MiniSonic analysers are hand-held, two-channel analogue audio test sets, which as well as performing subjective measurements, can be used for precision line-up. Automated measurements can be made through the use of sequences making it possible to perform frequency 'sweeps', noise, distortion and phase measurements and headroom tests with the press of two buttons. Calibrated microphones are available so that speakers, other microphones and acoustic spaces may be analysed in the same way. The MiniSonic enables an audio path to be evaluated in terms of frequency response, noise, distortion, crosstalk and phase in a matter of seconds and produces a full graphical presentation of the results on an integral display or on a PC running Lindos software.
Minisonic can act as a stereo PPM, a two-way balanced-unbalanced converter, a stereo microphone preamplifier, a headphone amplifier and a level converter. Sequences of tests can be run at any level and any necessary level normalisation is made automatically. Graphs of frequency response, noise-time, phase-frequency, distortion-level and level-level can all be displayed by the unit and by a computer using the included software, for saving, printing, tolerance testing and more.
There are three models available. The MS20 has a 128x64 pixel OLED screen making it most suitable for stand-alone use. The MS10 provides the same measurement functions as the MS20, but displays information on a 32 LED bar graph. The MS10 is therefore better suited for bench applications where a desktop or laptop computer running Lin4Win is available. The MS1 is an MS10 without sequence testing.
Common Features - All MiniSonic Models
Each has a 65mm speaker for monitoring, and a socket for headphones. The rechargeable battery is a slot-in 'Sony' style lithium ion type, which provides up to 15 hrs use. This charges internally when an external power source is connected. On the rear are two miniature jack sockets for microphones and a 2.1mm co-axial socket for power. Two 9-pin male D-sub connectors provide connection to a PC by RS232 and audio inputs. Two female types are used for oscillator and line outputs. The input and output connectors are wired to the 'UniSon' 'standard', used by Lindos, which combines two balanced analogue audio channels and power for an external device on one connector.
Technical Specification - Common to all models
Load: 600 ohms minimum, -72dB THD. Outputs: Two channels, 10ohm, balanced, centre-grounded, 9-pin D-sub. Inputs: Two channels, 44kohms balanced or 22kohms unbalanced, -60dBu to +19dBu. Microphone inputs: Two 3.5mm jack, 5V power, calibrated 30dBu =100dB SPL for MM3. Output frequency: 4Hz to 40kHz sine waves in 1/3rd-octaves or 1/12th octaves; 1kHz, 5kHz, 10kHz square waves. Accuracy +/-0.05% of specified synthesised frequency. Output level range: -90dBu to +19dBu in 1dB steps, balanced, centre grounded; 96dBu to +13dBu unbalanced. Accuracy+/-0.02dB at 0dB, +/-0.05dB -60dBu to +19dBu. Output distortion: -76dB distortion residue, weighted, -86dB/0.005% THD at 1kHz, 22Hz-22kHz bandwidth, typical. Output flatness: +/-0.02dB, 20Hz-20kHz, -0.05dB at31kHz, -0.6dB at 16Hz and 40kHz, typical. Noise: -86dBu residual noise, muted, to ITU468. Power source: Rechargeable battery or 11-14V DC, 500mA. Dimensions: 215 x x160 x 33 (w x d x h) mm. Weight: 0.6kg.
The main feature of the front panel is the 128x64 pixel OLED display, which at switch-on instantly displays the incoming level on both channels (to 0.01dB) the frequency on the left channel and the phase difference between the two. Opening the menu gives a list of pre-defined Lindos sequences. Once the sequence has been selected and completed, in 20 seconds typically, the results are displayed and the user can scroll through the different results screens. In sequence mode, user defined sequences can be assigned to two buttons, which in other modes act as frequency and level presets. The MS20 has non-volatile flash memory, used for storing user-sequences, configurations options and up to three complete sets of results, for transferring to a PC at a later point.
Measurement Modes
Level: Two-channel simultaneous level measurement, -50dBu to +19dBu in 10dB ranges (autoranging/manual). Accuracy +/-0.05dB -20dBu to +19dBu. Quasi-peak reading as standard with fast option. Frequency readout to over 50kHz with high precision (+/-1Hz resolution). Phase: +/-180 degrees, 20Hz-20kHz, +/-2 degrees resolution and accuracy (up to 40kHz with reduced accuracy).
PPM mode: Two-channel simultaneous display with PPM dynamics to IEC268 type II (BBC) standard. This mode also allows for -60 to +30dB precision variable gain on the loop-through output, with low noise, -85dB, weighted, and distortion, -90dBu, for studio use.
Noise measurement: ITU-R 468 weighting and quasi-peak dynamics. Residual input noise -88dBu weighted.
Distortion residue: Normalises and then nulls the fundamental and measures the residue on a 1kHz tone weighted according to IEC268 (ITU-R 468 curve and quasi-peak detector). Fully autoranging display relative to normalised level. Typical null depth -76dBu.
Crosstalk: Measures weighted crosstalk, automatically muting the channel selected, while driving the other at the selected frequency and level.
Sequence: Receives over 30 Lindos test segments. Displays the results of all sequence segments on the OLED screen with up-down cursor on all graphs. Graph normalisation for frequency response graphs. Stores four complete sets of results for later transferring to a PC.
Sequences: 19 pre-defined sequences and over 30 selectable test segments for user assembly including sweeps 20Hz-20kHz and 40Hz-40kHz, noise, crosstalk, distortion residue, noise time plot, headroom plot and phase plot.
Line-up: Special segments for repetitive GLITS and channel ident tests. Also PPM and ITU-R 468 inverse-weighted tone-burst tests.
Presets: 4 level and 4 frequency presets (user programmable).
Included accessories: Manual, 'Unison' to XLR leads and 'Unison' to RCA (phono) input and output adapter leads (1m), RS232 serial lead, RS232 to USB converter lead, lithium-ion battery. Lin4Win software on CD, AC in-line power adapter with power cord set; 100-240V AC 50/60HzAC.
Optional accessories: Unison to 3.5mm jack input and output adapter leads, MM3 calibrated microphone, hard carry case, soft carry case. Test CD2 contains forty tracks of Minisonic sequences and tones for testing CD players and use as a test source.
MiniSonic MS10
Both channels are displayed simultaneously on the same LED bar graph display; a single LED illuminates to show the level of the first channel. The level on the second channel is represented by an LED with lower level of illumination, the 'shadow bar'. The same technique is used for cursor and other functions. Since the resolution of the main bar graph is one dB per LED, a 'vernier' mode uses the shadow bar to indicate 0.05dB steps for precision line up when used without a PC. A MS10 can be upgraded to an MS20 at a later date by fitting a new front panel.
Measurement Modes
Level: Two-channel simultaneous, bar graph -20dBu to +9dBu, (-30dBu to+19dBu using ranges), in 1dB steps plus 'over' and 'under'. Extended range with Lin4Win; -50dBu to +19dBu with 0.01dB resolution. Accuracy +/-0.05dB, -20dBu to +19dBu. Quasi-peak reading as standard with fast option. Vernier mode displays one channel (selectable) plus a vernier on the shadow bar in 0.05dB steps for precision level line-up when used as a stand-alone unit without a PC.
PPM mode: Two-channel simultaneous display with PPM dynamics to IEC268 type II (BBC) standard. This mode also allows for -60 to +30dB precision variable gain on the loop-through output, which has very low noise, (-85dB, ITU-R 468, quasi-peak weighted) and distortion (90dB).
Frequency display: 25Hz to 25kHz 1/3rd octave shadow bar display with simultaneous level display of selected L or R channel.
Noise measurement: IEC268 (ITU-468) weighting and quasi-peak dynamics, reads 40dB to -70dB absolute or normalised. 0dB to -90dB with Lin4Win. Residual input noise: 90dBu weighted.
Distortion residue: Normalises and then nulls the fundamental and measures the residue on a 1kHz tone weighted according to IEC268 (ITU-468 curve and quasi-peak detector). Display is on a fixed scale -30dB to -60dB relative to normalised level. 0dB to -80dB with Lin4Win, typical null depth -75dB.
Crosstalk: Measures weighted crosstalk, automatically muting the channel selected, while driving the other at the selected frequency and level. Level measurement same as noise. Any frequency selectable.
Sequence mode: Displays the result of a frequency sweep using the shadow bar as up-down cursor with level readings on the main bar. Stores one set of results including 64-point two-channel frequency response. Full results from 16 possible test segments using Lin4Win.
Phase display: +/-180 degrees, 20Hz-20kHz, +/-2 degrees accuracy. Up to 40kHz with reduced accuracy.
Sequences: 12 Sequences instantly available from the keys including sweeps 20Hz-20kHz and 40Hz-40kHz, noise, crosstalk, distortion residue, at six levels to +18dB, noise / time plot, headroom plot.
Line-up: Special segments include repetitive GLITS and channel ident, PPM inverse-weighted tone-burst tests.
Included accessories: As the MS20.
Optional accessories: As the MS20.
The MS1 is a entry-level version which may be upgraded later. It is the same as the MS10, but the sequence testing capabilities are reduced and the supplied accessories differ (see below). All sequences may be output, but the unit will only respond to frequency sweeps. Note that no AC power adapter is included, since many users will already have a suitable adapter.
Measurement Modes
As the MS10, above.
Included accessories: Manual, 'Unison' to RCA (phono) input and output adapter leads (1m), serial lead, lithium-ion battery. Lin4Win software on CD.
Optional accessories: As the MS20. In addition: AC in-line power adapter with power cord set; 100-240V AC 50/60Hz.
Lin4Win - Software
Included with all MiniSonic test systems, the Lin4Win software offers a control panel, with fast-updating, twin precision bargraphs as well as digital display of level (to 0.01dB) and frequency displays. When used with the MS10 or MS1 the units are greatly enhanced with the addition of auto-ranging, manual range selection, and many other facilities not possible from the MS10s or the MS1s controls directly. Fast response has been given priority, so the controls have the feel of hardware rather than software. The analyser can be unplugged and 'hotplugged', with communication re-established in a second or two. When connected the units can be controlled from both the buttons on the front panel and the computer. Sequences can also be edited and run more easily, with full graphic presentation. Sequences run from Lin4Win can display high resolution sweeps (up to 128 frequency steps), with two-channel results in as little as five seconds. Tone bursts, presets, unlimited sequence results storage, and graph scaling are just some of the added features available with Lin4Win. The Minisonic supports a full set of remote commands for users who wish to write their own custom control software for embedded applications.
Lin4Win works on all Windows operating systems from Windows 95 to Windows 10.
MM3 MEASUREMENT MICROPHONE
This miniature electret microphone is calibrated and fitted with a jack for plugging directly into a MiniSonic test set. Calibration is such that 100dB SPL reads 0dB +/-0.5dB at 1kHz, making accurate measurements of monitor level and frequency response possible. The MiniSonic's sweep segments, with automatic triggering from the sound (no other connection needed) can be used to plot frequency response of rooms, speakers and other microphones. Acoustic noise levels can also be measured to low levels for comparing noise from air conditioning or other machinery.
Sensitivity: -30dBu, 100dB SPL. Response: 20Hz-20kHz +/-2dB, 40Hz-15kHz +/-1dB, typical. Noise: 42dB SPL 468-weighted, 30dBA SPL typical. Distortion: -46 / -40 / -37 dB at 100 / 110 / 115 dB SPL. Clipping: 125dB SPL, -32dB distortion. Minimum load impedance: 100k ohms. Power source: +5V DC, 0.5mA on jack tip. Cable: 3m.