Amplifier
Onkyo TX-NR555 |
Onkyo TX-NR545 |
7 channel Amplifier: Onkyo TX-NR555 features 7 channel power amplifier. It is rated at 80 W (8 Ω, 20 Hz - 20 kHz, 2 channel driven). |
7 channel Amplifier: Onkyo TX-NR545 features 7 channel power amplifier. It is rated at 65 W (8 Ω, 20 Hz - 20 kHz, 2 channel driven). |
- Dynamic Audio Amplification: Onkyo TX-NR555 features Dynamic Audio Amplification which is Onkyo’s amplification philosophy that focuses on capturing the energy and dynamism contained in the audio signal and reproducing it without loss. Audio signals are not static like a test tone, but rather a countless collection of constantly moving waves. While static measurements such as S/N ratio and Total Harmonic Distortion are important, Onkyo believes that excellent dynamic and transient response is the key to emotionally involving sound. Dynamism - the “life” in music - is achieved when the amp can respond to changes in the signal instantaneously, so notes start and stop naturally and the nuances in attack, decay, sustain, and release are voiced with conviction. Onkyo home theater receivers represent the culmination of almost 70 years’ experience in amplifier design. The unique elements of their amplification system comprise high-current, low-impedance architecture to accurately control large speaker cones while enabling instantaneous response to dynamic changes, and discrete wide-range amplifier circuit topology to eliminate phase shift for clear and accurate audio imaging.
- WRAT (Wide Range Amp Technology): Onkyo TX-NR545 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.
Speaker Configurations
Onkyo TX-NR555's and Onkyo TX-NR545's amplifiers can be assigned for different speaker configurations.
- Dolby Atmos Configurations: The following speaker configurations are supported for Dolby Atmos:
- Onkyo TX-NR555: 5.2.2 with internal amplifier.
- Onkyo TX-NR545: 5.2.2 with internal amplifier.
- DTS:X Configurations: The following speaker configurations are supported for DTS:X:
- Onkyo TX-NR555: The speaker configurations for DTS:X are the same as for Dolby Atmos - 5.2.2 with internal amplifier.
- Onkyo TX-NR545: Not supported.
- Configurations without height channels: There are also other speaker configurations available which do not include height channels:
- Onkyo TX-NR555: 5.2, 7.2 with internal amplifier.
- Onkyo TX-NR545: 5.2, 7.2 with internal amplifier.
- Bi-Amp: Onkyo TX-NR555 is able 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-NR555 and Onkyo TX-NR545 support 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: Both models support 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-NR555 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 Neural:X: Onkyo TX-NR555 supports DTS Neural:X which is an advanced upmixer that can take non DTS:X content and upmix it to the DTS:X speaker layout. It has replaced the DTS Neo family with improved flexibility.
- DTS Dialog Control: Onkyo TX-NR555 supports 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
- Compressed Music Enhancer: Onkyo TX-NR555 and Onkyo TX-NR545 feature Compressed Music Enhancer which enhances the quality of the music files with lossy compression.
- Advanced Music Optimizer: Compressed music enhancement in Onkyo TX-NR555 and Onkyo TX-NR545 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-NR555 comes with AccuEQ with AccuReflex™ and Onkyo TX-NR545 comes with AccuEQ Advance room correction system.
- 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.