Raw 16-bit 48 kHz stereo over the data channel — no codec, no compression. Uses ~1.5 Mbps and needs a reliable connection. This is as good as it gets. When this is on, HD Opus is ignored.

Stereo 48 kHz Opus at up to 510 kbps with forward-error-correction and a wider jitter buffer. Adds ~50 ms of latency in exchange for near-transparent quality. Turn off for lowest-possible-latency monitoring.

Skips the TURN relay. Lowest latency when both peers can reach each other. Turn off if the connection fails (symmetric NAT, restrictive firewall).