Onkyo TX-NR747

7 channel Amplifier

Onkyo TX-NR747 features 7 channel power amplifier. It is rated at 110 W (8 Ω, 20 Hz - 20 kHz, 2 channel driven) and is able to drive 4 ohm speakers.

• WRAT (Wide Range Amp Technology): Onkyo TX-NR747 features Onkyo’s Wide Range Amp Technology (WRAT) circuit layout that prevents phase shifting by pushing the roll-off point higher than the listening-level frequency. Amplifying sound without phase shift creates an uncommonly well-focused and realistic audio image. If phase shift occurs and signal timing is not accurate, then neither is the resulting audio image.

THX Select™2 Plus certified

Onkyo TX-NR747 is THX Select™2 Plus certified. This means that it is ideally suited for a room where the screen-to-seat viewing distance is approximately 3 to 4 meters, and the room size is approximately 56 cubic meters.

• THX™ Certification: THX™ Certification offers optimal performance, superior quality and seamless integration. THX works with partners from the ground up, so that certified products deliver professional quality audio-visual experiences right out of the box. They only certify the very best products with uncompromised quality, performance and consistency. They ensure that THX certified devices play well with lower performing devices and components. THX listening modes make the receiver to have one speaker set up for movies, music and games. They are tested for power output, bass management, signal-to-noise ratio and feature THX Loudness Plus, Boundary Gain Compensation, Timbre Matching and RE-EQ.
• Power Output: Power output is tested to ensure the receiver accurately plays source material at THX Reference Level in every input and mode and at every sampling rate for all possible playback combinations selected by the listener.
• Frequency Response: THX has strict requirements for frequency response to ensure that you hear all the details in high-resolution tracks, ensures dialog in movies, and vocals in music are clear while maintaining deep, impactful bass output that doesn’t overpower the listening experience.
• Signal-to-Noise Ratio: THX tests the signal-to-noise ratio to ensure the unit is designed to have low noise performance with very little to no audible hiss from the speakers.
• Bass Management: THX requires an 80Hz crossover point in the setup menu to ensure proper bass management in every THX Certified AVR. This setting confirms that the subwoofer handles low frequencies, freeing up the loudspeakers to handle mids and highs.
• THX Loudness Plus™: THX Loudness Plus™ is a volume control technology featured in THX Certified Dominus, THX Certified Ultra and THX Certified Select AV Receivers, and preamplifiers that automatically adjusts the front-to-back speaker level relationship as you turn the volume down. With THX Loudness Plus, home theater audiences can now experience the rich details of surround sound at any volume level.
• Boundary Gain Compensation: Sitting near a wall may result in increased acoustic levels at the lower frequencies. BGC corrects the way low frequency sound is perceived when seated near a wall. This results in a more accurate bass response.
• Timbre Matching: Your ears hear different tonal qualities in sounds coming from different directions. Timbre Matching restores the frequency balance between your front and surround speakers ensuring seamless and smooth panning between the front to back of the room.
• RE-EQ: Many movie soundtracks are mixed in studios for playback in large cinema auditoriums with an array of speakers. When played on home systems, they may appear abrasive and edgy. Re-EQ establishes a more accurate tonal balance when enjoying movies in your home.

Speaker Configurations

Onkyo TX-NR747's 7 channel amplifier can be assigned for different speaker configurations.

• Dolby Atmos Configurations: The following speaker configurations are supported for Dolby Atmos:
5.2.2 with internal amplifier.
• DTS:X Configurations: The speaker configurations for DTS:X are the same as for Dolby Atmos:
5.2.2 with internal amplifier.
• Configurations without height channels: There are also other speaker configurations available which do not include height channels:
5.2, 7.2 with internal amplifier.
• 2-ch Bi-Amp: Onkyo TX-NR747 allows you to bi-amp up to 2 main channels simultaneously. During bi-amplification two amplifiers are used for one speaker. One amplifier powers the midrange and tweeter section of the speaker and another amplifier powers the low frequency woofers. Each amplifier is less loaded and performs better. In order to use this feature speakers must have 2 pairs of connectors.

Dolby Atmos

Onkyo TX-NR747 supports Dolby Atmos. It is a cinematic audio format in which sounds exist as individual entities, called audio objects. In Dolby Atmos, any sound can exist as an independent audio object, free of channel restrictions. They can be precisely placed and moved anywhere in your room, including overhead, to flow above and around you in three-dimensional space. Through the use of audio objects, overhead sound, and all the richness, clarity, and power of Dolby sound, Dolby Atmos turns your room into an amazing place for entertainment. The format supports up to 128 simultaneous independent audio objects in a mix for rich, realistic, and breathtaking sound. It recreates the director's original concept through descriptive metadata to provide customized playback for home theater and delivers sounds above you through overhead speakers, special upward-firing Dolby Atmos speakers, or a Dolby Atmos enabled sound bar.

• Dolby Surround Upmixer: If the content is not mixed in Dolby Atmos then the Dolby surround upmixer will expand the audio to all channels including ceiling speakers. The upmixer has replaced the Dolby Pro Logic II family with improved upmixing algorithms.

DTS:X

Onkyo TX-NR747 supports DTS:X. A technique used in DTS:X is similar to the one used in Dolby Atmos. Instead of a fixed number of channels, DTS:X defines object locations from the listener in polar coordinates. An a/v receiver then dynamically renders sound according to the current speaker configuration. The speaker layout employed by DTS:X is the sum of Dolby Atmos and Auro-3D. It has standard 7.1 channel base layer, a 5 channel height layer above the base layer on the front and side walls, and 3 rows of speakers on the ceiling.

• DTS Dialog Control: This function adjusts the dialog levels during playback of the DTS:X stream. It allows you to separately increase the dialog levels in contrast with the background sound and hear dialog easily even under noisy circumstances.

Sound Processing

• Advanced Music Optimizer: Compressed music enhancement in Onkyo TX-NR747 is done by Onkyo’s Advanced Music Optimizer. While MP3 or AAC files may sound fine through the headphones of your portable digital player, the limitations of these files can be exposed when played back through a quality home entertainment system. This is because a significant amount of high-frequency bit information is lost during the file-compression process. To counter this, Onkyo has designed the Advanced Music Optimizer to compensate for lost bit information and improve the quality of compressed audio signals. This results in a clearer and more expansive sound. Also included in this technology is a loudness correction feature that further improves the audio character of compressed files.

Room Calibration

Onkyo TX-NR747 comes with AccuEQ Advance room correction system and includes the calibration microphone.

• AccuEQ: First, AccuEQ detects the presence of speakers and evaluates the impedance of each. Next, it pinpoints their distance relative to the main listening position using the mic and sets suitable sound-pressure levels. Then it selects the optimal crossover frequency so that deeper bass rolls smoothly off to the subwoofer. Finally, AccuEQ performs frequency response equalization based on room-acoustic and speaker data collected via microphone. The sound-field is now tailored around the listening position, resulting in a more immersive and realistic in-film experience.

HDMI

Onkyo TX-NR747 features 8 HDMI inputs. It has 2 outputs which work parallelly and output the same signal.

• 4K/60Hz Passthrough: All inputs pass up to 4K/60p (RGB/YCbCr4:4:4/YCbCr4:2:2, 24 bit) video signal.
• Analog To HDMI Upconversion: The a/v receiver supports video upconversion, so you can connect your analog Component and Composite video sources and Onkyo TX-NR747 will output them via HDMI. This means that you will need only one HDMI cable to connect to your TV.
• HDCP 2.2 Copy Protection: 3 inputs and 2 outputs are HDCP 2.2 compliant which is a requirement for 4K/HDR copy-protected content transmission.
• 3D Ready: Onkyo TX-NR747 is able to pass 3D video through HDMI.

Onkyo TX-NR747 supports HDR (high dynamic range) video formats such as HDR10. High dynamic range video has greater dynamic range than standard dynamic range (SDR) video with brighter whites and deeper blacks. The result is greater contrast and more details in dark and bright areas, better color and depth.

• HDR10: HDR10 uses the wide-gamut Rec. 2020 color space. It sends static metadata via video stream to the TV which calibrates its screen brightness and color according to that. HDR10 supports 10-bit color which corresponds to 1024 shades of the primary RGB colors. It is technically limited to a maximum of 10,000 nits peak brightness, however common HDR10 contents are mastered with peak brightness from 1,000 to 4,000 nits.