NSv5 18"

With the introduction of the new light-weight motors we also incorporated several new cooling / thermal management features to push the power handling up to an enormous 3000-watts RMS:

1. The motor utilizes N52H Neo (heat treated). The entire motor would need to be nearly 250 degrees F before the magnet is affected in any way. This is nearly 40 degrees more than is required to boil water! There are many myths surrounding Neo motors – and none of these apply to the Nightshade.
2. The Neo magnets are sandwiched between two aluminum plates which meet the air gap along their inner edge. These plates help carry the heat away from the gap and thus the magnets and voice coil. The bottom aluminum plate is cooled by the air going in and out of the holes around the motor. The top aluminum plate is cooled by the air-flow from the spider going in and out of vented spacer ring. These plates also serve as very effective shorting rings. Furthermore, the Neo magnets themselves do not directly come into contact with the “air gap” of the woofer like most Neo-Radial designs; meaning they will never be directly adjacent to the extremely hot voice coil. Instead, a flux distribution ring separates them from the magnetic gap (see patent). Coming from the NS v.4 to the v.5 the bottom ring was expanded all the way down the cylinder ID into a full-length shorting ring (a total of over 2 lbs of aluminum). All of this thermally conductive material in proximity to the coil serves to pull heat away from the gap.
3. Since we are talking about shorting rings – we are talking about inductance and, thus, inductive distortion. It represents the lowest % of distortion in a bass speaker but, arguably, the most objectionable (being odd order). This lower ring extends down inside of the main steel casing. It's main job in terms of LE is to reduce the LE as the coils moves down -- to even out the LE curve so it's even forward to backward. When the coil moves forward it is moving away from the big "iron" core (pole piece) so LE goes down (less of the coil is wrapped around the pole). As the coil moves backward it is getting more of an "iron" core so LE goes up. By adding this huge shorting ring below the magnet casing inside the motor we ensure that LE goes down at a similar rate in both directions.
4. That brings us to the vent ring itself (mounted between the frame and the motor). For the NS v.4/v.5 we developed and tooled solid cast aluminum vent rings. Thus allowing heat to more easily move through the aluminum “top plate” and into the vent ring and thus finally into the frame itself. Our “Sundown” frames are MASSIVE chunks of aluminum (e.g. Heat-Sinks) with the 18” frame being a full 10 pounds of metal!
5. Now let’s discuss the “active” cooling of the coil. As most people are aware a solid pole piece necessarily forces all of the air under the dust cap across the former as the woofer moves back and forth thus resulting in quick heat dissipation from the aluminum former. This air can then easily escape the side vent-holes of the motor and be exchanged with cooler air. Additionally; the “Sundown” frames features a “closed base” design which forces all the air movement from the spider to go through the vent ring creating a high velocity air stream across the top part of the coil. This type of cooling is used on everything we make from the SA series on up and has proven incredibly effective since we began using this method over a decade ago. For the NS v.5 we added four vent channels around the pole to help relieve just enough pressure to keep the dust-cap intact under extreme conditions.

As with all Sundown Audio products we set out to create something genuinely different with the Nightshade v.5 woofers. We weren't content with simply rehashing existing Neo motor designs. We started from the get-go with our own proprietary, patented topology to achieve the maximum possible performance at a much more reasonable weight (NS v.4/v.5 are over 30 lbs lighter than the v.3).

The NS v.5 series was designed from the ground-up to become the new standard in the low-frequency / small ported box sub-woofer category. They will work in the same small enclosures that are commonly used for for Sundown Audio's sub-woofers, although, they can be used with enclosures up to about 50% larger than those if you desire even more low-end extension.

The NS v.5 series, as with all of our “new-platform” (patented frame / Mega suspension) drivers 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 from all major sources – BL, CMS, and LE.