Bass Face SPL6M.4 is a unique product. It is a professional series driver for consumer: professional and automotive applications: where an extremely high power: high output: small form factor driver is required. This overbuilt heavy duty driver was designed to defy logic by providing extreme output and super sound quality in one driver. A strong cast basket and a massive ceramic magnet weigh a lot: but the weight helps adds presence to the lower midbass as well as eliminating distortion caused by flex and resonances in the basket assembly. The 2″ High temperature voice coil is supported buy a triple roll treated cloth surround and a heavy duty cloth spider. A dimpled textured surface to the cone acts to increase the effective piston area: in turn moving more air: creating more SPL. From every angle this product screams quality: and delivers. Great for small or large door builds but also lends itself well to a 2 way mid top box with an appropriate tweeter and crossover. Copper Faraday rings (shorting rings) are also fitted to smooth the response of the speaker compared to a conventional design. The unusual additional cone provides extra output at the higher end of the frequency spectrum. This is the 4 Ohm version.Version History   Prototype – Initially designed as a simple copy of SPL8M.2 this has evolved into a high specification niche filling product in its own right with the factory moving forward on features even before we received the V1. V1 – Added copper shorting rings: dual cone design: aluminium phase plug and production in both 4 and 8 Ohms to the original brief. Key Facts   Product Category Midbass & Midrange Speakers Version 1 Series Hammer Barcode 683422299247 Product Net Weight (g) (For Pairs/Sets Weight Is All Major Parts) 2090 Complete Product Pack Weight (g) 2240 Retail Carton L (mm) 180 Retail Carton W (mm) 180 Retail Carton H (mm) 100 Sold As Single Speaker Data Speaker Maximum Recommended Power (Watts) (One Speaker: Using Appropriate Crossover) 300 Speaker Maximum Recommended Power RMS (Watts) (One Speaker: Using Appropriate Crossover) 150 Overall Diameter (mm) 174 Magnet Diameter (mm) (Including Magnet Protector Where Applicable) 120 Installation Cutout Diameter (mm) 148 Overall Depth (mm) 88 Mounting Depth (mm) 78 Front Protrusion From Mounting Plane (mm) 10 System Frequency Response (Hz) (Indicative Of Usable Range But Not Suitability) 50-10000 Impedance (Ohm) (Nominal) 4 Sensitivity (db/1Wm) 100 Magnet Type Y30 Recommended Cable PSC12.2 Voice Coil Diameter (mm) 40 System Power Full Speaker System Recommended Maximum Power (Watts) (Using Pair/Full Set Of Speakers Not Necessarily Included & Appropriate Crossover) 600 Full Speaker System Recommended RMS (Watts) (Using Pair/Full Set Of Speakers Not Necessarily Included & Appropriate Crossover) 300 Technical Highlights Copper Shorting Ring (Faraday Ring) for Optimum Impedance Profile Unique Phase Plug / Dual Cone Design for Perfect Response Cast Aluminium Basket CNC Machined Bullet Phase Plug 1.5" High Temperature Voice Coil Lightweight Paper Cone Push Terminals Large Ceramic Magnet Heavy Duty Fabric Spider What's In The Box? 1 x High Performance 6.5" Cast Basket Midrange Driver TS Parameters Revc (Ohm) 3.4 Levc (uH) 29.318 Fo (Hz) 131.123 Sd (Cm sq) 132.6 Md (g) 11 BL (T m) 8.123 Qms 1.441 Qes 0.469 Qts 0.354 No (%) 1.546 SPL (Db) 93.9 Vas (Ltr) 3.328 Cms (uM/N) 133.277 Mms (g) 11.054 MMd (g) 10.176