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Eton's current line is dominated by its "Hexacone" Kevlar/Nomex (Nomex is a type of
nylon used in fire resistant suits for race drivers) honeycomb sandwich cones.
Although most of the numbers and the FR/impedance curves of these drivers look
impressive, the waterfall plots indicate some potential resonance problems only
slightly less severe than the Seas magnesium cone drivers. Fortunately, most of
these look like they might be fairly simple to filter.
As with the Seas units, these are actually used in some truly great high-end
systems, but their use may be beyond the resources of many DIY'ers. Although I
received only a few recommendations for Eton drivers (and none against), based on
detailed data provided by Solen (an Eton distributor) the following recommendations
seem appropriate:
- The 19SD1 3/4" soft dome tweeter
features a double magnet assembly with extended excursion, and excellent
passband FR data, all for an extremely competitive price.
view
response/impedance/phase
waterfall
- The 4-30025HEX 4" cone mid/bass
isexceptionally well behaved with its first breakup mode not coming into play
until around 10 kHz. Designed for use as a mid bass, it has a reasonable Xmax
and 89 dB sensitivity. The same driver is also available in a shielded variant.
view
response/impedance/phase
waterfall
- The 7-372-32HEX 7" mid/bass
driver. Similar to the 7-360-37HEX (see below), this is one of Eton's most
advanced drivers, featuring a large (for Eton) Xmax, lower Fs, and a
proprietary heat pipe cooling system for greater power handling capacity. The
usual Hexacone problems exist, but don't begin to cause any really serious
problems much below 5 kHz.
view
response
- The 8-800-37HEX 8" woofer
exhibits the large HF resonance apparently typical of the Hexacone material.
Fortunately, it falls an octave higher than the maximum recommended crossover
point. Within the passband, the data looks quite attractive.
view
response/impedance/phase
waterfall
- The 11-581-50HEX 11" woofer
follows the same pattern as the 8" unit, featuring attractive curves and
numbers within the passband combined with a 10 dB resonance peak well above the
maximum recommended crossover
point.
view
response/impedance/phase
waterfall
The following drivers are recommended FOR EXPERTS ONLY! They sound excellent, but
designing crossovers for them can be difficult.
- The 5-880-25HEX 5" mid/bass
driver. Featuring exceptionally flat passband FR, this driver has a strong
primary resonance which falls right at it's maximum recommended crossover
frequency (3 kHz). A notch filter is advisable in any case, but a crossover
frequency of 2 kHz or less would make for an easier design job with more
manageable phasing.
view
response/impedance/phase
waterfall
- The 7-360-37HEX 7" mid/bass
driver. Featuring even slightly flatter passband FR than the 5" unit, this
driver has a strong primary resonance which falls only slightly above its
maximum recommended crossover frequency (2.5 kHz). A notch filter is advisable
in any case, but a crossover frequency of 1.5 kHz or less would make for an
easier design job with more manageable phasing. A version of this driver is
used in Legacy Audio's top models, including the universally acclaimed Classic.
view
response/impedance/phase
waterfall
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