Here's a couple of designs that use that tweeter:
Paul Carmody's Classix II: https://sites.google.com/site/undefinition/bookshelf-speakers/classix-ii
Michael Chua's Lark: https://ampslab-spk.com/2021/03/07/lark-sm-studio-monitor/
The Lark used the SB16PFC25-08 that had an odd shaped frame that was hard to flush mount, It's been replaced by the round frame SB16PFCR25-8 (LINK) which is (AFAIK) a drop-in replacement.
Paul Carmody's Classix II: https://sites.google.com/site/undefinition/bookshelf-speakers/classix-ii
Michael Chua's Lark: https://ampslab-spk.com/2021/03/07/lark-sm-studio-monitor/
The Lark used the SB16PFC25-08 that had an odd shaped frame that was hard to flush mount, It's been replaced by the round frame SB16PFCR25-8 (LINK) which is (AFAIK) a drop-in replacement.
In my opinion, you can’t go wrong with Paul’s designs. I’ve built a number of them and have loved them all.
I haven't used the 8 ohm version of the Vifa , but would assume it sounds pretty much the same as the more common 4 ohm. Not sure about the differences in efficiency (dB) or FR between the two.
Have used the 4 ohm with the SB16 (Michael Chua's Lark SM); in Paul's Classix II; in a two way with a Peerless 830656 (5.5") courtesy Ralf Giralfino of this Forum; and with the Peerless SDS160 (6.5"). The latter two are shown, please excuse the amateurish cabinets.
With some XO tweaks to allow for the 8 ohm tweeter, these would give you some good options - and all pretty cheap, too. Ralf's design had the lowest XO parts count, if that's an issue.
Not sure how any XO parts value changes would affect the designers' good work on the originals.
Geoff
Have used the 4 ohm with the SB16 (Michael Chua's Lark SM); in Paul's Classix II; in a two way with a Peerless 830656 (5.5") courtesy Ralf Giralfino of this Forum; and with the Peerless SDS160 (6.5"). The latter two are shown, please excuse the amateurish cabinets.
With some XO tweaks to allow for the 8 ohm tweeter, these would give you some good options - and all pretty cheap, too. Ralf's design had the lowest XO parts count, if that's an issue.
Not sure how any XO parts value changes would affect the designers' good work on the originals.
Geoff
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If you're interested, I could input your supplied graph for the 8 ohm tweeter into fptrace, substitute that data for the 4 ohm in Xsim, and see what changes might be needed for the SDS160 project., for which I developed the XO from an existing DIY project. I wouldn't do that for the other projects for IP and courtesy reasons.
Geoff
Geoff
FYI, here's my Xsim comparison of the FR and impedance graphs of the 4 and 8 ohm BC25TGs, using Vifa supplied graphs and fptrace.
Please note that the Vifa data is not measured in your cabinet and may not, in any case, be accurate, but at least the comparison is like with like. Red line is the 8 ohm version.
The ZMA graph is a bit puzzling, as the stated resonant frequency of the drivers (1136Hz for the 8, 1128 for the 4 ohm) is almost identical, but the supplied ZMA shows that the 4 ohm has a much lower resonance peak - I think that's quite wrong; I'd expect them to be almost the same.
Geoff
Please note that the Vifa data is not measured in your cabinet and may not, in any case, be accurate, but at least the comparison is like with like. Red line is the 8 ohm version.
The ZMA graph is a bit puzzling, as the stated resonant frequency of the drivers (1136Hz for the 8, 1128 for the 4 ohm) is almost identical, but the supplied ZMA shows that the 4 ohm has a much lower resonance peak - I think that's quite wrong; I'd expect them to be almost the same.
Geoff
Attachments
Maybe that's from an older Vifa datasheet that had the wrong scale? The current one in Peerless's webpage looks fine:
https://products.peerless-audio.com/transducer/29