Short answer
Both are portable players, $1599 against $1699.
The iBasso DX340 reaches 100 dB on 566 of the 567 models here, the iBasso DX320 on 565.
| Specification | iBasso DX320 | iBasso DX340 |
|---|---|---|
| Power into 32Ω | 380 mW | 550 mW |
| Power into 150Ω | 81 mW | 117 mW |
| Power into 300Ω | 40 mW | 59 mW |
| Power into 600Ω | 20 mW | 29 mW |
| Output impedance | 0.34 Ω | not published |
| Output noise | not published | not published |
| Price | $1599 | $1699 |
| Headphones it reaches 100 dB on out of 567 | 565 | 566 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Balanced | iBasso DX320 | iBasso DX340 |
|---|---|---|
| Socket | 4.4mm | 4.4mm |
| Power into 32Ω | 1.2 W | 2.1 W |
| Power into 300Ω | 168 mW | 229 mW derived |
| Output impedance | 0.38 Ω | not published |
| Output noise | not published | not published |
| Headphones it reaches 100 dB on out of 567 | 567 | 567 |
Through the balanced sockets the two are level on the same test: each reaches 100 dB on 567 of the 567 models here. Derived figures are worked out from the loads the maker did publish.
| Load | iBasso DX320 | iBasso DX340 |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Published | Derived |
| 600 Ω | Derived | Derived |
Both makers publish a power rating. iBasso DX320 publishes at 32 Ω and at 300 Ω; iBasso DX340 at 32 Ω. The other rows are worked out from those.
So the two columns are not equally firm row by row: at 300 Ω only the iBasso DX320 figure is the maker’s own. On those rows the derived number is the one to doubt first.
1 headphone reaches 100 dB on the iBasso DX340 but not on the iBasso DX320 — Moondrop PARA.
565 of the 567 models here reach 100 dB on both.
Headroom is at a 100 dB SPL peak.
The widest gap on the list is the Sennheiser HD 600: iBasso DX340 has +9 dB of headroom there against +8 dB. 2 dB is about 1.5 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for iBasso DX320 and iBasso DX340 because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | iBasso DX320 headroom | iBasso DX340 headroom | iBasso DX320 hiss | iBasso DX340 hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +34 dB | +36 dB | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +14 dB | +16 dB | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +23 dB | +25 dB | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +19 dB | +20 dB | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +16 dB | +17 dB | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +12 dB | +14 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +8 dB | +9 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | +6 dB | +8 dB | not published | not published |
The iBasso DX340 costs $100 more than the iBasso DX320. Out of the 567 models here, that difference buys 1 more model driven to 100 dB.
Nothing runs the other way: there is no axis here on which the cheaper of the two does better.
Only published figures count here; blank axes are counted separately.
Each in full: iBasso DX320 and iBasso DX340.