Accuton C158-8-085 midwoofer measurements

The Accuton C158-8-085 ceramic cone bass - midrange driver measurements have been added. This is the first Accuton model featured hybrid magnet system.

A  FEA optimized  overhung motor design with 25 mm titanium voice coil former guarantees extraordinary low energy storage and good heat transfer. The low loss rubber surround and a  thin fabric spider  center the moving parts with high linearity. As a typical small home stereo  bass - midrange driver, we recommend our C158-8-085 for an application from 38 Hz – 3000 Hz.

  • Overhung Motor Design
  • Hybrid Ceramic/Neodymium Magnet System
  • 25mm Titanium VC Former
  • Soft Rubber Surround
  • Vented VC, Pole Piece and Spider


Design considerations:

Thiel & Partner GmbH wanted to create a bass-midrange driver for very compact two-way and - by the use of several units - slim three-way systems. So the C158-8-085 is a six inch bass-midrange that offers some remarkable features:

Company made it with the small 25mm voice coil of C153- series but it has almost the membrane area of  C173- systems, which makes it superiour in several ways.

Thiel & Partner GmbH designed a unique suspension system to give it a high excursion capability with very low distortion. An egg shaped soft rubber surround allows huge displacement without dragging the dome, supported by a new spider. It is made of "Bimax" tissue to an advanced geometry, expanding the excursion limits to uncommon values as can be seen in the first picture. During the testing with the aim to determine the excursion limits of these units, the voice coil was burnt but never the ceramic cones were killed.

The motor comes - first time with Accuton - as a hybrid system with both a ferrite and neodymium magnet, working in cooperation to achieve linearized BL(x) - and Inductance(x)-curves. This will guarrantee a clear and undistorted midrange quality even at high bass loads.

Stored energy was minimized by different means: we employed multiple venting techniques at the basket and the VC-former to avoid any compression effects and so could avoid the use of a vent hole in the yoke. A small titanium voice coil former with a light weight VC takes very little mechanical and electromagnetical energy out of the system, ensuring an open and dynamic response.

Go to the Accuton C158-8-085 measurements page