Ear Acoustic Audio SPA Custom Tuning Review : Easily the best single DD IEM under $500

Ear Acoustic, hailing from china is an evolution of TFZ. After a couple of quiet years they belted out a lot of IEMs under the new brand name. Initially they were just flooding the market with a bunch of similar looking, similarly equipped IEMs but lately they are getting wise. Launching a handful of tastefully curated IEMs. I have already heard a handful of their lower end IEMs and to my ears, they were good too. I was definitely looking for something special in this bunch and I have to admit SPA Custom Tuning not only looks different it easily punches well above its asking price of $400 even when it’s using the same 11.4mm driver with different material than others. Spa Custom Tuning uses double magnetic, double cavity titanium coated, silicon surrounded driver with 1.5T magnetic flux. Just like other Ear Acoustic IEMs it comes in only one color which has silver shell with gold plated back plate. I am comparing this with Dunu DN242. Lets drive deep.

Get one from here:

https://www.earacoustic-audio.com/ProDetail.aspx?ProId=107

UNBOXING AND ACCESSORIES:

This IEM ships with a huge box. I was expecting a very good set up tips but that wasn’t the case. Open the dual flap top cover and we have the IEMs stuffed in foam. We have all the accessories along with the cable placed inside the carry case. What we get are two set of TFZ like smoky white ear tips in wide and narrow bore trims. That’s all, there is a lot of empty space.

BUILD AND ERGONOMICS:

Ear Acoustic has the similar design language for all of their SPA IEMs and that’s true for the Custom Tuning too. Made out of aviation grade aluminum this shell is lightweight yet strong. We have a semi custom like shell design with a prominent wing like structure that helps with fit and stability. Yes, the back plate has a gold plating with an chequered pattern. It’s slightly depressed giving it a more 3D like visual effect. Nozzle is aptly long, it’s the shape of the inner shell that contributes to the depth, offering improved stability and leverage. There is a large vent on the side of the body to let the drivers breathe, eliminating driver flex. Isolation of this IEM is above average too.

CABLE:

This IEM ships with one of the supplest modular cables I have used on an IEM in this price range. This 4 core cable uses an unique hybrid structure with silver plated OFC and single crystal copper plated with silver and separate gold-silver strands. Definitely one of the most exotic material I have seen on a $400 IEM cable. There is barely any microphonics, this cable is not bouncy, doesn’t have much memory issues and uses high quality, light weight metal parts. The cable slider and Y-splitter are slightly on the larger sie but the cable guides are aptly supple and soft.

PAIRING WITH SOURCES:

I tried pairing this beauty with various sources but I have to admit this IEM doesn’t change a lot with them. Even with the weaker Hidizs AP80 Pro Max it didn’t show any weakness maintaining very good air and resolution. Yes, the smaller stage size of the source did limit the imaging of it but there is nothing wrong with it. When paired with Shanling UA7 I got excellent imaging and extra texture but that’s what the source adds to all the IEMs.

So, in short, pair this IEM with a decent source and it will do well, more capable source is obviously better.

SOUND QUALITY:

How many types of tuning can we get out of the same 11.4mm driver? Yes, the diaphragm material has changed but it’s still is being driven by the same magnet and I have to admit Earacoustics are perfecting this driver. CT is something fantastic to be precise. It performs on level with similarly priced tri-brid and hybrid IEMs.

We get a detail oriented presentation with very good balance of everything yet the bass notes can go boom when needed. The best part of this tuning is it sounds transparent and detailed yet effortless. It has a bit of brighter overtone that keep the definition clean and transparent accompanied by a warmer undertone that keeps things organic and emotional. Fantastic tuning to say the least. It does have a mildly W shaped signature. Lets expand!!

I have used stock wide bore tips and iBasso DC07 pro and Tanchjim Space Pro as source for this review.

BASS:

This driver can easily do the heavy lifting without breaking sweat. It has the required amount of vim and vigor for a full bodied, meaty presentation. Sub-bass is deep enough with very good rumbles with it, the operative phase here is “when needed”. SPA CT has one of the best control over bass notes. It’s simply outstanding with it’s accuracy with decay. It can be fast and make the notes clean and can be rumbly, adding layers behind the notes depending on the requirements of the track. In easier words, it can let the notes get heavy but only when needed. This is an aptly bassy IEM but one with a mind to it. It’s not the depth but the definition that impresses me. We usually do get this kind of resolution with sub-bass especially in this price range. Mid-bass is something special too. It has the body and weight behind the notes while maintaining clarity. We get very good layered delivery and class leading texture. There is literally no problem with contrast as this IEM can easily separate back and foreground notes in a cohesive manner. Dynamics are excellent too. It can easily hit variety of frequencies at different regions of the stage with good directional projection that changes angles depending on the track. Notes usually move in and up but can fire downward too. There is literally no softness with the upper bass. It’s squeaky clean.

MID RANGE:

This has a mild W shape to it. Vocals slightly prominent and the instruments around it aren’t lacking energy. Unlike tribrid IEMs this doesn’t have any issues with the lower mids, transition phases. Finishing definition is precise and clean with a bit of extra energy while the body under it is full and highly textured. Biggest beneficiary of this are the vocals, especially male vocals. They have aptly sharp yet throaty delivery with right amount of grunt and emphasis behind them. Female vocals are a bit taller with right amount of energy and sharpness. Tonality and timbre are very accurate, they are aptly juicy while maintaining right amount of crispiness. Instruments around the vocals have excellent clarity and resolution. There is no sharpness but if you are looking for a smooth, lush kind of presentation, this is not it. There is no problem with micro details and even the smaller details, placed between the notes can be perceived in the background, cleanly, thanks to the excellent Z-axis depth. If you are sensitive, upper mids can feel a bit bity but there is no devil here. It’s just prioritizes clarity by sacrificing a bit of smoothness.

HIGHS:

Most of the times, even with tri-brid IEMs, something comes up as the weaker phase. If the bass and mid range are strong, it’s the treble that gives way but this single DD IEM pulls through the highs without a single scratch. This treble range is agile, sparkly and highly entertaining thanks to it’s slightly grippy finishing energy. It’s not sharp but definitely grabs the attention and the cleanliness is immaculate. We get excellent layering and separation with plenty of air between the instruments. It easily matches the clarity of Dunu DN242, that IEM has 2 dedicated micro planar drivers so you can imagine the kind of tuning Ear acoustics have done. That’s not it, it not only has class leading extension and clarity it doesn’t lack with resolution, definition or transparency.

STAGE AND IMAGING:

This is something special in my opinion. This type of imaging is easy to fall in love with. SPA Custom Tuning IEM is excellent with the imaging. It has one of the biggest stage with excellent cue placements. It has a concert hall like reverby, cohesive presentation. The amount of air, separation and directional accuracy this single DD IEM can offer can easily rival more expensive tribrid IEMs. Spa CT has a nicely rounded stage with very good height, width and depth but the stage is mostly presented in a stereo kind of projection. Most of the notes are placed aside and wrapped around the back. It doesn’t have a lot of presence up front yet most of the instruments are placed out of the head. Majority of vocals and lower end notes are placed inside the head yet the overall imaging is one of the biggest under $500. Another excellent thing is, instrument density is even throughout the stage. Sonica too are fantastic. Yes, the background instruments could have been slightly more subtle to create a more cohesive and conteasty imaging yet the clarity and transient effects are thoroughly enjoyable.

COMPARISON:

VS Dunu DN-242 :

This is an obvious comparison in my opinion. This Tribrid IEM is one of the most cable IEMs in this price range with a more V shaped signature with a musically inclined presentation.

DN242 has bigger, rumblier bass with a bit more depth too. Its dynamics and contrast is good but lacks a bit of control and cleanliness in comparison. Area impact is similar but the notes are heavier with the 242. CT has cleaner upper bass, better resolution and definition. CT and 242 has exactly same kind of mid range presentation but the 242 is slightly less forward. But the CT has the edge when it comes to lower mid clarity. Both have a brighter over tone and warmer under tone that balances everything masterfully but the upper mis are slightly more energetic with the 242. high too are very much similar with presentation but again the 242 is more forward and slightly more fatiguing in comparison. Both are excellent with overall resolution, definition and micro details with mids and highs but the stage of the CT is a bit deeper in the Z-axis.

For me, it’s a tie. I will pick the CT for its unique design and fit though.

CONCLUSION:

I have heard a handful of these Ear Acoustic IEMs with 11.4mm drivers and I have to admit this tuning is easily the best. It sounds like a SPA Hi End Pro Max but Custom Tuning is not a bad name for this unique sounding IEM. Its seamless presentation is something special unlike the tribrid counterparts that can struggle a bit with the lower mids.

Is this really a single DD IEM? This has the capability of multi driver IEMs and I have no problem in labeling it as one of the best single DD IEMs under $500. A complete performer that can handle nearly any type of music without breaking a sweat. It balances everything nicely. This is the IEM under $500 for me. If you can get one, get one unless you want a warm, smooth and laid back presentation.