18SOUND 12NTLW3500
18SOUND (Eighteen Sound) 12NTLW3500 — 12" / 12 inch · Woofer/Midrange (WM) · Bass · Neodymium · Dual-Gap
2x3.5" voice coil · 8 Ω
Part no.: 42A-CHS-TT-18S-0059
Documents
18SOUND 12NTLW3500 — 12" · Woofer
900 W AES · 97 dB Sensitivity · Frequency range 50 Hz – 3000 Hz
Technical data
- Diameter: 12 "
- Voice coil: 3.5 "
- Power handling: 900 W AES
- Sensitivity: 97 dB
- Impedance: 8 Ω
- Magnet: Neo
- Weight: 4.7 kg
- Mounting depth: 193 mm
- Frequency range: 50 – 3000 Hz
Datasheet (PDF) · Manufacturer page
Series: NTLW · Part no.: 42A-CHS-TT-18S-0059
18Sound 12NTLW3500: 900 W dual-gap woofer for loud, compact 12" tops
900 W AES from a 12" driver weighing just 4.7 kg – that is the combination that makes the 18Sound 12NTLW3500 interesting. The neodymium motor with two air gaps and a 2x3.5" voice coil spreads the heat across two windings and keeps inductance very low at 0.46 mH. Sensitivity is 97 dB and the frequency range 50 to 3,000 Hz.
With Fs 53 Hz, Qts 0.33, Vas 45 l and Xmax 8.3 mm the woofer/midrange is laid out for compact reflex enclosures. The 19.5 Tm motor and the 80 g moving mass result in a driver that converts power into level without giving up efficiency. The Qms of 8 points to a low-loss suspension. The 8 Ω version with Re 5.1 Ω is the one listed in the shop; the woofer is also made in 4 and 16 Ω.
Use and enclosure
The EBP of 151 points to bass reflex. The guideline is 28 l net tuned to 60 Hz with an f3 around 65 Hz – a compact, very robust top or a stage monitor with plenty of level headroom. Sealed, you get 13 l with a 114 Hz system resonance, a suitable low-mid chamber in a 3-way box. Work out volume and port dimensions for your cabinet with the enclosure calculator on 42.audio.
Usable to 3,000 Hz, the 12NTLW3500 is the partner for a 1.4" compression driver and horn combination from 18Sound's Horns & Waveguides category, letting you set the crossover low. The low Le keeps the crossover predictable. With 900 W AES, size the amplifier accordingly and place a high-pass below the tuning frequency so excursion stays controlled at 8.3 mm Xmax.
What to look out for
- 900 W AES at 8 Ω, Re 5.1 Ω – an amplifier with decent headroom.
- Dual-gap motor: Le 0.46 mH, two windings for heat dissipation.
- Mounting depth 193 mm – deeper than the classic ND models.
- Only 4.7 kg despite the high power handling.
- Bass-reflex guideline 28 l at 60 Hz.
Frequently asked questions
12NTLW3500 or 12NW350 – what is the difference?
Both have Fs around 53 to 54 Hz, Qts 0.33 to 0.34 and a Vas around 45 to 46 l, so they are nearly interchangeable in the cabinet. The 12NTLW3500 offers 900 W with a dual-gap motor and 0.46 mH, while the 12NW350 uses a classic 3.5" single coil with correspondingly higher inductance. The NTLW is the choice when power and impedance behaviour come first.
Why two air gaps?
Two windings in two gaps double the area available for heat transfer and allow a shorter magnetic circuit with lower inductance. The result is 900 W AES at 0.46 mH and a motor that works more evenly over the excursion than a long single coil.
Does it fit a small top with a subwoofer?
Yes, 28 l bass reflex tuned to 60 Hz with a hand-over to the sub is exactly the intended use. The 8.3 mm Xmax and 900 W give enough reserve to stay clean above the crossover even at high levels.
At 42.audio you get the 18SOUND 12NTLW3500 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 | 53 Hz |
| Total Q Qts | 0.33 |
| Electrical Q Qes | 0.35 |
| Mechanical Q Qms | 8 |
| Equivalent volume Vas | 45.0 l |
| Moving mass Mms | 80.0 g |
| Cone area Sd | 531 cm² |
| Linear excursion Xmax | 8.3 mm |
| Force factor BL | 19.5 Tm |
| DC resistance Re | 5.1 Ω |
| Voice coil inductance Le | 0.46 mH |
Enclosure suggestion
The EBP of 151 suggests a bass-reflex enclosure. EBP = fs / Qes = 53 / 0.35
Sealed (Qtc 0.707)
- Enclosure volume Vb
- 12.5 l
- System resonance Fc
- 114 Hz
- Cut-off frequency F3
- 114 Hz
Bass reflex (QB3 after Small)recommended
- Enclosure volume Vb
- 23.2 l
- Tuning frequency Fb
- 65 Hz
- Cut-off frequency F3
- 71 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 %.
- B&C Speakers 12FW88fs 53 Hz · Qts 0.33 · Vas 45.7 l · in the database
- 18 Sound 12LW801fs 54 Hz · Qts 0.33 · Vas 41 l · in the database
- 18 Sound 12W750fs 55 Hz · Qts 0.33 · Vas 61 l · in the shop
- 18 Sound 12NW350fs 54 Hz · Qts 0.34 · Vas 46 l · in the shop
- PRV Audio 12MB2000FTfs 55.6 Hz · Qts 0.32 · Vas 66.9 l · in the database
- Ciare PW328fs 48 Hz · Qts 0.32 · Vas 91 l · in the database
Specifications
| Allgemein | |
|---|---|
| Manufacturer | 18SOUND |
| Category | Low Frequency |
| Series | NTLW |
| Magnet | Neo |
| Impedance (Ω) | 8 |
| Power handling (W) | 900 |
| Sensitivity (dB) | 97 |
| Frequency from (Hz) | 50 |
| Frequency to (Hz) | 3000 |
| Abmessungen & Korb | |
|---|---|
| Diameter | 12 |
| Voice coil (inch) | 3.5 |
| Mounting depth (mm) | 193 |
| Weight (kg) | 4.7 |
| Thiele-Small-Parameter | |
|---|---|
| Re (Ω) | 5.1 |
| Le (mH) | 0.46 |
| Fs (Hz) | 53 |
| Qms | 8 |
| Qes | 0.35 |
| Qts | 0.33 |
| Vas (l) | 45 |
| Xmax (mm) | 8.3 |
| BL (Tm) | 19.5 |
| Mms (kg) | 0.08 |
| Sd (m²) | 0.0531 |