More than 2 years ago we started thinking about making a new and better bass unit that would excel everything else of this range on the market. Here are some of the key features:

We started with the basket design, eliminating any compression effects and resonance characteristics of the basket itself. We used multiple, slightly bent spokes with 4 different curvatures to provide just this. The backside of the dome is 100% vented and as a nice benefit offering improved safe handling of the unit. Look at our first picture here.

Within the reasonable working range, the motor system should be extremely linear. This can be achieved with a thick top plate and a quasi-symmetric underhung geometry plus a low inductance voice coil, unfortunately imposing the need for lots of steel and neodymium. The FE simulation in picture 2 shows the extremely linear flux profile within the gap.

The force of the voice coil must be transferred to the dome with maximum accuracy, which implies the need for a voice coil former with high internal speed of sound and special stiffness. As aluminum would add severe eddy currents to the system, titanium is the material of choice here.

For the membrane, we used our recently invented sandwich cone, a structure that is extremely stiff in the middle section where the voice coil is attached and equipped with a higher damping section at the outer rim, exactly where it is needed. 

The entirely new designed high excursion surround is higher than wide and provides a piston area that is up to 20% larger as comparable bass units. It combines a large mechanical excursion limit with a unique narrow shape and very low distortion.

Get more detailed specs of our S280-6-282 on our website...  

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

We 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. As we tried to determine the excursion limits of these units, we eventually burnt the voice coil but we never killed the ceramic cones.

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. 

For more information and support, please visit the C158-8-085 on our website.

With CVD diamond and alpha corundum ceramics we have already two of the very best membrane materials on earth, so why search for a new one?

Let's summarize it: CVD diamond is definitely the best material available. It's stiffness to weight ratio is unsurpassed, the internal sound velocity unrivaled. However, until today, we can only make tweeter and small midrange units, cost and serious technical problems prevent the manufacturing of larger cones. It is quite similar with ceramic domes, these are second to and almost as good as diamond (still better than anything else exept diamond) but also restricted in size. The largest dome we can feasibly produce is a 160mm dome for the C220 series.

Doing research for larger bass cones we found some interesting results. Laser scans of moving membranes taught us that the voice coil area is the most critical and deformation is strongest here while the outer area is fairly stable (this is however only valid for concave domes like we build, not for different membrane shapes). So we took a special, exclusively made for us, white honeycomb membrane and doubled it up with a fitting, asymmetrically shaped ceramic dome (to put one and a half year of tedious research into one sentence). Let's look at the benefits:

• Large cones (up to 15 inch basses) are economically producible
• Stiffness in the VC area is even better as with a pure ceramic cone
• Outer area has very high damping factor, the unit is easily usable with a first order passive filter
• The ceramic part of the dome has an asymmetrical (Wankel) shape, killing resonances
• The cone is indestructible, even at severe overload (remember, you can still burn the voice coil !) 

Bandwith and resolution is almost but however not as good as with a ceramic cone but this, after all, is not so important for a pure bass unit. Get more info about the family of Sandwich cone units here.....

Since our old website had more than 10 years of service, we decided to open a new chapter and realize a  website with more modern and stylish design, a faster and easy to understand navigation and a much more comprehensive content.  The site is entirely programmed in PHP and based on an extensive CMS (content management system) that enables us to make updates and additions as easy as writing an email.

We have also updated and corrected all driver measurements, taking an average production unit of every model, burning it in for 100 hours and then measuring all data and specs with our new Klippel system. To help you find the driver that fits best to your project, we implemented a driver selection menue that will filter out all units not matching your personal selection. You can then compare all driver specs online, print a 2 page PDF with all important info, print a drawing with dimensions and even download a 3 dimensional PDF that enables you to watch the single driver from all directions, an absolutely unique Accuton feature. To check out all possbilities, have a look at our website manual here.....

Your comments and suggestions are very welcome, we made this website for YOU!

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