KEF Model 109 The Maidstone

Commentary

A floor-type speaker system developed by integrating cutting-edge audio technology.

At Maid Stone, the position of each driver's diaphragm is designed by computer acoustic analysis technology based on verification of enormous data in the past the past, and the time axis phase of all units is matched by setting the tilt angle of the body.

A 38 cm cone type woofer of short coil long magnetic gap type is installed in the low range.
A doped paper cone is used for the diaphragm, and the unique twin suspension system increases the motion efficiency of the voice coil to more accurately convert the input source to acoustic energy.

A 25 cm cone type mid-bus unit using doped paper cone is installed in the middle and low range.

A 5th generation coaxial 2-way UNI-Q driver unit is installed in the mid - and high-range and high-range.
This unit is a combination of a 16 cm doped polypropylene cone type unit and a 2.5 cm fabric dome type tweeter. By matching the position of the diaphragm in the depth direction of the two drivers, the time axis phase matches.

A 2.5 cm dome type super tweeter using a ceramic system pure corundum inverted dome is mounted in the super high frequency range.
The unit is mounted in a solid brass machined cabinet and is isolated from unwanted vibrations.

The network section uses parts developed specifically for maid stones, and features particularly excellent audio components such as air-core coils with less phase distortion and high-quality film capacitors.
A glass-epoxy circuit board with high insulating properties is used for the wiring board.

All five speaker units are equipped with individual external terminals and can be used for multi-amplifier systems with up to five amplifiers by using channel dividers etc.
The built-in crossover network also supports bi-wiring and bi-amplifier connections.

High-purity wire is used for wiring, and gold plated terminals are also used for speaker terminals to reduce impedance.

The Madestone enclosure is designed independently for each unit to eliminate interference between units, provide ideal capacity for each band, and is made from 25 mm thick MDF.
The low-frequency enclosure is a large capacity type with a capacity of 145 liters. The length of the bass port is set to 25 Hz and the baffle material is 50 mm thick MDF to eliminate unnecessary resonance.
The exterior features a wood-grain design with rosewood grain on the baffle surface, a pair of left and right design controls, and a reddish-brown MDF covering from the surrounding edge to the back for a streamlined ergo design.

Model Rating

Method	5-Way, 4-Speaker, Bass Reflex System, Floor Type
Units Used	For low band : 38 cm cone type For middle and low band : 25 cm cone type For Middle and High Areas : 16 cm Cone Type (Coaxial Unit) For High Range : 2.5 cm Dome Type (Coaxial Unit) For Super High Range : 2.5 cm Dome Type
Frequency characteristic	23 Hz to 45 kHz
Sensitivity	91dB(2.83V/1m)
Maximum sound pressure level	118dB
Allowable input	400W
Impedance	4 Ω
Crossover slope	LF-LMF : -12dB/oct. (LF), -24dB/oct. (LMF) LMF-UMF:-12dB/oct UMF-HF:-24dB/oct SHF:-18dB/oct
Enclosure	Low : 145 liter internal volume, 25mm/50mmMDF baffle Mid-low range : 19 liters, 25 mmMDF Mid-High and High Frequency : Internal capacity 6.5 liters, 25 mmMDF Very High : Brass Unpolished
Maximum external dimensions	Width 600x Height 1,335x Depth 671 mm
Weight	89.0kg