KH 420
speaker
$4,999
Used market: $3,600*
Specifications
3 of 5 values have a recorded sourceExpert Audio Engineering Commentary
Headroom Notes
A three-way midfield with a 10-inch woofer. The figure recorded is the full-space one, 116.4 dB SPL at 3% THD at 1 m averaged 100 Hz-6 kHz, which is the row this catalogue uses for every Neumann monitor. The half-space row on the same page reads 122.4 dB - exactly 6.0 dB higher, because half space is the arithmetic of a hemisphere rather than a second measurement.
What the datasheet actually says
Quoted verbatim from the manufacturer’s own page, with the date we checked it. We state what is printed, not what anyone intended by it.
«Max. SPL calc. in half space at 3% THD at 1m (averaged between 100 Hz and 6 kHz): 122.4 dB SPL»
The word in this row is «calc.»: the half-space figure is calculated, not measured separately. The same table gives 116.4 dB SPL for full space under otherwise identical conditions, and the difference is exactly 6.0 dB - the textbook gain from radiating into a hemisphere instead of a sphere. Half space assumes the monitor is flush with a large boundary; a monitor on a stand in free air does not get those 6 dB, and a monitor on a desk gets some unknown part of them. Neumann is unusually explicit about this, publishing both rows side by side and marking which is arithmetic - most makers publish one number and name neither condition.
checked 8/6/2026* Estimated with the depreciation fallback (~72% retained value). · checked on 8/6/2026