The change for this year is the new mids utilizes and actualy metal phase plug that's separate from the cone. I believe the previous mids had the phase plug integrated into the cone, and was made out of polypropylene. The old mid's cone were made out of fiberglass, but the new ones have weaving in them just like you see in carbon fiber hoods.
The previous set uses the TN 47 tweeters while the new set uses the TN 44 version. Changes were made to the crossover because the TN47 were 8ohm and the TN 44s are 4ohm. They had to change a few things in the crossover network to utilize that 4ohm configuration.
As far as performance, the new tweeters are more efficient, but the frequency response isn't as flat as the TN47 (which are higher end). The TN44 tweeters rolls off at about 3khz (fs= ~3.0khz). There is almost a difference of 6db in response (rolls off) between 3.0khz and 20,0khz. Ideally, it should be HP around 6.0khz, but you're able to get away with a lower xover point depending on our mounting axis and crossover steepness.
The older TN47 ideally should be crossed at ~ 4.0khz since its FS is ~2.0khz. If mounting on-axis, the tweeter has a difference of ~3db at most from 2.0khz-20khz. (ignoring environmental factors).
The old mids look fine to me, except for a slight boost around 1.0khz, by approximately 5db. The new mids are able to extend to 6khz to comphensate for the Tn44's lack of low end extention. It comes with a price though because from 3-6khz, there is a pretty nasty spike. The new mids aren't exactly as smooth in frequency response as the old mids. :sad:
ok i'm done. sorry for the long post //content.invisioncic.com/y282845/emoticons/banghead.gif.8606515f668c74f6de0281deb475b6fd.gif
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