DT 990 Pro 80 ohm or 250 ohm on a Scarlett 2i2 4th Gen: which is actually louder?
Two versions of one headphone on the best-selling interface, and the answer is not the one the impedance suggests. The 80 ohm version reaches 110.5 dB, the 250 ohm one 108.2 — and both sit under the 8x output-impedance rule. The whole comparison rests on a sensitivity figure beyerdynamic prints once, for both versions, without ever naming the unit.
Signal Chain Compatibility Matrix
Select gear and parameters for live gain, impedance and SPL calculations.
Input Equipment Setup
PASS: Optimal Signal Chain
Requires minimum +60dB of clean pre-amp gain. Most budget entry interfaces max out at +50dB to +56dB and introduce hiss at max pot. An inline preamp booster (Cloudlifter CL-1 / FetHead) is strongly recommended.
The interface preamp provides sufficient headroom.
$538
$405
-25%Tonal & acoustic characteristics: Flat, wide-range frequency response for clean music and speech. Smooth, warm acoustic character with air-suspension shock isolation.
Technical advisory: With +69dB max gain, the Gen 4 Solo can drive demanding dynamics like the Shure SM7B natively without requiring an external inline booster.
Physical Interconnect Topology
Shure SM7B
Direct Cable Connection (No Intermediate Box)
1x Shielded Balanced XLR Cable (3-Pin XLR Male to XLR Female)
Focusrite Scarlett Solo (Gen 4)
Host: Apple MacBook Pro (M1/M2/M3/M4)
The 80 ohm version is the louder one here — by 2.3 dB — and both versions fail the output-impedance rule.
Level. The Scarlett 2i2 4th Gen publishes 2.45 V and a 50 Ω output impedance. That resistor and the headphones form a divider, so what reaches the driver is less than 2.45 V:
| Version | Reaches the driver | Peak SPL | Against the 110 dB target | Z ratio | |---|---|---|---|---| | DT 990 Pro 80 Ω | 1.51 V | 110.5 dB | +0.5 dB | 1.6 | | DT 990 Pro 250 Ω | 2.04 V | 108.2 dB | −1.8 dB | 5.0 |
The 250 Ω version needs 2.51 V to reach 110 dB, the 80 Ω one needs 1.42 V — 4.9 dB apart. The higher impedance is the quieter one, which is the opposite of what «the 250 ohm needs an amplifier» implies about the mechanism.
Tonal balance. The rule wants the load to be at least eight times the source. 80 Ω against 50 Ω is 1.6; 250 Ω against 50 Ω is 5.0. Both are under, so neither version escapes the lift at the driver's bass impedance peak — the 250 Ω one is simply three times further along.
The pearl: beyerdynamic prints one sensitivity for two different voice coils, and never names the unit. The datasheet lists «80 Ω / system» and «250 Ω / system» with separate weights and separate cables, then a single «Nominal SPL . . . 96 dB» for both. We read it as dB/mW, following how beyerdynamic spells the unit out on the Amiron: «102 dB (1 mW / 500 Hz)». Read the same 96 dB as dB/V instead and this page inverts: 99.6 dB for the 80 Ω version, 102.2 dB for the 250 Ω one — the 250 becomes the louder of the two by 2.6 dB. One missing unit reverses the ranking of the two products the sheet is comparing.