AKG K702 vs Sony MDR-7506: which needs more amplifier?

The AKG K702 is 62Ω at 92.9 dB/mW; the Sony MDR-7506 is 63Ω at 106.0 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 AKG K702 needs 13.1 dB more than the Sony MDR-7506 to reach the same loudness — 5.1 mW against 0.25 mW.

The numbers that decide it

SpecificationAKG K702Sony MDR-7506
Impedance62 Ω63 Ω
Sensitivity92.9 dB/mW106.0 dB/mW
Sensitivity (voltage)105.0 dB/V118.0 dB/V
Power for 100 dB5.1 mW0.25 mW
Voltage for 100 dB0.56 V0.13 V
Current for 100 dB9.1 mA2.0 mA
Highest source impedance
that leaves them alone (one-eighth rule)
7.75 Ω7.88 Ω
Sources that reach 100 dB
out of 280
280280

Where the two part company

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.

1 source stays below the audible-hiss threshold with the AKG K702 but crosses it with the Sony MDR-7506 (Schiit Mjolnir 3).

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.

What each one needs from 80 to 105 dB

The gap between these two in decibels does not change with volume — it is a property of the two headphones. What changes is the size of the numbers, and it changes fast: every 10 dB costs ten times the power. The row that matters is the one nearest the level you listen at, and for most people that is nearer the top of this table than the bottom.

The AKG K702 is more demanding than 89% of the 567 non-electrostatic models in this database; the Sony MDR-7506 than 40%. Both figures use the same measure as the rest of the site: whichever runs out first against a 2 V, 100 mW dongle, voltage or power.

dB SPLAKG K702 powerAKG K702 voltageSony MDR-7506 powerSony MDR-7506 voltage
800.05 mW56 mV2.5 µW13 mV
850.16 mW0.10 V7.9 µW22 mV
900.51 mW0.18 V0.03 mW40 mV
951.6 mW0.32 V0.08 mW71 mV
1005.1 mW0.56 V0.25 mW0.13 V
10516 mW1.00 V0.79 mW0.22 V

105 dB is included because forum power figures are usually quoted there or higher. It is also a level that damages hearing in minutes — how many minutes is its own calculator.

The cheapest source that satisfies both

SourcePriceHeadroom, AKG K702Headroom, Sony MDR-7506Output impedanceNoise
JadeAudio JA11$204.8 dB17.8 dB0.5 Ω1.7 µV
FiiO KA11$2913.1 dB26.1 dB0.7 Ω1.7 µV
FiiO BTR11$364.8 dB17.8 dB0.5 Ω8.0 µV

Of the 280 sources here, 280 reach 100 dB on both. That is the easy axis. 69 of them also publish an output impedance low enough for both under the one-eighth rule and a noise figure that stays below the audible-hiss threshold with both — the rest either fail one of those or never printed the number at all, and 208 of them are in the second group.

The cheapest of the 69 is the JadeAudio JA11, at $20. It leaves 4.8 dB of headroom on the AKG K702 and 17.8 dB on the Sony MDR-7506, its output impedance is 0.5 Ω against a one-eighth limit of 7.75 Ω and 7.88 Ω, and its noise figure puts the hiss floor 30 dB and 17 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.

Cheapest that satisfies three published numbers is not the same as best, and none of it is about how either headphone sounds. To put either model against a source this page does not mention, or to change the target loudness, use the amplifier matcher.

What each sheet prints, and what it is worth

ModelAs printedToleranceStandard
AKG K70210 - 39800 Hznot printednot printed
Sony MDR-750610 - 20,000not printednot printed

AKG prints 10 - 39800 Hz for the K702. Sony prints 10 - 20,000 for the MDR-7506.

Neither range has a tolerance printed beside it, and that is the whole of what this section can tell you. A wider range on one sheet is not deeper bass or more treble on that headphone: without a tolerance, neither number says how loud either model is at the ends of its own range, so the difference between the two is a difference between two pieces of marketing copy. A ±dB figure is what turns a range into a specification, and of the 490 models whose maker prints a range, 58 print it.

None of this is a measurement. What each maker publishes, and what it is worth, is set out in the frequency response audit.

Both pages in full

Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: AKG K702 and Sony MDR-7506. Every figure on this page comes from what AKG and Sony published, or is derived from it — what AKG publishes and what Sony publishes, both counted.

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