Stanislav Malikov has a history at Accuton and
Morell companies and has started his own production of this unusual
large aluminum/magnesium dome and offered me a pair for testing. Click
here to go
to website and download data sheet
here.
I've had a long term affair with large domes
from my
8008-HMQ constructions.
Here some more stuff on large domes.
What got me interested in this dome is the claimed aluminum/magnesium
alloy dome of variable thickness.
Secondly its narrow suspension. Current hard-dome manufacturing favours
wide fabric suspensions, adding significantly to the radiating area, thus a mixture of soft-dome and hard-dome, although I cannot
tell the percentage of sound pressure generated from each. And I rush to
say I very much like the performance of current Be domes from ScanSpeak
and SBAcoustics, but you never know what a Be dome would sound like if
it had a very narrow suspension. Alu domes started life badly back in
the late Seventies and one company (JBL) even withdraw their first alu
dome due to poor reviews. And bad it was. Later we had better alu domes
from e.g. B&W and not least Celestion with their SL6S, which I owned for
quite some time. Titanium domes came along and generally got a better
reputation, although I never liked them much, maybe due to poor
implementation.
280 mg moving mass is quite low for such a large dome compared to most
modern soft domes of 25-28 mm diameter, often having 300-500 mg moving
mass. The SEAS T35 has 470 mg moving mass.
Click image to view large
So, from what you can see below, we here have is a very well
performing large dome tweeter, high sensitivity, flat frequency
response up to 25 kHz, low distortion, exceptional dispersion
(better than many 3/4" domes!), exceptional clean waterfall plot,
very nice finish, etc. I can't point to anything this dome doesn't
do well - and even better than many other domes - and price will be
around 290 € + VAT.
I tried setting up the dome with the
ATiRi midbass, made a quick crossover and went through some
familiar recordings and nothing stood out for not being a worthy
candidate for future construction. The tricky part is finding the
right partner for this dome, a midbass in need for a fairly low
point of crossover - or - you may just use it as any other dome and
take advantage of the large radiating area and get the benefit of
low distortion, because size matters.
Based on modeling from preliminary data, the T34A-4 seems a worthy
candidate for an alternative tweeter for the
8008-CORNER speaker delivering on the very same simple series
crossover (different values that is). No immediate plans for such
experiments, so please do not ask.
So, find the right partner and here you have what appears to be a
very versatile dome tweeter.
High sensitivity and linear response is what appears from flush mounted
unit on a 60 x 100 cm baffle.
The break-up peak at 29 kHz is for dogs and bats and should not disturb
our peace.
What cannot be ignored is that this dome does flat to 25 kHz despite is
large size! Quite impressive.
What came as a real surprise was the dome's dispersion characteristics.
Above dispersion at 0, 10, 20, 30, 40 and 50 deg. off-axis. Very good
indeed. This calls for a very even power response.
Above distortion measured at 0.25 m distance normalised for 84, 90 and
96 dB @ 1 meter distance.
Data suggest a dome suitable for very low points of crossover, probably
even 2nd order @ 1.5 kHz.
Cumulative spectral decay display a very clean performance, even below 1
kHz.
Above an impedance plot. Fs = 800 Hz.
The T34A-4 displays a fairly wide impedance peak that may need attention
in applications with a low point of crossover.
Should we want to flatten the impedance, 5R6+82 uF+0.47 mH does the job,
although it's not always desirable.
Click images to view large
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