https://www.parts-express.com/dayton-audio-nd25fn-4-1-neo-silk-dome-tweeter-element-4-ohm--275-053 https://www.parts-express.com/cat/capacitors/68 Tried replacing the OEM speakers in my vehicle with a set of aftermarkets ...without exchanging the OEM head unit. Terrible idea, and I knew better. As far as efficiency/sensitivity goes, OEM blows aftermarket right out of the water. So I stuck my OEM speakers back in. I can handle the muddiness out of my midwoofers, but the OEM tweeters are fatiguing. It is my understanding that tweeters don't need a lot of power, so I am interested in replacing them. They are wired in parallel with my front midwoofers, and filtered with a capacitor. They need to go high in my doors off axis, and fitted in a rather tight location. There's only a handful of 4 ohm tweets from parts express that will fit the physical constraints. I'm not sure how to choose the correct cap value or the type of cap. Ceramic, polypropylene, electrolytic..? Desired tweeters are linked at the top of the page. Guess I'm just worried that the tweeters won't be able to keep up with the mids. Couldn't find the sensitivity rating on the daytons, but I assume they're much lower than oem ...which isn't a good thing.