It’s strongly recommended to compare different receivers if you want to choose the best one: Pioneer Elite SC-LX704 vs Pioneer VSX-531.
The number of channels for receivers is different - 9.2 versus 5.1, respectively, for devices. In terms of power, there are differences, the Elite SC-LX704 has such a ratio W/Ohm - 135/8, while the VSX-531 has a power of 80/8, 140/6. A common feature for devices is the same total harmonic distortion - 0.08%.
The manufacturer installed different DACs, the Elite SC-LX704 received the model ES9026PRO 384 KHz/32-bit, but the VSX-531 is equipped with 192 KHz/24-bit. The Bi-amping function is implemented only in the Pioneer Elite SC-LX704. Both Pioneer Elite SC-LX704 and Pioneer VSX-531 can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Wireless Internet connection via WIFI is only possible with Elite SC-LX704. Each of the receivers has a Bluetooth connector. The Elite SC-LX704 has access to the Spotify service. 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 Elite SC-LX704 and the VSX-531. Video scaling is only possible with the Elite SC-LX704. Operation with the Dolby Vision is only possible with the Elite SC-LX704.
The number of HDMI inputs/outputs varies depending on the receiver, the Elite SC-LX704 has 7/3, and the VSX-531 has 4/1. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is not supported by the Elite SC-LX704 and the VSX-531. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. The Elite SC-LX704 has support for the standard HDCP 2.3, compared to the VSX-531, which supports the standard HDCP 2.2. In the presence of a built-in phono stage for connecting a vinyl player only at Pioneer Elite SC-LX704. There is an ECO mode in VSX-531. The Pioneer Elite SC-LX704 can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the Elite SC-LX704. Only in the Elite SC-LX704 realized a DTS:X surround technology.