Questions concerning mobile audio: Capacitor to filter tweeters

Click For Summary
SUMMARY

This discussion focuses on replacing OEM tweeters in a vehicle audio system with Dayton Audio ND25FN-4 tweeters, which have a 4-ohm impedance. The user expresses concerns about matching the sensitivity of the new tweeters to the existing midwoofers and seeks guidance on selecting the appropriate capacitor value for filtering. It is established that non-polarized capacitors are essential to prevent damage to the tweeters, with recommendations of using an 8uF capacitor for conservative filtering, or increasing to 16uF or 20uF for better midrange performance.

PREREQUISITES
  • Understanding of speaker impedance and sensitivity ratings
  • Knowledge of capacitor types: non-polarized, ceramic, polypropylene, electrolytic
  • Familiarity with audio crossover concepts and frequency response
  • Experience with vehicle audio system installations
NEXT STEPS
  • Research the specifications and performance of Dayton Audio ND25FN-4 tweeters
  • Learn about the impact of capacitor values on audio crossover frequency
  • Explore the differences between non-polarized and polarized capacitors in audio applications
  • Investigate methods for measuring and matching speaker sensitivity in audio systems
USEFUL FOR

Car audio enthusiasts, DIY audio installers, and anyone looking to upgrade or modify vehicle sound systems for improved audio performance.

LightFantastic
Messages
41
Reaction score
0
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.
 
Last edited:
Engineering news on Phys.org
8uF would be a conservative value so you are less likely to blow them out with too much mid-range power. If you need more midrange going to 16uF (or possibly 20uF) will boost the mids.

Remember that you Must use non-polarized (non-polar) capacitors. Ordinary electrolytics act like they have an internal diode across them and will block the bass in only one polarity of the waveform; they will let half the bass thru to smoke the tweeters.

The tweeters you have chosen are good down to 2.5kHz and have an impedance of 4 Ohms. A 8Uf cap will cut the power to 1/4 at 5kHz with further cuts as the frequency decreases. A 16uF cap extends down to 2.5kHz (the tweeter rating), and 20uF will get you down to 2kHz.
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
15
Views
6K
  • · Replies 27 ·
Replies
27
Views
6K