The Beyerdynamic Custom Studio is 80Ω at 96.0 dB (no reference unit printed); the Beyerdynamic DT 700 Pro X is 48Ω at 100.0 dB/mW. 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 Custom Studio needs 4.0 dB more than the DT 700 Pro X to reach the same loudness — 2.5 mW against 1.0 mW.
| Specification | Custom Studio | DT 700 Pro X |
|---|---|---|
| Impedance | 80 Ω | 48 Ω |
| Sensitivity | 96.0 dB | 100.0 dB/mW |
| Sensitivity (voltage) | 107.0 dB/V | 113.2 dB/V |
| Power for 100 dB | 2.5 mW | 1.0 mW |
| Voltage for 100 dB | 0.45 V | 0.22 V |
| Current for 100 dB | 5.6 mA | 4.6 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 10.00 Ω | 6.00 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
One caution before reading the rows. Beyerdynamic Custom Studio printed a decibel figure with no reference unit, so this page reads it as per milliwatt. If it is really per volt, that model needs far more than the table says. Why the two readings differ by so much.
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.
9 sources are low enough in output impedance for the Custom Studio under the one-eighth rule but not for the DT 700 Pro X (Zoom AMS-22, Arturia MiniFuse 2, Arturia MiniFuse 1, 6 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: Beyerdynamic Custom Studio and Beyerdynamic DT 700 Pro X. Each figure on this page is labelled on those pages with where it came from, including the ones Beyerdynamic never published — what that maker publishes, counted.