LINDOS MINISONIC MS20 Audio Analyser

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.

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

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.

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.

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.