Rerurn to Romy the Cat's Site

We enter a complicated region as the lower driver we go the drivers could be used for different purposes and it is very hard to generalize. A 10-incher might be MF driver and LF driver. In my past I experimented with few MF 10-inchers, including some vintage field-coil 10-inchers, but I was not able to find any interesting driver. Giving this I have to note that in context of acoustic system that I was experimenting I had no proper application for 10-incher MF driver. Still, I did not see anyone ever has any reasonable use of the 10-inchers in MF. Sure there are wonderful older Tannoy dual-concentrics 10-incher but they are for different purposes. I’m sure that for correct application it would be possible to find/make a good MF (to be more precise: lover midrange – upper bass) driver.

What I did search and experimented were 10-inchers woofers. I very much like the Scan-Speak woofer made around their SD1 motors.  They use a very interestingly intentionally overhang constriction that has very soft sounding “enter into distortions”. The cones are very soft and the rubber suspension is very interesting for given resonance frequency. It has 20Hz of Fs but the suspension is not soft and uncontrolled like with most of the drivers. They are kind of stiff but flexible at the same time. What is the most beautiful in them that the “stiffness” of the suspension is very “smartly” relates to the firmness and mass of the cone. As the result, sonically the driver’s cone and the driver suspension act together as a semi-“varimotion transducer” when the stiffness of the cone is not identically access the cone but gently changes with radial proximity to the peripheral. Of course they are very much not varimotion but the special anti-resonance rubber that Scan Speak uses in their 25W/8565-00.

It is important to mention that there is a faulty notions the LF driver should act as a piston and the cone should not break. I do not feel this way and the best sounding “bandable” and breakable paper cone drivers are the direct evidence of it. Tone it is exactly what comes from the “band” of cone and it the cone is too stiff that you have the “jazzy upper pPPP’ass” bass…

For a first time I discover them when John Dunlavy introduce his Dunlavy SC-IVA model as a replacement of SC-IV. The SC-IV wee horrible speakers but had no bass at all, despite of their size. In the SC-IVA Dunlavy trashed the garbage drivers that he use and put the 25W/8565-00 in the game. The result was remarkable and the SC-IVA had much more interesting bass then SC-V and monstrous SC-VI. Of course Dunlavy normalized impedance of 25W/8565-00 and did some other thing that screw them up but still, even given all of this I feel that Dunlavy SC-IVA  (if they were properly used) had the best bass among all commercial speakers.

The only problem that I see in the 25W/8565-00 is to low sensitively. The key with them is to use more of them. Still, they do not handle a lot of power and should not care too much upper bass sound in them. I cross the arrays of 6X25W/8565-00 at 60Hz, first order and I do not feel that it is best configuration for them, since my line array is essentially a compromise between a line array and not existing midbass horn. I feel the best crossover point for 25W/8565 would be 40Hz and second order. It would be interesting to put them deep into low pass transition slope but with the restricted power handling it would be difficult to do.

So, if you find any other 10-incher with primary resonance of sub 20Hz and with “this tone” then let me know. Until then I would consider the SS 25W as an exceptional driver. Still if this drive would be 100dB sensitively then it would be ….more exceptional…

Rgs,
Romy the caT

Rerurn to Romy the Cat's Site