The Grado GS1000 (Classic) is 38Ω with a sensitivity of 99.8 dB/mW, which is 114.0 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 1.0 mW, or 0.20 V across the drivers.
That puts it in the easy category. A phone, a laptop headphone jack or the cheapest USB dongle will drive it to painful levels. Of the 280 sources in the database, 280 have at least 10 dB of headroom and another 0 have enough. The cheapest portable source that does the job is the Apple USB-C dongle (US) at $9.
Sensitivity here is in dB per milliwatt. Why the unit matters.
Grado publishes this directly as 99.8 dB SPL/mW (1 mW), per milliwatt, so nothing was converted.
Source: gradolabs.com. How this data was built.
| As it is labelled | As printed | Tolerance | Standard |
|---|---|---|---|
| Frequency Response | 8-35 | not printed | not printed |
Grado prints 8-35 for the Grado GS1000 (Classic), under the heading “Frequency Response”. Source: gradolabs.com.
There is no unit beside those numbers. Not hertz, not kilohertz: two figures and a dash. Read as hertz at one end and kilohertz at the other they make sense, and that is almost certainly what is meant, but Grado does not say so, so this page does not say so either. It is the same failure as a sensitivity printed without dB/mW or dB/V, which the spec sheet audit counts across the whole database.
No tolerance is printed with it either, and that would have been the problem even if the unit were there. Of the 490 models whose maker prints a range, 58 print the ±dB figure that would make it mean something.
Only what the maker printed; maker by maker.
| Level | What it is | Power | Voltage | Current |
|---|---|---|---|---|
| 85 dB SPL | quiet background listening | 0.03 mW | 35 mV | 0.9 mA |
| 95 dB SPL | normal listening | 0.33 mW | 0.11 V | 3.0 mA |
| 100 dB SPL | loud listening | 1.0 mW | 0.20 V | 5.2 mA |
| 105 dB SPL | very loud | 3.3 mW | 0.35 V | 9.3 mA |
| 110 dB SPL | peaks on dynamic music | 10 mW | 0.63 V | 16.6 mA |
Most people listen between 75 and 85 dB; the 100 dB row leaves room for peaks.
The 15 cheapest of the 280 sources here that reach 100 dB SPL into 38Ω with at least 10 dB of headroom and no known hiss or output-impedance problem with these headphones. All 280 sources, judged for these headphones.
| Source | Type | Price | Power into 38Ω | Headroom | Verdict |
|---|---|---|---|---|---|
| JadeAudio JA11 | USB dongle | $20 | 25 mW | +14 dB | Comfortable |
| FiiO SnowSky Tiny A | USB dongle | $22 | 29 mW | +14 dB | Comfortable |
| FiiO SnowSky Tiny B | USB dongle | $22 | 29 mW | +14 dB | Comfortable |
| FiiO KA11 | USB dongle | $29 | 169 mW | +22 dB | Comfortable |
| Tanchjim Stargate II | USB dongle | $40 | 63 mW | +18 dB | Comfortable |
| ddHiFi TC35AL | USB dongle | $46 | 177 mW | +22 dB | Comfortable |
| ddHiFi TC35Air | USB dongle | $46 | 177 mW | +22 dB | Comfortable |
| Fosi Audio N3 | Bluetooth receiver | $50 | 116 mW | +20 dB | Comfortable |
| Hidizs SD2 | USB dongle | $50 | 59 mW | +18 dB | Comfortable |
| FiiO BTR13 | Bluetooth receiver | $59 | 84 mW | +19 dB | Comfortable |
| iFi GO link | USB dongle | $59 | 60 mW | +18 dB | Comfortable |
| Kiwi Ears Allegro Pro | USB dongle | $60 | 57 mW | +17 dB | Comfortable |
| ddHiFi TC35Pro (Mountain2) | USB dongle | $66 | 55 mW | +17 dB | Comfortable |
| iBasso DC03 Pro | USB dongle | $69 | 83 mW | +19 dB | Comfortable |
| DUNU DTC 480 | USB dongle | $70 | 55 mW | +17 dB | Comfortable |
Hiss. At 114.0 dB/V these are sensitive enough to reveal a source's own noise floor. The noisiest source in the database, the Schiit Mjolnir 3, would put its hiss at roughly 22 dB SPL in these headphones — clearly audible in quiet passages. Check your own source.
Output impedance. At 38Ω these want a source output impedance below 4.75Ω to satisfy the one-eighth rule; 34 of the 192 sources that publish one miss it. Check yours here.
38Ω · 98.0 dB/mW · Easy
See requirements →38Ω · 98.0 dB/mW · Easy
See requirements →38Ω · 98.0 dB/mW · Easy
See requirements →25Ω · 98.0 dB/mW · Easy
See requirements →40Ω · 100.0 dB · Easy
See requirements →80Ω · 103.0 dB · Easy
See requirements →Compared with its stablemates: vs PS2000e · vs Signature HP100 SE · vs Signature S550 · vs Signature S750 · vs Signature S950.