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r/diyaudio•
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Vifa tweeters: BC25TG15 vs BC25SG15

Hi,

I live in Australia and I am trying to build a set of Classix II/2.5 for a 2.0. The BC25TG15 tweeter is harder to get (backorder with ??? time from digikey) compared to the BC25SG15. I hunted down the datasheets:

BC25TG15

BC25SG15

and had a look but they are not *quite* the same, the SG is slightly more sensitive and has a 50Hz lower FS, but the impedance profile looks really similar. I have never done any DIY audio before, could anyone tell me if I should worry about this difference? Does the crossover need to be changed?

I can always build overnight sensations (drivers are easy to get but I 'waste' more on shipping comparatively)

Edit: I'm going to put my own research here in case anyone finds this post. So far, let's say the SG is 2dB higher response than the TG, and the response profile and impedance profile is close enough. I guess I'd just have to modify the L pad on the tweeter part of the crossover to suit?
It seems the only physical difference might be an additional piece of metal attached on the back of the driver

Posted Jun 17, 2020, 2:53 PM UTC · edited

63
GeckoDeLimon•

1dB of real-world sensitivity is going to be an extremely subtle difference, and they track almost identically through the crossover region.

I would call those two drivers interchangeable.

3
team-all•

The one is shielded (S) and the other (T) isn't. Technically if there are any differences the crossover would have to be adjusted. As well it looks deeper so technically the box volume might need to be increased. But it's a very small amount so it doesn't matter. I would just stick to the regular one.

1
prozackdk•

Maybe try contacting the designer directly and ask?

https://sites.google.com/site/undefinition/contact

1