Aura 3"...phase plug?

[planet10]

a very cute little speaker ....

 

[planet10]

one wonders why you'd cut one of these up... a shot of th voice coil... quite long and as it turns out, quite deep...

 

[planet10]

here we are with te cone trimmed out over the centre of the voice coil. The cone is quite complex. looks like 3 layers to me, aluminum, paper, coating... note the grill over the vent out the back...

 

[planet10]

1st i tried a standard FE103 plug... too short (and too fat)

 

[planet10]

and an earlier 103 prototype, right diameter, still too short

 

[planet10]

and this is with an FE127 prototype. in the 127s just a bit too tight but the cone would at least move. In this case just skinny enuff to fit in, but tolerances such that the cone has no hope of moving...

 

[planet10]

and another shot ... i have a pair of these in natural i'll be able to sand down to fit (more work than making the hole in the Al cone though

 

[planet10]

and a head-on shot...

 

[planet10]

the dremel tool made a lot of aluminum dust ... the foam plug i put into the VC before i started did a pretty good job, but i decided to play it over night firing down to encorage any strays to leave... here is the tempoary enclosure... the 2 1.3H chokes hold the cup down.

 

[planet10]

after my initial misgivings, i think it turned out quite striking with the big black nose...

dave

 

[pinkmouse]

Looks good!

If you fold a piece of sellotape into a diamond shape with the glue on the outside, you can run it around the VC gap and get the last few bits of stuff out.

 

[planet10]

Originally posted by pinkmouse
Looks good!

If you fold a piece of sellotape into a diamond shape with the glue on the outside, you can run it around the VC gap and get the last few bits of stuff out.

If there is anything in there, and it doesn't work its way out, then i'll give that a try... the VC is awefully deep thou, may be real tricky.

dave

 

[jeremyg]

that last head on pic is damn sexy imho

 

[planet10]

measured (i didn't take a baseline for the slice & dice driver)

[SIZE=3]
Driver              Fs        Qms     Qes      Qts 
#1 no dust cap     96.74    7.286    0.766    0.693
#1 no phase plug   96.64    7.070    0.763    0.689
#2 stock          103.29    7.553    0.902    0.806
#3 stock           98.63    7.887    0.864    0.779
#4 stock           98.94    8.187    0.870    0.786
[/SIZE]

with no reference we can only note that the modded driver has a lower Fs than the other 3 (i would expect it to rise due to lower mass), and the Qts is lower.

dave

 

[planet10]

And the impedance curves. They pretty much fall on top of each other...

Red is #1, no cap, yellow dashed with the dust cap, the other 3 drivers in darker colors. Note the small glitch at just above 500 Hz & larger one just below 3 khz. These are absent in the stock drivers.

dave

 

[planet10]

And a couple pictures with the phase plug that i made to fit...

 

[planet10]

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