..Den røde tråd og Scanspeak SS D3804's efterfølger ....efter mere end fire årtier huserer Scanspeak stadig med en "D3806" på markedet... en dansk højttaler konstruktør anvender gerne D3806 med en "super tweeter" på toppen.:
Læs:
http://www.troelsgravesen.dk/SP38.htm The D3806/8200 driver: Well, this is the driver that makes this construction special. To be honest, few 6-7” drivers manage to perform well in the 2-4 kHz range. Most drivers will start rolling off around 3 kHz or they start beaming when the wavelength equals the membrane diameter and would be better off with a smaller driver taking over from around 1-2 kHz, but in commercial designs, cost is an object and the crossover may be more complicated and final production control more time consuming. Not a problem for the diy people. We have all the time in the world for our hobby. Well, cost may be an object, but the 3806/820000 is no more expensive .....and so on ..... (for good reasons this doesn’t apply for the bass driver!).
Essensen:
Left: The frequency response of the D3806 driver (blue) is not that flat, but it is easily equalised to gain a flat response up to 15 kHz. This driver (D3806) can almost be used as a stand-alone tweeter. I guess some damping material on the pole piece might do well.
Det er dette "tisss-shiss" vi slås med fra D3804.....og som tilsynelandende også opstår fra D3806.. måske kan det lineariseres?:
Raising the 3806 series resistor from 1R0 to 2R2 removes some of the forwardness sometimes coming from this driver from less than supreme recordings.
Det er da stof til eftertanke, at der stadig kan høres lidt "forwardness" (fremme i skoene mellemtone lyde) fra en 38mm dome konstrueret første gang ca. 1971?
Det er også værd at bemærke den målte frekvensgang fra D3806...måske lidt dæmpemateriale på polstykket ville ændre på den "forwardness" ?...som antydet på hjemmesiden.....
Måledata fortæller at D3806 har brug for at blive lineariseret over 5-6 kHz........