Here’s my review of the excellent Fidue Thunder an earbud that plays in the big league
Fidue Thunder 5Stars✨
TOTL EARBUDS
Pros: 1, Premium build
2. Natural timbre
3. Balanced reference tuning across the whole signature
4. cohesive sound signature
5. Hybrid configuration
6. High quality cable with changeable terminations 3.5mm and 4.4mm
8. Beautiful design
9. Good accessories with nice case
Cons: 1. Not for bass lovers
2. Not for treble sensitive
3. Fit is subjective
4.Expensive
Fidue an are an established company whose iems have garnered plaudits for their reference balanced monitor like iems so I was very interested to see what they could bring to the earbud market. When receiving the box you are greeted with a very premium unboxing experience a pair of beautifully machined aluminium earbuds with a high quality SPC 2pin cable that matches the look of the ear pieces. The Buds are shaped like Apple airpods rather than flat head with a resonance chamber on the back. I worried about fit but turns out they fit like a dream..
This what Fidue has to say about the Thunder
Fidue Thunder 1 Dynamic Driver & 2 Balanced Armature 3 Drivers Hybrid Audiophile 2Pin 0.78mm Flat Earbud with Modular Cable
Description
Brand new sound, the premium HiFi audio in ears.
Independently developed 15mm Dynamic Driver
High elasticity silica gel diaphragm
Customized high-frequency Balanced Armature
30 years ago, flat earbuds were unrivalled. IEM took place of flat earbuds gradually due to its better sound performance. While IEM also has its own problems, such as unnatural listening sensation or discomfort due to prolonged wearing.
To pursue natural, comfortable and perfect sound, “FIDUE” spent three years focusing on R&D of flat earbuds and tackled key technical problems under unremitting effort, effective method of improving flat earbuds sound was finally found out - “THUNDER” was born, which provides a totally new and fantastic music listening experience in order that music lovers would love flat earbuds and thus earbuds could remove its dust, return to the stage and shine again.
Acoustic Master Meticulous creation
Benny Tan, 3 years of polishing and carving based on 30 years of acoustic experience and toughening, taking the ultimate pursuit of sound, only for bringing incomparable supreme feedback to those who love music and giving them a surprise which is just like spring thunder after rain!
HiFi audio in ears - Patent No.: 2024209065570
Acoustic cavities of 3 drivers are separated and independent SO that the sounds do not mix and go directly into ears, which works in the similar way to that of audio. Under assist of both customized low & mid frequency DD and exclusive high-frequency BA of Fidue, the sound detail is revealed clearly, just like a mini HiFi audio in ears!
Sound multiply technology - Patent No.: 2024209065481
By applying repeatedly AI simulation of rear cavity acoustic wave, opposite its phase accurately and make full use of it afterwards, which makes sound wonderful and full of tension.
Flat-bud design Attack IEM key problems precisely
Open ear canal, No more covering ears, no more worry about ear hurt, no more safety concern, Release ears genuinely and let soul fly freely accompanying ultimate music.
Square top & round bottom, Combination of strength & flexibility
High precision 5-axle CNC process, the top shape is like shining gemstone, the bottom surface is smooth and skin friendly which ensures free putting on and taking off.
Wear with comfort
Double advantages of both exquisite design based on big data and ergonomics structure which ensures firm wear without ear tips; meanwhile, the surface is processed carefully to keep it fine and smooth to avoid tearing and hurting the auricle. “THUNDER” fits ears precisely and make wearing a king of enjoyment and fashion.
Topology weaving, non- destructive transmission
The topology weaving of 70 silver plated copper and 24 oxygen free copper achieves true non-destructive transmission.
Stable connection, easy disassembly
0.78mm 2pin 5U gold-plated durable and everlasting
Specification
Brand: Fidue
Model: Thunder
Driver: 15mm DD + 2 BA
Frequency response: 4-41000Hz
Impedance: 20ohm
Sensitivity: 103dB
Max input power: 30mW
THD: <1 %
Plugs: 4.4mm Balanced plug/3.5mm stereo plug
Cable: 2pin 0.78mm interchangeable cable
The Fidue Thunder is categorically the new king of the castle when it comes to earbud style earphones in my opinion with their reference style tuning and what’s most pleasing for me is its fit and detailed razor sharp clarity its reference style sound signature balanced with a W presentation . Now I have to say upfront my preferences would have a little more bass quantity the quality is outstanding just a few db short in quantity later I’ll be talking about how I was able to tune the thunder to my preferences
The configuration of the Thunder exotic in the fact that it uses a single 15mm DD and 2 ba drivers.
The Title of this review is “TOTL BUDS” why you may ask well with a price of $399 they are definitely not cheap but and it’s a big but they are by far the best bud style earphone with outstanding build quality that I’ve experienced.
I’d just like to say upfront I believe we are all biased when giving our subjective thoughts about IEMs and earbuds be it a particular type of signature that works with our music library or how they look and feel in our ears. On the subject of ears everyone’s ear anatomy is different and this effects fit and seal which in turn effects the perception of bass response so I recommend finding the right ear tips or foams that suit your ears to get the best of any earphone.
My review star ratings are linked to the price range of the iem eg a 5 star review of a $100 iem is not equal to one of a $500 iem.
I’m and audio enthusiast with a collection of over 200 iems, 30 different sources with a music collection that numbers over 100,000 tracks and 18 flathead buds I share my impressions as a way to share my enthusiasm for the hobby I approach from the premise of music first technology 2nd, what does this mean? For me the technicalities are not of prime importance but does the music move with this particular iem.
I’m a connoisseur of many different sound signatures. The only prerequisite is musicality I’m not a fan of analytical cold playback. My scale of success when it comes to evaluating earphones is; do I get goosebumps when they playback my favourite tunes. There are many good earphones but do they give me goosebumps? Unfortunately I have a draw full of just good earphones.
I want the earphone that I reach for without thinking because I instinctively know it will bring the thrill I’m seeking from my music. The Thunder has a bright reference sound signature with excellent technicalities and very natural presentation while being free of any unnatural tone or timbre colouration, the bass is there with great texture and detail just a little shy in quantity for my tastes. The standout quality is the zero amount of distortion or congestion even with fast speed prog metal. This ability combined with super comfortable fit (more on that later)had me reaching for the thunder more than any other earbud in my collection.
Now I know there are those who don’t believe in burn in of earphones, all I’m going to say is, I burn in all my earphones the Thunder really opened and up and smoothed out at the 200 hour mark.
Disclaimer
Penon was kind enough me a sample of the Fidue Thunder. I am not affiliated with Penon and of course was not asked for any copy checking before publishing, they are seeing this the same time as you. All pictures taken be me or sourced from the Penon website . ALL opinions shared in this review are my subjective thoughts.
Make sure to research any earphone before you buy!
The Fidue Thunder is available from the Penon website,
see the non affiliated link below
From https://penonaudio.com/Fidue-Thunder.html
What do they sound like?
Ive already covered the tuning above but I will add in more detail, the Thunder have more mid-bass than sub-bass as is the case with most earbuds the focus here is the mids and treble with the bass playing second fiddle not to say there isn’t any mid-bass snap and attack its there just not dominant. The mids are at the forefront with a clarity and detail Ive not experienced even with in ear iems they have some brightness without sounding thin the upper mids have enough bite to give guitars a pleasing aggressive presence. The treble is crisp but not sibilant or fatiguing, cymbals sound natural with a nice decay placed right where they should be not artificially forward. They manage to have a very wide staging while being bassy enough to make drums and bass guitar sound natural. The impressive thing is these little wonders have great depth allowing for a far more realistic layering experience than I expected.
I want to really enjoy my music. Something that releases the full scope of what the artist created in the studio. The Thunder does that with cohesion ensuring to there’s no jarring transitions between the frequency range. The Thunder is nota a warm lush signature, its not thin though it has an very open detailed signature bass is textured, dynamic and layered. The mids are free of any colouration and don’t colour the vocals there is a little extra body to males vocals, female are realistic and sweet with a natural timbre. The vocals are front and centre with instruments placed exactly where they should be showing depth to the stage with natural wide holographic presentation . The Thunder’s dynamic driver and double ba sounds very coherent no trace of uneven timbre just everything working together as one.
The mids are natural and organic, with just enough edge to add excitement to vocals and guitars causing me to be drawn into the music, Pianos and Guitars are given a really even treatment with good note weight sounding exactly as you would expect if you were in a concert hall.
The Transition from upper mids to lower treble is boosted slightly but still sibilance free, even with songs that have sibilance bult into the recording. The little bump in this region just edges them into excitement in this area. I have very big ears so to make the Thunder fit securely applied some Apple Airpod silicone sleeves which I bought off Amazon for a couple of dollars.
The timbre and tactility of drums, strings, guitars and brass instruments is very natural all instruments find their own place. Vocals both male and female are reproduced authentically with emotion, every inflection, intonation is apparent as a singer climbs the scale to the crescendo it is presented well cutting through, if a voice has gravel you hear it. The Thunder is not forgiving of poorly produced music.
When I’m evaluating earphones I have a play list of roughly 100 songs of mixed genres. With the Thunder I was analysing the different frequency ranges listening to albums in their entirety just loosing myself in the music. I found they I worked across all the genres in my library with exception of Hip hop where the bass is a little lacking for the big bass drops though always smooth and spacious and detailed .
Aerosmith - Hangman jury sounded wonderfully full and clean with the crisp drums and keyboards . Steve Tylers throaty gritty vocals sounding full and sweet with no thinness the layering in this 80s classic blues/rock song was produced with expert precision a really enjoyable listen
Marc Coen and the Alabama blind boys – Baby King, this multi-layered live vocal is a classic with moody piano intro and fabulous vocals reproduce with just enough weight to draw you in slowly building to the voal acrobatics of the Blind boys of Alabama. The staging is also brilliantly reproduced increasing the atmospherics greatly. The Thunder works incredibly well with live recordings putting you front and centre in the room with the artist.
Steely Dan’s – Black Cow, one of the best produced albums in my opinion was played with a breath-taking expertise at this price range, drums, keyboards, vocals , hi-hats and cymbals were natural with excellent decay space and staging with good height, depth and width enabling me to pick out instruments in the mix, this song felt open and airy with the layering of the instruments in a class above any earbud I’ve listened to.
Steven Tyler- My own worst enemy this is one starts with a sparce acoustic guitar and tambourine with Tyler’s gritty vocals and slowly builds with new instruments being introduced as this slow ballad builds Tyler’s elastic vocals stays front and centre as the song becomes a multi-layered wall of sound the Thunder manages to keep the huge production in control avoiding any congestion, impressive.
Led Zepplin – Since I’ve been loving you
The lead guitar intro is perfectly presented sweet and keening the drums with that slow heavy rhythm, then as the song builds, keyboards the cherry on the cake comes with Plants unmistakeable vocals reaching for the sky as the song builds in intensity to a cohesive whole with the wailing Plant cutting through like a hot knife in butter. The Thunder excels presenting Zepplin vocals they are the star of the show never overpowered by the drums and guitar.
The Hu – This Mogul (with William DVall) –
The dynamics of this track are huge with drums guitars and Mongolian instruments, the Horsehead fiddle, Tovashuur, Tumar Khuur, Tsuurare and Mongol throat singing with a special guest William DuVall of Alice in Chains. The power of this dense, complex and rhythmic masterpiece is reproduced with accuracy but does lack a little bass quantity though the driving rhythms are dynamic and punchy, I didn’t hear any congestion in the instrumentation despite the density of this track. The vocals of William DuVall stood out against the wall of instruments and were on point and unveiled. The Thunder didn’t feel exposed with faster tracks with instruments in the same frequency range still being given space to be heard with little to no congestion.
The Thunder is quite easy to drive earbud I had no issues using them with my , Daps, Dongles in getting loud enough, the dynamics and open sound was present with all sources the texture and layering they are capable of was available for all to some degree.
They sounded good with warm sources. This is an iem that doesn’t need a powerful source but it does scale impressively.
I’m not a fan of analytical sounding IEMs that force details into your ears like a photograph with HDR and sharpening set at max a decidedly digital representation. I’m more Vinyl on a turntable, Leica manual focus, sumptuous colours on kodak colour gold film, kinda guy, where if you look really close all the details are there but it’s the whole image you appreciate rather than just how sharp it is. Having said that the the Thunder is a very technical cooler sounding earbud with all the clarity and detail up front that grew to appreciate and really enjoy.
Sources used:
Onix XM5 Overture
Shaning M6 Ultra
Shanling H5
Cayin N3 Ultra
Cayin N7
When using my different sources I didn’t favour the more powerful ones the extra dynamics and layering and technical presentation was apparent but the overall musical presentation was the same.
Comparison
This is quite difficult as the thunder is multiple levels above all the earbuds in my collection.
LRay Aurora
The Aurora is far more bass dominant with elevated sub bass and midbass
This is the only frequency range that I find superior to the Thunder everything else is left in the dust with the levels of distortion free detail sever; levels above the Aurora.
Shozy Cygnus
The Cygnus is way less detailed, with inferior texture and timbre the bass while being greater in quantity is lacking in quality. Its almost comical how much the Thunder is superior in every aspect.
Tuning the Thunder to my preferences.
With all the iems and earbuds I have I experiment to see what I can do to enhance the experience. The thunder really reacts well to cable rolling the two best cables for me were the Penon OCC849 and OS849 these high quality cables that easily match the build quality and sound attributes of the Effect Audio Ares S 8W and Cadmus S 8W.
The absolute best combination was with the Penon OCC849 it brought a warmth and elevated the bass frequencies adding more body to the mids.
The OS849 elevated the bass without the touch of warmth the OCC849 gave it was more similar to the included cable with just that touch more bass.
The final piece of the puzzle was to use doughnut foams places over the earpiece to cover the rear vents which added a touch of warmth while not effecting the clarity and detail resolution.
Penon OCC849 (penonaudio.com)
Penon OCC849 Single Crystal Copper HiFi Audiophile IEMs Cable
Type-4 Litz configuration
Description
6n single crystal copper cable
8 strands, single strand is 49 cores, a total of 8 × 49.
The plug contains 68% copper
The solder joints is silver – contained tin
Carbon fiber metal splitter and CNC integrated slider
Cable length: 1.2M
Penon OS849 (penonaudio.com)
Penon OS849 Single Crystal Copper Silver-plated HiFi Audiophile IEMs Cable
Type-4 Litz configuration Description
6n single crystal copper silver-plated cable
Contained 8% silver, the thickness is 10μm,
8 strands, single strand is 49 cores, a total of 8 × 49.
The plug contains 68% copper
The solder joints is silver –contained tin
Carbon fiber metal splitter and CNC integrated slider
Sound field is very big and very natural
Cable length: 1.2M
The Fidue Thunder has been a revelation to me while on the surface an earbud that goes against my preferences of warm thick lush sound signatures with its razor sharp detail forward bright signature. The revelation was that once my brain adjusted it became a really enjoyable listen that I would reach for and listen to music for hours without fatigue.
Once I tuned it, it actually became one of my favourite earphones that I reach for on a regular basis so for me its worth every penny of its $399 asking price.