Tweeter notch board:
Woofer dual notch board:
Tweeter CR plus woofer tank:
Woofer coil:
Completed w/o leads:
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The coils look fantastic! I am guessing the resistor tied down touching the cap won’t get hot enough to pop it.
I learned the hard way doing something like that and destroyed a cap! 
That particular circuit may change slightly in the near future after I put the mic on them.
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Let me elaborate a bit…
I got the leads added to the boards yesterday and fired them up. These are really good sounding drivers, but tonality needs a little adjustment. There is a hint of sibilance I want to reduce, and it sounds like maybe a peak and neighbor dip that is making them sound just a bit off. I am pretty stoked and confident I’ll sort it out easily.
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Okay, I took whoops to verify, but with and without the lift 2.7uF cap in the tweeter contour was fairly dramatic. Turns out the tweeter was fairly flat without the cap in place. I tried a 1.0uF and adding a 0.5 ohm resistor in various positions, but nothing was as good as without. There is a small peak about 7kHz that sometimes I think I hear, with a 2nd order HD chaser behind it to boot, but unfortunately there is no easy way to ameliorate it. It’s too narrow band that the fixes affect more than wanted and ruin more than what is possibly needing fixed in the first place. I will just have to leave it as it is.
Stock as simulated:
Switched to 1.0uF:
No Cap:
No cap HD:
I’ll have to do more listening to make sure I’m really happy with them now, but I feel I’m close to that point. The system HD is -45dB for most of the bandwidth, and what isn’t is mostly HD2.
EDIT: …and no- I could not find the 300Hz culprit. I walked around the room with my phone blaring it, then had the speaker do it, then tried 150Hz just to make sure it wasn’t a harmonic. I couldn’t find it.
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less is sometimes more - looks good
When you look at the tweeter’s natural response, it is dropping pretty quickly compared to many others on the market. The sensitivity over all when flattened is likely one of the lowest I’ve used. Due to the inherent waveguide, the smaller cap can be used, but if padding is also used, you can sometimes get the top-end back a little. This is what I was thinking and initially trying to do by tilting the teeter-totter type response. Due to how this tweeter has to be used, I doubt it would have enough output for an MTM usage. It is really meant for this kind of build you see in this thread.
Had to scroll back to see the lifter (RC) at front of tweet network. Guessing the 1.8 notch for eager low end that doesnt wanna be quiet otherwise.
Eager to hear these as have only lightly experienced fiber cone or woven woof’s (small curvs, wavecor and thumpy epics).
Also curious how the tweets sound to other mag-alum tweets like in the tb w4’s and seas titan.
Messing around more to see if a fix is remotely possible. The shunt-series notch uses much smaller value components to get the job done with pretty good control and lower losses where I don’t want them. A plain 25 ohms across the tweeter affects the output over all, but not just the problem area. Using a set of notch values of 0.2mH/3.3uF and a resistor of variant value shows a 12-15 ohm value to be most maximally flat. 10 ohms is more recessed than flat by a hair, and 20 ohms leaves a bit of the 6-7kHz area still prominent. What could it hurt, right? I’ll have to try it out.
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I mocked this up Sunday and connected them yesterday. I went with the 10 ohm, but was apparently a little overzealous. I’m on the right track to finish now, as these are much closer to where I want them, but a hair dull and lacking air. I’ll try a 12 and 15 later today to give them a little ‘life’ back. If I don’t like how either of those sound, then I may have to reduce the front 2.7 ohm padding resistor back to 2.0 ohms.
This broadband notch to flatten the tweeter hill centered at 7k is exactly what this build needed. The brash sibilance that was occasionally coming through has been mitigated. The 2nd order HD peak is not as noticeable as it was before.
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I’ve now listened to several different resistances in the 10 ohm spot. Frankly, this took a lot of listening to nail down and was very finicky. Even 1 ohm added was what I call bright. I have been swapping between no added resistance, and 0.6 ohms added, and just now placed a 0.22 ohm resistor adjacent and feel its the best it can possibly be at tonal balance. Unfortunately, the 2nd order HD is still something inherent in the character these tweeters employ.
To clarify, doing the math, the initial resistor is 10 ohms even measured, the 0.2mH/20awg coil is 0.34 ohms measured, and I added in finale a 0.22 ohm resistor measuring 0.23 ohms. The total net DCR of the coil and resistors is 10.57 ohms. The difference from the simulation at lowest value of 10 ohms is only roughly a half ohm where I consider them to be dialed in.
Edit: I may even listen to these in the conference room and decide the 10.34 ohms is right over the 10.57.
Edit2: I’ll split the difference and add 0.115 ohms by paralleling 2x 0.22 ohm resistors and leave it alone.
Edit3: I added the 2x 0.22 ohm pair (in parallel) in series with the 10 ohm resistor, but placed an SPST switch across them to short them out if I want. This way, I can demonstrate what I was hearing.
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