Sound For a Calmer Mind

While 2025 hasn’t brought any major planar IEM releases, Sivga is in the works to claim the title with a rebirth of its flagship Nightingale. Enter the Nightingale Pro, a refinements upgrade that aims not only to be the best planar IEM of the year but perhaps the best in its class. At its heart lies a refined planar magnetic driver with upgraded techs and tuning without compromising the flagship build quality that Sivga is known for. The beautiful signature Zebrawood faceplate stays, continuing Sivga’s tradition of incorporating natural wood into their designs and ensuring the Pro version is as much a visual pleasure as an auditory one. In hand, the Nightingale Pro is undeniably a beautiful product but does it deliver the planar performance we’ve been waiting for? We’re about to find out.

We’d like to thank Lily from Sivga for providing a sample of the all-new Nightingale Pro for review. As always, we are not affiliated with Sivga, have received no monetary compensation, and our assessment will reflect our honest, opinionated perspective.

Functions & Specifications

Before we start the review, here are the specifications of the Sivga Nightingale Pro;

• Driver type: φ14.5 mm Planar diaphragm
• Frequency response: 20 Hz – 40K Hz
• Sensitivity: 100 dB +/- 3 dB
• Impedance: 16Ω+/-15%
• Cable length: 1.2 M +/-0.2 M
• Plug size: φ4.4 mm or 3.5mm
• Weight: 15g

The Sivga Nightingale Pro can be purchased through their website or any other platforms like Linsoul.

Nightingale PRO

SIVGA Nightingale

Packaging & Accessories

The packaging here is rather simple and it comes in a cube, textured black box but it does feel so premium and well packaged. Here’s what’s inside the box;

Inside the Box

• 1x SIVGA Nightingale Pro
• 1x 8 core cable
• 1x Hard leather carrying case
• 2x Eartip size M
• 2x Eartip size L
• 2x Eartip size S
• 1x Eartip case

The accessories here are high quality and the eartips come with their own case with Sivga’s branding on them. The cable is exquisitely braided with high quality metal parts and they matched with the IEM visually and sonically. The hard case is made from real leather as they do have a distinct leathery aroma truly a worthy inclusion of a flagship product.

Design

The design language here is typical of Sivga’s style especially with the zebrawood faceplates that are sanded, polished and coated to showcase the wood grains giving a classy and visually pleasant appearance. The shape is unique as it is an oval, raindrop shape that has great ergonomics with a rather small size that will fit even smaller ear conchas. The shell material is made up of CNC magnesium aluminium alloy that will give a more controlled resonance effect, improving the overall sound while being lightweight for a more comfortable fit. Overall, the unique shape with the hand finished zebrawood faceplates is something refreshing to look at and it does show Sivga’s attention to details in their design.

The insides of the Nightingale Pro is a new dual sided magnets proprietary planar driver with a multi-magnetic structure that Sivga claims to deliver a high sensitivity, balanced soundstage with a  fast transient response. The new planar driver features a newly developed composite 0.008mm diaphragm paired with an ultra-thin 0.006mm aluminum ribbon conductor claiming to deliver crystal-clear highs, wider frequency extension and richer sound details. The tuning here is precision tuned with multiple high-performance neodymium magnets to achieve greater efficiency producing richer details with more powerful dynamics.

The nozzle here has a width of 6mm at the tip and they are fitted with a unique mesh to improve the sound flow while protecting them against dust and moisture. The nozzle length is a tad shorter than most IEMs in the market.

There are 2 pinhole vents where one is situated near the nozzle and another one near the 0.78mm connectors. The Nightingale Pro is a very well vented pair of IEM that doesn’t possess any flex or whatsoever but the isolation here is just average and some eartips rolling is recommended to achieve a good seal. They are a different type of fit that is pressureless and might need some time to get used to their fit.

The 0.78mm connectors are shortened QDC type pins similar to TFZ and Dita Project M but will fit most 0.78mm and QDC convex cables.

The cable included is a high quality 26 AWG Litz cable with a mixture of OCC copper and silver plated OCC in 8 cores. The cables are indeed high quality with metal parts used and a spring tension relief is used on the 4.4mm side. Currently the Nightingale Pro seems to only provide 4.4mm balanced output but a 3.5mm version might come soon.

Gears Used for Comparisons

Songs list

Tone and Presentation

The tone of the Nightingale Pro is a unique mid centric sound that has a thick, full bodied sound with solid bass and sparkly highs. It does remind me of the sound from Shure SE535 back in the days but with a more analogue presentation with an energetic high range alongside a wider dynamic range. Tonally they are tilting slightly towards a brighter side of the spectrum and they do possess a clean, clear sound that isn’t muffled. It is a refreshing, unique sound that is pleasantly tuned but a rather niche tuning that isn’t for critical listeners that yearn for clinicalities or neutralities. They are a fun type of tuning that is inviting and immersive, focusing on emotions rather than analytics.

Soundstage

The soundstage here is wide and expansive with a good height to them. They do indeed sound like an open back sound due to their vented, pressureless design that gives an airier, spacious sound that doesn’t have a boxy, closed in feel. The soundstage is holographic and quite accurate in terms of 3D spatial positioning. The sound type here is more of a free field sound that projects sound into your ears giving  a forward, intimate sound that creates a unique experience alongside open soundstage.

Separation and Timbre

Separation is great with a decent stereo separation that is wide and has no crosstalk issue even but with single ended, low powered source, they do exhibit some compressedness, giving a rather small dynamic range and changing to the 4.4mm balanced cable with better amplifications does solve this issue. Timbre here is organic, thick, rich and smooth, giving a highly musical sound experience that is highly enjoyable. There is some minor metallic planar timbre present in the upper mids to high range giving a slightly unnatural snare and that might deter some users that seek accuracy.

Drivability

Rated at 16 ohms with a 100 db sensitivity, they are relatively easy to drive on paper but the Nightingale Pro do need power to perform to their maximum abilities and to have ample loudness as well. A simple dongle won’t do justice as it does suppress their dynamics, giving a lacklustre sound with limited volume. Switching to a higher power output source, a bigger, better sound improvements like a fuller, cleaner and higher dynamic range are audible. Source matching does lean towards a neutral bright sound and the Nightingale Pro isn’t picky with their types of files being played and streaming will work fine most of the time. They aren’t a revealing type of sound that show minor flaws in recordings and that makes it not a suitable pair of IEM for monitoring or professional usage.

The Bass (Low)

The bass here is neutral in their amount as they are relatively flat and the bass here is linear but has their presence. There is a mild focus on the mid-bass that gives a tight slam with good texture and they are clean with a slightly fast roll off. These are certainly not the type of bass for bassheads nor for those who love a high impact bass but they aren’t muted, instead an accurate amount of bass that doesn’t interfere with the rest of the frequencies with bloat or bleed. Details here are great with bass notes presented in a clean manner. Resolution on the bass is great with their textured bass alongside a good transparent sound that is natural and accurate. Sub-bass on the other hand does sound a little low in their rumbling amount as the Nightingale Pro puts the bass focus mainly at the mid bass region and with bass heavy tracks, they might sound uneven but in a small margin. The overall bass has a good depth and they have a great amount of air that gives a rather spacious lows.

 The Mids

Midrange is a forward, warm mids that has a good amount of body that gives a rich, luscious presentation that is inviting especially with vocals. The details here are decent with a focus more on the macro details with average micro details and it possesses a clear midrange that is natural with a little analogue signature sprinkled in. The mids here does have a good intimate sound that actually pulls you into the music and it actually works really well with vocals as it possesses great emotions rather than being cold and sterile. The mids excel with their resolving capabilities and they are vivid mids that have a dash of coloration that goes well with their warmish sound signature without majorly affecting the naturalness of sound but transparency here is rather average due to the slightly coloured sound. There aren’t any major peaks in the upper midrange but there is enough to give a lively brilliance to the mids that gives some bite in the music that prevents the overall sound from being too dull. Vocals are quite balanced here with adequate depth for male vocals and lively, luscious brilliance for female vocals. Instruments fare mostly well but for low, bassy instruments may sound a little hollow due to their low sub-bass amount.

The Highs

The high here is a flat signature that has a mild bright tone that is mostly inoffensive while having a good energy and extension. The highs have a good amount of sparkle and they are crisp in their presentation that produce a lively high range that blends well with their overall sound presentation. The transition from the upper mids is smooth with a mild peak into above 10khz region that gives an airy, sparkly highs that is free from sibilance. There is some metallic timbre present that is typical for a planar driver but they manage to stay relatively natural and accurate. Details here are great with great clarity that present high nuances well and they are able to keep up with fast tracks which is a good trait of planar drivers. The roll off here is slow and it has a mild lingering high range that is enjoyable and the overall high range amount is somewhat safe for treble sensitive users while still able to have a satisfying sheen for treble lovers. Treble here is quite balanced while leaning more towards the relaxed side and that gives the overall sound a smooth sound that is free of harshness,  suitable for extended listening sessions.

Comparisons

VS Letshuoer S15

The legendary single planar driver from Letshuoer and they are indeed touted as one of, if not the best sounding planar IEM in the market for a while now that punches above their asking price. They are priced similarly with the Nightingale Pro and have similar sized planar and shell. The build on Nightingale pro does feel more classic while the S15 has a more modern look. There is some minor driver flex present on the S15 and they have better isolating sound but less open than the Nightingale pro. The S15 tuning does focus more towards a more balanced, neutral sound with a mild bass boost while the Nightingale pro mid-centric tuning has the analogue allure that is unique.

High range is pretty similar with the amount of sparkle and a mild crispness and has the same clarity but the S15 sounded more natural with less planar timbre in a small margin. The Nightingale Pro does have smoother highs with better air and extension but the S15 possesses better energy with a livelier sound and a more intense treble.

The midrange on the Nightingale Pro sounded fuller and thicker with a more vivid, coloured sound while the S15 has a more spacious, accurate midrange. Transparency on the S15 is better due to the less coloration. Vocals on the Nightingale Pro have better intimacy with a sweeter sound while the S15 has better accuracy.

Bass quantity on the S15 has the better part of being fuller with a bigger mid-bass lift and they have a more present sub-bass rumble but the Nightingale Pro has a more forgiving bass that suits acoustics more. Bass texture on the Nightingale Pro is slightly better but energy on the S15 bass is bigger suiting a wider range of genres.

Soundstage on both the Nightingale Pro is slightly bigger and due to their open sound, they are airier.

Verdict: Technical wise, the S15 is the better one but the analogue sound of the Nightingale Pro is unique in its own ways.

VS Kiwi Ears Aether

The most cost effective single planar driver from Kiwi Ears which released a while back but still is the best price versus performance index of any planar IEM. It houses a huge 15.4mm planar which is the largest in its class giving a speaker-like sound that is truly mesmerizing. The packaging here is rather simple with a normal case and basic cable but the cost is around 25% cheaper than the Nightingale Pro. Similar to the Letshuoer S15, the Aether possesses a balanced sound with a less aggressive sound than the S15 but the Nightingale Pro does sound smoother and has a luscious sweetness to them.

Highs on the Aether do sound a little brighter and stronger with better energy but both possess a mild metallic timbre. Sparkle on both are similar but the Nightingale Pro are crisper with smoother highs with slightly better extension. Treble on Aether is livelier and has better overall clarity.

The midrange of the Aether does sound more accurate with less coloration and has better transparency while the Nightingale Pro more forward mids that has better intimacy but lacks space. Details are better on the Aether with better  clarity but resolution is more vivid on the Nightingale Pro.

Bass on the Aether has a bigger impact but the amount of mid-bass is almost the same. Extension and air is also better with a deeper and stronger sub-bass rumble. Clarity and texture sounded better on the Nightingale with slightly cleaner bass.

Soundstage on Nightingale Pro does sound wider and a tad airer.

Verdict – The Aether is better in the sense of being more well balanced but it lacks the organic, lushness sound present in the Nightingale Pro.

Synergy

The Nightingale Pro indeed needs some power to be driven to its fullest potential and it is recommended to use a balanced setup for a wider dynamic range as well as better separation. As for source, I do prefer setups from AKM, Burr Brown and Cirrus Logic to give the lower mids and lows better presence while keeping the smoothness in the midrange. A neutral bright source does exacerbate the unnatural planar timbre and the highs will get a little harsh.

Good synergy

FiiO BTR7, Hidizs S8 Pro, Questyle M15, Time Ear BTE9 , Qudelix T71, EPZ TP35

Not so good synergy

Moondrop Echo B, FiiO KA5, FiiO Q7, EPZ TP30, Dunu DTC100

Who Is It For?

Suitable for – Classicals, acoustics, instrumentals, rock, metal, ACG

Not really suitable – EDM, hip-hop, modern pop

Final words

The Sivga Nightingale Pro is a distinctive IEM, from its teardrop shape and zebrawood faceplates to its refreshingly mid-centric, analogue tuning that sways away from the sea of Harman tuning products. It delivers a warm and intimate sound that presents vocals with lush, emotional resonance and the smooth, sparkly and crisp treble elevates the listening experience a step further. While its reserved sub-bass and relaxed technicalities limit its genre versatility, this trade-off creates a unique soulful musical experience. For the listener prioritizing emotion over analytical detail, the Nightingale Pro is a compelling and singular choice.

I would rate this product a 4 over 5 stars.

Pros

• Solid magnesium alloy build with zebrawood faceplates
• Lightweight, ergonomic and pressureless fit
• Unique, highly musical tuning
• Rich, organic, breathy timbre
• Wide, spacious soundstage
• Warm, luscious tuning
• Good overall details and clarity
• Good cohesion
• Linear, accurate bass
• Full-bodied, vivid midrange
• Highly resolving overall sound
• Smooth extended high range with great sparkle and crispness
• Fatigue free
• Good, high quality accessories

Cons

• Lack transparency (nit-pick)
• Not for monitoring or clinical listeners
• Technicalities isn’t the main takeaway
• Sub-bass rumble lack authority
• Coloured midrange
• Mild planar timbre 
• Doesn’t isolate outside noise well