Sundown Audio - Z-Series Zv.7 18"

The Z v.7 is the third step up in Sundown's 2025 "ultra-high excursion" sub-woofer lineup after the M and X v.4 series. All models (12,15,18) feature our custom tooled and patented frames (US Patent Numbers D691597, D691598, and D741841) – the Sundown “mega-platform.” Please note – the Z v.7 is not available, aside from special orders, in 10s due to the motor size.

We mate these new platform frames to a quad stacked 265mm (10.43”) diameter motor structure with a total magnet stack height of 100mm (3.94”) featuring a hyper-extended pole and extreme clearances (allowing over 4" p-p travel before mechanical bottom effectively making it bottomless). This is, by far, the largest motor we have ever produced on a Z series sub-woofer. The motor force factor (BL^2/RE) is ~50% higher than the previous generation Z v.6 series.

This motor drives a 3.3" diameter 4-Layer Round Wire Aluminum Voice Coil wound on a thick aluminum former. These new round wire coils use a special Sundown designed “fat wire” winding method to handle significant amounts of power and abuse.

Based on Sundown's years of experience with the Z v.4, 5, and 6 series we've also improved the voice coil ventilation yet again. The Z v.7 features an entirely new and patent-pending airflow directing pole cap, six pole OD channels, SIXTEEN gap vents, and a cross-drilled / slotted top plate to keep the voice coil running cool under extreme conditions.

The Z v.7 motor also features a 9mm thick magnet ID Faraday ring which is locked into both the top and back plates. This ring combined with an all-new pole-extension inductance sleeve gives the Z v.7 the most linear inductive performance of any mega-platform sub-woofer to date. As if all of this were not enough to cement the Z v.7as a legend... we were also able to achieve 42mm of one-way linear excursion by 70% BL with an extremely uniform curve via our extensively FEA optimized motor and 95mm long voice-coil winding length.

The Z v.7 series was designed from the ground-up to become the new standard in the low-frequency / small, ported box sub-woofer category in this price range. They will work in the same enclosures that are commonly used for Sundown Audio's mega-platform sub-woofers.

The Z v.7 series, like its other mega-platform brethren, is really a different kind of woofer due to its incredibly linear suspension. They are designed for the LOWEST level of bass extension possible in a small enclosure while maintaining extremely low levels of distortion.

Dual 1-Ohm T/S Specs
RMS Power (D1)	3500
Peak Power (D1)	7000
RE-Ohms (D1)	2.03
Fs-Hz (D1)	23.483
Vas-L (D1)	98.844
Qes (D1)	0.462
Qms (D1)	6.282
Qts (D1)	0.433
Le-mH (D1)	2.038
BL-NA (D1)	23.588
Mms (D1)	858.079
Cms (D1)	53.531
Sensitivity-db @ 1w/1m (D1)	92.111
Xmax (D1)	42mm
Dual-2-Ohm T/S Specs
RMS Power (D2)	3500
Peak Power (D2)	7000
Re-Ohms (D2)	3.97
FS-Hz (D2)	27.246
Vas-L (D2)	94.972
Qes (D2)	0.451
Qms (D2)	6.365
Qts (D2)	0.421
Le-mH (D2)	4.026
BL-NA (D2)	33.742
Mms-Grams (D2)	756.359
Cms-uM/N (D2)	45.112
Sensitivity-dB @ 1w/1m (D2)	91.07
Xmax (D2)	42mm
Subwoofer Measurements
Displacement (Inches)	0.34 cu ft
Depth (Inches)	15.61
Cutout (Inches)	16.68"
Motor Diameter (Inches)	10.8
Ported Enclosure Specs
Ported Enclosure Size	7.0cu ft
Recommended Port Area	100sq in
Sealed Enclosure Specs
Sealed Enclosure Size	Not Recommended
4th Order Enclosure Specs
4th Order Sealed Side	3.0cu ft
4th Order Ported Side	9.0cu ft
4th Order Port Area	180sq in
4th Order Port Length	8"