The Onkyo TX-RZ30 and TX-RZ70 are two high-performance AV receivers designed for home theater enthusiasts. While both belong to Onkyo's RZ Series and share many modern features like Dirac Live and HDMI 2.1 support, they serve different purposes depending on your setup, room size, and goals. Here's a fair comparison to help you decide which one best fits your needs.

Amplification & Channel Configuration

The TX-RZ70 offers 11 powered channels, supporting systems up to 7.2.4 without an external amplifier. The TX-RZ30 provides 9 powered channels, capable of driving 5.2.4 or 7.2.2 setups out of the box.

Both receivers support preamp outputs for expansion, but if you're not planning to run more than 9 channels, the RZ30 already covers that need.

Summary:
- TX-RZ30: Ideal for standard Atmos configurations without overcomplicating setup.
- TX-RZ70: Better for larger or more advanced multi-speaker setups.

Power Output

The TX-RZ70 is rated at 140 watts per channel (2-ch driven), while the RZ30 delivers 100 watts per channel under similar conditions. In real-world use, this difference is most noticeable in larger rooms or when driving inefficient speakers at higher volumes.

That said, power isn’t everything — especially in smaller or acoustically treated spaces where the RZ30 performs more than adequately.

Summary:
- TX-RZ30: Sufficient for most home theaters.
- TX-RZ70: Extra headroom for large rooms or power-hungry setups.

Room Calibration

Both models support Dirac Live Full Bandwidth out of the box, which is a premium room correction system. The RZ70 includes Dirac Live Bass Control, while the RZ30 offers it as a paid upgrade.

If subwoofer tuning is a priority — especially with dual subs — the included Bass Control in the RZ70 is a nice bonus. However, users satisfied with standard Dirac calibration may not need the upgrade on the RZ30.

Summary:
- TX-RZ30: Dirac Full included, Bass Control optional.
- TX-RZ70: Full Dirac package included.

HDMI and Connectivity

Both receivers feature HDMI 2.1 support with 8K and 4K/120Hz passthrough, along with gaming features like VRR and QFT. The RZ70 has one extra HDMI input and output, which may be helpful for complex setups with multiple zones or displays.

Unless you need a third HDMI output or are maxing out your sources, the RZ30 has more than enough ports for most users.

Summary:
- TX-RZ30: Plenty of HDMI for typical use.
- TX-RZ70: Slight edge for multi-zone or source-heavy setups.

Audio Hardware

The RZ70 uses ESS Sabre digital-to-analog converters, which are known for their high-performance audio processing. The RZ30 doesn’t use the same DACs but still offers excellent audio quality for both movies and music.

While audiophiles may notice subtle differences, for many users the real-world experience will be similar — especially in home theater applications where room acoustics and speaker quality have a bigger impact.

Summary:
- TX-RZ30: Great audio performance for its class.
- TX-RZ70: Slightly more refined for music and critical listening.

Design and Usability

The TX-RZ30 has a cleaner, modern front panel design with accessible USB and headphone ports. The RZ70 has a traditional flip-down door, hiding more front controls for power users.

Both offer app control, voice assistant support, and multi-zone capabilities.

Summary:
- TX-RZ30: Streamlined and intuitive.
- TX-RZ70: More control options for advanced users.

Price and Value

The RZ30 comes in at a significantly lower price than the RZ70, making it a strong value for those who want premium features without going overboard. The RZ70 justifies its higher cost with more power, more channels, and a more expansive feature set — but that only matters if you’ll use it.

Summary:
- TX-RZ30: Excellent value for 9-channel setups.
- TX-RZ70: Worth it for high-end, high-channel-count systems.

Final Thoughts

Choose the TX-RZ30 if:

• You're building a 5.2.4 or 7.2.2 system.
• You want top-tier audio performance at a lower price point.
• You don’t need more than 9 powered channels or included Bass Control.

Choose the TX-RZ70 if:

• You’re building a 7.2.4 or larger system.
• You want everything included from the start (Dirac Bass Control, more HDMI, more power).
• You prioritize long-term expansion and higher-end audio architecture.