Fountek NeoX 2.0


2010-12-08 1:27 pm
Perhaps one of you folks could give me some input on this question. It will definitely be appreciated.

I bought Fountek NeoX 2.0 ribbons to mess around with and so out of curiosity I just replaced my tweeters with these without changing the crossover. The crossover is a 6db single cap. I figured that for testing purposes I would keep the power to it low. As it turns out, it sounds very good and so I increased the volume until I got to my normal listing level, which is at about 10 watts total power. I rarely go over this amount of power and if I do, it's only a few watts more, 15 watts at most. At that point it still sounds very clear with no distortion.

This 6db crossover puts the crossover point slightly under the recommended crossover point and the recommend crossover suggests a 12db crossover.

Here are the specs:

Sensitivity - 94dB
Power handling - 25W nominal,43W max
Frequency range - 1,200-40,000Hz
Nominal impedance -8 ohm
recommend cut frequency - 2,500Hz with 2-order

In addition, I padded the tweeter down by about 1.5db.

Considering that I only use about 10-15 watts total power for the bass and treble drivers combined, I think this is doable. Honestly, this tweeter and my SEAS woofer sounds really good together with the existing crossover and I don't want to mess with it if I don't have to.

All things considered, I believe that the amount of power going to the tweeters is well below the published amounts even with the 6 db crossover. For instance, if 25% of the power/music goes to the tweeters, that means the tweeters are only receiving about 2.5 – 3.75 watts. Even if I drove my (40 watt tube amp) amp to full power (I would never do that – way too loud), it would only put 10 watts to the tweeters. 10 watts is still less than half of what the specs claim it can take. This all assumes that the tweeter only gets 25% of the wattage of the total power.

What are your thoughts?


2013-05-10 4:11 pm
Ribbons are pretty delicate, personally I would reconsider, especially if you are pushing the Xover.

Ribbons tend to be pretty flat impedance. Why don't you add an 0.8 mH coil and 2 ohm resistor after your cap and listen again?

That's assuming you don't have a good way to measure things. I'd suggest analyzing what you have and rethinking the crossover.


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2010-12-08 1:27 pm
Thank you Erik. I haven't done anything with the crossover till last night. I don't have many parts, but I did have enough to raise the crossover point from 2000Hz to 3000Hz (woofer and tweeter, of course), but I kept the slope at 6db. That should help some. Anyway, I've taken your suggestion to heart and "will" look into it. Thank you again.

Just so you know, the tweeter seems to be able to handle the 6db slope at 2000Hz at the volume I play it at. My speakers are about 90db so I don't use much power.

When I was doing this last night I did the woofer first (and listened to the results) so there was an overlap with the woofer at 3000Hz and the tweeter at 2000Hz. I expected it to sound brighter (which it did), but more interestingly voices sounded grainy and harsh more so than bright. I then raised the tweeter to 3000Hz and it smoothed right out. I didn't expect that. This makes me wonder if there was a phase effect going on and the overlapping frequencies were interfering with each other creating triangle waves or something? Anyway, when I get around to it I'll see if I can see this on a scope.

In any case, it sounds very good and the 3000Hz crossover sounds better than the 2000Hz crossover.