Monacor MSH-115, 4" hifi midrange drive unit. IN UK STOCK NOW Good replacement for ELAC IMF 4/200 found in various IMF models such as TLS50, IMF Compact, Super-Compact & others. Critically damped pulp cone gives a wide usable bandwidth with a text book response between 400-5000 Hz - excellent linearity, no significant peaks in the response. The flat profile front chassis allows hassle free flush mounting - no need for a rebate or router. This versatile driver can replace and upgrade a huge number of midrange units and offers a level of performance that is exceptional at this price. A full datasheet can be downloaded from this page. Key Features: Low Profile Steel Chassis Aluminium Voicecoil Former Wide Usable Bandwidth Excellent Linearity Universal Replacement Basic parameters: Resonant frequency (fs) 85 Hz Nominal impedance (Zn) 8 Ω Mechanical Q factor (Qms) 1.98 DC resistance (Re) 6.3 Ω Electrical Q factor (Qes) 0.55 Max power handling 120W Total Q factor (Qts) 0.43 Sensitivity (2.83V/1m) 89 dB Equivalent volume (Vas) 4 L Chassis (across flats) 115 mm Here's the full datasheet: MSH115