18SOUND 8NMA610
18SOUND (Eighteen Sound) 8NMA610 — 8" / 8 inch · Midrange without Bass (Mid) · Midrange · Neodymium · Pole-Piece Coil
3" voice coil · 16 Ω
Part no.: 42A-CHS-MT-18S-0027
18Sound 8NMA610: 8" midrange with 3" voice coil, pole-piece coil and neodymium motor
The 8NMA610 is an 8" midrange with no bass ambitions from 18Sound's NMA series. Its defining features: a neodymium motor, a 3" voice coil and an additional coil on the pole piece. The latter works like a shorting ring: it damps the modulation of the magnetic field by the voice-coil current, keeps the inductance largely constant over the excursion and thereby lowers distortion in the upper midrange, where inductance variation is otherwise most noticeable.
A 3" voice coil on an 8" cone is a decision in favour of power handling and motor force: a lot of wire in the gap, a large surface for heat dissipation, high force factor with a cone that can stay light for pure midrange duty. The 16 Ω impedance is typical for drivers that are paralleled in multiple arrangements, for example two on one amplifier channel in a line-array element.
Use and enclosure
A midrange of this type covers the mids between woofer and compression driver in a 3-way system, usually in a sealed midrange chamber or in front of a midrange horn. For the chamber design you need the driver's Thiele-Small parameters; as soon as they are entered in our driver database, you can calculate volume and in-box resonance directly in the enclosure calculator. Until then, the rule of thumb for midranges without bass applies: a small, well-damped chamber and a steep high-pass with clear margin above the in-box resonance.
Going up, a compression driver from the 18Sound range fits, and the horns and waveguides for it are in the manufacturer's category. Since no datasheet PDF is on file for the 8NMA610 yet, a look at the database or a quick question to us is worthwhile before the design.
What to look out for
- 16 Ω nominal: two in parallel give 8 Ω, good for dual-midrange arrangements.
- 3" voice coil: high thermal reserve, strong motor.
- Pole-piece coil: reduces inductance modulation and distortion in the upper mids.
- Neodymium magnet: compact motor assembly, check driver weight before mounting.
- TSP via the 42.audio driver database, enclosure via the calculator.
Frequently asked questions
Is the 8NMA610 also suitable as a mid-woofer?
No. It is designed as a midrange without bass and belongs in a 3-way system where a dedicated woofer covers the range below. If you need an 8" driver with lower midrange, 18Sound's NTLW and NMB series are the place to look.
Which amplifier do I need at 16 Ω?
An amplifier channel delivers less power into 16 Ω than into 8 Ω. With two drivers in parallel you are back at 8 Ω and use the amplifier fully. A limiter is advisable for any midrange in PA duty.
What does the pole-piece coil add compared with a driver without one?
The coil on the pole piece counteracts field modulation by the voice-coil current and stabilises the inductance. The result is lower distortion and a smoother impedance towards high frequencies, which simplifies crossover design.
18Sound 8NMA610: 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 8NMA610 is a 8-inch midrange driver with neodymium magnet from the NMA 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 8NMA610 with all key data in the driver database and the enclosure calculator. More drivers from this manufacturer: Atlas 18Sound.
Specifications
| Allgemein | |
|---|---|
| Manufacturer | 18SOUND |
| Category | Mid Frequency |
| Series | NMA |
| Magnet | Neodymium |
| Impedance (Ω) | 16 |
| Abmessungen & Korb | |
|---|---|
| Diameter | 8 |
| Voice coil (inch) | 3 |