The Meze Rai Penta is 20Ω at 110.0 dB (no figure from the maker at all); the Meze Rai Solo is 16Ω at 105.0 dB (no figure from the maker at all). This page is only about what they ask of an amplifier — not how they sound, which no specification on either sheet can tell you.
The Rai Solo needs 5.0 dB more than the Rai Penta to reach the same loudness — 0.32 mW against 0.10 mW.
| Specification | Rai Penta | Rai Solo |
|---|---|---|
| Impedance | 20 Ω | 16 Ω |
| Sensitivity | 110.0 dB | 105.0 dB |
| Sensitivity (voltage) | 127.0 dB/V | 123.0 dB/V |
| Power for 100 dB | 0.10 mW | 0.32 mW |
| Voltage for 100 dB | 45 mV | 71 mV |
| Current for 100 dB | 2.2 mA | 4.4 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 2.50 Ω | 2.00 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
One caution before reading the rows. For Meze Rai Penta and Meze Rai Solo the maker publishes no sensitivity figure at all. The number in the table was collected when this database was first built and has never been traced to a manufacturer document, so treat every row below it as an estimate rather than a specification.
Every source in the database that drives one of them drives the other. On power, the choice between these two changes nothing about what amplifier you need.
12 sources stay below the audible-hiss threshold with the Rai Solo but cross it with the Rai Penta (Lake People G103-S Mk II, Lake People G111 Mk II, Grace Design m900, 9 more).
280 of the 280 sources here reach 100 dB on both. That count is about power only — the output-impedance and hiss lines above are separate questions, and a source can pass this one and fail those.
Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: Meze Rai Penta and Meze Rai Solo. Each figure on this page is labelled on those pages with where it came from, including the ones Meze never published — what that maker publishes, counted.