Having had an opportunity to test Onkyo TX-SR343 vs Denon AVRX4300H, I’d like to share my impression here to facilitate your choice of a new AV receiver.
The number of channels for receivers is different - 5.1 versus 9.2, respectively, for devices. In terms of power, there are differences, the TX-SR343 has such a ratio W/Ohm - 100/6, while the AVRX4300H has a power of 125/8, 165/6. The value of total harmonic distortion is also different, and for the TX-SR343 it is 0.08%, but for the AVRX4300H it is 0.05%.
The manufacturer installed different DACs, the TX-SR343 received the model TI Burr-Brown 192 KHz/24-bit, but the AVRX4300H is equipped with 192 KHz/32-bit. The Bi-amping function is implemented only in the Denon AVRX4300H. The model AVRX4300H can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Wireless Internet connection via WIFI is only possible with AVRX4300H. Each of the receivers has a Bluetooth connector. The AVRX4300H has access to the Spotify service.
Support for the HDR function can only boast of the AVRX4300H. The quality of 4K/60Hz signal remains unchanged when transmitting from a source to a TV or projector via HDMI for both receivers. Signaling over HDMI in standby mode can provide the TX-SR343 and the AVRX4300H. Video scaling is only possible with the AVRX4300H. Operation with the Dolby Vision is only possible with the AVRX4300H.
The number of HDMI inputs/outputs varies depending on the receiver, the TX-SR343 has 4/1, and the AVRX4300H has 8/3. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is not supported by the TX-SR343 and the AVRX4300H. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. TX-SR343 and AVRX4300H support the standard HDCP 2.2. In the presence of a built-in phono stage for connecting a vinyl player only at Denon AVRX4300H. There is an ECO mode in AVRX4300H. The Denon AVRX4300H can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the AVRX4300H. Only in the AVRX4300H realized a DTS:X surround technology.