MLD9 MultiLoop Driver 2 x 9.2Arms for areas up to 3,300m sq
MLD9 MultiLoop Driver 2 x 9.2Arms for areas up to 3,300m sq
The MLD9 is the new global benchmark for professional audio induction loop systems. The elegant, sturdy units feature the most compact design on the market, requiring only a single 19” rack mount.
The MLD9 provides the highest output available in any dual channel loop driver and is capable of driving a wide variety of multiple loop configurations from multiple simple loops to phase shifted array systems for the most challenging requirements.
With an Ampetronic MultiLoop™ Low Loss design, the MLD9 will drive an area up to 3,300m2, or can be used to drive two perimeter looped areas of up to 1,300m2each.
The MLD9 also features Class G technology which halves power consumption and heat dissipation. Designed to provide optimum efficiency and ample current for standard compliant field strength, coupled with unmatched voltage headroom to ensure crystal clear sound reproduction without clipping or distortion at practical loads. MLD units are built to our
exacting standards and are backed by our 5 year warranty.
The flexibility of Ampetronic MLD units allows each output channel to drive separate loops, or two drive two overlaid loop patterns, with or without the selectable phase shift between the two channels.
Two separate simple area loops (or perimeter loops) can be driven at the same phase or with 90° phase shift. This can be used to cover large areas with no metal losses, or multiple different areas in the same facility.
Two loop layouts can be driven configured as multiple loop segments with or without phase shift. Simple array, low loss array or low spill array designs can create different performance to optimise field strength
over any area, and minimise loop ‘spill’ for adjacent systems or for confidentiality.
Most commonly used design types are low loss and low spill:
MultiLoop™ Low Loss Systems are used to:
- Compensate for high losses due to metal structures
- Drive large areas where perimeter loops cause too much variation
MultiLoop™ Low Spill Systems are used to:
- Perform the same tasks as a Low Loss systems, but also minimise ‘spill’
– confines signal to within 1.5m of looped area, suitable for adjacent rooms e.g. cinemas, classrooms, or confidential applications.
|Loop Design||No Metal Loss*||Moderate Metal Loss**||High Metal Loss***|
|Perimeter Loop @ 1:1 Aspect Ratio||2 x 1,000||max 5m loop width||n/a|
|Perimeter Loop @ 3:1 Aspect Ratio||2 x 1,300||max 5m loop width||n/a|
Typical scenarios are based on *a building with no structural metal, **a building with reinforced concrete (re-bar) construction.
- Drives 2 output channels at 9.2ARMS each, featuring accurate and stable 90° phase shift
- Up to 3,300m2 MultiLoop™ area coverage
- Space saving 1U rack mount unit, the most space efficient loop driver available
- Front inlet & rear exhaust fan cooling for true rack mount integration
- High efficiency Class-G amplifier with low heat dissipation
- Rack mount or free standing installation
- Can be used with or without phase shift to drive independent loops
- Optimised to reproduce speech frequencies with unmatched intelligibility
- Supreme musical reproduction
- Automatic Gain Control
- Metal loss correction
- Active loop error monitoring & dual loop fault detection at start-up
- Versatile input selection
- 2 x XLR balanced mic / line switchable inputs
- Low lifetime cost
- Based on proven technology to ensure excellent reliability
- 5 year warranty
- Tested to, and compliant with: IEC 62489-1 induction loop amplifier performance standard
- Free technical support
- Conference facilities
- Stadia & Sports Halls
- Cinemas & Theatres
- Courts & Confidentiality
- Classrooms & Lecture Halls
- Airports & Railway Stations
Equipment supplied as standard
- Handbook and installation instructions
- 197 x 252mm loop system present sign (deaf logo)
- Region specific mains cable
- Loop connector for each output
- Rack mount brackets
- Status Connector
- DC Connector
MLD9 optional accessories
Ashton Audio can supply a range of accessories to meet the specific needs of your installation:
- 18mm x 0.25mm copper tape
- PVC extrusion to protect copper tape
- Installation / warning tape to fix cable or tape to a floor
By using the appropriate input adaptor or preamplifier the MLD9 will accept multiple additional inputs or audio inputs from other sources:
|100V line input|
Low impedance speaker line
|ATT-UX transformer isolated attenuators|
|Unbalanced microphones||MAT1 adaptor|
This product is designed to form part of a system that can meet all of the requirements of the international loop performance standard IEC60118-4:2006, and the relevant parts of BS7594. To fully meet requirements of these standards, correct design, installation, commissioning and maintenance are required.All specification data has been compiled in accordance with IEC62489-1, the international standard for audio frequency induction loop equipment. Specification data should only be compared with data compliant to this standard.This product is CE market to all relevant safety and EMC standards, and is NRTL(ETL) approved for sale in North America.
220W 230V AC nominal, 45-65Hz [120V option available]
Power switch & LED indicator (Hearing Loop logo) on front panel
Input 1 & 2
Microphone specification; 200 - 600Ω, sensitivity -55dBu.
Selectable 12V phantom power on microphone only
Line sensitivity; -30dBu
Scredriver adjustable front panel recessed gain control
6.35mm jack socket for linking more than one amplifier.
Inserting plug disables other inputs
Loop Output Drive Voltage
31.8Vrms (45Vpk) at maximum output current per channel
9.2Arms (13Apk) up to 60 seconds continuous 1kHz sine wave
peak >13A per channel
• Cont. pink noise 3.2Arms short term peaks >19A per channel
• Front panel recessed controls
• Drive current indicated on two 6-LED displays in 3dB increments
6.35mm jack socket to connect to other slave amplifiers
Neutrik NL4 Speakons (supplied) for each output
Provides access to monitor actual loop current via a 3.5mm
stereo headphone connector on front panel
Channel A on left, channel B on right
A pair of isolated relay contacts to indicate system status;
fault = open circuit: system O.K. = short circuit
Resettable, fuse protected 12V 0.1A.
80Hz to 6.5kHz
Automatic Gain Control
The AGC is optimised for speech. Dynamic range >36dB
Metal Loss Correction
Corrects system frequency response due to metal structures in a building.
Gain constant at 1kHz, adjustable gain slope from 0 to 3dB per octave.
This does not compensate for signal loss from metal structures which can be significant.
User selectable at 0° or 90° between outputs
Fault indicators on the front panel;
• Clipping – delivering over the rated voltage (per channel)
• Temp – unit is too hot (temporarily mutes output signal)
• Loop error – short circuit / open circuit error (per channel)
A pair of relay contacts are provided for remote fault monitoring
Twin variable speed fan cooled. Front inlet, rear exhaust.
Full width 1U 19" rack mount
Width 430mm Depth 330mm Height 44mm
• 1U 19" rack mount (brackets included)
IP20 rated; 20 to 90% relative humidity; 0 to 35ºC
Ashton Audio in conjunction with Ampetronic can design your induction loop system for you. Simple induction loop designs are free, complex array systems will be charged for at a nominal rate. You can request a design through our 'Contact Us' Enquiry Form.