Hifi-Apps on Android
measure - listen - improve!
Hifi apps help you realize the full potential of your sound system. Enjoy a completely new listening experience. You don't need any prior knowledge: Hifi apps use established measurement methods, but use the results to generate easy-to-understand suggestions for improvement, which are clarified by listening tests. Even the built-in microphone of your Android device provides many important insights. In the next step, a measurement microphone can be worked with.
Music Player with Convolver
The music player was developed with a single goal in mind: The highest possible playback quality via loudspeakers. To achieve this, two components from the high-end sector are used: a measurement program that measures the characteristics of the speakers in interaction with the listening room and a correction program that uses the results. It plays mp3, flac... sound files from your local store (no streaming services) with digital room correction, the next evolutionary step after the equalizer. Until now, this was only possible in the high-end range. Meanwhile, Android devices are powerful enough to measure the characteristics of the listening room and calculate appropriate corrections for music playback.
Features
- Guided measurement of the speaker and room properties
- Automatic calculation and use of digital room correction during music playback
- Simple and functional player
- Serial function for fast measurement at many microphone positions
- Fade-in of calculated reflections (comb filter) for comparison with the measurement data
- Phase: raw data, rolled up and group delay
- Display of correction curve and predicted result
- Adjustable limitation of correction strength
- Editable target curve
- Optional partial adjustment of the correction to the smoothed frequency response of the speakers to maintain the sound characteristics
- Options for using the Excess Phase
- Frequency-dependent windowing
- Use of measurement microphones (import of calibration curve)
- Import and export of DRC files
- Export of corrected music files, e.g. for playback on high-end systems
- English and German
- No advertising
- Comparison of burst response, impulse response and frequency response with and without DRC
- Listening tests for burst response, adjustment of dealy between right and left channel
Speaker Setup
This app helps to set up the loudspeakers. Connect your Android device to your sound system and start the measurement. Go to your designated listening places according to the instructions and play one test signals. In addition to technical data, the app also provides automatic interpretation of the results with suggestions for improvement. Various speaker, listening position and damping material configurations can be directly compared.
Features
- Simultaneous measurement of two channels, e.g. right/left in stereo.
- Automatic interpretation: The results are readable without prior knowledge.
- Display of the raw data for the frequency response in different smoothing levels on request
- Display of raw data for impulse response (linear, logarithmic) on request
- Difference measurements: By comparing different measurements, even an uncalibrated built-in microphone provides meaningful results.
- Calibration of the built-in microphone by comparison measurements, if a measurement microphone is available.
- Use of measuring microphones (import of calibration curve)
- Assessment of bass quality based on found room modes and reflections
- Suggestions for improving the bass range (positioning of speakers and listening positions, absorbers)
- Replay precision evaluation based on impulse response and frequency response
- Geometrical calculation of floor reflections and comparison with measured values
- Evaluation of early reflections based on uniformity impulse response
- Rating Channel Equality
- References to the listener enviroment using the reverberation time
- Recommendations for absorbers
- Suggestion for setting an equalizer
- Discussion about when the use of an equalizer is useful
- Thresholds and parameters for assessments and suggestions for improvement can be changed
- Export the results to HTML format
- measured values accessible in CSV format, if an external memory (e.g. SD card) is used
Download via Google Play 
Subwoofer Optimizer (XO, Distance, Phase, Delay)
Get the maximum out of your subwoofer. Many receivers today offer automatic calibration of subwoofers and speakers. This app takes you to the next level. Start a few listening tests and a measurement. You will receive the necessary adjustment parameters and can also evaluate different set-ups (room corner, wall...) and subwoofer combinations. A favourable placement creates a solid physical foundation. Only then the use of DSP(digital signal processing) for the final touch is worthwhile. Wrongly placed equipment will always sound unsatisfactory, even if it was expensive and is replaced by more expensive equipment. Sound engineers have been trying for decades to transport this painful truth to the end user. The app is meant to make a contribution to this.
Features
- Detailed explanation. The results can be read without prior knowledge.
- Display of the frequency response with explanation for beginners
- Display of the group delay with explanation for beginners
- Explanation of how to use it to set subwoofer delay (distance) on your receiver.
- Use of measuring microphones (import of the calibration curve)
- Simultaneous measurement of two channels, e.g. right/left for stereo.
- Evaluation of resonances and reflections based on the frequency response
- Listening test with different soundtracks
- Smallest audible delay? A/B/X comparison of different delays
- English and German
Download (via Google Play)
Privacy
Room Acoustics Meter offers a more technical approach. The app is written in such a way that a close-meshed network with many measurements can be quickly created. Together with the corresponding outputs, this provides a deep understanding of the acoustic behavior of the listening room. A single measurement takes about a minute: The algorithm automatically determines the microphone position and saves the result by OK-clicking. Common Android devices and clip-on measurement microphones simplify handling: Depending on the setup, it is possible to work without any cable. Each output is documented with examples, so that first steps are also possible here with relatively little prior knowledge. Connect your Android device to your sound system and start the measurement. The results are curves for frequency response, phase, impulse response. Waterfall diagrams and sound pressure maps can also be output.
Room Acoustics Meter
Features
- Measurement via logsweep
- Serial function for fast measurement at many microphone positions
- Automatic determination of the microphone position based on the sound propagation times
- Automatic generation of file names - fast saving of single measurements by OK-click
- Frequency response: sum frequency response and windowed
- Fade-in of calculated reflections (comb filter) for comparison with the measurement data
- Phase: raw data, rolled up and group delay
- Impulse response - linear: raw data, smoothed data, step response, energy-time curve
- Impulse response - logarithmic: raw data, smoothed data, maximum values, Energy-Time-Curve, Schroeder Curve
- Impulse response filter for windowed frequency responses or waterfall plots
- Display of tangents of the Schroeder curve for EDT, T15, T20, T30 or freely definable rules
- Display of frequency response and impulse response customizable: zoom, curves can be shifted against each other, different orders...
- T60 as a function of frequency and comparison with DIN 18041, IEC 60268 13, EBU Tech 3276 (2nd)
- Waterfall display (time evolution of frequency response) via wavelet or FFT analysis
- Spectrogram representation
- Frequency-dependent sound pressure map
- Calibration possibilities for the built-in microphone by comparison measurements, if a measurement microphone is available.
- Use of measurement microphones (import of calibration curve).
- Export of results: in HTML format
- Export of measurement data: Impulse response accessible as .wav file and measured values in CSV and .FRD format.
- Export of frequency response and phase in .FRD format (allows import and further processing with many audio measurement programs)
- English and German
Car Audio Setup can be seen as an acoustic multimeter for real-time measurements: In the car, neither the mounting location of the loudspeakers nor the listening positions can be changed. The focus of the measurements is therefore on optimizing the frequency response. The app provides the necessary tools with function generator, real-time analyzer and spectrogram. In addition, an oscilloscope helps in troubleshooting: Before the first measurement, experience has shown that it should be ensured that speakers and crossovers have been connected and adjusted correctly. In addition to real-time measurements, frequency response and impulse response can be measured via logsweep for more precise analyses.
Car Audio Setup
This app helps to set up a car audio system. Connect your Android device and measure in real time.
Real-time measurements
- Two views, freely configurable with oscilloscope, function generator, real-time analyzer and spectrogram)
- Mono and stereo microphones supported)
- Use of measurement microphones (import of calibration curve)
- Oscilloscope
- Trigger and rolling display)
- 4 channels: Microphone (L, R), function generator (L, R))
- Switchable automatic gain control for microphone channel (AGC)
- Function generator
- Two separately configurable generators, output mixable)
- Sine and white noise)
- Burst)
- Polarity, balance and delay of stereo channels adjustable
- Realtime Analyzer and Spectrogram
- FFT window, length, average and overlap of consecutive FFTs)
- Zoom with 2-finger gestures)
- Pause button and snapshots of multiple curves for analysis of short sound events
Measurement by logsweep
- Series function for fast measurement at many microphone positions)
- Automatic determination of microphone position based on sound travel times)
- Fade-in of calculated reflections (comb filter) for comparison with measurement data)
- Impulse response - linear: raw data, smoothed data, step response, energy-time curve)
- Impulse response - logarithmic: raw data, smoothed data, maximum values, energy-time curve)
- Display of frequency response and impulse response customizable: zoom, curves can be shifted against each other, different orders...)
- Export of results: in HTML format)
- Export of measurement data: Impulse response as .wav file and measured values in CSV and .FRD format accessible)
- Export of frequency response and phase in .FRD format (allows import and further processing with many audio measurement programs)
All measurements
- Use of measurement microphones (import of calibration curve)
- Calibration possibilities for the built-in microphone Calibration possibilities for the built-in microphone by comparison measurements, if a measurement microphone is available.
- English and German
