12"+ 4" wideband. Construction thread

Your post #10 green curve and my post #34 green curve basically agree on driver (semi-) nude without baffle reinforcement. I simply broad-notched the HF shelf flat. You might either place it on top of the cab baffle-less (except below driver), or co-axially over the woofer cone and possibly get a ~1khz in-phase bounce of the backwave (17cm halfwave travel). Or try AllenB post #30 baffle placement (driver center ~17cm to right-edge; maybe top too). And there are other things to try on the baffle/backwave.

p.s. flip cab, Eazy on new top
 
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Didn't like opamp 2.1 sound so went back to tweaking passive. Only had time to do one channel (and only one $30 vintage 12" oh well) but it's about as "high fidelity" as I've yet managed 2+ years into diy. Well almost, 8khz still a little bit over.

The bits are my hoarded Jantzen: 2.7uF Silver || 1.5mH copper-foil || 6ohm notch-filter before 1ohm before Eazy; 9mH air-core (1.85ohm) LPF before the woofer.
 

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I have already the box made, drivers at hand.
So ill continue this project and finish it. I hope break in will help here!
ill use a 300hz first order xo.
for the first time in my life, ill say **** the measurements. better this then end up with drivers on the shelf right?
 
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My measurements are bad due to poor speaker placement… dont look under 200hz
heres a few xo points
250hz, 800hz and 1200hz
as we can see, the 900hz dip is bad
i can only make this speaker work with a min 800hz xo

the pics with the yellow line is the 250hz xo. Look at that dip!

so yeah, the fe108ez… i would only use it in a 800hz min xo points. Id need a more efficient woofer to make the sound balanced as its too efficient for the 12br70. Back to the shelf!
 

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Heres the ff105wk measuements
much better
800hz xo points

i think that can work.
ill try a 500hz xo but already i feel both driver sensitivity works well
 

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the balance just works. sounds is impressive to me with the xo set at 800hz.wow.
now im happy
the fe108ez is quite a bit more efficient .a better match would be a 96db woofer

gotta go buy some caps and coils to try a 500hz xo points for the 105WK
Ive tried 250hz xo and it didnt work as i had a dip in the lower mids.
 
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pair is done
first order xo around 400hz.
less efficient that I hoped for: circa 91db. My BIG REF 150L is way more efficient at 95db

I can confirm the 12br70 doesnt work perfectly in a 30L cabinet
I get a high shelf from 80hz up to 200hz. I dont mind the +-5db boost down there however

how do they sound? the 12'' sealead bass is extremely tight, with a satisfying amount of punch and kick. mid and treble is surprinsgly linear with great amount of details.
 
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So the 7khz peak of the FF105wk is not a problem for you?
on axis, definitely. off axis helps a lot. the peak is audible though and I hope i can somehow make it less so

for the cost of about 700$, they are laughably insane sounding. I think im starting to become addicted to designing speakers. ive been living with a big 3 way for a year now, and going back to a 2 way is interesting. I need to design a proper BIG 2 way.

after a few minutes of acclimatation, im quite surprised by the overall sound. Bass is good. mid is good. treble is ok, the peak is bad.