AIRCHIVE IR library: impulse responses of the Salzburg Dom crypt, the Kleiner Tunnel at Scharfling and Schloss Frohnburg

Impulse responses of three spaces in Salzburg and its surroundings, recorded for the artistic research project AIRCHIVE (Die Luft, die sich erinnert) by Noh Seung Ju, supported by the Jahresstipendium Musik 2025 of the Land Salzburg. Sites DK: Salzburger Dom, crypt (Domkrypta), Salzburg, 3 August 2026. 5 sine sweeps of 20 s (4 in the main room, 1 in an adjacent room), 5 balloon bursts. TN: Kleiner Tunnel (Scharflinger Tunnel), former Salzkammergut Lokalbahn, km 30.4, between Scharfling and Hüttenstein, Sankt Gilgen, 25 September 2026. 3 balloon bursts. Built in 1891, in service until 1957, 21 m long, open at both ends. FB: Schloss Frohnburg, vaulted entrance hall with stone floor, Hellbrunner Allee 53, Salzburg, 30 September 2026. 8 sine sweeps of 10 s (5 at microphone position 1, 3 at microphone position 2), 3 balloon bursts. Contents of AIRCHIVE_IR_library_v1.1.zip ir/: 24 impulse responses, each as mono (measurement microphone) and XY stereo, WAV 48 kHz 32 bit float, peak normalised to minus 1 dBFS. raw/: the unprocessed recording excerpt of every event. excitation/: exponential sine sweeps, 20 Hz to 20 kHz, 48 kHz, 20 s (DK) and 10 s (FB). data/: parameters.csv (EDT, T20, T30, C50, C80, D50 and centre time Ts per IR and octave band, after the practice of ISO 3382, part 1) and metadata.json. figures/: waveform and energy decay per IR; comparisons of T30, C80, decay and spectrogram, in German and English. code/: the processing chain in Python. Equipment: recorder Zoom H4essential (48 kHz, 32 bit float); Behringer ECM8000 omnidirectional measurement microphone; built in XY pair; loudspeaker JBL 305P MkII for the sweeps. Method: exponential sine sweep after Farina, deconvolved by regularised spectral division; balloon bursts recorded directly. Truncation and noise compensation after Lundeby, Schroeder backward integration. Method, results and notes per site are given in README.md. Files outside the archive: README.md; four comparison figures (spectrogram, T30, C80, decay at 1 kHz); twelve photographs of the three sites and of the measurements (photo_DK_*, photo_TN_*, photo_FB_*). Version 1.1 (30 September 2026) adds Schloss Frohnburg. The impulse responses of version 1.0 (DK, TN) are unchanged.