Test ScanSpeak D2104/712000 dome tweeter
Copyright 2020 © Troels Gravesen

Unpacking the new ScanSpeak Revelator D2104/712000, I showed it to my wife and asked if she didn't think it was cute? "Cute? How can a tweeter be cute?". I couldn't explain, but to a gadget-happy nerd like me, it's cute, because it's tiny compared to other tweeters, and thinking of the engineering that goes into making such a product and the exquisite finish of materials - it's just cute.
Anyway, but is it good? Better take it to the test bench and see what it does. It's been many years since I used what we usually referred to as a 3/4" dome tweeter. I used the Oskar Wrønding HIQUPHON OW1 many years ago and I still use his OW4 for calibrating my CLIO measuring system.
Small domes usually have excellent dispersion and well made, they may go well up to 30-40 kHz, should anyone fancy super-sonic performance.
My plans for the D2104 is a 4-way speaker with the 12MU midrange, but this won't be until the Autumn months of 2020.

Download specs here.

Tweeter flush mounted on my test baffle, 100 x 120 cm. Measuring distance is 0.25 meters from the tweeter face plate.

Measurements

Frequency response of the two units. Quite a matched pair.
My microphone is not valid above 20 kHz, but surely this dome goes high.
Sensitivity around 92 dB/2.8V, well in accordance the SS measurements.

Impedance of the two units. Some minor resonance around 1200 Hz and main point of resonance around 500 Hz, quite low for such a small dome.

Distortion measured for unit I equivalent to ~86 dB/1 meter.
Green = 2nd harm., blue = 3rd. harm.

Distortion measured for unit I equivalent to ~92 dB/1 meter.
Green = 2nd harm., blue = 3rd. harm.

Distortion measured for unit II equivalent to ~86 dB/1 meter.
Green = 2nd harm., orange = 3rd. harm.

Distortion measured for unit II equivalent to ~92 dB/1 meter.
Green = 2nd harm., blue = 3rd. harm.

These domes seem suitable down to 2 kHz although I probably won't use them below 3 kHz when mated with a 4" midrange driver.

CSD for dome unit I.

CSD for dome unit II.

Overall very well behaved with only a tiny wrinkle around 17-18 kHz, which doesn't show up on impedance, nor distortion measurements.
Generally very clean performance.

So, let's see whether the claim of superior dispersion holds water. Here at 0, 10, 20, 30 and 40 deg. off-axis.
Down some 7-8 dB @ 20 kHz/40°.
Looks pretty good, but let's compare to my reference dome, the OW4 3/4" dome.

Above the HIQUPHON OW4 tweeter.
Down some 17 dB @ 20 kHz/40°.
The OW4 is very much related to the classic D2008 and D2010 domes from ScanSpeak.

Above my favourite low-cost dome, the ScanSpeak D2608/913000.
Down some 15 dB @ 20 kHz/30° (note 30° here as the 40° is a bit hard to evaluate due to the dip). 

Above the SBAcoustics SB29BN-B-8 tweeter.
Down some 16-17 dB @ 20 kHz/40°. Pretty good for such large dome.

Overall we can conclude this new D2104 is pretty good when it comes to dispersion.