio M Series M21d-H8R
Tested using Methodology v1.3
Updated Oct 24, 2024 02:30 PM
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Amazon.comTested using Methodology v1.0
Updated Jan 12, 2024 03:54 PM
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Amazon.com
Channels5.1
Channels2.1
Variants
- V Series V51-H6 (Black)
- M-Series M21d-H8R (Black)
Our Verdict
Vizio V Series V51-H6
Vizio M Series M21d-H8R
The Vizio V Series V51-H6 is a better soundbar than the Vizio M-Series M21d-H8R. The V Series is a 5.1 setup that has a dedicated subwoofer and two surround speakers, and it has better center and surround channel performances. It also has a more neutral sound profile and gets louder with less compression at max volume. That said, the 2.1 M-Series is better built and has a Full HDMI In port that supports 4k passthrough.
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Black
V Series V51-H6
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Amazon.comBlack
M-Series M21d-H8R
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Amazon.comBlack
V Series V51-H6
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M-Series M21d-H8R
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Amazon.comBlack
V Series V51-H6
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Walmart.comBlack
V Series V51-H6
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B&HMain Differences forMixed Usage
Mixed Usage
Threshold
Mixed Usage
7.4
6.8
Stereo Dynamics
8.6
6.5
Surround 5.1
7.0
4.4
Center
8.1
6.7
Stereo Frequency Response
7.6
7.3
Full Comparison
Design
Style - Bar
Style photo - bar
Style - Subwoofer
Style photo - sub
Sub Wireless
Yes
No
Enclosure
Ported
Integrated
Style - Satellites
Style photo - satellites
Satellite Wireless
Partial, wired to wireless sub
No
Dimensions - Bar
Dimensions photo - bar
Width
36.0" (91.5 cm)
36.0" (91.5 cm)
Height
2.2" (5.7 cm)
2.2" (5.7 cm)
Depth
3.2" (8.2 cm)
5.3" (13.5 cm)
Dimensions - Subwoofer
Dimensions photo - sub
Width
8.3" (21.2 cm)
N/A
Height
9.8" (25.0 cm)
N/A
Depth
8.3" (21.2 cm)
N/A
Dimensions - Satellites
Dimensions photo - satellites
Width
4.8" (12.1 cm)
N/A
Height
2.2" (5.7 cm)
N/A
Depth
3.2" (8.2 cm)
N/A
Mounting
Bar Mounting Holes
Satellite Mounting Holes
Mountable Bar
Yes
Bar Brackets Included
Yes
Mountable Satellites
Yes
Satellite Brackets Included
Yes
Build Quality
7.0
7.5
Build quality photo
In The Box
In The Box photo
HDMI Cable Length
1.5 m (4.9 ft)
Digital Optical Cable Length
1.5 m (4.9 ft)
Back - Bar
Back photo - bar
Bar Mounting
Proprietary
Back - Subwoofer
Back photo - sub
Enclosure
Ported
Integrated
Back - Satellites
Back photo - satellites
Mounting
No
Sound
Stereo Frequency Response
7.6
7.3
Stereo Setup
Raw Frequency Response
Frequency Response Small
Channels
5.1
2.1
Tested Preset
Direct
Music
Slope
-0.66
-0.44
Standard Error
3.28 dB
2.64 dB
Low-Frequency Extension
40.0 Hz
53.4 Hz
High-Frequency Extension
19.9 kHz
19.9 kHz
Stereo Frequency Response With Preliminary Calibration
7.7
7.3
Frequency Response Calibrated
Suggested Preset
Direct
Music
Suggested Bass Setting
-3
-2
Suggested Treble Setting
1
2
Slope
0.07
0.05
Standard Error
2.76 dB
2.56 dB
Low-Frequency Extension
43.0 Hz
54.2 Hz
High-Frequency Extension
19.9 kHz
19.9 kHz
Stereo Soundstage
7.0
6.5
Crosstalk Error
2.14 dB
3.37 dB
Stereo Dynamics
8.6
6.5
Dynamic Range Compression
SPL @ Max Volume
95.3 dB SPL
96.2 dB SPL
DRC @ 90dB
0.21 dB
DRC @ Max Volume
0.97 dB
4.88 dB
Stereo Total Harmonic Distortion
8.1
Weighted THD @ 80dB
0.29
Weighted THD @ Max Volume
1.46
Center
8.1
6.7
Center Setup
Frequency Response
Localization
Discrete
Phantom
Slope
-0.81
-0.72
Std. Err.
3.42 dB
3.06 dB
SPL @ Max Volume
91.1 dB SPL
92.9 dB SPL
Weighted THD @ 80dB
0.63
0.37
Weighted THD @ Max Volume
1.68
1.50
Surround 5.1
7.0
4.4
Surround Setup
Frequency Response
Localization
Discrete
Stereo (Downmix)
Slope
-1.86
-0.66
Std. Err.
4.85 dB
2.86 dB
SPL @ Max Volume
90.2 dB SPL
94.6 dB SPL
Weighted THD @ 80dB
0.87
0.32
Weighted THD @ Max Volume
2.61
1.55
7.1 Rears
No
No
Height (Atmos)
0.0
0.0
Height Setup
H Frequency Response
Localization
Not Supported
Not Supported
Slope
N/A
N/A
Std. Err.
N/A
N/A
SPL @ Max Volume
N/A
N/A
Weighted THD @ 80dB
N/A
N/A
Weighted THD @ Max Volume
N/A
N/A
Sound Enhancement Features
7.1
4.6
Room Correction
No
No
Dialogue Enhancement
Yes
Yes
Auto-Volume/Night Mode
Yes
Yes
Subwoofer Level Adjustment
Yes
No
Bass Adjustment
Yes
Yes
Treble Adjustment
Yes
Yes
EQ
Presets
Presets
Surround Level Adjustment
Yes
No
Rear Level Adjustment
No
No
Height Level Adjustment
No
No
Virtual Surround
Yes
Yes
Connectivity
Inputs/Outputs - Bar
Physical Connections Bar Photo 1
Physical Connections Bar Photo 2
Optical Audio In
1
1
HDMI Out
ARC
1 (shared)
HDMI 2.1 Class Bandwidth
No
Full HDMI In
No
1
Analog Audio In 3.5mm (Aux)
1
1
RCA In
No
No
USB for Files
1
1
Ethernet
No
No
Subwoofer Output
No
HDMI ARC
1 (shared)
Audio Format Support: ARC/eARC
6.3
7.1
Dolby Atmos
Not Supported
No
Dolby Digital
Supported
Yes
Dolby Digital Plus
Not Supported
No
Dolby TrueHD
Not Supported
No
DTS
Supported
Yes
DTS:X
Not Supported
No
eARC
No
DTS-HD MA
Not Supported
No
PCM Channels
2.0
5.1 PCM (eARC only)
No
Audio Format Support: HDMI In
0.0
6.4
Dolby Atmos
Not Supported
No
Dolby Digital
Not Supported
Yes
Dolby Digital Plus
Not Supported
No
Dolby TrueHD
Not Supported
No
DTS
Not Supported
No
DTS:X
Not Supported
No
DTS-HD MA
Not Supported
No
PCM Channels
Not Supported
5.1 PCM
No
Audio Format Support: Optical
10
10
Dolby Digital
Supported
Yes
DTS
Supported
Yes
PCM Channels
2.0
Audio Latency: ARC
7.3
ARC Latency Video
PCM-2.0 ch
N/A
PCM-5.1 ch
N/A
Dolby MAT (PCM) Atmos
N/A
Dolby Digital
109 ms
Dolby Digital Plus
N/A
Dolby Digital Plus Atmos
N/A
Audio Latency: HDMI In
0.0
5.0
HDMI Latency Video
Latency Video
PCM-2.0 ch
N/A
PCM-5.1 ch
N/A
Dolby MAT (PCM) Atmos
N/A
Dolby Digital
N/A
Dolby Digital Plus
N/A
Dolby Digital Plus Atmos
N/A
ARC
195 ms
Optical
179 ms
Full HDMI In
49 ms
Audio Latency: Optical
6.9
Optical Latency Video
PCM-2.0 ch
N/A
Dolby Digital
366 ms
Video Passthrough To TV
0.0
0.0
1080p Max Refresh Rate
Not Supported
1080p @ 4:4:4 Max Refresh Rate
Not Supported
4k Max Refresh Rate
Not Supported
4k @ 120Hz @ 10-Bit
Not Supported
4k @ 4:4:4 Max Refresh Rate
Not Supported
8k Max Refresh Rate
Not Supported
HDR10 Passthrough
No
Yes
HDR10+ Passthrough
No
Dolby Vision Passthrough
No
HDMI Forum VRR Passthrough
No
4k @ 60 Hz Passthrough
Yes
FreeSync Passthrough
No
G-SYNC Passthrough
No
ALLM Passthrough
No
4k @ 60 Hz @ 10 bit Passthrough
Yes
4k @ 60 Hz @ 4:4:4 Passthrough
Yes
Wireless Playback
6.0
6.0
Bluetooth
Yes
Yes
Wi-Fi Playback
No
No
Chromecast built-in
No
No
Apple AirPlay
No
No
Spotify Connect
No
Connectivity - Subwoofer
Physical inputs subwoofer photo 1
Physical controls subwoofer photo 1
Sub Wireless
Yes
No
Connectivity - Satellites
Physical inputs satellites photo 1
Physical controls satellites photo 1
Sat Wireless
Partial, wired to wireless sub
No
Additional Features
Interface
Interface photo
Display
No
No
Bar Controls
Controls photo
Remote
Remote photo
Universal Remote
No
Voice Assistants Support
Amazon Alexa
No
No
Google Assistant
No
No
Apple Siri
No
No
Microphone Mute
No
App
App image
App Name
No App
iOS
No
Android
No
Acts As A Remote
No
Controls Soundbar's Settings
No
Casts Device Files
No
Other Features
Power Saving
Auto-off
HDMI CEC (TV Remote Control)
Yes
Check Price
Black
V Series V51-H6
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Amazon.comBlack
M-Series M21d-H8R
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Amazon.comBlack
V Series V51-H6
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BestBuy.comBlack
M-Series M21d-H8R
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Amazon.comBlack
V Series V51-H6
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Walmart.comBlack
V Series V51-H6
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Vizio V Series V51-H6
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Vizio V Series V51-H6 vs Vizio M Series M21d-H8R: Main Discussion
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