Dynaudio 18s Pro Subwoofer w DSP Demo Plays Down to 16hz!!!

This is a demo Pro Sub  Woofer. It plays down to 16HZ sealed box. It uses dual woofers and is very compact.

From the website 
True bass. Adding 18S to your monitors will open up a new world of performance that lets you mix and master with painstaking accuracy… and deliver tracks that translate beautifully to any playback system.

We’ve applied advanced DSP modelling technology that acoustically matches 18S to any Dynaudio Pro Studio Monitor from BM Classic, LYD and upwards, turning two-way systems into three-way set-ups. Its punch is delivered by two of our brand-new MSP+ Hybrid Drive units and a 500W amp for absolute control and power.

Getting the 18S to match seamlessly with our professional monitors is key for absolute accuracy when mixing and mastering. That has meant assessing the acoustic characteristics of each of our popular high-end studio speakers and creating custom performance maps for each one. And it’s future-proof: when we add new studio speakers to the line-up, we’ll release a firmware update for the 18S to add their performance maps – so it can grow along with your needs and equipment.

With this information at its disposal, the 18S’s display and menu system lets you select the specific Dynaudio speakers you’re using in your monitoring setup. This means the roll-off can be tailored perfectly to suit. And, if you combine a LYD 48 stereo or surround setup, you’ll essentially have a full-blown four-way monitoring system at your disposal.

The 18S has a selection of RCA or XLR connections for flexibility with your studio setup, and comes with a number of handy features to help more advanced systems too. This includes the ability to set a time delay to ensure the sub and speakers are working perfectly in sync: all you need to do is enter the distance from the sub to the speakers and the sub adjusts itself automatically using both time and phase delays.

There’s also a full three-filter parametric EQ to easily defeat room modes that could affect the accuracy of your final recording.