Amiga DX25 tweeter update

Post date: Sep 9, 2016 8:34:46 PM

In the years since I originally published the Amiga, Vifa/Peerless/Tymphany/whatever you want to call them has changed suppliers of the dome material of the DX25. In doing so, they also changed the model number from DX25TG09-04 to DX25TG59-04. I have been asked countless times if the newer version was compatible with the existing crossover, but I didn't have any of the new tweeters on-hand to measure so I winged it as best I could from mfr. spec sheets. I finally got a pair of the new "59" models to measure in the design, and the good news is that it's very close. The bad news is that you might want to swap out a resistor in the crossover to compensate, if you built the old XO with the new tweeter. From the Amiga page:

It turns out that the spec sheets are precisely true, and the new ("59") tweeters are 2 dB hotter than the originals ("09"). Will they drop into the original crossover? Yes. Will the treble be a bit bright? To some ears, yes it might. There is a fix, though, and it's super-easy. Simply swap resistor R2 (4.7 Ohms in the original crossover) for the updated value of 2.4 Ohms. (Or, if for some reason you cannot access and/or modify the crossover, you can accomplish the same result electronically by putting another 4.7 Ohm resistor across the + and - leads of the tweeter--essentially creating a parallel resistor pair with a total of 2.35 Ohms)

So, to clarify, if your tweeter is labeled DX25TG09-04, use this old crossover.

If your tweeter is labeled DX25TG59-04, use the new, updated crossover below

I apologize profusely if I have inconvenienced anyone with this. This is only a hobby for me, and as we've seen in the past, I can't always keep up with manufacturers changing things. I have notified Parts Express and they are aware of the issue as well. If you are ordering the Amiga kit from Parts Express and have any concerns, please feel free to call them; their customer service is excellent.