18SOUND 8NM610
18SOUND (Eighteen Sound) 8NM610 — 8" / 8 inch · Midrange without Bass (Mid) · Midrange · Neodymium
3" voice coil · 16 Ω
Part no.: 42A-CHS-MT-18S-0026
Documents
18SOUND 8NM610 — 8" · Midrange Driver
400 W AES · 104 dB Sensitivity · Frequency range 400 Hz – 5000 Hz
Technical data
- Diameter: 8 "
- Voice coil: 3 "
- Power handling: 400 W AES
- Sensitivity: 104 dB
- Impedance: 16 Ω
- Magnet: Neo
- Weight: 4.5 kg
- Mounting depth: 113 mm
- Frequency range: 400 – 5000 Hz
Datasheet (PDF) · Manufacturer page
Series: NM · Part no.: 42A-CHS-MT-18S-0026
18Sound 8NM610: 8" horn-loaded midrange with 104 dB, 3" voice coil and neodymium motor
With 104 dB sensitivity and a resonance frequency of 260 Hz, the 8NM610 is not an ordinary midrange but a driver designed for horn loading. 18Sound's NM series stands for neodymium motors with large voice coils, here 3" at 16 Ω, and a BL of 31 Tm at only 17 g moving mass. That ratio of motor force to mass is the reason for the efficiency, and it explains the working range of 400 Hz to 5,000 Hz.
A Qts of 0.23, Vas of 1.6 l and an EBP of 929 show the design intent plainly: very stiff suspension, minimal compliance, minimal movement. Xmax is 3 mm, and a driver that moves only fractions of a millimetre in front of a horn needs no more. With 400 W AES power handling and 4.5 kg weight it is built for continuous duty in large systems; the 113 mm mounting depth needs to be allowed for in the horn design.
Use and enclosure
The 8NM610 belongs in front of a midrange horn, in line-array modules or large-scale sound reinforcement systems where a highly efficient midrange section is needed between a bass section up to about 400 Hz and a compression driver from 5,000 Hz. Behind the driver sits a sealed chamber; the classic approximation formulas give 0.2 l with an in-box resonance around 799 Hz, but with a horn-loaded driver the rear chamber and horn mouth together define the lower limit, not the free-air resonance. A vented volume of 0.4 l tuned to 410 Hz is mathematically possible but not a sensible concept for this driver in practice. Use our enclosure calculator as a starting point for the rear chamber.
Do not cross below 400 Hz, and use a steep slope. Going up, the range ends at 5,000 Hz; a 2" compression driver from the 18Sound range takes over there without a gap, and the matching horn is in the manufacturer's category. The 16 Ω nominal impedance lets you run two drivers in parallel on one channel at 8 Ω.
What to look out for
- 16 Ω nominal, Re 10 Ω: two in parallel give an easy 8 Ω load.
- 3" voice coil, BL 31 Tm: a motor for horn loading, not for excursion.
- Fs 260 Hz, Xmax 3 mm: do not cross below 400 Hz.
- Mounting depth 113 mm, 4.5 kg: a massive motor despite neodymium.
- Datasheet PDF and TSP in the 42.audio driver database.
Frequently asked questions
Can I run the 8NM610 without a horn in a normal enclosure?
Technically yes, but it makes little sense. Without a horn you give away part of the efficiency, and the lower limit stays at 400 Hz because of Fs 260 Hz and Vas 1.6 l. The driver is built for horn loading and shows its strengths there.
Which amplifier suits the 8NM610?
Power handling is 400 W AES at 16 Ω. An amplifier delivers less power into 16 Ω than into 8 Ω, so with two drivers the parallel connection to 8 Ω pays off. With 104 dB sensitivity you only need moderate power for very high levels anyway.
8NM610 or Beyma 8MC500Nd?
The Beyma 8MC500Nd, with Fs 69 Hz, Qts 0.18 and Vas 15.9 l, is a midrange for direct radiation with a much lower resonance. The 8NM610 at Fs 260 Hz and 104 dB is a specialised horn midrange. The choice depends on whether a midrange horn is part of the concept.
At 42.audio you get the 18SOUND 8NM610 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 | 16 Ω |
|---|---|
| Resonance frequency fs | 260 Hz |
| Total Q Qts | 0.23 |
| Electrical Q Qes | 0.28 |
| Mechanical Q Qms | 1.2 |
| Equivalent volume Vas | 1.6 l |
| Moving mass Mms | 17.0 g |
| Cone area Sd | 220 cm² |
| Linear excursion Xmax | 3 mm |
| Force factor BL | 31 Tm |
| DC resistance Re | 10 Ω |
| Voice coil inductance Le | 0.5 mH |
Comparable drivers
Same size, same type, Qts within ±30 %.
- Beyma 8MC300Ndfs 62 Hz · Qts 0.22 · Vas 18 l · in the shop
- PRV Audio 8MR500CF-NDY-4fs 62.9 Hz · Qts 0.25 · Vas 18.62 l · in the database
- 18 Sound 8NMB750fs 88 Hz · Qts 0.27 · Vas 6.9 l · in the database
- Beyma 8MC500Ndfs 69 Hz · Qts 0.18 · Vas 15.9 l · in the shop
- PRV Audio 8MR600X-NDYfs 87.6 Hz · Qts 0.29 · Vas 12.58 l · in the database
Specifications
| Allgemein | |
|---|---|
| Manufacturer | 18SOUND |
| Category | Mid Frequency |
| Series | NM |
| Magnet | Neo |
| Impedance (Ω) | 16 |
| Power handling (W) | 400 |
| Sensitivity (dB) | 104 |
| Frequency from (Hz) | 400 |
| Frequency to (Hz) | 5000 |
| Abmessungen & Korb | |
|---|---|
| Diameter | 8 |
| Voice coil (inch) | 3 |
| Mounting depth (mm) | 113 |
| Weight (kg) | 4.5 |
| Thiele-Small-Parameter | |
|---|---|
| Re (Ω) | 10 |
| Le (mH) | 0.5 |
| Fs (Hz) | 260 |
| Qms | 1.2 |
| Qes | 0.28 |
| Qts | 0.23 |
| Vas (l) | 1.6 |
| Xmax (mm) | 3 |
| BL (Tm) | 31 |
| Mms (kg) | 0.017 |
| Sd (m²) | 0.022 |