Improving tweeter power handling

[AllenB]

I have 1" silk domes with 1st order crossovers. They play down to 1750. I like their sound and the simplicity of the crossovers.

When I turn them up, it sounds like they get thick and loud around the tweeters resonance. My mids and lows are fine at these levels so I think I want to either reduce the low content going to the tweeters or protect their resonance but I don't want to upset the crossover too much.

The options I've come up with are:
1. Put a resistor in parallel with the tweeter and adjust the capacitors accordingly.

2. impedance notch filter.

3. A large (out of band) inductor to turn the crossover 2nd order at some low frequency.

4. some combination of the above.

5. A full 2nd order conversion.

I think I only really want another 6-10dB.

[jol50]

Have you tried running them higher? I've run ceramic resistors on drivers a lot of times to cut them back if running multiple drivers & one amp. I ran soft domes a lot too, 1", and didn't like them that low so I ran a smaller cap except I forget the value now. Also experiment with one or both out of phase, but if they are screaming/raspy you are either into resonance or too low for that power level. You might be able to run a larger mid dome, some can get fairly high and with some EQ be used as a tweeter...if you like that sound with them running lower. I'm sure you can cut the lows down some with the right xover as well. Another benefit of running them higher and having the midrange get in there is the domes can blow up easily running low.

[tinitus]

Originally Posted by AllenB

I have 1" silk domes with 1st order crossovers.
They play down to 1750.

I dont know if your tweeters are budget ones, whatever that is
But cheaper ones often have highish ressonance
Which makes low crossover point a problem
May work fine at low SPL, but not at higher SPL
Well, ofcourse there could be some other reasons

I have removed LCR curcuit on my woofers and mid, with some succes
Though it took a lot of work on xo afterwards
But on my tweeters the ressonance "killer" had to stay
Couldnt make it work without
And Im not even crossing it low

But Im curious, how do you know it plays down to 1750hz

[richie00boy]

#1 won't do anything but load your amp more. I would go with #3 or #5.

[tsmith1315]

Originally Posted by AllenB

I have 1" silk domes with 1st order crossovers.


I think I only really want another 6-10dB.

1750 is pretty low for a first order crossover on a 1" tweeter. If it is indeed that low, the impedance peak is bound to be affecting the crossover performance. A notch filter would be a good idea in that case, but...

6-10dB additional output is a very significant increase when you're already having problems. A 2nd or 3rd order crossover would be no more complex than a first order with a notch filter, and would be my only bet to achieve the gains you're looking for without raising the crossover frequency.

[AllenB]

With 3 x 1u5 capacitors per side, it looks like the impedance peak is having an effect. I confirmed the response by measuring it.

I'd like to try an out of band inductor across the tweeter. All I have on hand that's matched is a pair of 0m82's. These give about a 2.6kHz rolloff with a Q below 0.3 which may not be helpful but....

If the impedance peak is happening there, what affect will it have on this option?

[richie00boy]

Really with passive you need to work above resonance, i.e. cross at 2x or 3x resonance frequency. Else the impedance peak just screws everything up. As you are also trying to get significantly more output from the tweeter, 1st order is just no longer an option.

[AllenB]

OK then. At least I can play with the level and reverse the phase if I have to. On the other hand I could look for a more versatile set of tweeters. I don't see many car tweeters sold separately...are there many out there?

[richie00boy]

You are going to struggle to find any tweeter that will take a 1.7kHz cross at 1st order. You will have to move to looking at drivers like the Jordan HD.