Previously, Astrotec's flagship hybrid model, AX60, turns out to be quite a disappointment. Not only its sound signature is nowhere close to that of AKG K3003, which is claimed reference target of the IEM, but also the sound quality itself is simply not up to the standard set by other Chinese manufacturers, such as Unique Melody or Vsonic.
Meanwhile, AX35 is Astrotec's low-end hybrid, featuring a ⌀10 mm dynamic woofer and a balanced armature tweeter. There is nothing too fancy about AX35: The filter is not replaceable, and only one pair of normal size sleeves come with the IEM. What can possibly be expected from such normalcy?
PRO: Sturdy built-quality, well-matched channel balance, low distortion, and intuitive acoustic damping design. Time domain characteristic is excellent too.
CON: Short bandwidth & the acoustic damping design in stock configuration loses a lot of sub-bass response.
ON SECOND THOUGHT #1: Since the frequency bandwidth is short as is, insertion depth doesn't play much of a role in terms of treble extension.
ON SECOND THOUGHT #2: Due to the IEM's impedance characteristic, additional resistance boosts the treble slightly.
ON SECOND THOUGHT #3: Users may choose to remove the stock metal mesh + white cloth filter placed on the nozzle, and replace it with one of the acoustic dampers designed for hearing aids. This increases the mid-range sensitivity tremendously.
ON SECOND THOUGHT #4: Depending on how these vents are configured, AX35 may become one of the best sounding hybrids in the market. While the front vent attenuates the sub-bass response, the rear vent does the exact opposite to counter balance what's lost. Users must be aware exactly what they are trying to achieve before executing any type of modification on acoustic vents.
ON SECOND THOUGHT #5: Recommendation 1: First of all, equip a 100 Ω resistor to the IEM, and a pair of Sony MH1 sleeves(Sony hybrids, Phonak stock, or Shure EA510). Second, seal off all vents. Third, remove all of the stock dampers placed on the nozzle, and replace them with a 680 Ω white damper. Fourth, equip the metal mesh back for safety if possible.
Recommendation 2: First of all, equip a 100 Ω resistor to the IEM, and a pair of Sony MH1 sleeves(Sony hybrids, Phonak stock, or Shure EA510). Second, seal off all vents but puncture a smaller hole in the rear. Third, insert the IEM into the ear canal as deep as possible. Now AX35 sounds like Sony's EX-series.
ON SECOND THOUGHT #6: Except with the emphasis in the mid-low range, AX35's tonal signature matches the Olive-Welti reference quite well.
IN CONCLUSION: With high affordability, solid built quality, and robust acoustic damping design, Astrotec AX35 is truly the hybrid of the next level. The IEM easily outperforms the flagship model, AX60, in every possible aspect. Although the stock configuration lacks "the fine touch" to be considered as of a high-end product, users may still retweak the sound as they wish, and simply fill up what they think it is lacking. AX35 has a great value, and I can highly recommend it to anybody who is on low budget, but still wants good sound. Do I like it? You bet.
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