Tweeters

[sai]

Hello, I'm new here and though I see a majority of AR and KLM on this site maybe someone here can help me anyway. I have an old-vintage system, dbx soundfield 100, picture of the tweeters on left, that has the following specs: freq/res- 40-20 khz +- 3db, sen; 91 db SPL/2.83 V/1 m, 4 ohm nominal, 20-250 w/ch (music, not tones or noise) @ 4 ohms. The system has 3 tweeters per box. The enclosure is unusually shaped, with no parallel sides (except the top and bottom -- but they're not sides anyway!). A 10"woofer, a 4"mid range driver and a tiny 1/2" tweeter per enclosure are arrayed on the largest vertical face. These three speaker elements, in each unit, are situated so that they are aimed mostly at the other loudspeaker, the two remaining tweeters are situated- one facing you and the third facing away to the other side. Picture if you will a tower speaker with 3 asymmetrical sides and a flat rear; looking at the front vertical side (facing the listener) you have only 1 tweeter , on the left vertical side you have a woofer, a mid-range and the tweeter (and a port below the tweeter) this side would be facing the other speaker some 8 feet away, the right vertical plane you have 1 tweeter facing the opposite side. Anyway after this long drawn out description my question is: when looking for tweeter replacements on the market sensitivity seems to vary from about 88db, or lower, to beyond 91 db. Since my system is 91db and 4 ohm (checked tweeters and they are 4 ohm, not 8 and controlled to 4 ohm by the crossover like someone somewhere else suggested to me) do all three tweeters need to be at least 91 db, or better, and each equal, or only the two apposing sides need be 91 or higher and the front, facing the listener, be 88 or 89 db. My limited knowledge about speakers lead me to think the higher sensitivity tweeter can be heard more distinctly than the lesser sensitivity db driver, meaning the two apposing side tweeters need to be a higher level because they are not facing you and therefore need to be just a bit better than the one directly facing you, or is my thinking all wrong and all three need to be exactly the same. I contacted the dbx company but since these are from 1987 no one there knows anything about them and gave the answer that another company, dak, built them, which isn't true. One other limiting factor: the cutout size can not be more than 57mm. Any and all suggestions/help greatly appreciated, out side of buying an entire new system. Also I was told a David Morson, who at one time worked for dbx is somewhere on this site but I can't seem to locate him. Thank You

[RoyC]

Are your original tweeters damaged? Replacing tweeters in an existing design is more complicated than simply attempting to match sensitivity and rated impedance. New tweeters of any type will likely require crossover changes to work as well (much less "better") than the originals.

Roy