Sony STR-ZA3100ES vs Sony STRZA1100ES comparison definitely makes sense.
Considered AV receivers have the same number of channels 7.2. And as for power, it is the same and equal to 70/8, 90/6. The THD is the same and is 0.09%. Both the STR-ZA3100ES and the STRZA1100ES support Bi-amping. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Both models do not have WI-FI support. Only the STR-ZA3100ES has Bluetooth support. Each of these units does not support Apple Music. Competitors do not have built-in Spotify service. Compared AV receivers retain the quality of 4K/60Hz signal when transmitting from a source to a TV or projector. HDMI signal transmission in standby mode is implemented in each of the devices. The STRZA1100ES can scale the input HDMI signal, unlike the STR-ZA3100ES. The HDR standard - Dolby Vision is supported by these receivers.
The Sony STR-ZA3100ES has 6/2 HDMI inputs/outputs versus 5/2 HDMI connectors of the Sony STRZA1100ES. The HDMI Audio Return Channel (ARC) feature supports both devices. HDMI eARC is available in each model. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. Both models support the standard HDCP 2.2. Receivers do not have a built-in phono stage for connecting a vinyl player.
Each of the AV receivers from our review supports 2 Multi-room zones. A voice control is not available. An ECO mode is not present in each of the AV receivers. Both STR-ZA3100ES and STRZA1100ES can be configured using the Setup assistant.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.