mFonken and Aura tweeter tweak suggestions

[MichaelPublic]

Hi folks,
I have some mFonkens (which are enbld) and I enjoy using an Aura tweeter for some "sparkle". (the Aura is like the Linaeum tweeters but monopole)
I've used the search function but would like suggestions on what resistor to use or range to try to match the tweeter to the fe127e. I'm guessing 15,000hz and up would be a good range for the tweeter to cover?

I'm currently amping the tweeters separately from the fe127's and would like to drive them both from 1 amp.

The fe127e is a fairly known quantity so the specs of the tweeter are:
Nominal Diameter (ÿ) . . . . . . . . . . . 2.5 x 2.5 inches (210 mm)
Nominal Impedance (Z) . . . . . . . . . . 4 Ohms
Sensitivity, 1W/1m (E) . . . . . . . . . . . 92 dB
Power Capacity, RMS (Pe) . . . . . . . . 10 W
Power Capacity, Peak . . . . . . . . . . . 20 W
Frequency Range (-10dB) . . . . . . . . Fo - 2-20 kHz
Minimum Impedance . . . . . . . . . . . . 4 Ohms
Voice Coil Length . . . . . . . . . . . . . . . 35.4 mm
Voice Coil Winding Length (h) . . . . . 1.9 mm
Voice Coil Number of Layers (n) . . . . 1
Magnetic Gap Depth (He) . . . . . . . . 2.0 mm

and the obligatory picture, please note, that is just a temporary tweeter housing to see what they sound like.

[chrisb]

Aren't these little guys are more fun than they have any right to be?

Well from the specs for the tweeter, sensitivity looks close enough that a simple 8ohm L-pad might work quite well enough for attenuation.

The FE127E's response extends smoothly enough on axis to well past 12kHz, that I'd be inclined to start as simple as possible. Your guess at 15kHz sounds more than reasonable - start with a 2.6mf cap for HP filter on the tweeter. If you want to play with lowering the XO point, you could always add .1mF in parallel until it sounds just right.

As for permanently mounting, how deep is the tweeter? I might be possible to add a layer or two of 1/2" ply to the top of the box, and rebate it in flush, adjoining the 127.

[MichaelPublic]

Originally posted by chrisb
Aren't these little guys are more fun than they have any right to be?
................how deep is the tweeter? I might be possible to add a layer or two of 1/2" ply to the top of the box, and rebate it in flush, adjoining the 127.

I agree, I've been tinkering with a sub and I still have to find the "perfect" crossover frequency but it's near 100hz and sounds good to me.

The tweeter is 32.5mm deep measurements below; modifications to the cabinet...Hmmmm... in the interest of science it might have to be done.

[chrisb]

I know a guy who nose a guy who can be bribed with a cold beer.

[planet10]

Hi Michael....

Just a note for those looking in, Michael managed to score 1 of the 2 sets of the mark 2 betas of the mFonken.

We are also playing with a sub for these (actually subs for the entire family). Right now the µFonken woof is connected up to the Fonkens (or the JX92 in the breakin box) with a 100 Hz XO and results are encouraging. What are you using for woofer duties?

dave

[badman]

The concern is the very big change in dispersion pattern. This is why horn-loaded or waveguided designs are preferred (IMO) as supertweeters, as they help maintain the narrow dispersion of a cone driver playing into it's directional region.

[MichaelPublic]

Originally posted by planet10
Hi Michael....

Just a note for those looking in, Michael managed to score 1 of the 2 sets of the mark 2 betas of the mFonken.
.......What are you using for woofer duties?
dave

Alright! I didn't know I was a beta tester.
I'm using the often on sale silver version of the Klipsch RW-8 which I believe is some kind of folded sub-horn specs here:
RW-8

I think I've got it nearly dialed in, fiddling with phase helps, also worth noting I'm using them all in a small room due to dangerous children and adults frequenting the living room.