Decware makes a product to smooth out the response of the Lii Audio Fast-15.
https://www.decwareproducts.com//product-page/fast-15-network
It is, of course, optimized for the low power tube amps that company specializes in. I just came across this article by Nelson Pass in which he details a more complicated network intended for use with solid state current source amplifiers
https://www.firstwatt.com/pdf/art_cs_amps.pdf
In the article he tests a range of smaller wide range drivers made by Lowther, Fostex, and others and defines values for each component that optimize the high end response to minimize the nasties. Tests were with the drivers in a sealed box. I'm curious to try this network with a pair of Lii Audio Fast-15 drivers I'm building tall open baffles for (they will be used with a distributed bass array). Has anybody tried adapting this network to any of the newer, larger full range speakers from either Lii company or other Chinese manufacturers? How would values change in an open baffle setup? Disclaimer-I understand the basics of crossovers but not the details. I was trying to avoid anything between the speakers and the amp! However, it seems it might be needed for these drivers.
https://www.decwareproducts.com//product-page/fast-15-network
It is, of course, optimized for the low power tube amps that company specializes in. I just came across this article by Nelson Pass in which he details a more complicated network intended for use with solid state current source amplifiers
https://www.firstwatt.com/pdf/art_cs_amps.pdf
In the article he tests a range of smaller wide range drivers made by Lowther, Fostex, and others and defines values for each component that optimize the high end response to minimize the nasties. Tests were with the drivers in a sealed box. I'm curious to try this network with a pair of Lii Audio Fast-15 drivers I'm building tall open baffles for (they will be used with a distributed bass array). Has anybody tried adapting this network to any of the newer, larger full range speakers from either Lii company or other Chinese manufacturers? How would values change in an open baffle setup? Disclaimer-I understand the basics of crossovers but not the details. I was trying to avoid anything between the speakers and the amp! However, it seems it might be needed for these drivers.
Note that Nelson’s article was dated 2004, and in the intervening years many of the drivers have long since been replaced by models with quite different operating parameters.
And yes, Steve’s circuit would have been optimized for use with his generally lower power tube amps, which while I can’t remember seeing any verified figures, likely have higher output impedances than most solid state amps.
And yes, Steve’s circuit would have been optimized for use with his generally lower power tube amps, which while I can’t remember seeing any verified figures, likely have higher output impedances than most solid state amps.
Conclusion says unless the value of R0 is lower than 47 ohms, 300 watts would be best for voltage source amplifiers--how did I miss that first time? As a relatively low powered push pull amp owner I'm probably out (but it sounds like a fun project for those with current source amps).
Note that Mr. Pass has a newer version of his full range equalizer which is available at the diyAudio Store. See https://www.diyaudio.com/community/threads/full-range-eq.399413/ for Nelson's recent thread.
There's no particular reason a simple low-Q parallel notch / bypassed HF shelving circuit (which is what the Decware filter is) needs extensive concept optimisation in that regard, and from a quick eyeball of its values, they're roughly what I'd expect anyway, albeit with the resistance value a little higher than you'd often find, though nothing out of sight.
No big deal here: hold L & C static & if you don't want to measure the FR, simply dial it in to 'taste' with a suitably rated potentiometer, and when you have the balance you like, either leave it alone or measure off the resistance & substitute a fixed value. Give yourself (as Steve has done) the facility to bypass it if desired with a suitable switch, or simply short out as desired. Job-jibbed. 🙂