Measurement data

Every measurement of speaker L, in two forms:

• csv/ — plain text, opens in any spreadsheet: frequency responses (1/12 octave), impedance (magnitude and phase) and the near-field bass sums. Start here.
• *.npz — the raw recordings (impulse responses, complex impedance) for anyone who wants to re-window or re-smooth; a .png overview of each sits next to it.

CSV files

File	Columns
<session>-far.csv	frequency_hz, level_db_300ms (in-room at the mic), level_db_gated_3.4ms (room-free direct sound, valid above ≈ 290 Hz; empty below)
<session>-near-driver.csv, -near-port.csv	frequency_hz, level_db_300ms
<session>-bass-sum.csv	frequency_hz, driver_db, port_scaled_db, sum_db — near-field driver + port, complex sum, port scaled by its area
L-z-*.csv, T-z-10r-check.csv	frequency_hz, impedance_ohm, phase_deg

Levels are dB relative, with the same reference for all sessions (loopback-referenced, fixed gains), so curves can be compared directly. The first line of every file describes the speaker's state for that session.

Raw format (.npz)

Each .npz is a NumPy archive with a JSON metadata string:

import json, numpy as np

d = np.load("L-11-tube175-far.npz", allow_pickle=False)
meta = json.loads(str(d["meta"]))      # fs, sweep f1/f2, level_db, note, peak, start, ...
ir = d["ir"]                           # acoustic: impulse response (loopback-referenced), float32
# impedance files instead hold  f (Hz), Z (complex ohms), G (voltage ratio VB/VA)

• Acoustic (ir): the impulse response deconvolved against the loopback. meta["peak"] is the sample index of the direct sound; window around it (e.g. 1 ms before, 3.4 ms after for the gated far field, 300 ms for in-room/near field) and FFT. meta["placement"] is far, near-driver or near-port.
• Impedance (f, Z, G): sense resistor 50.1 Ω (meta["r_sense"]), channel calibration applied (zcal.npz holds the calibration itself).

Files

Files	What
zcal.npz, T-z-10r-check	jig calibration; jig verification with a 10.1 Ω resistor
L-z-00 … L-z-03-tube175-taped	impedance: untreated, damped, 175 mm port, port + taped seams
L-00-baseline-*	untreated box: far field, near-field driver, near-field port, bass sum
L-01, L-02	leak test: port near field with the back panel seams untaped / taped
L-03 … L-09	damping variants (see Step 1); L-07 measured twice (_2)
L-10-damped-sealed-*	the chosen damping, panel closed (friction fit — the name predates that note)
L-11-tube175-*	damped + 175 mm port
L-history-*.png, compare-*.png	overlays of several sessions

Session names: L-<nn>-<change>; L is the left speaker. The note field in each file describes the state of the speaker for that session.