There is no chance you can build anything for $100 . I am speaking quality
I have been dojng this for over 20 years , my standards are much higher
having been into Audio for 40+ years, for example these white $2 resistors I use $30 each X4. Path audio ,much better detail ,clearer more open , if on a budget put in 12 watt mills resistors $12 each ,the inductors are Jantzen and good
the white Mundorf are their lower mid grade Evo capacitors, Mundorfs Best quality are Black their Supreme line . Foil capacitors are better then sprayed conductors.
myself use the much more expensive Jantzen AlumenZ capacitors ,
and Duelund tinned Copperfoil Bypass caps for the tweeters to complement the Jantzen ,I spent without the Upgraded Cardas wire $1300 just in parts .
that being said you can build a external Xover and use the Best Duelund capacitors
depending on sizes 3x the monies, why don’t $50k speakers use top quality parts
is all about saving $$ . I am just pointing out these from a 20 year+ point of expertise . Just go to Humble homemade hifi capacitor test, the white Evo caps are respectable , and used by a lot of companies but rated roughly a 9
pThe best Duelund a 15, Just get rid of the 4 -$2 resistors and put in all Path Audio resistors , and a .01 uf Duelund tinned Copper foil cap for the tweeter capacitor you will hear a solid increase in resolution and refinement for under $300.
I am just suggesting it’s your speaker I have been there done many combinations and still do for others ,all depending on budgets.