CELESTION CNX0820
CELESTION CNX0820 — 8" / 8 Zoll · Koaxial-Chassis · Neodymium, common motor
50 W AES - 107 dB - 1200 – 20000 Hz - 8 Ω
Art.-Nr.: 42A-CHS-KO-CEL-0001
Documents
CELESTION CNX0820 — 8" · Coaxial driver
8-inch cast aluminium chassis, neodymium magnet coaxial driver
50 W AES · 107 dB Sensitivity · Frequency range 1200 Hz – 20000 Hz
Features
- Neodymium magnet assembly acts as common motor for both LF and HF
- Polyimide HF diaphragm: field repairable
- Twin demodulation rings to reduce harmonic and intermodulation distortion
- Integrated 50° dispersion constant directivity horn
Technical data
- Diameter: 8 "
- Voice coil: 1.75 "
- Power handling: 50 W
- Programme power: 100W
- Sensitivity: 107 dB
- Impedance: 8 Ω
- Magnet: Neodymium, common motor
- Chassis: Cast aluminium
- Diaphragm: Kevlar-reinforced paper
- Surround: Polyimide
- Suspension: Single
- Voice coil former: Polyimide
- Voice coil wire: Copper-clad aluminium, edge-wound
- Weight: 2.5 kg
- Mounting depth: 115 mm
- Cut-out: 187mm / 7.4in
- Frequency range: 1200 – 20000 Hz
- Rec. crossover (12 dB/oct.): 2,000 Hz
Thiele-Small parameters
- Fs: 94.6 Hz
- Qts: 0.395
- Qms: 3.293
- Qes: 0.448
- Vas: 9.89 l
- Xmax: 6 mm
- BL: 12.02 Tm
- Re: 5.1 Ω
- Le: 0.46 mH
- Mms: 0.0209 kg
- Sd: 0.0227 m²
Datasheet (PDF) · Manufacturer page
Part no.: 42A-CHS-KO-CEL-0001
Celestion CNX0820: 8" coaxial with common neodymium motor and 50° CD horn
In the Celestion CNX0820 the low- and high-frequency sections share a single neodymium motor: the magnet drives both the 1.75" voice coil of the 8" cone and the HF unit, whose polyimide diaphragm is field replaceable. Twin demodulation rings in the motor reduce harmonic and intermodulation distortion, and the integrated constant-directivity horn with 50° dispersion ensures that the treble does not simply radiate freely but is focused in a controlled way. Cast aluminium chassis, Kevlar-reinforced paper cone, edge-wound copper-clad aluminium voice coil.
The headline figures of 50 W AES, 107 dB and 1,200 to 20,000 Hz describe the HF section; its continuous rating is given as 100 W. The LF section is characterised by the Thiele-Small parameters: Fs 94.6 Hz, Qts 0.395, Vas 9.89 l, BL 12.02 Tm against 20.9 g of moving mass and 6 mm Xmax. That is an 8" cone with a tight motor that works as a mid-woofer in compact enclosures. Weight 2.5 kg, mounting depth 115 mm, cutout 187 mm.
Use and enclosure
The recommended crossover between cone and HF section is 2,000 Hz at 12 dB per octave; this keeps the HF unit well above its lower limit of 1,200 Hz and free from excursion stress. The EBP of 211 favours bass reflex: as a guideline, about 10 l tuned to 92 Hz with a lower cutoff around 90 Hz. Sealed, around 4.5 l is enough, giving a corner frequency of 169 Hz, which suits a mid-high chamber above a woofer. Port and fine tuning are calculated in the enclosure calculator on 42.audio.
With 50° dispersion the CNX0820 is a driver for directional coverage: installations with long throw, delay lines, speech reinforcement in reverberant rooms, and compact tops where the narrow beam reduces reflections. For wide nearfield coverage, coaxials with a wider horn are the better choice. The Thiele-Small parameters are in the driver database and the manufacturer page is linked.
What to look out for
- 50° constant-directivity horn: narrow beam, good for throw and reverberant rooms.
- Recommended crossover 2,000 Hz at 12 dB/octave: do not load the HF section any lower.
- Mounting depth 115 mm, cutout 187 mm, 2.5 kg: compact and light thanks to neodymium.
- 8 Ω, Re 5.1 Ω, Le 0.46 mH: allow for the cone's inductance in the crossover.
- Field-replaceable polyimide HF diaphragm: service-friendly for installations.
Frequently asked questions
What does the common motor for LF and HF mean?
A single neodymium magnet powers both voice coils. That saves weight and depth, the driver weighs 2.5 kg at 115 mm mounting depth, and the two sections are mechanically locked to each other, which simplifies acoustic alignment at the crossover.
Which enclosure suits the CNX0820?
Bass reflex with about 10 l tuned to 92 Hz gives a compact mid-woofer with a cutoff around 90 Hz. As a mid-high unit above a woofer a sealed chamber of around 4.5 l is enough. Both are guidelines derived from the Thiele-Small parameters.
Which crossover and which amplifier?
The recommended crossover is 2,000 Hz at 12 dB per octave. Because the HF section is rated at 107 dB you have to pad the HF branch down to match the cone. On the amplifier side 8 Ω is uncritical; a high-pass below the cone's working range is advisable.
Celestion CNX0820: manufacturer, spellings and classification
Celestion is the British loudspeaker manufacturer Celestion International Ltd. of Ipswich, England; its PA drivers are also known as Celestion Pro Audio. The CNX0820 is a 8-inch coaxial driver from the CNX series, available from 42.audio, Celestion dealer in Germany, with datasheet and full specifications in the driver database.
At 42.audio you get the CELESTION CNX0820 with all key data in the driver database and the enclosure calculator. More drivers from this manufacturer: Atlas Celestion.
Specifications
| Allgemein | |
|---|---|
| Manufacturer | CELESTION |
| Category | Coaxial |
| Series | CNX |
| Magnet | Neodymium, common motor |
| Impedance (Ω) | 8 |
| Power handling (W) | 50 |
| Sensitivity (dB) | 107 |
| Frequency from (Hz) | 1200 |
| Frequency to (Hz) | 20000 |
| Abmessungen & Korb | |
|---|---|
| Diameter | 8 |
| Voice coil (inch) | 1.75 |
| Mounting depth (mm) | 115 |
| Weight (kg) | 2.5 |
| Thiele-Small-Parameter | |
|---|---|
| Re (Ω) | 5.1 |
| Le (mH) | 0.46 |
| Fs (Hz) | 94.6 |
| Qms | 3.293 |
| Qes | 0.448 |
| Qts | 0.395 |
| Vas (l) | 9.89 |
| Xmax (mm) | 6 |
| BL (Tm) | 12.02 |
| Mms (kg) | 0.0209 |
| Sd (m²) | 0.0227 |