Diego
Everything perfect. Apollo worth any euro.
Comment from 5 February 2025 — Experience from 25 January 2025
Sendy Audio Apollo
Sendy Audio Apollo, open-back planar headphones
A steel grille forms a sun on each lacquered rosewood ear cup, giving the headphones their name. Behind it, a 68 mm planar driver uses Sendy’s Quad Former structure, with magnets and coils on both sides of the diaphragm. At 395 g, with 16 Ω impedance and 95 dB sensitivity, the Apollo is Sendy Audio’s entry-level planar headphones, supplied with a 4.4 mm balanced cable.
Four coils around a 68 mm diaphragm
In planar headphones, the signal travels through a thin conductive trace deposited on the diaphragm, which sits between magnets. Sendy doubles everything: a row of magnets on each side, and coils etched onto both sides of the diaphragm, making four circuits in total. The manufacturer calls this arrangement Quad Former. The force driving the diaphragm is distributed symmetrically, limiting unwanted movement as the volume rises.
The diaphragm measures 68 mm in diameter, and Sendy specifies a frequency response of 20 Hz to 40 kHz. The manufacturer describes more than three years of development to combine high damping in the bass with a rigid, very thin layer for the treble.
Lacquered rosewood and perforated steel
The ear cups are CNC-machined from rosewood, then polished to a glossy finish. The grille layers black steel and nickel-coloured steel. The radiating pattern also serves an acoustic purpose: on open-back headphones, the grille openings contribute to the sound tuning, and Sendy says it has adjusted them accordingly.
The open-back design has its trade-off. Sound leaks out, and noise from the room gets in. The Apollo is for listening at home in a quiet setting, not on a train or in a shared office.
Planar headphones under 400 g
Planar headphones are often heavy because of their magnets. At 395 g, the Apollo remains within a reasonable range for long listening sessions. The lambskin head strap distributes pressure beneath a dual-band headband, and the ear cups swivel by 30° to follow the contours of the face. The bowl-shaped protein leather ear pads, filled with memory foam, clip into place and can be replaced without tools; an L or R marking is printed inside.
Balanced cable and compatible sources
The 2 m 6N OCC copper cable terminates in a 4.4 mm balanced plug, a common format on recent portable players and headphone amplifiers. A 3.5 mm adapter allows it to connect to an unbalanced output. At the headphone end, the plugs are angled so that the cable runs down alongside the neck. The cable is detachable, allowing it to be replaced if worn or swapped for another.
With 16 Ω impedance and 95 dB sensitivity, the Apollo does not require high voltage. Like all low-impedance planar headphones, however, it needs a source capable of supplying current: a headphone amplifier or a portable DAC rather than a basic laptop output.
Apollo or Apollo Pro
The Apollo Pro keeps the name but changes almost everything: a 78 mm driver with a nanometre-thick diaphragm, zebrawood ear cups, 354 g weight and a composite cable. The Apollo retains the four-coil Quad Former structure and lacquered rosewood.
What the press says
The Sendy Apollo is a beautiful success. First of all, it is a marvel of design and comfort. For its price, it is a true gem in this regard. In terms of sound, it also hits the mark with a very soft, hyper-relaxing signature. While it may struggle to appeal to fans of rock, metal, and other high-energy genres, it will have no problem convincing those who enjoy softer genres like jazz. If you want a warm, calm sound to relax peacefully on the couch, go for the Sendy Apollo without delay!
Automatically translated — Show original (French)
Le Sendy Apollo est une belle réussite. Tout d’abord, c’est une merveille de design et de confort. Pour son prix, c’est une véritable pépite de ce point de vue. Côté son, il fait aussi mouche avec une signature très douce, hyper relaxante. S’il aura du mal à séduire les amateurs de rock, métal et autres genres qui bougent fort, il n’aura aucun problème à convaincre les personnes qui aiment les genres plus soft comme le jazz. Si vous voulez un son chaleureux, calme pour buller tranquille dans le canapé, foncez sur le Sendy Apollo sans tarder !
Documentation
French
Technical specifications
Acoustic design
- Type: open-back over-ear headphones with planar magnetic drivers
- Drivers: “Quad Former” technology, 68 mm diameter
- Magnets arranged on both sides of the diaphragm, in a double row
- Voice coils on both sides, four in total
- Magnet material: not found
- Diaphragm: not specified by Sendy, thickness and material not found
Audio performance
- Frequency response: 20 Hz to 40 kHz
- Sensitivity: 95 dB ± 3 dB
- Impedance: 16 Ω ± 15%
Construction and comfort
- Earcups: CNC-machined solid rosewood, hand-finished, high-gloss lacquer finish
- Grilles: black perforated steel and nickel, sunburst pattern
- Metal parts: black anodized aircraft-grade aluminium and steel
- Headband frame: dual metal band, spring band for optimal pressure distribution
- Head strap: lambskin, height-adjustable
- Ear pads: ergonomic, round and bowl-shaped
- Covering: faux leather, protein leather
- Padding: memory foam
- Attachment: clips
- Markings: left / right
- Earcup swivel: 30°
- Colour: black and rosewood, a single colour listed by Sendy under the name “Black”
Connectivity
- Headphone-side connections: two 2.5 mm mono jack sockets, according to retailers, not specified by Sendy
- Earcup-side plugs: angled
Included accessories
- Package contents: according to retailers, list not found on Sendy’s website
- Headphones
- Detachable braided 6N OCC copper cable
- Length: 2.0 m ± 0.2 m
- Termination: 4.4 mm Pentaconn balanced connector
- 4.4 mm to 3.5 mm adapter, according to retailers
- Soft pouch for the cable
- Hard carrying case for the headphones
Weight
- Weight: 395 g
Frequently asked questions
Can the Apollo be connected to a smartphone?
Yes, with an adapter or an external DAC, as most recent smartphones no longer have a headphone jack. A portable DAC with a 4.4 mm output accepts the supplied cable directly.
What is the difference between the 4.4 mm output and the 3.5 mm output?
The 4.4 mm plug carries a balanced signal, with separate conductors for each channel all the way to the amplifier. The included 3.5 mm adapter allows you to use a standard unbalanced output.
Do the headphones block out external noise?
No. These are open-back headphones: sound can be heard by those around you, and ambient noise remains audible. They are suitable for listening at home.
Are the ear pads replaceable?
Yes. They clip into place and have left and right markings on the inside.
Is the cable detachable?
Yes. It connects to each earcup via a right-angled plug and can be replaced.
Is the wood identical from one unit to another?
Rosewood grain varies naturally. No two pieces ever have exactly the same pattern.
User reviews
Review highlights
- All 9 buyers give the Apollo 5/5: enthusiasm is unanimous.
- The sound receives the most praise: detailed, natural and well balanced from bass to treble.
- Comfort is excellent, even after long listening sessions.
- The finish and aesthetics are considered superb by the majority of customers.
- Value for money is rated excellent by four out of nine customers.
Based on reviews from customers who purchased this product, summarised by AI
Eduardo
Perfect ! Beautiful sound and elegant design.
Comment from 26 December 2024 — Experience from 12 December 2024
Fabrice
The headphones have an exemplary finish, even more beautiful in person than in the images. You can feel it's a quality product, but what about the sound? Calm? Made for jazz? Jazz, classical, and baroque music, no doubt. But rock and even metal fans can rest assured, good old thrash sounds magnificent. For me, I find it quite punchy, perfectly reproducing the double bass, so yes, the bass is lively. The soundstage is wide, and it really picks up the details well. And the comfort is top-notch. In short, it's beautiful, comfortable, and has superb sound, even the box is practical. In a word, really top-notch 👍.
Comment from 7 May 2024 — Experience from 25 April 2024
Automatically translated — Show original (French)
Casque d'une finition exemplaire, il est encore plus beau en vrai qu'en image, on sent que c'est un produit de qualité mais alors le son ?. Calme ? Fait pour le jazz ? Le jazz, musique classique, baroque je n'en doute pas. Mais que les amateurs de rock, voir de métal se rassurent, du bon vieux thrash passe magnifiquement bien, bah oui pour ma part je le trouve bien percutant, il retranscrit parfaitement les doubles, donc oui, les basses sont vivantes. La scène est large et oui, il récupère vraiment bien les détails… Et le confort au top. Bref il est beau, confortable et super son, même la boîte est pratique. Bref, vraiment top👍.
- Eco-contribution of €0.08 included in the sale price.
- Manufacturer reference: SENDY-APOLLO
- GTIN / EAN: 6973869470458
