18SOUND 12MB700
18SOUND (Eighteen Sound) 12MB700 — 12" / 12 inch · Midrange with Lower Midrange (ML) · Midrange · Ferrite
3" voice coil · 16 Ω
Part no.: 42A-CHS-MT-18S-0006
Documents
18SOUND 12MB700 — 12" · Midrange Driver
450 W AES · 100.5 dB Sensitivity · Frequency range 60 Hz – 5000 Hz
Technical data
- Diameter: 12 "
- Voice coil: 3 "
- Power handling: 450 W AES
- Sensitivity: 100.5 dB
- Impedance: 16 Ω
- Magnet: Ferrite
- Weight: 8.3 kg
- Mounting depth: 147 mm
- Frequency range: 60 – 5000 Hz
Datasheet (PDF) · Manufacturer page
Series: MB · Part no.: 42A-CHS-MT-18S-0006
18Sound 12MB700: 12" ferrite mid-woofer with 3" coil, 100.5 dB and 16 Ω
16 Ω instead of 8 Ω: the 18Sound 12MB700 is designed for dual-driver use – two drivers in parallel give 8 Ω, and that is exactly how dual-12" tops and larger array modules are built. Run alone, it draws less power at the same amplifier voltage, but also puts less current stress on the channel. Re 9.5 Ω and Le 1.84 mH belong to this 3" winding, which handles 450 W AES.
With 100.5 dB sensitivity, Fs 46 Hz, Vas 100 l and Qts 0.25 the 12MB700 is a low-mid/midrange driver with plenty of efficiency. Qms 7.27 indicates low mechanical losses, BL 22.1 Tm at 46 g moving mass a strong ferrite motor. 4.5 mm Xmax is enough for low mids from 60 Hz, the upper end lies at 5,000 Hz. Weight 8.3 kg, mounting depth 147 mm.
Use and enclosure
The bass-reflex guideline is 28 l tuned to 67 Hz, lower cutoff around 83 Hz – the largest volume among the 12" drivers of the MB series, a consequence of the high Vas. For a midrange chamber in three-way systems about 14 l sealed with a 130 Hz corner frequency is enough; the high-pass then belongs well above 60 Hz. The EBP of 177 suggests bass-reflex whenever the low mids are to be used. Fine tuning: enclosure calculator at 42.audio.
Note for passive crossovers: the 1.84 mH inductance makes the impedance rise markedly towards the top end, which makes a Zobel network or active filtering sensible. For the treble a 2" compression driver crossed well below 5,000 Hz is suitable; 100.5 dB efficiency leaves plenty of room before the driver becomes the SPL bottleneck.
What to look out for
- 16 Ω: for parallel operation of two drivers, less power from the amplifier when used alone.
- 100.5 dB: very high efficiency for a 12" low-mid/midrange driver.
- Vas 100 l: bass-reflex guideline 28 l, larger than the other 12" MB models.
- Le 1.84 mH: impedance rise, compensate in passive crossovers.
- 8.3 kg, 147 mm deep: ferrite, no lightweight.
Frequently asked questions
When 12MB700 instead of 12MB650?
When you want to run two drivers per box in parallel or need more efficiency. The 12MB650 has Fs 48 Hz, Qts 0.23 and Vas 90 l, a similar alignment, but 8 Ω and a smaller enclosure.
How much power does a single 12MB700 get from an 8 Ω amplifier?
About half of what the amplifier delivers into 8 Ω, because the current is halved at 16 Ω. You reach the 450 W AES on a single driver only with an amplifier that delivers considerably more into 8 Ω – or with two drivers in parallel.
Which enclosure for a two-way top with subwoofer?
Bass-reflex around 28 l tuned to 67 Hz. Cross to the subwoofer above the tuning frequency and to the tweeter well below 5,000 Hz. The figures are guidelines; the exact design is done in the enclosure calculator.
At 42.audio you get the 18SOUND 12MB700 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 | 46 Hz |
| Total Q Qts | 0.25 |
| Electrical Q Qes | 0.26 |
| Mechanical Q Qms | 7.27 |
| Equivalent volume Vas | 100.0 l |
| Moving mass Mms | 46.0 g |
| Cone area Sd | 531 cm² |
| Linear excursion Xmax | 4.5 mm |
| Force factor BL | 22.1 Tm |
| DC resistance Re | 9.5 Ω |
| Voice coil inductance Le | 1.84 mH |
Enclosure suggestion
The EBP of 177 suggests a bass-reflex enclosure. EBP = fs / Qes = 46 / 0.26
Sealed (Qtc 0.707)
- Enclosure volume Vb
- 14.3 l
- System resonance Fc
- 130 Hz
- Cut-off frequency F3
- 130 Hz
Bass reflex (QB3 after Small)recommended
- Enclosure volume Vb
- 20.6 l
- Tuning frequency Fb
- 75 Hz
- Cut-off frequency F3
- 92 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 12MB650fs 48 Hz · Qts 0.23 · Vas 90 l · in the shop
- 18 Sound 12NMB420fs 53 Hz · Qts 0.28 · Vas 105 l · in the database
- 18 Sound 12MB710fs 46 Hz · Qts 0.2 · Vas 81 l · in the database
- 18 Sound 12MB720fs 46 Hz · Qts 0.2 · Vas 81 l · in the database
- 18 Sound 12MB810fs 46 Hz · Qts 0.2 · Vas 81 l · in the database
- Ciare PWA12.75fs 53 Hz · Qts 0.3 · Vas 52 l · in the database
Specifications
| Allgemein | |
|---|---|
| Manufacturer | 18SOUND |
| Category | Mid Frequency |
| Series | MB |
| Magnet | Ferrite |
| Impedance (Ω) | 16 |
| Power handling (W) | 450 |
| Sensitivity (dB) | 100.5 |
| Frequency from (Hz) | 60 |
| Frequency to (Hz) | 5000 |
| Abmessungen & Korb | |
|---|---|
| Diameter | 12 |
| Voice coil (inch) | 3 |
| Mounting depth (mm) | 147 |
| Weight (kg) | 8.3 |
| Thiele-Small-Parameter | |
|---|---|
| Re (Ω) | 9.5 |
| Le (mH) | 1.84 |
| Fs (Hz) | 46 |
| Qms | 7.27 |
| Qes | 0.26 |
| Qts | 0.25 |
| Vas (l) | 100 |
| Xmax (mm) | 4.5 |
| BL (Tm) | 22.1 |
| Mms (kg) | 0.046 |
| Sd (m²) | 0.0531 |