Onkyo TX-NR646 vs Denon AVR-X2500H

GENERAL	Onkyo TX-NR646	Denon AVR-X2500H
Brand	Onkyo	Denon
Model	TX-NR646	AVR-X2500H
Type	A/V Receiver	A/V Receiver
Country	USA	UK
Release Year	2015	2018
Predecessor	Onkyo TX-NR636	Denon AVR-X2400H
Successor	Onkyo TX-NR656	Denon AVR-X2600H

AMPLIFIER	Onkyo TX-NR646	Denon AVR-X2500H
Channels	7.2	7.2
Power Output	100 W (8 Ω, 20 Hz - 20 kHz, 2 channel driven)	95 W (8 Ω, 20 Hz - 20 kHz, 2 channel driven)
Front Wide Channel Support
Discrete Amplification
WRAT (Wide Range Amplifier Technology)
VLSC (Vector Linear Shaping Circuitry)
Optimum Gain Volume Circuitry
THX™ Certification
Continuous 6 Ω Rated
Certified 4 Ω Performance
Discrete Output Stage Circuitry
3-Stage Inverted Darlington Circuitry
PUSH-PULL Design
Mono Block Power Amplifier Construction
Independent Block Construction (Amp/Preprocessor)
Bi-amp Capability		assignable
BTL (Bridged Transless or Bridging)

AUDIO FEATURES	Onkyo TX-NR646	Denon AVR-X2500H
Digital Signal Processing (DSP) Engine	Dual 32-bit DSP for Powerful Advanced Processing	Four 300 MHz DSP cores
DAC	Asahi Kasei AK4458	AKM AK4490EQ
DAC Specs	384 kHz/32 Bit	384 kHz/32 Bit
Maximum Channel Processing	7.1	7.1
D.D.S.C. HD Digital
Alpha Processing
Air Studios Monitor Certification
Dolby Atmos	up to 5.1.2 after firmware update	up to 5.1.2
Dolby Atmos Height Virtualization
Dolby Atmos Music
Dolby TrueHD
Dolby Digital Plus
Dolby Surround Upmixer
Dolby Pro Logic
Dolby Digital EX
Surround EX
DTS:X	up to 5.1.2 after firmware update	up to 5.1.2
DTS Neural:X	after firmware update
DTS Virtual:X
DTS Neo	Neo:6 until firmware update
DTS-HD Master Audio
DTS-HD High Resolution Audio
DTS 96/24
DTS Express
DTS-ES		Discrete 6.1, Matrix 6.1
IMAX Enhanced
Auro 3D with Auro-Matic Upmixer
PCM	2-ch/Multi-ch Input	2-ch/Multi-ch Input
Network Audio Formats		MP3, WMA, MPEG-4 AAC, Apple Lossless, WAV, FLAC, DSD
Music Playback via USB	FLAC, WAV, Apple Lossless, WMA, WMA Lossless, Ogg, MP3, DSD, AAC, LPCM, Dolby TrueHD	MP3, WMA, AAC, Apple Lossless, WAV, FLAC, DSD
High Resolution Music Playback via USB and/or Network	up to 96 kHz	up to 192 kHz
High Resolution Audio Formats via USB	FLAC, WAV, WMA Lossless, Apple Lossless, DSD, AAC	Apple Lossless, WAV, FLAC, DSD
Gapless Playback
DSD via HDMI	2-ch/Multi-ch Input
DSD via USB	2-ch Input	2-ch Input
DSD to PCM Converter
USB DAC
Jitter Reduction	PLL (Phase Locked Loop) Jitter-Cleaning Circuit Technology for S/PDIF Audio
DTS Dialogue Control
Dialog Enhancement
Dialog Level Adjustment	DTS:X only
Dialog normalization
Dialogue Lift
Tone Control	Front L/R Channels
Compressed Music Enhancer	Advanced Music Optimizer (bluetooth included)
High-resolution Music Enhancer
THX Processing Mode
Audyssey Dynamic EQ
Audyssey Dynamic Volume
Audyssey LFC
Audyssey Sub EQ HT
Audyssey DSX
Phase-Matching Bass Boost	for Deep Bass and Clear Mid-Range
Direct Mode
Pure Audio Mode
Pure Direct Analog Path Mode
Pure Direct Mode
Virtual Speakers	T-D (Theater-Dimensional)
Independent Subwoofer Outputs

CALIBRATION	Onkyo TX-NR646	Denon AVR-X2500H
Auto Speaker Calibration System with Mic.	AccuEQ Advance	Audyssey MultEQ XT
Audyssey App Support
Optimized Bass Redirection
Bass Sync

VIDEO FEATURES	Onkyo TX-NR646	Denon AVR-X2500H
HDR10
HDR10+
Dynamic HDR
BT.2020 color space
Dolby Vision
HLG (Hybrid Log Gamma)
HDBaseT Compatible
Enhanced Audio Return Channel (eARC)
HDCP Version	2.2 (3 inputs / 2 outputs)	2.2
QMS (Quick Media Switching)
ALLM (Auto Low Latency Mode)
VRR (Variable Refresh Rate)
QFT (Quick Frame transport)
3-D Ready
Video Signal Passthrough	up to 4K/60p (RGB/YCbCr4:4:4/YCbCr4:2:2, 24 bit)	up to 4K 50/60Hz 4:4:4
Video Signal Upscaling		up to 4K 24/25/30p 4:4:4
Analog To HDMI Upconversion	Component**, Composite
Component Video Upscaling
Analog to Analog Video conversion
Component Video Maximum Resolution	480i/576i
isf Certified Calibration Control

CONNECTIVITY	Onkyo TX-NR646	Denon AVR-X2500H
Wi-Fi
Bluetooth		SBC
Bluetooth Headphone Transmission
Works with Amazon Alexa
Chromecast Built-In
Works with SonoS
HEOS
DTS Play-Fi
MHL Input
DLNA 1.5
AirPlay	AirPlay	AirPlay 2
Apple Product Connection	iPod, iPhone and iPad	iPod, iPhone and iPad
Remote App	Onkyo Remote App for iPod touch/iPhone and Android-Powered Devices	Denon 2016 AVR Remote App for iOS and Android devices and Kindle Fire
InstaPrevue Input Source Prevue

TERMINALS	Onkyo TX-NR646	Denon AVR-X2500H
HDMI Inputs	8 (1 front)	8 (1 front)
HDMI Outputs	2 (simultaneous)	2 (simultaneous)
8K Inputs
USB Input	1 (Rear)	1 Front for USB memory
USB DC Out Port
Optical Inputs	2	2
Optical Outputs
Coaxial Inputs	1
RCA Line Inputs	7	4
RCA Line Outputs	1
XLR Line Inputs
Phono Input
Multi-Channel Input
RCA Pre-Outs	0.2	0.2
XLR Pre-outs
Composite Video Inputs	3	2
Composite Video Outputs		1
S-Video Inputs
S-Video Outputs
Component Video Inputs	2	2
Component Video Outputs		1
Ethernet
Ethernet Switch
PC In
Front A/V Inputs	HDMI	HDMI, USB
Speaker A/B		assignable
Headphone Out	6.3 mm (1/4")	6.3 mm (1/4")
Detachable Power Cord
uport

ZONES	Onkyo TX-NR646	Denon AVR-X2500H
Number of Zones	2	2
Powered Zones	2	2
Zone 2 Outs	RCA Line Out	Pre Out
Whole House Mode
RS-232C Interface
+12V Trigger Output	0
Remote (IR) Input/Output	0 / 0	0 / 0

MISCELLANEOUS	Onkyo TX-NR646	Denon AVR-X2500H
On-Screen Display	Graphical Overlaid On-Screen Display (OSD) via HDMI with Quick Set-Up	Advanced Graphic User Interface
GUI Languages		9
Web Control
IP Control
Control4 SDDP
Display		1 line
Remote Controller		RC-1228
Pre-programmed / Learnable / LCD Display		/ /
ONKYO-RI System Control
RIHD (Remote Interactive Over HDMI)
Pre-Pro/Learning Remote	/
On Screen Remote Programming
Bi-directional Remote Setup via GUI
Smart Grid-Ready
Denon Link HD
Setup Assistant
Quick Select plus / Quick Select		/

RADIO	Onkyo TX-NR646	Denon AVR-X2500H
Analog Tuner	FM/AM	FM/AM with RDS
Presets	40
Digital Radio
Internet Radio	TuneIn	TuneIn
Pandora
Spotify
Tidal
Deezer
Napster
SiriusXM

CONSTRUCTION	Onkyo TX-NR646	Denon AVR-X2500H
Front Panel		not Metal
Solid Aluminum Front
Speaker Terminals	9	7
Large Speaker Terminals	9	7
Color-Coded Speaker Terminals
Transparent High-Grade Speaker Terminals
High Grade Audio Components
Gold plated RCA terminals

POWER	Onkyo TX-NR646	Denon AVR-X2500H
Power Supply	AC 120 V, 60 Hz	AC 230 V, 50/60 Hz
Independent Power Supply	2
H.C.P.S. (High Current Power Supply)	Massive High Power Transformer
Toroidal Transformer
Power Consumption	6.4 A	500 W
No Sound Power	70 W	ECO On/Off: 35 W/75 W
Standby Power	0.1 W	0.1 W
Capacitor Bank	8,200 µF
ECO Mode / Hybrid Standby Function
Auto Power off

PHYSICAL	Onkyo TX-NR646	Denon AVR-X2500H
Dimensions (W x H x D)	435 mm x 173.5 mm x 329 mm 17-1/8" x 6-13/16" x 12-15/16"	434 mm x 167 mm x 341 mm (with antenna: 434 mm x 237 mm x 341 mm) 17 1/8" x 6 5/8" x 13 1/2" (with antenna: 17 1/8" x 9 3/8" x 13 1/2")
Weight	9.4 kg (20.7 lbs)	9.4 kg (20 lbs 12 oz)

SPECIFICATIONS	Onkyo TX-NR646	Denon AVR-X2500H
Power Output (8 Ω, 20 Hz - 20 kHz, 2 channel driven, FTC)	100 W (0.08% THD)	95 W (0.08% THD)
Power Output (6 Ω, 1 kHz, 2 channel driven, FTC)		125 W (0.7% THD)
Power Output (6 Ω, 1 kHz, 1 channel driven, FTC)	170 W (0.9% THD)
Maximum Effective Power Output (6 Ω, 1 kHz, 1 channel driven, JEITA or IEC)	175 W	185 W (10% THD)
Rated Power Output (6 Ω, 1 kHz, 1 channel driven, IEC)	160 W (1% THD)	150 W (1% THD)
Dynamic Power per Channel (3 Ω, Front)	240 W
Dynamic Power per Channel (4 Ω, Front)	210 W
Dynamic Power per Channel (8 Ω, Front)	120 W
THD	0.08% (20 Hz - 20 kHz, Half power)
Phono Distortion		0.03% (1 kHz, 3 V)
Damping Factor	60 (Front, 1 kHz, 8 Ω)
Input Sensitivity and Impedance (Line)	200 mV/47 kΩ (Line)	200 mV/47 kΩ
Input Sensitivity and Impedance (Phono MM)	3.5 mV/47 kΩ (Phono mm)	2.5 mV
Phono Overload	70 mV (MM, 1 kHz 0.5% Direct)
S/N Ratio (Line, IHF-A)	100 dB	100 dB
S/N Ratio (Phono MM, IHF-A)	80 dB	74 dB
Phono RIAA Deviation		±1 dB (20-20 kHz)
Frequency Response (Analog In)	10 Hz - 100 kHz/+1 dB, -3 dB (Direct mode)	+1/-3 dB (10 Hz to 100 kHz, Direct mode)
DSD Sampling Rates via HDMI	2.8 MHz, 5.6 MHz
DSD Sampling Rates via USB	2.8 MHz, 5.6 MHz	5.6 MHz, 2.8 MHz
Video Input Sensitivity/Output Level and Impedance	1 Vp-p/75 Ω (Component Y) 0.7 Vp-p/75 Ω (Component PB/CB, PR/CR) 1 Vp-p/75 Ω (Composite)	1 Vp-p/75 Ω (Component Y) 0.7 Vp-p/75 Ω (Component PB/CB, PR/CR) 1 Vp-p/75 Ω (Composite)
Video Frequency Response	5 Hz - 100 MHz/+0 dB, -3 dB (Component)	5 Hz to 60 MHz, 0 dB/-3 dB (Component) 5 Hz to 10 MHz, 0 dB/-3 dB (Composite)
Ethernet Standard	10BASE-T/100BASE-TX	100BASE-TX
Wi-Fi Standard	IEEE 802.11 b/g/n	IEEE 802.11 a/b/g/n
Wi-Fi Terminal Frequency	2.4 GHz	5 GHz, 2.4 GHz
Bluetooth Version	2․1 + EDR	3․0 + EDR
Bluetooth Frequency	2.4 GHz	2.4 GHz
USB Terminal	5 V, 1 A	USB2.0 5V, 1 A
FM Frequency	87.5 MHz - 107.9 MHz	87.5 MHz - 108.0 MHz
FM 50 dB Quiet Sensitivity (IHF, 1 kHz, 100% MOD.)		Mono: 2.8 µV (20.2 dBf)
FM Effective Sensitivity		1.2 µV (12.8 dBf)
FM S/N Ratio		Mono/Stereo: 70 dB/67 dB
FM Harmonic Distortion (IHF, 1 kHz)		Mono/Stereo: 0.7%/1.0%
AM Frequency	522/530 kHz - 1611/1710 kHz	522 kHz - 1611 kHz
AM Effective Sensitivity		18 µV
Warranty	2 Years	3 Years

* - 480i/576i and 480p/576p only
** - 480i/576i only
*** - no 1080p/24 upconversion
**** - 1080p signal is not converted

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