Update on The Nightingale
By Lars Mytting
04 Jan 1997
New Revelator measures better
In our description of the ScanSpeak Revelator 2905/9900, we criticised the poor consistency between the two samples of the driver. We have now received a set of Revelator drivers from a new production series. These show far better consistency, with a difference of only +1/-0.5 dB. There are no visual changes on the new tweeters, but they are now packed and delivered in pairs, while the former drivers were delivered one by one.
The impedance peaks on the new drivers were located at 507 Hz at 23,0 ohm and 501 Hz at 26,4 ohm. The impedance peaks on the old drivers were located at 522 Hz with 27,6 ohm and at 537 Hz with 25.4 ohm.
Note that these graphs show the difference between the samples, not the frequency response itself Fig. 1. Old Revelator drivers Fig. 2. New Revelator drivers.
Error in crossover schematic
In the first version of the article, there was a error in the schematic for the crossover. It showed the RLC network (to correct for the resonance peak in the tweeter) connected before the filter network. The correct is to connect it after the filter network. Nothing wrong happens if you connect it before the filter, it will simply have no effect. The RLC circuit increases power handling, but causes no practical change in the frequency response of the current filter (12 dB electrical). However, it will be necessary if you want to use a 6 dB filter.
Hylo-idealistic explained
Several people has asked what the term "hylo-idealistic" means. Full understanding of it is difficult, but the following link contains complete reference literature:
http://www.mk.net/~dt/Bibliomania/Fiction/wilde/stories/oscar3.html
Happy listening and happy reading!
Lars Mytting
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