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The Next Generation Western Electric 555

The new Model 1 compression driver is the modern interpretation of the out-of-production Western Electric WE555 drive unit. This legendary driver provided seamless performance across a wide bandwidth, and the design goal for the LAMAR AUDIO Model 1 was to be true to that legend, making use of modern materials and technology even to exceed its original standards. The Model 1 represents the transition into a new era, where more power handling is a priority, and the performance of the driver has been greatly improved by the use of modern materials and design techniques. The beautiful design does not compromise the sound quality, and leaves “industrial” design behind, instead delivering a timeless appearance to enhance your living room and your life quality.

The new LAMAR AUDIO MODEL 1 has the following technical features, which enable it to produce the finest sound and meet the highest standards:

  • Aluminium housing, precisely machined, incorporating a ventilated back chamber which can be adjusted to optimize performance when paired with any horn.
  • Newly designed tangential phase plug to maximize the sound translation to higher frequencies while keeping the same smooth response.
  • Large neodymium magnet with optimized nickel-plated magnet structure for high efficiency and better voice coil control with reduced harmonic distortion. The massive magnet structure acts also as a heat sink for the voice coil.
  • Large air gap in the magnetic structure keeps the magnetic flux density constant over a long distance
  • Lightweight under-hang 2” Aluminium ribbon voice coil (ccaw) on paper former (available with 8 ohm and 16 ohm resistance)
  • Extremely ridged high modulus carbon diaphragm with glass fiber suspension for optimal behavior over a wide frequency range. (Carbon diaphragm is lighter and stiffer compared to aluminum or titanium diaphragm)
  • Standard WE555 thread fitting for easy compression driver replacement. Optional thread fitting for a 1 3/8” horn mounting or optional simple 3 or 4 hole flange.
  • Gold plated terminals to connect ø 4mm banana plug terminals to prevent oxidation for long-term reliable connection

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TECHNICAL SPECIFICATIONS

Throat Diameter:
18 mm (0.71 in)

Nominal Impedance:
M1-8  8 ohms
M1-16 16 ohms

Minimum Impedance:
6.5 ohms (Model M1-8), @ 5 KHz
12.5 ohms (Model M1-16) @ 5 kHz

DC Resistance:
6.3 ohms (Model M1-8)   ± 10%
12.5 ohms (Model M1-16) ± 10%

Power Capacity¹:
30 W continuous above 500 Hz
50 W continuous above 1 kHz

Sensitivity:
115 dB SPL, 1 W @ 1 m on-axis on horn²
118 dB SPL, 1 mW on plane-wave tube³

Frequency Range:
50 Hz to 5 kHz ± 3db

Recommended Crossover:
80 Hz or higher, 12 dB/octave minimum

Diaphragm:
0.08 mm (0.00275 in) high modulus carbon composite

Voice Coil Diameter:
50 mm (2 in)

Voice Coil Material:
Edgewound aluminum ribbon

Flux Density:
1.9 T (19,000 gauss)

Dimensions:
128 mm (5 in) diameter
99 mm (4 in) depth

Mounting:
WE555 thread
Optional adaptor for 1 3/8” thread and 1” exit mounting flange 4”dia.

Net Weight:
3.5 kg (7.72 lb)

Positive voltage to black terminal gives diaphragm motion toward the phasing plug
¹Continuous program is defined as 3 dB greater than continuous pink noise and is a conservative expression of the transducer’s ability to handle normal speech and music program material. Continuous pink noise power ratings are rested with pink noise input having a 6 dB crest factor, with a high-pass filter set at the specified lower limiting frequency for two hours duration
²Sensitivity measured with 1 W input at 1 m distance on axis from the mouth of a horn with a Q off 3 averaged in the 2 kHz octave band
³As specified by recognized standards organizations, sensitivity is measured with the driver coupled to a terminated tube. The sensitivity rating represents the SPL in a 25 mm (1 in) terminated tube, using a 1 mW input signal (0.126 V into 8 ohms) swept from 50 Hz to 10 kHz. The sensitivity rating with a 1 W input would be 30 dB greater.

M1_500_100_01_ZSB_M1_COMPRESSION DRIVER

 

 

Frequency response of Model M1-8 Driver coupled to a 25.4 mm (1 in) diameter terminated plane wave tube (PWT),
with sensitivity referenced to a 25 mm (1 in) tube. This is the power response of the transducer, and is the frequency response that will be obtained on a true full-range constant directivity horn design.

Graph Measurement on Plane Wafe Tube

 

LAMAR AUDIO M1-8 (Blue Line)
WE 555 REPLICA (Black Line)
Measurement with1W input on rated impedance @ 1m distance on axis coupled to a WE15A horn

Graph Measurement on WE15A Horn

 

 

 

LIMITED WARRANTY
LAMAR AUDIO products, when sold domestically within the EU, are guaranteed for a period of five (5) years from the date of original purchase against malfunctions due to defects in workmanship. If such a malfunction occurs, the product will be repaired or replaced at our option, without charge, if delivered prepaid to the factory. Product will be returned prepaid via ground transport. This warranty does not extend to damage resulting from improper installation, misuse, neglect or abuse. The warranty does not apply to external finish or appearance. The warranty does not apply to burnt voice coils. In no event shall LAMAR AUDIO be liable for incidental or consequential damages including, without limitation, injury to persons or property or loss of use.