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 :)