Car Audio: Replace the tweeters?

[mrbrian200]

It's not so much the tweeters themselves **if they're the full textile dome type, which is what I think you find in most S80s**. The 'unclean' sound harmonic noise is being induced by the small NP electrolytic capacitor (crossover) built into the tweeter assembly. It doesn't pass a clean signal and ends up making the high end sound 'shrill and synthetic'. My S60 came with the mylar semi-dome tweeters (low end) that don't sound good no matter what you do. I switched them with better dome tweeters out of an S80. Those textile dome tweeters are actually really good clean sounding drivers but you have to remove/bypass the electrolytic crossover capacitor and replace it a better (cleaner) film type capacitor as well as bring down it's output a little to balance it's spl/watt output with the less efficient mid-woofers, otherwise the tweeter overpowers and simply turning down the treble on the HU begins to cut the upper midrange handled by the midwoofer which you wan't to leave as a matter of retaining clear unmuffled vocals.

After removing the factory crossover cap I used Dayton Audio metallized polypropylene caps with either a 10 or 12 ohm non-inductive resistor all wired in-line-series with the tweeter. I get these from partsexpress.com which specializes in speaker/crossover/audio components. I don't remember what size cap I used as you have to do some calculations when using an in-line resistor in place of an L-pad resistor setup to achieve your desired crossover frequency. As my HU isn't set up with the higher powered external amp I lowered the crossover frequency to ~2khz. If your system has an external amp you'll probably want to design it to cross over at a higher frequency somewhere between 3.5-4.5khz for first order crossover (single in line capacitor) or design it as a second-order (capacitor in series with a inductive coil shunt to the neutral speaker wire between the cap and the input side of the tweeter.

When chucked the factory crossover cap in leau of this 'mod' it really cleaned up the high end and sounds 1000% better.