qLouder

A tool to measure and design loudspeakers.

It is loosely inspired by the famous Room EQ Wizard. However, it aims to provide a better user experience as well as pleasing aesthetics. qLouder can also be considered as the successor of qloud:
http://gaydenko.com/qloud/
https://github.com/molke-productions/qloud/

Target use

The measurement and design features of qLouder can help you to create an optimal filter set and crossover for your DIY loudspeaker.

Measurement process

generate and play back an audio test signal (sine sweep) via sound card, amplifier and loudspeaker box
measure signal via measurement microphone
generate impulse response from recorded signal
time gate impulse response
generate frequency response
apply microphone calibration file
design a target curve (house curve)
design correction filters to match your target curve
design a crossover for your 2-way speaker

Current features

Sine sweep generation (including proper windowing).
Time gating of measured impulse response
Microphone calibration
Crossover
Loudness based house curve
Parametric equalizer
Different sample rates for playback and recording
Simple music player

TODO

Port to Qt6
SPL meter
Persistent measurements
~~Harman house curve~~
Separate handlers for bass and treble for loudness target
Remove QtMultimedia and use miniaudio instead
Detect hot plugged audio devices
Improve crossover handles for order of 4
Improve equalizer handles for shelving filters
Align crossover filter settings to equalizer filter settings

Requirements

GCC >= 9.4.0
Qt >= 5.12 (Qt6 not yet supported)
e.g. Ubuntu >= 20.04 (Focal)
PulseAudio is running

Installation (based on Ubuntu)

sudo apt install \
  zlib1g-dev \
  libcurl4-openssl-dev \
  libfftw3-dev \
  libfontconfig1-dev \
  libgl-dev \
  libmpg123-dev \
  libpulse-dev \
  libsndfile1-dev \
  libtag1-dev \
  libxcursor-dev \
  libxi-dev \
  libxinerama-dev \
  libxrandr-dev \
  pkgconf \
  qtbase5-dev \
  qtdeclarative5-dev \
  qtmultimedia5-dev \
  qtquickcontrols2-5-dev \
  qml-module-qtcharts \
  qml-module-qtquick-dialogs \
  qml-module-qtquick-shapes \
  qml-module-qt-labs-folderlistmodel \
  qml-module-qt-labs-settings \
  libqt5charts5-dev \
  libqt5svg5-dev \
  libqt5multimedia5-plugins

git clone https://github.com/mincequi/qLouder
cd qLouder
mkdir build && cd build
cmake ..
make

Contribute

Contributations are always welcome. In the best case in the form of a pull request :)