BEST HARMLESS/SIGNATURELESS SPEAKERS CAPACITORS.

Clarity CMR, bypass > 5uF with a 0.1 copper film

But I have to ask, a 3 way speaker system is 2x as difficult to make correctly than a 2-way, if this is your first speaker, I strongly recommend:
1 - Visit DIYaudio for help
2 - Learn your taste and build up your skills by making something inexpensive first or

3 - Make a kit

Also, consider a 2.5 way. Smaller, fewer parts, higher efficiency and the bass extension is such that it does really well in a lot of living rooms compared to super speakers.

@erik_squires  Two-way is much easier. Don’t post here much, but I do a lot of DIY speaker building.  The Jantzen Alumen Z are very neutral and pretty reasonable cost for the sound quality they provide.

Hi raul, you helped me pick the Jantzen alumen z's a while back. Have you changed your mind. I think it my be hard to find a boutique cap without a little flavor. Please understand I'm not very experienced with all caps out there only what I have used.  I tried the Jantzen z's in a 2.5 crossover calling for 2 caps in the tweeter section. I ran across a couple used Clarity CMR and bought it for the hell of it to try in same crossover using a combination of CMR and Z's. I really like this combo. I did bypass it with a copper foil Jupiter and Miflex. I did prefer the Miflex so I settled on CMR, Z and Miflex combo. I did use the path resistors with nice results. I have used Duelund as bypass in Preamp as bypass with nice results also but not speakers.Parts Connextion is now having there 25% sale now. Good luck on your search please let us know if you find something better than Z's because I really like that cap.

Dear @erik_squires  @paulcreed  : No it's not my first speaker, as a fact my ADS speakers are heavy modified by me with out changing the caps/resistors/inductors values.:

https://systems.audiogon.com/systems/3080  

and mno I still really like the true neutrality of the Jantzen Alumen Z that I listen through them by one year now.

But I want to up-grade my speaker crossover caps and in this forum exist several gentlemans with a lot first hand experiences on a variety of capacitors that I not have.

I know for sure that I can have a very good up-grade using Teflon caps through the tweeter/band-pass/midrange crossover but at an insane price.

I know too that I can buy for each crossover speakert 10 AlumenZ for the woofer it self but Jantzen designed the Alumen Z mainly for tweeters and Michael Jantzen told me that I could use it too in midrrange drivers and that's what I did it and I'm satisfied but ...? ? ? .

What I want is to invest for the " last " time in those crossover caps in my speakers. Maybe some of you could say: " hey, change your speakers for a today better speakers " and this can sound reasonable till you listen my " vintage " speakers: Believe me but not easy to bet it at a reasonable price that could can goes over 60+K dollars because the main issue in my system is exactly this: the whole room/system.

Other option that I already took in count is to go with the Alumen Z Cu but I already know is not enough for what I'm looking for.

The premises in my thread are because that's are what I'm listened from some years now. In the past I was a tube guy till I learned and in the premise of digital sources experiences from any one of you are due that even that I'm a LP lover ( over 7K LPs. ) digital already outperforms it and in the very first time that instead to fine tunning my room/system through the analog alternative and started to fine tunning tghrough the digital alternative the analog one improved as digital alternative too.

I appreciated truly all those 3 posts opinions and I hope other gentlemans can give me their advise for I can have choices good choices to decide about.

Thank's.

R.

I'm sorry, it wasn't clear from your original post if you were building a new speaker set, or upgrading an existing.
My advice was given for a new build, not an upgrade. The brand recommendations remain in either case. :)