Rythmik Audio FM8 BM

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. FM8 is a variant of F8 subwoofer with a slightly different extension filter arrangement. The Low-music and Low-HT positions on the extension filter allows FM8 to be used as a regular subwoofer. The “high” position implements a 4th LR filter to allow FM8 only play down to 50hz and crossover to low bass subwoofer unit at 50hz (for instance, the 50hz/24 setting of our larger subwoofers). For upper end extension, this sub is designed to effortlessly play up to 250hz . Customers should note signals above 80hz can be localized and therefore placement is important if FM8 is used above 80hz. 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. FM8, when used as a subwoofer, 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.

Product features include:

Patented Direct Servo technology
8″ light weight cone mass high excursion driver
Solid and very inert enclosure available in a range of finishing options
Bass extension controls allowing adjustment of bass extension and excursion control
Selectable 12/24 db/octave crossover filter slope
Parametric EQ
120V-240V switchable power

Driver: Dual 8″ high excursion with custom sensing coil

Driver Materials: Paper cone with lightweight foam surround, cast aluminum basket, aluminum flux de-modulation shorting rings

Amplifier: 600W RMS Class D (dual Hypex UcD modules), patented servo controlled

Dimensions: 11.5″ (W) × 20″ (H) × 15.5″ (D)

Shipping Weight: 68 lbs

Frequency Response: 18 – 250 Hz (-3 dB @ 20Hz), 50 – 250 Hz (High setting)

Crossover Slope: Selectable 12 or 24 dB / octave

Crossover Range: 50 – 200 Hz

Rumble Filter: 20 Hz, 18 dB / octave

Phase Adjustment: 0 – 180° continuously variable

Bass Damping: Low (Q=0.5), Low-HT (Q=0.9), High (Q=0.8)

Standby Power: 7W (standby), 13W (on)

Finishes: Black matte vinyl, black oak vinyl

Warranty: 5 years (driver), 3 years (electronics)

Guarantee: 45-day satisfaction guarantee

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. FM8 is a variant of F8 subwoofer with a slightly different extension filter arrangement. The Low-music and Low-HT positions on the extension filter allows FM8 to be used as a regular subwoofer. The “high” position implements a 4th LR filter to allow FM8 only play down to 50hz and crossover to low bass subwoofer unit at 50hz (for instance, the 50hz/24 setting of our larger subwoofers). For upper end extension, this sub is designed to effortlessly play up to 250hz . Customers should note signals above 80hz can be localized and therefore placement is important if FM8 is used above 80hz. 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. FM8, when used as a subwoofer, 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.

Product features include:

Patented Direct Servo technology
8″ light weight cone mass high excursion driver
Solid and very inert enclosure available in a range of finishing options
Bass extension controls allowing adjustment of bass extension and excursion control
Selectable 12/24 db/octave crossover filter slope
Parametric EQ
120V-240V switchable power

Driver: Dual 8″ high excursion with custom sensing coil

Driver Materials: Paper cone with lightweight foam surround, cast aluminum basket, aluminum flux de-modulation shorting rings

Amplifier: 600W RMS Class D (dual Hypex UcD modules), patented servo controlled

Dimensions: 11.5″ (W) × 20″ (H) × 15.5″ (D)

Shipping Weight: 68 lbs

Frequency Response: 18 – 250 Hz (-3 dB @ 20Hz), 50 – 250 Hz (High setting)

Crossover Slope: Selectable 12 or 24 dB / octave

Crossover Range: 50 – 200 Hz

Rumble Filter: 20 Hz, 18 dB / octave

Phase Adjustment: 0 – 180° continuously variable

Bass Damping: Low (Q=0.5), Low-HT (Q=0.9), High (Q=0.8)

Standby Power: 7W (standby), 13W (on)

Finishes: Black matte vinyl, black oak vinyl

Warranty: 5 years (driver), 3 years (electronics)

Guarantee: 45-day satisfaction guarantee