> Home
> Products
> Technology
> Plans & DIY
> Ordering
> Reviews
> About us
> Contact






  G25HP Direct Servo subwoofer
Dual opposed 15" sealed audiophile sub with 1800WRMS amplifier


Dual Opposed Mounting and Direct Servo Technology

Dual opposed subwoofers mount two drivers on opposite walls of enclosures in an effort to reduce the reaction force exerted onto the enclsoure from drivers . However, the disadvantage of the conventional non-servo dual opposed subwoofers is the boxy bassinside the enclosure is still audible with re-radiation via the cones. With our patented Direct Servo technology, it enables precise control over the cone to resist and dissipate any energy acting on the cone and the so-called re-radiation of boxy bass coloration can be reduced by up to 10x in energy. This is essential for tight, dynamic and accurate bass. It also counteracts many different driver non-linearities and allows us to use lighter drivers which avoid the need for excessive amounts of amplifier power.

Some of the benefits of Direct Servo include:

  • Dramatic reduction of the re-radiation of bass from inside the box, which is commonly referred to as boxy bass.
  • The effects of thermal compression are eliminated under normal operation
  • Higher efficiency allowing output which would normally require a more powerful amplifier
  • Deep bass extension can be achieved using a low mass driver with superior transient response
  • Mechanical and thermal memory effects are reduced, further improving transient response
  • The (temperature-independent) effective in-box Q value is 0.3 (0.1 for driver itself) resulting in much tighter and accurate bass than conventional designs with typical value of 0.8-0.9 (and even higher when voice coil becomes hot)

Read more about Direct Servo in our technology section.

View animation demonstrating how Direct Servo works >

HX2000XLR3 Amplifier and Dual DS1520 Driver

G25HP comes with grilles. The above photo is shown with grill taken off. It uses our new high power HX2000XLR3 servo amplifier and two DS1520 driver. DS1520 features anodized aluminum cone, a 3" voice coil, and 200 oz magnet. Its linear excursion range has increased to +/- 20mm.

The response curves with various extension frequency/damping combinations of both amplifiers can be found in our EQ page.

The sub comes with standard screw-in rubber feet. Chrome spike feet are sold separately.

Integration guide

G25 has received AVS 2018 Top Choice Award.

Price includes freight shipping to 48 US continental states only. Shipping to other region or country should inquire us for actual cost.

All G25HP piano black has been discontinued.

Customers in Hong Kong alert: we have only sold one piano finish unit in Hong Kong and unfortunately that unit has been blacklisted due to a credit card fraud. We will not provide any service to blacklisted units. Please check with us for details if you intend to buy a used G25HP in that region.

A few things to note for freight delivery: 1) Freight delivery is not as date-accurate as UPS ground delievery. Do prepare for unexpected delay, 2) If the order can be delivered without appointment/signature required, there is a $30 credit. Please use the order button to do so. The options available in the checkout process are for UPS ground only, and 3) All freight delivery included with the price is standard curb side delivery. Inside delivery and gararge delivery are extra and please ask us for a quote.

  Description: FREE SHIPPING to 48 US continental STATES Price  
  G25HP black oak finish with HX2000XLR3 amplifier and dual opposed black cone driver with freight shipping $2950 buy it now
  G25HP black matte finish with HX2000XLR3 amplifier and dual opposed black cone driver with freight shipping $2950 buy it now
  Delivery without appointment/signature required (per order) $-30 buy it now
  Upcharge for shipping to New York City and Long Island(per unit) $150 buy it now
  Upcharge shipping to these states: WA/OR/MT/ID/VT/MA/NJ/NY(per unit) $100 buy it now
  A set of 4 large furniture mover pads for carpet $10 buy it now
  A set of 4 large furniture mover pads for hard floor $10 buy it now