Updates for this pair of reversible projects will be posted here.
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Oct 5th will mark 2 months since my last contact with Misco. I sent a query on Sept 7 and no response yet. I am pending starting on further development with the Jaekels, and awaiting their reply for Itasca and the Bold North tweeter.
Sent another query on Oct 5th, heard back today.
It looks as though 4B will be longer in the tooth. They actually suggested I progress with my previously stated backup tweeter, as demand for their other products is currently higher than the Bold North product line. Due to the currently yet unresolved issues in the BDT-2901 Bold North tweeters, and the present demand status, this driver will take longer to resolve than anticipated.
Therefore, there will be a version 4C for these acacia butcher block baffles, utilizing the Wavecor tweeters previously stated. I will likely adapt the baffles to take the slightly larger cutout of the Wavecor tweeters and commence further in the next few months.
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Just to restate, 4C will be called Wanlü.
I’m at least glad you’ll move forward with something using the mid. That is what I was most excited to hear
The midbass was destined, just a matter of what method of arrival.
4C Wanlu update…
Bought a Freud 1.25” mortise bit and a 1.125” bearing from Amazon to make this relief adjustment. This yields a 1/16” trimming.
The Wavecor tweeters have that plastic ridge behind the face, and it was too large to fit within the Misco’s previously cut through hole. The 1/16” trim radius was all I needed, and a bit with that dimension cut could come in VERY handy quite often. I did use my dremel to remove the red paint on the shaft and locate the bearing closer to the cutters. Those with a mill could likely reduce this gap further.
The notches at the mounting holes are for the input terminal relief. They have a solder blobbed tab that sticks out enough to require these.
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Edit: Never mind 
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Excellent work.
Easy to work with is a bonus at that price point.
Just a note on the Wavecor TW030WA10, it is being replaced with a Graphene reinforced model, TW030WA22, and is now available at PE:
The newer model FR according to the spec sheet has a dB less resonance bump, and a 2dB higher bump at 16k. The HD is improved to be below 0.5% from 1.5k+, whereas the former had 1.75k+ save for a mild peaking at 4.7k that was still below 1%.
I doubt for the most part that these improvements will change the audible character of the tweeters by more than very minute magnitudes.
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The woofer HD, off axes, and other stuff was posted back a ways, likely on the old forum. Basically, I just took the individual driver measurements both on tweeter axis at a meter, as well as the parallel for Z offset finding. Then I took horizontals on the tweeter to +/-45 degrees. As you’ve also seen in JR’s build thread, these are pretty darn clean tweeters.
Right-Cab_Wavecor-TW030WA10_1
HD/45/30/15/0
Left-Cab_Wavecor-TW030WA10_2
I didn’t save the graphic of the Left tweeter measurement, but suffice to say they overlay very nicely.
Comparison of woofer plots, both at 1m on tweeter axis:
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Okay, after hours of fiddling around, I think the blending is as good as I can get it. Getting a good result for each driver in this case was easy, but blending them was a little more difficult.
The summation came out LR4 net through the xover, and then tapers steeper outside the range.
Here is the simulation below. I was able to keep the sensitivity at 81-83dB, but that is about the most you can expect from a long-throw 7” 2way made for power and low bass extension in a small box. If it were 4 ohm impedance, that would add about 3dB to the sensitivity, but it’s not. The tweeter was managed 4 with parts. The woofer was not as much a champ when it came to trying to blend well, and took twice the tweeter’s parts count. Parts total is 12 in this simulation. The 150Hz dip is floor bounce.
Phase alignment is good to just above the xover point, but that is how 2ways commonly diverge.
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I increased the front series resistor for the tweeter from 2.7 to 3.3 ohms for balance.
I must say these are nice sounding. The drivers blend well sonically.
Here’s where I’m at currently:
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Took these to Brad’s (@Impious) this afternoon as they sit.
Brad and I both feel there is a blemish in the tweeter around 8-10k, as it sounds sibilant at times. It is possible this could be component influenced in some way, as the tweeter did not exhibit this issue when initially measured. I will get to the bottom of what is causing it if possible.
However, on the mating Bold North driver, we both like it very much. It held its composure well, even under longer excursions at high output, and never complained at all. The 2.5” dia ports were moving some serious air. An internal flag-tag of tape for wire connection identification was smacking the inner port end under this effort, and caused light concern until it was identified. It was not coming from the driver.
I found a Dakota DIY 2017 disc, and we put them to the test with 50c, etc. More heavy and low bass tracks followed, including Queen Mary and some taiko drums. Queen Mary would tell you this was no ordinary 7” woofer.
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Ben was gracious enough to bring the Wanlu over today as I’d been dying to hear those Misco XBL drivers.
Y’all, those mids have been overlooked by the DIY community. They are fantastic. Their bass response is incredible for a 6.5” driver. They dig deep and have a ton of output, but they sound absolutely composed, natural and detailed while doing it. And to top it off the midrange sounds excellent as well. Detailed and articulate but also natural and not dry or clinical like the Purifi sometimes can sound. Great dynamics. Top to bottom, these are really great drivers based on what I heard this afternoon.
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How do you like the Bevenbi caps?
I like them, but I’m not certain what is causing the sibilance yet as I have not had time to investigate this issue. I hope they are not the root cause. Otherwise, they sound fine with good detail.