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No Ohmage quoted on the box but on my multi meter they show 3.5 Ohms, and most car audio including my cars sound system is 4 Ohms. Specs quoted on the box are a freq. response of 3kHz - 40 kHz, and crossover slope of 12dB/octave. No expanded spec sheet inside (or instructions FWIW).



While the DC ohmmeter check can tell you something about the impedance of a driver of any kind that has voice coils, it won't tell you that much about a Ribbon Tweeter. And, of course, can tell you nothing about the crossover. This is because of capacitance in both, which does not "pass" DC. Your audio, of course, is AC of varying frequency.

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The car head unit is a Kenwood KDC - MP5039U of ~ 22 watts RMS per corner, ~50W peak per corner.

I am contemplating installing the tweeters without the crossover per 4. above. I realise it's a risk but am guessing the worst that can happen is popping the ribbons. I don't routinely listen at deafening volumes, or to very dynamic "doof doof" music, too old.



Do NOT do that. The tweeters cannot take fullrange at ANY volume level. Without a crossover, those tweeters will not last long. Ribbon design will die even faster without a crossover, although its a moot point. The low frequencies must be blocked from reaching the tiny diaphragms of any tweeter.

John, I noticed one thing you said-- that the crossovers are using Shielded wiring. I suspect that Capacitance is rearing its ugly head here, and throwing your wideband power amplifier into distortion. This is a rather common phenomenon with Ribbon and Electrostatic tweeter systems. Quite often, the actual AC Impedance of them will drop down below 1 ohm! You can't measure that with the simple DC ohmmeter. It would take an Audio Impedance Bridge to do that. But you are in luck, for I have used the Impedance Bridges and Distortion Analyzers on the test bench many times to prove this rather commonly found situation happening with Electrostatic and Ribbon speaker systems. Sometimes the workaround is to use cheap 20 AWG gauge parallel (NOT shielded) speaker wire, about 20 feet of it for each side, coiled up. This can iron out the problem, but in a vehicle, where to put all that wire? Since your crossover already has shielded cable as part of its design, I don't think I'd even want to try that stunt, though. Shielded cable also is capacitance in and of itself, by the foot.

Not being able to put your crossovers and tweeters on the test bench (and very likely removing that shrink tubing and finding out what's really underneath...) I can't give you a reliable answer to this one that wouldn't involve trying to do things that are obviously outside your scope of reference on the subject.

You might just send these back, or write them off and find a simple set of dynamic tweeters with crossover instead.

Or -- you could purchase another smaller power amp and an electronic crossover to place between the two power amps and safely send the lows to the original amp and woofers and the highs to the new tweeter amp and ribbons.

If it was me, I'd likely go with the first choice, standard dynamic tweeters with a simple capacitive crossover. Less $$, less complexity, for about the same performance, considering it is a vehicle.

Bottom line -- This product is not performing satisfactorily for you and you should send it back.




--Mac

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