18SOUND 15NCX910N
18SOUND (Eighteen Sound) 15NCX910N — 15" / 15 inch Coaxial Driver · Coax / Coaxial Driver · Neodymium · NSD-Dome
3"/3" voice coils · 8 Ω
Part no.: 42A-CHS-KO-18S-0012
Documents
18SOUND 15NCX910N — 15" · Coaxial Driver
450 W AES · 99.5 dB Sensitivity · Frequency range 50 Hz – 4000 Hz
Technical data
- Diameter: 15 "
- Voice coil: 3 "
- Power handling: 450 W AES
- Sensitivity: 99.5 dB
- Impedance: 8 Ω
- Weight: 6.5 kg
- Mounting depth: 205 mm
- Frequency range: 50 – 4000 Hz
- Cone material: Titanium
- Coverage angle: 80 °
- Rec. crossover: 1.2 kHz
Datasheet (PDF) · Manufacturer page
Series: NCX · Part no.: 42A-CHS-KO-18S-0012
18Sound 15NCX910N: 15" coax with NSD HF diaphragm, 99.5 dB and 450 W AES
The 15NCX910N is the version of the 15NCX910 fitted with 18Sound's NSD diaphragm in the tweeter. Everything else stays: a 15" neodymium woofer with a 3" voice coil, a tweeter with a 3" voice coil, 450 W AES power handling and 99.5 dB sensitivity. The low-frequency section spans 50 Hz to 4000 Hz, and the HF horn radiates through an 80° cone.
In a coax, the tweeter defines the character in the presence and treble region because it sits in the middle of the woofer and uses its cone as a horn extension. The diaphragm type is therefore a real point of difference, even when woofer parameters and enclosure stay the same. For the woofer: Fs 55 Hz, Qts 0.33, Vas 107 l, BL 21 Tm, Mms 86 g and 7 mm Xmax. That is a tightly driven 15" that delivers a lot of level from a moderate volume.
Use and enclosure
With an EBP of 162, bass reflex is the natural choice. Guideline: about 67 l net tuned to 63 Hz with f3 around 68 Hz. That yields a top that copes with club levels alongside a sub and is enough on its own for speech and acoustic music. Sealed gives around 30 l with fc at 118 Hz, which only makes sense with a subwoofer. The enclosure calculator at 42.audio works out port and volume for your target. With 205 mm mounting depth, even a shallow monitor needs a decent cabinet depth.
The recommended crossover frequency is 1.2 kHz. Actively with steep filters you can work there; passively it pays to go higher and protect the 3" HF coil from low-frequency content. The 80° dispersion suits front-of-house in mid-sized rooms, stage monitors and installations where a point source is wanted. If you are choosing between the 15NCX910 and the 15NCX910N, look at the datasheets and measurements of both tweeters; the PDF is available right on the product page.
What to look out for
- NSD diaphragm in the tweeter: the only difference from the 15NCX910
- 99.5 dB and 8 Ω: an amplifier in the 450 W AES range is sufficient
- Mounting depth 205 mm and 6.5 kg: factor these into the cabinet design
- Qts 0.33, Vas 107 l: bass reflex around 67 l as a guideline
- Xmax 7 mm: set a high-pass below the tuning frequency
Frequently asked questions
Does the NSD diaphragm change anything about the enclosure?
No. The woofer is identical to the one in the 15NCX910, so the same guidelines apply: bass reflex around 67 l tuned to 63 Hz, or sealed around 30 l. Only the tweeter is fitted differently.
Which comparable 15" coaxials exist?
The 18Sound 15NCX1000 with Vas 75 l and Qts 0.31 needs less volume and handles more power. The B&C 15CXN88 with Fs 47 Hz and Vas 124 l is tuned similarly and is listed in the driver database at 42.audio.
How high can the passive crossover be?
The recommended 1.2 kHz is the lower limit. With passive, shallow filters go well above it so the 3" HF coil is relieved thermally and mechanically and the woofer works cleanly up to that point.
18Sound 15NCX910N: manufacturer, spellings and classification
18Sound, 18 Sound and Eighteensound all refer to the same manufacturer: Eighteen Sound S.r.l. of Reggio Emilia, Italy. The 15NCX910N is a 15-inch coaxial driver from the NCX series, available from 42.audio, 18Sound dealer in Germany, with datasheet and full specifications in the driver database.
At 42.audio you get the 18SOUND 15NCX910N with datasheet PDF, all key data in the driver database and the enclosure calculator. More drivers from this manufacturer: Atlas 18Sound.
Thiele-Small parameters
| Nominal impedance | 8 Ω |
|---|---|
| Resonance frequency fs | 55 Hz |
| Total Q Qts | 0.33 |
| Electrical Q Qes | 0.34 |
| Mechanical Q Qms | 8.2 |
| Equivalent volume Vas | 107.0 l |
| Moving mass Mms | 86.0 g |
| Cone area Sd | 881 cm² |
| Linear excursion Xmax | 7 mm |
| Force factor BL | 21 Tm |
| DC resistance Re | 5 Ω |
| Voice coil inductance Le | 1.1 mH |
Enclosure suggestion
The EBP of 162 suggests a bass-reflex enclosure. EBP = fs / Qes = 55 / 0.34
Sealed (Qtc 0.707)
- Enclosure volume Vb
- 29.8 l
- System resonance Fc
- 118 Hz
- Cut-off frequency F3
- 118 Hz
Bass reflex (QB3 after Small)recommended
- Enclosure volume Vb
- 55.1 l
- Tuning frequency Fb
- 68 Hz
- Cut-off frequency F3
- 74 Hz
Vb is the required net internal volume, Fb the tuning frequency of the reflex port and F3 the frequency at which the level has dropped by 3 dB. Calculated approximation after Small. A starting point for simulation, not a finished build plan.
Comparable drivers
Same size, same type, Qts within ±30 %.
- 18 Sound 15NCX910fs 55 Hz · Qts 0.33 · Vas 107 l · in the shop
- 18 Sound 15NCX910BEfs 55 Hz · Qts 0.33 · Vas 107 l · in the database
- 18 Sound 15NCX1000fs 53 Hz · Qts 0.31 · Vas 75 l · in the shop
- B&C Speakers 15CXN88fs 47 Hz · Qts 0.3 · Vas 124 l · in the database
- B&C Speakers 15HTX100fs 52 Hz · Qts 0.29 · Vas 78 l · in the database
- 18 Sound 15NCX750fs 49 Hz · Qts 0.37 · Vas 141 l · in the shop
Specifications
| Allgemein | |
|---|---|
| Manufacturer | 18SOUND |
| Category | Coaxial |
| Series | NCX |
| Impedance (Ω) | 8 |
| Power handling (W) | 450 |
| Sensitivity (dB) | 99.5 |
| Frequency from (Hz) | 50 |
| Frequency to (Hz) | 4000 |
| Abmessungen & Korb | |
|---|---|
| Diameter | 15 |
| Voice coil (inch) | 3 |
| Mounting depth (mm) | 205 |
| Weight (kg) | 6.5 |
| Thiele-Small-Parameter | |
|---|---|
| Re (Ω) | 5 |
| Le (mH) | 1.1 |
| Fs (Hz) | 55 |
| Qms | 8.2 |
| Qes | 0.34 |
| Qts | 0.33 |
| Vas (l) | 107 |
| Xmax (mm) | 7 |
| BL (Tm) | 21 |
| Mms (kg) | 0.086 |
| Sd (m²) | 0.0881 |