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  F12 Direct Servo subwoofer
12" sealed audiophile sub

F12SE has received Secret of HT and HI 2020 Best Subwoofer Award. Click the award for the article.

The standard amplifier is A370XLR3. (370WRMS with both RCA and XLR inputs). The quickguide of the A370XLR3 amplifier for sealed subs can be found here . A370XLR3 amps do not have high pass filter RCA outputs. But it does have dedicated LFE inputs allowing for easy integration of a 2-ch-plus-HT system setup. A370PEQ3 has both speaker level inputs and LFE/LINE RCA inputs for those with AV receivers. A370PEQ amplifiers are available for those who still need high pass filter (or HPF) RCA outputs. The response curves with various extension frequency/damping combinations of both amplifiers can be found in our EQ page. Manual for each amplifier choice is available below in documentation section.

For those who are on a tight budget, we do offer F12-400. The frequency response plots of that model can be found on the same page.

The sub comes with screw-in rubber feet. Spike feet are available as add-on for $25 with no extra shipping cost.

Black cones are made of anodized aluminum. Silver cone driver is available for $50 extra. Price includes shipping to 48 US continental states only. Shipping to other region or country should inquire us for actual cost. Due to tariff increase, we have reduced the mult-sub discount to 5%.

Our speaker level inputs are only compatible with power amplifiers having single ended outputs with black lead output labelled as "COM", "GND", or "Ground". Wyre4sound power amplifiers and others with differential outputs are not compatible. These amps need an XLR type 3-wire (one positive, one negative, and one ground) for safe speaker level input operation.

Using Y-splitter on input connection increases the subwoofer gain by 6db. High efficiency horn speakers (105db/Wm and above) may require custom modification for "gain matching" of the volume control knob (not to be mistaken as sub not keeping up with horn speakers) when this connection method is not option (e.g., single sub accepting both L and R inputs). To summarize, customers who need to consider higher gain are those with all these conditions: 1) has high efficiency horn speakers, 2) has no AVR or pre-processor, and 3) cannot use Y-splitter to connect to multiple inputs on a sub to increase gain by 6db. Please select "High gain" option in the order.

Efficiency of newer Klipsch horn speakers are overrated by 6db and not an issue for gain matching. Please inquiry us when using our subs with horn speakers if you are not sure what to do.

Shipping is included only for 48 US states with additional shipping charge for other areas. Upcharge per subwoofer to Canada with prepaid tax is now added.

A370PEQ Quickguide
A370PEQ3 Quickguide (limited qty)
A370XLR2 Quickguide
A370XLR3 Quickguide
Integration guide

  Description: Standard A370XLR3 amp (with RCA and XLR inputs, but no speaker level inputs) Price  
  F12 Black Oak Grain with A370XLR3 amp (with both LFE and Line RCA inputs) (back order till mid July) $1139 buy it now
  F12 Black Matte with A370XLR3 amp(with both LFE and Line RCA inputs) (back order till mid July) $1139 buy it now

  Description: Other Options (amps such as A370PEQ, , XLR2) Price  
  High gain option to match horn speakers $20 buy it now
  Upgrade to A370PEQ with HPF outputs for those without bass management $50 buy it now
  Upgrade to A370PEQ3 amp with RCA and speaker level inputs (limited qty) $50 buy it now
  Upgrade to A370XLR2 (with one XLR in and one XLR out) $50 buy it now
  A set of black coated metal spike feet (add-on only at time of sub purchase) $40 buy it now
  A set of black coated metal spike feet (purchase without sub) $50 buy it now

The subwoofer for audiophiles

For audiophiles looking for uncompromising accuracy, our F12 subwoofer is the ultimate choice. It features our Direct Servo technology to ensure accuracy and definition. As an audiophile you appreciate that bass is the foundation of a satisfying music or home theater experience. You also appreciate that there is more to a home theater subwoofer than shaking the room, and that music can be far more satisfying with a subwoofer that can play deep.

What makes our subwoofers suitable for audiophiles? It's not that they can plumb the depths with authority. There are already many subwoofers on the market which can do that. The difference is that they reproduce bass with a level of realism that is normally only associated with much more expensive high end full range loudspeakers.

What is the difference between F12 and F12G? Read our comparison >

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 and thermal memory effects are reduced, further improving transient response
  • The effective in-box Q value is 0.3 with enclosure (0.13 for driver itself), resulting in much tighter and accurate bass than conventional designs with typical in-box Q value of 0.8-0.9 (and even higher when voice coil becomes hot)
  • 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

Many of our customers marvel that we are able to produce such exceptional subwoofers at such a low price. One Direct Servo technology makes it possible, allowing us to get the most out of a 12" driver without the need for kilowatts of power. Don't be fooled into thinking that other more expensive subwoofers with much more powerful amplifiers will offer more output. The output of a subwoofer is determined by how much air the driver can displace, not the power rating of the amplifier. We could supply a more powerful amplifier, but there would be no increase in output, only extra cost.

To understand further how this works, you may wish to read our article on smart Q.


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