Klara Geist

Exclusive high-end mobile and stationary PA soundsystems. Handcrafted in Berlin. Designed with passion for detail. Highest quality components. Skillfully crafted. High-end audio performance. 
The official sound-outfitter for Bullitt Cargo Bikes. Professional Soundbike rental service. Branded promotion Soundbikes. Custom designs.

The Radioeins Soundbike / Branded Promotion Soundbike / 2013

Over the years we have tested and reviewed the performance characteristics of each our newly developed models. Specifically we have observed the qualitative acoustic impact of our systems in open spaces, but we also seek with each new development to generally optimize the ease of their functionality.

We have found that positioning of the loudspeakers in the direction of travel is particularly effective, for example, especially where promotional activities are concerned. And to achieve perfect reproduction, this soundsystem uses a set of high performance PA coaxial speaker chassis, which function as a source point to render sound without any time lag.

We technically customized the Radioeins sound bike to be compatible for broadcasting tasks in conjunction with the rest of the station's motorized broadcast vehicle fleet. This is just one example of the way the properties of our mobile PA can be meaningfully tailored to the needs of the individual customer.

In summer 2013, Radioeins used their soundbike for diverse promotional projects, among them an escorted soundtour to the Greenville Festival for the radioshow listeners. We supported them at the tour and live at the studio:


The chassis' composite elements and qualities include: Neodymium Coaxial Transducer; 3 "Copper Sandwich Voice Coil; Triple Aluminum demodulating Rings; Elliptical 80 ° x 60 ° waveguide for precise directivity; Single Point Source providing coherent Wave Front; very high SPL for superb quality sound.

The gain of the input signal is attained via 3 high-end Class D amplifier units that deliver a total energy of 2 x 90 Watt and 1 x 45 watts to the chassis. These units are designed for low output impedance, very low frequency-independent THD and very low noise. This total wattage may not seem much at first glance, but the cooperation of the chassis with the amp is thereby balanced in such a way that a constant, distortion-free end volume of 110 dB can be achieved in an open field.

The individual signals are separated by an unimprovable 24db crossover, and they are phase-corrected (there is also zero phase rotation, a precision and reference switch; the filter design is based on psycho-acoustic evidence).

This technical interaction of the individual components is important. A mobile PA system will not necessarily have a limitless power source available, so we have chosen as efficiently as possible the resources or energy needed for each task. The PA system reaches a playing time of more than 6 hours at maximum volume. And playing predominantly bass-heavy pop music, for example, allows for a further extension of playing times without the need to recharge.

Customization in this area is possible, such as the construction of larger battery packs for an even further extended playing time.

We also offer a bespoke service for the design of the case. Here we have a degree of spatial freedom to adapt and adjust to the individual customer's own equipment storage needs.

A design of the ensemble according to the company's own corporate identity ( Bike + sound system ) usually forms the basis for our branded promotional sound bikes. To this end, the system boasts ample customizable surface area that, in combination with an appropriate Bullitt model, forms a unified ensemble with a high recognition value.

The system has been developed using our already proven methods and designed to be as light as reasonably possible. For the user, this results in a high level of driving comfort compounded by the integrated damping system.

After various prototypes, production models and tests, we have arrived at our ultimate mid-sized portable sound tool. Ideal for use as a promotional tool because of its compactness and ease of handling.

Many Lifestyle brands have come to realize that using zero-emission vehicles for advertising communicates a better image, and generates higher interest (as well as quicker acceptance ) among potential customers than a conventional motorized vehicle.

Our soundbikes also have the great advantage that they are speedy, flexible and can be easily used in otherwise hard to access places (no special permits are required for pedestrian areas / beach etc. → they're efficient, cost-saving, and of course green... ).

Our soundsystems need not solely be used for external promotional activities, their intuitive ease of use and huge power means you need never again hire extra equipment or personnel for the sound requirements attaching to any internal company event.

And they're always visually unmissable.


Technical Data

Housing material: Wood (of layered plate materials)
Dimensions: 70 x 60 x 55 cm
Weight: ~ 45 kg
Frequency response: 50 – 20.000 Hz
Amplifier: Class D Amplifier (225 Watt / max. 115 dB SPL.)
Input: 1 x Line In (Player or Mixer) / 1 x 43 Volt (Charge)
Battery: Li- Ionen battery (~ 6 hours runtime on max. Volume)
Accessories: Jack- cable; Charger


Klara Geist / Lautsprechermanufaktur
Gartenstraße 90 / 17309 Pasewalk / Germany