A CROAKY FROG?
To name a loudspeaker “Bullfrog” certainly calls for a little daring,but Berlin manufacturer Martion never was one to worry aboutan unconventional approach in his thinking.
Yes, it’s a cube – a dice. Exactly the shape that speaker manufacturers avoid as the Devil does Holy Water. After all, there are three so evilly-placed frequencies inside the unit: and all at one frequency. Berlin’s “founding father” in the loudspeaker field Basil Martion is not bothered at all: with a price per pair of 3,200 Euro, the Bullfrog pays homage to this uncommonly practical shape.
With its dimensions of 44 cm per axis, it may well be a touch too large to throw when starting a game of Monopoly, but there are certainly no other limitations to its use, even in the case of the ”rougher” variations of musical enjoyment. The driving force of this extreme transducer is in fact a full-grown 38 centimetre bass. and what a bass it is!
Sensitivity in high doses is required for this special design, where it is required to keep pace with an equally unusual mid-range unit: a horn construction of the type that is very similar to those which Martion uses in his “Orgon” and “Exodus” full range horns that are so highly sought-after (and highly-priced) in insider circles.
Considering the fact that this system has been in development for almost twenty years, he cancertainly be credited with being a perfectionist to some degree. In the Bullfrog, the horn is concentrically situated inside the cone of the bass loudspeaker and is only nominally smaller than it.
Given the physical design of the Bullfrog, any other physical arrangement than this coaxial one would have been impossible, and at the same time, Martion thus achieves “point source” – well known as the Holy Grail of all loudspeaker manufacturers.
Both units come and go in a continuous stream at around 1,5000 Hertz and that – it can be said right now – without frictional loss. While you should expect no “deep range athletics” à la bass reflex from such a closed system, you can expect brutal attacks. The giant bass membrane works within a relatively tiny volume of air, which in turn, thanks to crackling reserves of power, promises the very finest of impulse processing. A thoroughly “fat” multiplex housing also assures that the walls of the cabinet can handle the pressure.
Although the manufacturer promises power handling of 350 Watts and consequent suitability for P.A. systems (for which the Bullfrog was originally developed), its respectable sensitivity provides a broad range of freedom in choice of amplifier.
It’s true that we didn’t try it with a single-ended triode, but rather with the Einstein valve mono ”The Final Cut MK23″ from STEREO 01/2003, which is indeed anything but a raging bull. The Bullfrogs were securely screwed in a bombproof manner to the stands that can be supplied for a supplement of 300 Euro. This was definitely no bad idea, as we had certainly not expected such a spontaneous release of energy. Whoever thinks that they need deeper tones than the ones that are punched out here with the consistency and force of a steam hammer clearly has problems with their perceptive faculties.
The Bullfrog is a wonderful music machine of absolute top quality, which varies from other norms in that it favours a different form of spatial depiction. It performs tremendously, it permanently generates a feeling of tingling musical presence, reinforced with an insane dynamic range, thus putting paid to the ancient legend that the area of the membrane is the only decisive criterion.
From a tonal point of view, there are also no complaints. Although it is true that the mid-range area is relatively strong because of its sheer energy, anyone who expected this Bullfrog to croak will be pleasantly surprised.
Certainly not a loudspeaker for everyone, but whoever is prepared to accept an optical design which might take a little getting to used to, can certainly expect to have found a bargain.
A truly extreme “compact” speaker:
Thanks to its 38 cm bass unit and mid-high range horn, the Bullfrog provides genuinely high sensitivity in the smallest of rooms. It reproduces every frequency range down to the lowest, in a delightfully balanced way, that is also lively and with a rapid impulse. Apart from that, it can be driven by just about any amp. Top class!
Completely remarkable for such an extrovert concept: The Bullfrog measures up well. The amplitude characteristic is pleasantly linear and doesn’t even drop at 20 Kilohertz. In the bass, it’s cleanly adequate up to 60 Hertz. The impedance progression is extremely friendly and lies on average at maybe ten to twelve Ohms, and there is certainly over 90 decibels of sensitivity. Hardly any complaints about the step response either. Minimal irregularities are excusable, and the bass keeps pace with the high-range extremely quickly.