Comparison of DT 48, TDH 49, and TDH 39 earphones

The frequency responses of the earphones TDH 49, TDH 39, and DT 48 (the latter with and without free‐field equalizer) were compared by means of measuring hearing threshold curves. While the TDH 39 and TDH 49 give almost identical results (average deviations 2 dB), the TDH 49 and DT 48 show moderate (5 dB) differences. In the most usual application mode, i.e., TDH 49 without and DT 48 with free‐field equalizer, distinctly different threshold curves were found, indicating rather different real‐ear frequency resonses. Accordingly, using the latter two earphone systems, psychoacoustic experiments with broadband stimuli may lead to somewhat different data.