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






  F8 Direct Servo bass and midbass subwoofer
Sealed audiophile sub with dual 8" drivers (replaced by FM8)

The subwoofer for audiophiles with the need to play up to upper bass

For audiophiles looking for uncompromising accuracy in both bass and upper bass frequency range and higher crossover frequency up to 250hz, our F8 subwoofer is the ultimate choice. It features two light cone weight 8" drivers with our Direct Servo technology to ensure accuracy and definition. This sub is designed to effortlessly play up to 250hz . While there are already many subwoofers on the market which can play deep bass, their sound quality and transient response degrade as the frequency goes up above 120hz. F8 is a subwoofer that can cover more than a decade of frequency range of servo control from below 20hz to 250hz.

Direct Servo Technology

You may have heard about other servo subwoofers which are generally well regarded for their accuracy. It is a well established technology, most often based around an accelerometer which measures cone movement. Our Direct Servo technology has significant advantages over other servo technologies. We use a sensing servo coil which acts like a microphone which compares the original signal to what the subwoofer is actually reproducing. The signal is then corrected instantly to compensate for any differences. Once you understand the concept, you may wonder like we do why anyone would make a subwoofer any other way.

All our subwoofers use our patented Direct Servo technology. The most significant benefit is that it provides high end performance at an affordable price. Conventional subwoofers require heavy drivers in order to achieve deep bass extension. Direct Servo allows the use of a lighter driver which is more efficient so that a very high powered amplifier is not necessary. At the same time, Direct Servo reduces detrimental memory effects which detracts from the realism of reproduction.

Some of the benefits of Direct Servo include:

  • Reduction of 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 memory effects, such as spider hysteresis and creep effect of surround material, is reduced, further improving transient response
  • The effective Q value is 0.3 resulting in much tighter and accurate bass than conventional designs
  • Dramatic reduction of the re-radiation of bass from inside the box

Many audiophiles aren't aware of all of these issues, but we believe they are critical to the design of an accurate subwoofer. While it's not necessary to understand them to enjoy accurate bass, for those who wish to understand how we do it, we have articles to describe our unique approach.

Read more about Direct Servo in our technology section.

View animation demonstrating how Direct Servo works >

View animation demonstrating the reduction of bass re-radiation >

Better value through intelligent design

F8 uses two Hypex Ucd class D modules in the power amplifier with each module independently driving an 8" driver. Hypex Ucd modules are considered as one of the best sound quality class D modules available. The standard amplifer is HX580 (300WRMS x 2 for a total of 600WRMS), It has one RCA and one mini-XLR input. The quickguide of the F8 can be found here . Three different finishes are available: piano black, black matte vinyl, and black oak vinyl. Price includes shipping to 48 US continental states only. Shipping to other region or country should inquire us for actual cost.

Male mini-XLR to femaie XLR cable can be purchased from guitar-cable.com: cable model MC17-XX as 2-ft or 3-ft adapter cables. Then use full length of regular XLR cables plus these adapter cables.

F8 has been replaced by FM8