Rythmik E15HP/HP2 15" Subwoofer

E15HP SUBWOOFER FEATURES

Features & Options

Product features include:

• Patented Direct Servo technology
• 15" silver anodized aluminum high excursion driver
• 600w high power H600PEQ amplifier
• Solid and very inert enclosure
• Bass extension controls allowing adjustment of bass extension and excursion control
• Balanced XLR input option
• Parametric EQ

Direct Servo technology

All our subwoofers feature our Direct Servo technology, which is our secret to achieving tight and accurate bass. The benefits are far more than simply achieving low distortion.

Learn more in our technology articles 

15" black anodized aluminum high excursion driver

DS1510 Driver features include:

• 3" voice coil for high thermal power handling and low thermal compression
• Rigid black anodized aluminum cone ensuring control at high SPL
• Low moving mass to ensure an exceptional transient response
• High flux density in the gap to ensure low distortion
• Flux modulation shorting rings to lower inductance and improve linearity

Compared to our standard range of drivers, our DS1510 has a 3" voice coil which has a high thermal power handling and features lower power compression. While designed primarily for their sound quality, these custom designed drivers are also stylish in appearance with a anodized aluminum cone and rubber surround. Unfortunately, it's not possible to judge the accuracy of a driver by observing its appearance. There are other drivers on the market which in fact look quite similar, and it's tempting to think that they are comparable. Many of them are inferior in performance due to a heavy moving mass, the absence of shorting rings, wider gaps around the voice coil and high inductance which limits the useable high frequency cut off point. Many aren't suitable for a crossover point higher than 50 Hz. This is very limiting when one considers the large number of home theatre speakers which perform better when relieved of bass duties.

Read more 

Quality enclosure

Our enclosures are very solid and well braced to minimize any cabinet resonances or coloration. The baffle into which the driver is mounted is double thickness.

We also provide a range of finishes.

Bass extension controls

All of our subwoofers feature unique bass extension controls which are not normally provided on subwoofers. This enables the user to customize the output and extension to achieve the best compromise in any room. Most subwoofers neglect to provide bass extension control, and the result is that dynamic headroom is compromised.

The bass extension controls enable the user to customize the frequency response of the low end. The controls customize a high pass filter, which attenuates frequencies below a given frequency. If set to 14 Hz, bass below this point will be filtered. The damping control determines the slope of roll-off and the amount of time domain ringing. High damping provides the least amount of time domain ringing and the most gradual roll-off curve. Low damping provides the steepest roll-off at the low end at the expense of added time domain ringing. The combination of 28hz and low damping is recommended for maximum SPL ouptut for all of our sealed subwoofers.

Crossover options

To suit different setups, we provide a 12 db and 24 db/octave crossover. If you are using an AVR, then we recommend "AVR/12" (or EXT/12 in older amps). If you are still using stereo receiver or conventional pre/power amp setup, then we recommend the 80hz/24 db/octave setting. To understand more about how to correctly integrate your subwoofer, read our phase alignment article.

Further details on the various controls and settings included are available on our amplifier page 

Balanced professional version

For professional use, a balanced input version is available. The outputs allow multiple subwoofers to be connected. Simply daisy chain the connections, running output from the first (master) subwoofer to the input of the next. For home use, balanced connections are not normally required. However, for those using studio processors and EQ units with balanced outputs, this option may be more convenient. If connection to a source with RCA connectors as found on my home audio equipment, an adaptor may be used. In this case it should be noted that the connection can no longer be considered balanced.

Shown above is XLR2 option. Slave subwoofer units each have their own phase and PEQ adjustment, allowing for placement apart from each other. All other controls will use the same settings as the master sub. Therefore you can adjust the gain on the first and it will control the gain on all the others. The servo will still function normally, correcting any non linearities in each individual subwoofer. We also have XLR3 options with two XLR inputs and no XLR output.

For more information, including charts showing response with different settings, view our amplifier page 

PEQ parametric version

Our PEQ version comes with a few extra options which aren't provided on our standard amplifier. First, there is one band of parametric EQ with adjustable frequency, gain and bandwidth. This means you can not only control the boost or cut, but also the width of the filter. Additional bass management options are also provided. A switch allows the user to select a 12 or 24 db/octave crossover slope setup option. Where the higher slope (24db/octave) is selected, the amplifier uses a variable 12db/octave filter in addition to a fixed 12db/octave filter. One can choose with a switch the corner frequency of the fixed filter as either 50 or 80 Hz, which will suit most situations. The variable filter can be used for fine tuning.

E15HP SUBWOOFER SPECIFICATIONS

We use high quality high excursion drivers which make it possible to achieve high output in a relatively compact enclosure. Only with Direct Servo is it possible to achieve such deep bass extension, high output and very high damping simultaneously. The effective system Q is 0.3. A lower Q factor represents a higher level of damping, indicating control of the cone. A typical subwoofer has a Q of 0.707 and some achieve a Q as low as 0.5. The penalty is that the box is larger and the output is lower in order to achieve lower damping, but Direct Servo can achieve much lower damping without sacrificing output and making the box bigger.

When more output than one subwoofers can provide is desired, it may be tempting to look for a higher output option. Our subwoofers represent what we consider to be the output limit for an affordable and accurate subwoofer. It's possible to get higher output with one subwoofer, but not without significant compromise and additional cost. We suggest multiple subwoofers as a much better option. A side benefit is that this can also improve the integration with the acoustics of each particular room.

The bass extension controls allow the user to customize the deep bass extension and the rumble filter to control cone excursion. For high SPL, one can set a higher cut off. For music one may prefer a lower cut off. Changing the settings can also result in a better integration with the acoustic gain of the room.

E15HP SUBWOOFER MEASUREMENTS

A quick glance at our frequency response plot will reveal that our subwoofers do exactly what we claim. In the chart below, with bass extension controls set to 14 Hz, the response is 3 db down at 14 Hz. The response is flat and extended.

Fig 1.0 - E15HP Frequency response chart - LINE-IN 14hz high damping

The frequency response with LFE input is shown in Figure 1.1.

Fig 1.1 - E15HP Frequency response chart - LFE-IN 14hz high damping

Looking at the frequency response you will notice that this is not a one note boom box designed to impress with exaggerated bass. Unlike conventional subwoofers, the frequency response remains flat at all output levels until the output limits have been reached.

Integration

With many subwoofers, it is difficult to get a correct and seamless integration with the main speakers because the amplifier settings are often very different to the measured response. You may set the crossover point to 80 Hz, but the actual crossover point may be anywhere between 60 and 100 Hz!

With our subwoofers the upper and lower -3 dB points are a very close match to the settings selected. If you set bass extension to 14 Hz, that is exactly what you will get. All this is possible because Direct Servo ensures a stable and flat response.

Another aspect of getting a correct integration is phase alignment. We have written a guide on how to achieve a phase aligned subwoofer. More 

E15HP SUBWOOFER SUMMARY

These are some of the finest subwoofers ever manufactured and the difference in sound quality between these subwoofers and the typical big-box ported subwoofer is surprising. You will hear the difference the very first time you listen and as so many have said, you will never go back to a non-servo subwoofer.