18SOUND 12NTLX3500
18SOUND (Eighteen Sound) 12NTLX3500 — 12" / 12 inch · Hi-Fi/Studio Woofer · Bass · Neodymium · Dual-Gap
2x3.5" voice coil · 8 Ω
Part no.: 42A-CHS-TT-18S-0068
Documents
18SOUND 12NTLX3500 — 12" · Woofer
600 W AES · 95.5 dB Sensitivity · Frequency range 40 Hz – 4000 Hz
Technical data
- Diameter: 12 "
- Voice coil: 3.46 "
- Power handling: 600 W AES
- Sensitivity: 95.5 dB
- Impedance: 8 Ω
- Magnet: Neo
- Weight: 4.6 kg
- Mounting depth: 194 mm
- Frequency range: 40 – 4000 Hz
Datasheet (PDF) · Manufacturer page
Series: NTLX · Part no.: 42A-CHS-TT-18S-0068
18Sound 12NTLX3500: 12" hi-fi/studio woofer with Fs 39 Hz and dual-gap motor
With a resonance frequency of 39 Hz the 18Sound 12NTLX3500 is the lowest-tuned twelve in this range. It is laid out as a hi-fi and studio woofer: neodymium dual-gap motor with a 2x3.5" voice coil, 600 W AES, 95.5 dB sensitivity and a frequency range of 40 to 4,000 Hz. The 0.52 mH inductance keeps impedance flat into the midrange.
Qts 0.33, Vas 79.6 l, Xmax 7.9 mm and a moving mass of 86 g add up to a driver that carries deep bass in a medium-sized enclosure without losing control. The motor delivers 17.1 Tm, and the Qms of 6.2 is in the usual range. At 4.6 kg even a larger floor-standing cabinet stays manageable; the 194 mm mounting depth, however, has to be planned for.
Use and enclosure
The EBP of 111 pulls the decision towards bass reflex without ruling out sealed designs. The bass-reflex guideline is around 50 l net tuned to 44 Hz with an f3 near 48 Hz – a good ratio of volume to extension for hi-fi floorstanders or large studio monitors. Sealed, 22 l gives a system resonance of 84 Hz, quite practical with active equalisation in a studio monitor. The enclosure calculator on 42.audio helps you compare both options with your dimensions.
For a 2-way system with a tweeter crossed low, the range up to 4,000 Hz is sufficient; in 3-way designs the 12NTLX3500 takes the bass up into the fundamental range. The 600 W AES is more than enough reserve for home and studio; what matters more is an amplifier that behaves cleanly into 8 Ω with Re 5 Ω.
What to look out for
- Fs 39 Hz, Vas 79.6 l – deep bass in around 50 l bass reflex.
- Dual-gap motor with Le 0.52 mH: flat impedance, easy passive crossover.
- Mounting depth 194 mm – build the cabinet deep enough.
- 95.5 dB and 600 W AES: for hi-fi and studio, less so for sustained PA levels.
- 4.6 kg thanks to neodymium.
Frequently asked questions
What distinguishes the 12NTLX3500 from the 12NTLW3500?
The 12NTLW3500 is the PA model with Fs 53 Hz and 45 l Vas for small reflex boxes. The 12NTLX3500 aims at extension for hi-fi and studio with Fs 39 Hz, 79.6 l Vas and 600 W. Same motor type, different tuning.
What volume for a hi-fi floorstander?
The guideline is a bass-reflex enclosure around 50 l net tuned to 44 Hz with f3 near 48 Hz. If you prefer it tighter, go sealed with 22 l and equalise the 84 Hz system resonance electronically.
Can the 12NTLX3500 also be used as a low-mid driver?
Yes, thanks to the 0.52 mH inductance and a range up to 4,000 Hz. In a 3-way system it is more of a bass driver, though, because its 79.6 l Vas and 39 Hz resonance are designed for extension. The frequency response is in the datasheet PDF.
At 42.audio you get the 18SOUND 12NTLX3500 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 | 39 Hz |
| Total Q Qts | 0.33 |
| Electrical Q Qes | 0.35 |
| Mechanical Q Qms | 6.2 |
| Equivalent volume Vas | 79.6 l |
| Moving mass Mms | 86.0 g |
| Cone area Sd | 531 cm² |
| Linear excursion Xmax | 7.9 mm |
| Force factor BL | 17.1 Tm |
| DC resistance Re | 5 Ω |
| Voice coil inductance Le | 0.52 mH |
Enclosure suggestion
The EBP of 111 suggests a bass-reflex enclosure. EBP = fs / Qes = 39 / 0.35
Sealed (Qtc 0.707)
- Enclosure volume Vb
- 22.2 l
- System resonance Fc
- 84 Hz
- Cut-off frequency F3
- 84 Hz
Bass reflex (QB3 after Small)recommended
- Enclosure volume Vb
- 41.0 l
- Tuning frequency Fb
- 48 Hz
- Cut-off frequency F3
- 52 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 %.
- FaitalPRO 12RS1066fs 42 Hz · Qts 0.33 · Vas 31.5 l · in the database
- 18 Sound 12NTLS3500fs 41 Hz · Qts 0.34 · Vas 63 l · in the database
- FaitalPRO 12HP1010fs 45 Hz · Qts 0.34 · Vas 56.5 l · in the database
- Ciare PW328fs 48 Hz · Qts 0.32 · Vas 91 l · in the database
- 18 Sound 12NTLW3500fs 53 Hz · Qts 0.33 · Vas 45 l · in the shop
- B&C Speakers 12FW88fs 53 Hz · Qts 0.33 · Vas 45.7 l · in the database
Specifications
| Allgemein | |
|---|---|
| Manufacturer | 18SOUND |
| Category | Low Frequency |
| Series | NTLX |
| Magnet | Neo |
| Impedance (Ω) | 8 |
| Power handling (W) | 600 |
| Sensitivity (dB) | 95.5 |
| Frequency from (Hz) | 40 |
| Frequency to (Hz) | 4000 |
| Abmessungen & Korb | |
|---|---|
| Diameter | 12 |
| Voice coil (inch) | 3.46 |
| Mounting depth (mm) | 194 |
| Weight (kg) | 4.6 |
| Thiele-Small-Parameter | |
|---|---|
| Re (Ω) | 5 |
| Le (mH) | 0.52 |
| Fs (Hz) | 39 |
| Qms | 6.2 |
| Qes | 0.35 |
| Qts | 0.33 |
| Vas (l) | 79.6 |
| Xmax (mm) | 7.9 |
| BL (Tm) | 17.1 |
| Mms (kg) | 0.086 |
| Sd (m²) | 0.0531 |