AL 130 - 8 Ohm

The COUPLET is a d'Appolito configuration shelf speaker. in the low to mid-range two 13 cm drivers, model AL 130 - 8 Ohm, take over the work. These high-end speakers can really show what they're capable of in a 25 litre bass reflex cabinet. Their long stroke and low mechanical losses guarantee powerful, rich bass reproduction. This is due to a large extent to the BR 25.50 bass reflex tube, mounted on the back of the cabinet, with its flow-optimised shape.

In the high-frequency range above 3000 Hz, the 20 mm textile domed G 20 SC - 8 Ohm demonstrates its very linear frequency response and excellent omnidirectional sound distribution.

The specially designed crossover circuitry optimises the interaction between the mid-bass unit and the tweeter and effectively suppresses unwanted resonance from the aluminium diaphragms before it becomes noticeable. The frequency response in the mid-range is made more linear.

The result is a speaker that maintains its linear characteristics right across the frequency range. Due to the well balanced medium range, the fine details of music reproduction, in particular, comes across particularly clearly. The excellent omnidirectional sound distribution creates a particularly room-filling music reproduction and clear location of each individual instrument or voice. The lowest-range bass comes across equally powerfully. In short, the COUPLET is a speaker that is really good fun.

There are plenty of transmission line fans among the speaker-building fraternity. HOBBY HiFi recently developed a super-slim speaker with a folded transmission line (TML). The VIB 130 TL cabinet suggestion is based on that idea and uses an AL 130 - 8 Ohm and a G 20 SC - 8 Ohm.

This speaker cabinet works on the basis of an organ pipe. At one end is the driver while the other end is open. Certain frequencies generate resonance which causes particularly powerful sound reproduction at the open end. The longer this tunnel, the lower the frequency.

In order to make use of this principle for low frequencies, a length of several metres would be necessary which is only possible by "folding" the transmission line tunnel twice within the cabinet to achieve convenient dimensions, as integrated in the VIB 130 TL. Apart from the intentional low frequency resonance, TML's also generate interference resonance at higher frequencies. It is only by damping the space very carefully that the desired results can be achieved.

Two internal Helmholtz resonators are in use directly behind the woofer as sound absorbers and, in conjunction with the extremely carefully positioned damping material, will ensure that the frequency response is kept beautifully smooth.

VIB 130 TL solves the problem of reproducing low-frequency bass in small rooms where the speakers have to be positioned close to walls. A distance of 10 cm is perfectly adequate.

Real deep bass is not to be confused with disco bass, which one tends to feel through the stomach rather than hear. Deep bass is soft, smooth yet powerful. However, in order to produce such power with small speakers, there has to be a trade-off with the sound pressure. As a result, the efficiency of the VIB 130 TL is relatively low but still well able to cope with normal conditions. This is counterbalanced to a large extent by the extensive frequency response. The cleanliness of the sound picture produced is remarkable with well-placed spatial locations, especially when positioned near a wall. The 20 mm G 20 SC - 8 Ohm tweeter guarantees crystal-clear, lively high-frequency reproduction and provides a smooth upper end to the range.

The VOX 253 is an upright speaker with its subwoofer TIW 250 XS - 8 Ohm let into the side-wall. This design enables the front panel to be kept very narrow making it that much easier to position. One of the most outstanding features of the TIW 250 XS - 8 Ohm is its unbelievable ability to reproduce the lowest range bass in surprisingly small cabinets. In the listening area, the bass pressure becomes tangible rather than audible, the sort of effect you would normally only expect from much larger speakers. As a result of the side-opening position of the TIW 250 XS - 8 Ohm, the separating frequency between the subwoofer and the mid-range drivers has to be very low. This has been achieved by means of an especially intelligent frequency cross-over design.

In order not to restrict the dynamics at higher bass levels, a bass reflextube with an exceptionally large cross-section and corresponding length has been designed. In this way, flow-related losses are kept to a minimum. The vent is at the bottom in the rear wall so as not to interfere with the attractive appearance of the front face.

The only difference between VOX 253 and VOX 252 is the new woofer TIW 250 XS - 8 Ohm. A change of the crossover was not necessary.

This version of the VOX contains the high-end ceramic dome tweeter KE 25 SC - 8 Ohm. An 18 dB high-pass filter produces an optimum phase relationship between tweeter an midrange. This creates an improvement of the clear location of each individual voice or instrument.

Due to the deep starting frequency of the MHT 12 - 8 Ohm it is possible to make use of this magnetostat in the VOX 253. Of course, the crossoverhas to be changed from that used in the original version with its KE 25 SC - 8 Ohm. Fortunately, the AL 130 - 8 Ohm 's only have to be separated slightly higher which means we are still a long way from the baffleresonance levels. Here, too, the transfer frequency is 3000 Hz. As can be seen from the dotted frequency curves for the individual drivers, the AL 130 - 8 Ohm drop off at 2000 Hz and the MHT 12 - 8 Ohm at 4500 Hz and meet again at 3000 Hz and -6 dB. The magnetostat need not by any means produce its full output at 3000 Hz, as some people often believe. This would not make sense in terms of achieving the lowest possible distortion factor.

Since the front panel of the MHT 12 - 8 Ohm is slightly larger, the AL 130 - 8 Ohm 's have to be spaced a little further apart (10 mm).

As regards their sound quality, both versions (original VOX 253 with KE 25 SC - 8 Ohm and VOX 253 MHT) are at the same high level. The version preferred by each particular customer will depend on personal taste, the type of music you listen to and how you listen.

The VOX 253-CENTER is the corresponding centre speaker to match the VOX 253. This is a horizontal speaker equipped with identical drivers. The TIW 250 XS - 8 OHM bass speaker and a bass reflex tube tube are positioned to left and right of the mid- to high-range unit, which is arranged vertically, behind a fabric-covered frame. If required, the drivers in the speaker can be fitted with compensating magnets to shield them magnetically. The VOX 253-CENTER has the same excellent soundproperties as the VOX 253. The reproduction of the unbelievably sonorous low-range bass and, at the same time, extremely clear-cut mid- and high-range reproduction, is mastered effortlessly by the VOX 253-CENTER.

This centre speaker is the ideal choice if you want to build up a multi-channel system around the VOX 253, that will appeal to both seasoned music lovers and aficionados of the cinema.

The VOX 301 extends the high-end VOX series upwards. While the mid-to-high-range is the same as in the VOX 253, the TIW 300 - 8 Ohm has been chosen as the woofer for this model. As a result, while the excellent characteristics experienced in the mid-to-high range remain the same, the level accuracy and dynamics in the bass department have been increased and the lower limiting frequency reduced to a remarkable 23 Hz. The VOX 301 can, therefore, be seen as the VOX variant for high-volume aficionados who like to hear concerts at close to the original sound levels in large rooms.

The CONCORDE MK III 3-way system may not be able to fly, but in terms of sound, it really soars. The mere shape and the drivers used give an idea of its qualities. The tailored baffle in the medium to high-frequency range produces optimised omnidirectional sound distribution one of the reasons why the sound distribution throughout the room is so smooth. Arranging all the drivers according to the D'Appolito principle, reduces interference from floor and ceiling reflection. Two AL 200 - 8 Ohmaluminium bass drivers join forces to produce profound and yet precise bass reproduction thanks to the extra-large, flow-optimised bass reflextube. The two AL 130 - 8 Ohm mid-range speakers guarantee crisp mid-range sounds as a result of their stiff cones, long stroke and impedancecontrol ring.

At the top end of the frequency range we have used the innovative KE 25 SC - 8 Ohm ceramic tweeter, which has been incorporated using a sophisticated crossover arrangement to optimise timing. This sophisticated design of tweeter can be wired up to blend in from a very low level and, as with all the other drivers, produces extremely distortion-free sound even at high volume settings. Any defects in the source signal are laid wide open. Even at louder settings, listening to music remains a real pleasure. This is always a good sign that the baffle is working correctly and that nothing is being smuggled in that should not be there.

In the MK III version, the cut-off frequency between the low- and mid-range has been shifted from 500 Hz to 300 Hz. The filter of the tweeter has been changed to 18 dB/oct additionally. That causes a more evenly sound radiation at different angels. This is especially noticeable in less damped rooms.

The completely neutral tonality and the remarkable dynamic characteristics of this stand-up CONCORDE MK III cabinet make it an all-round talent for discerning listeners of all types of music.

The BIJOU is a compact shelf-top speaker with high-end drivers. The AL 130 - 8 Ohm, which is responsible for the lower mid-range in the compact, 10-litre cabinet, together with the large bass reflex vent at the front generate powerful, deep bass reproduction. This is magnified still more if the speakers are positioned near a wall.

In the BIJOU speakers, the tweeter is the KE 25 SC - 8 Ohm ceramic dome driver which cuts in at 2000 Hz. Due to its low resonant frequency, this driver is ideal for full-range use.

Thanks to its high level-accuracy, this driver produces crystal-clear, distortion free treble whatever the volume level.

It is in part thanks to these high-quality drivers that the sophisticated crossover, which uses only very few components, produces a virtually linear frequency response from this classic 2-band combination. The result is a compact loudspeaker whose balanced and yet fully-developed overall sound quality is totally convincing.

The naming of the Studio 1 was very easy due to the optics, which are reminiscent of typical studio monitors. This does not mean that the Studio 1 is solely a studio monitor. This speaker can also be used in larger home theater systems and, of course, as a pure stereo system, supported by a powered subwoofer if necessary.

By using the Waveguide WG 220x150, coupled with the excellent properties of the well known G 25 FFL - 8 Ohm tweeter, and the two AL 130 - 8 Ohm woofers, an interesting and extraordinary construction speaker kit came into being, which can be described as extremely rich in detail and lifelike in terms of precise focus and soundstage.

During the development of the STUDIO 1, some tricks had to be employed to achieve the above mentioned properties. The bassreflex port is installed at an angle of 45° upwards, which eliminates the well known problem of standing waves in the channel itself.

Additionally, the Waveguide WG 220x150 adds substantial improvements to the qualities of the G 25 FFL - 8 Ohm: On the one hand, the height of the waveguide brings the sound generation zone of the tweeter and the woofers into line, as on the other hand the exponentially expanding shape of the waveguide optimizes the radiation pattern and puts less strain on the tweeter in the lower frequency range. An optimized radiation pattern in this context means that the width of the acoustical beam of the tweeter is adapted to the beamwidth of the woofers in the region of the transition. Thereby, a homogeneous sound also arises in rooms with unequal reverberation times.

These important points allow for the excellent sound of the Studio 1, which can be described in summary by the word "directly".

With a cabinet volume of just over 56 litres, the QUINTETT could not be said to be a small speaker. Despite its size, it comes across as elegant and sophisticated, thanks to the arrangement of its drivers and the slim baffle. Fitted with no less than five AL 130 - 8 Ohm, it is generously equipped but stopping short of exaggeration.

Four of the AL 130 - 8 Ohm, with a combined diaphragm area of 316 cm², are fitted in the bass reflex cabinet and generate sufficient bass, so no subwoofer is needed. The QUINTETT is based on a development idea suggested by the German "Klang & Ton" Hi-Fi magazine which was then finalised by modifying the crossover.

The uppermost of the five AL 130 - 8 Ohm, which is neatly housed in its own enclosed 5-litre cabinet, together with the tried-and-tested KE 25 SC - 8 Ohm ceramic dome tweeter, produce clear mid-to-high-range soundabove 500 Hz.

In terms of its sound quality, the QUINTETT can be described as rich in detail and very precise. It uncompromisingly shows up every defect in a recording but, on the other hand, reproduces good recordings perfectly, without the slightest distortion and with remarkable positioning accuracy. Bass sound is reproduced very accurately and clearly and, thanks to the be-wiring connections, can be controlled separately from the mid- and high range frequencies. The QUINTETT is, as a result, not a speaker that produces some softened-down mash, it is, on the contrary, a realist that can easily cope with maximum volume settings.