H-100 corner horn subwoofer                199,- € 

Improvements over the previous model:

1. The housing is better braced and sealed
2. The horn shape has been optimized
3. The new horn driver provides impressive cone stability, cancelling any ripple effect

 4. The top plate is made of silicone rubber and is removable. In the horizontal position the plate may be
     rotated and glued down.
Many consumers are not aware of the fact that the complete, musically important octave, from low C to high C, fits into the 20 Hz difference from 20-40 Hz as well as between 10.000 to 20.000 Hz. This lack of understanding results in an overevaluation of the high frequencies and underevaluation of the low frequencies. No music enthusiast or audiophile would purchase a speaker with a frequency limit of 10.000 Hz.  Many expensive speakers, however, produce little sound below 40 Hz; few will go somewhat lower, but the sound pressure levels will be weak.  Electronically generated tones and sound effects, particularly in movies, create a desire for more deep bass, which in fact is produced by some good subwoofers, unfortunately at high distortion. An excellent test for the deep bass capability of a speaker is the  short impulses produced by a bass drum played at  high volume, approaching the limits of the power band of the amplifier.  When such signal is compared with a live performance, 99% of subwoofers will disappoint, primarily because the sound from the speaker will sound muddy and smeared in comparison to the origional sharp and dry attack of the bass drum beat. Why is this?
1.The skin of the bass drum is much larger but also lighter than the cone of a bass speaker, therefore its signals start and stop much faster. With its 2 mm linear excursion it generates a 3-5 time higher sound pressure into the listening area compared to a 25-28 cm speaker at the same linear excursion.  The speaker must compensate for that with a much larger cone excursion, which naturaly will also be slower. This results in a signal which still exists, while the skin of the bass drum has already stopped to emit sound. In quick succession of following beats, the speaker cone still moves from the first signal, thus producing an overhung and smeared bass beat tone.
2.Attempts to compensate for weak bass response of various speaker designs such as Bass Reflex, Bandpass, etc., numerous cunning tricks have been employed, however most degraded the impulse accuracy even further. This is not the case in an acoustic suspension design but it in turn is very inefficient at the low end.
3. The most expensive long throw woofers require high amplifier power to drive the heavy speaker cones in order to achieve realistic and satifactory volumes. This, however, results in an increased reaction time of the speaker in comparison to the original bass drum beat. Electronic compensation can reduce some of the distortion, but cannot compensate the heavy cone weight.
The Horn Concept
Vintage tube/valve amplifiers rarely produced even 50 Watt RMS, therefore Hi-Fi speakers had to be of high efficiency.  Today "the side benefits", most important, unbeatable precision and high dynamics  are demanded. The large horns evolved into expensive exotics and as amplifier power increased, acoustic suspension designs of small dimensions, but also Bass Reflex, Transmission Line and Compound systems emerged producing good low bass but were unable to produce high sound pressure levels. With box volumes of 20-80 liters, drivers of 25-28 cm need to have heavy speaker cones and long excursion. This decreases the efficiency dramatically and can hardly be compensated even with 1000 Watts and electronic compensation circuits. The heavy cone with long excursion delays the impulse response leaving the signal lagging behind. Even the best dynamic suspension or bass reflex designs have higher distortortion than a good horn speaker.
Good horn speakers designed and produced before 1960, driven by an average power amplifier of around 30 Watt RMS were superior regarding distortion, signal fidelity and dynamics than the above-mentioned "modern" boxes.
The corner horn
Strictly according to the formulas a  horn with great bass for 20 Hz have a length of about 8 meters and a mouth opening of over 20 square meters. Even folded this monster is too big for an ordinary houshold. Already in the 40's ingenious inventors built corner horns, which include the walls as horn extension.
Cylinder enlcousure
A high sound pressure will generate high pressure on the housing walls. Containers for extreme pressure are therefore of spherical or cylindrical design. They provide more and better stability than containers with straight walls even if they are heavily braced. A loudspeaker enclosure must withstand changing pressure at different frequencies. Each housing wall reduces the quality and the sound pressure. Additional parallel internal walls produce unwanted standing waves.
The RECKHORN cylinder housing design avoids these problems. By utilizing the room walls and floor, plus the internally constructed down firing  pressure chamber, an expotential horn system is created.