jackfish Posted May 2, 2007 Report Share Posted May 2, 2007 The New Large Advent has a reported frequency response of 33Hz to 17,000Hz +/- 3dB. I thought I might try to extend the high frequency of the Large Advent by adding a Radio Shack Piezo Tweeter 40-1218 http://support.radioshack.com/support_audio/doc63/63021.pdf . Although no crossover is needed and this driver supposedly does not significantly affect the impedence of the speaker it is wired to, I found the following ‘crossover’ circuit and modifications to the driver that is said to eliminate its "spitty and lispy" fatiguing harshness:8 ohm resistor across the piezo terminals (Radio Shack part # 271-120, $1.49 each) What affect does this resistor have? Does it make the piezo an 8 ohm driver?0.47 uf capacitor wired in series (Hovland, $1.50 each from Madisound) I assume this only allows frequencies above 15,000 Hz (based on 12dB filter parameters) go to the piezo tweeter?Application of damar varnish on the piezo’s cone element is said to add refinement to the sound and almost completely reduce the fatiging sibilance:1. Remove the three screws from the back of the piezo 2.Coat the paper cone with one coat of damar 3.Remove ‘pooling’ of damar with a tissue 4.Let dry overnight 5.Reattach horn An application of rope caulk to the back and sides of the horn helps to deaden any plastic sound.http://www.melhuish.org/audio/images/diy35-2.jpgI would put the driver and ‘crossover’ circuit in a small box to be placed on top of the Large Advent cabinet and wire in parallel to the Large Advent terminal posts. One could put the driver and ‘crossover’ circuit in the cabinet and perhaps wire it to the Advent tweeter, but I wouldn't know the best placement for it on the baffle.Anybody tried this or have any observations about the described setup? Link to comment Share on other sites More sharing options...
This topic is now archived and is closed to further replies.