Hybrid monitors have been very popular lately, and it has come as no surprise that more and more manufacturers jump on this train. Dynamic drivers are often used for bass, as they offer a very natural and airy response, whereas balanced armatures often tend to be too technical and tight.
Jomo’s ACU system makes use of a conventional practice from the HiFi world. As the balanced filter comes as standard, we’ll go over the sound of this one first and cover the respective filters one by one.
With the black filter installed, bass is well defined and just a touch above neutral. It possesses good extension into sub-bass and shows an airy and well resolved presentation. The body is very nice and not overly bloated or boomy. Upper-bass does give a slight boost to lower mids, resulting in small warmth of the overall sound. Mid-bass in general enjoys the most prominent portrayal of bass, which makes it nicely dynamic.
Midrange has excellent air and emotions in them. Where Quatre shines the most to me, is clearly the vocals. They stand out right in front of you with a holographic type reconstruction. Both male and female singers have very nice amounts of emotion in them, where you can feel the pain or joy they want to transport. Instruments sound organic with great texture and are separated with good care with decent amounts of air between them. Mids are in general rich and full. Upper mids have moderate glow in them, which gives certain instruments and tones a nice appearance.
The created sound stage spreads in good dimensions of width and depth, where both are close to even in measures. Height is also nice and maybe slightly above average. What I like especially is the great levels of layering, achieved with very good resolution. Details are brought forward in good manner, however the Quatre is not a typical macro-detail focused IEM.
Treble is north of neutral with good extension. There is pleasant amounts of sparkle in it. Highs are not overly bright or harsh, but also not laid-back or shy. They’re tuned with a balanced neutrality. Treble is energetic and agile, but misses out on richness in my opinion.
The Quatre has a nicely coherent tuning where the entire spectrum is seamlessly connected with perfect transition from bass to treble.
Musical Filter (silver)
When changing from Balanced to Musical filter one thing is quite apparent, not only did the bass response get altered, but also the lower midrange. The Musical filter is supposed to add four Decibels to the low ends. Bass does get a higher priority in the picture and seems to extend further into sub. Sub bass has a very nice visceral punch and more impact compared to the black filter.
Lower midrange is also a bit warmer now, which results in excellent musicality, where the entire music just seems to possess a harmonic flow. Especially deeper male vocals shine more now with bigger body. Treble appears slightly more laid back with the silver filter, but still has great energy and sparkle.
Energetic Filter (blue)
With the blue filter installed, bass gets attenuated by nine Decibels. Now low ends enjoy a pretty prominent place in the signature. Bass is fast and forward, the description energetic fits like a glove. Sub-bass gained a bit in quantity. Mid and upper bass get elevated further. The other frequencies move back in line, where vocals and instruments can sound a bit recessed and distant. Treble really struggles to perform at the same level as before as it gets overshined by the immense bass. For my taste this filter has too much bass and the imbalance is too heavy. Bass heads might dig this one a lot though. As the bass is of high quality.
Impact Filter (red)
This is the filter with the highest bass alteration of 15dB. Basshead’s delight? Extreme basshead maybe, yes. The impact filter indeed adds quite some impact to the sound, but at this stage it’s mostly a bass only monitor then. Mids and treble get pushed back pretty far, making everything except bass sound distant. I’m sure some people will enjoy that heavy weight champion of a bass response, it doesn’t fit my type of signature though.
The ACU filter system has proven to be well working, and I can see people going through some of them for different Genres. My personal favourites are the black and silver filters. Though the Musical filter seems to be the one with the most ear-time lately.
Sound tweaking with Aftermarket Cables and Sources after the jump.