Kvalsvoll Design AS About Products & Services Sound! Logo


English text ENNorsk tekst NO

Related articles:


A new standard for sound.

Small size, works in ordinary rooms, and sound quality so much better it makes a real difference.

This is the sound of the future.

The sound

F205 is accurate, precise, analytic.

There is clarity and separation that makes you hear each instrument as individual objects.

Dynamic transients makes percussive instruments like drums sound live and realistic.

Resolution and detail at higher frequencies sets a new standard, and it still sounds so smooth and clean even at very loud volumes.

The soundstage becomes 3-dimensional with full depth, and instruments appear as real objects with physical size. Even if your room is far from perfect, you can achieve some of this magic.

This sound makes it very engaging to listen to music, it becomes addictive.

How it works

Almost normal

The F205 is a floor-standing, quite small, passive loudspeaker.

It does not play bass, and it has optimized sound radiation pattern.

Output capacity is loud enough to enable live concert levels, while also providing finesse and accuracy.

Use a good power amplifier, one that can handle a 4 ohm load with ease, and high power if you want to play loud.

F205 needs active crossover and separate bass-system. This is integrated in our sound system solutions. Or you can use other alternatives - a standard AV-receiver/processor with sub output solves the crossover part, if you already have subwoofers those can be used with the F205.

Radiation pattern makes the difference

Sound is focused towards the listening area, just wide enough to cover most of the room, so that the sound is tonally similar if you move around in front of the speakers, while radiation to the sides and back from the speaker is attenuated.

This minimizes reflections from surfaces close to the speaker, making the speaker less affected by placement and improves clarity and spatial location of instruments in the soundstage.

There is less total sound power emitted from the speakers for same sound level at the listening position, which again means there is less sound to bounce around between reflective surfaces inside the room. This reduces the impact of room acoustics on sound quality. A bonus benefit is that this also reduces sound outside the listening room.

Tonal balance may be perceived as brighter compared to a traditional speaker, and this is due to less coloration and energy from room reflections in the lower midrange. Tonal balance can be adjusted with equalization.

Separate bass-system

Bass is handled by separate subwoofers. This is beneficial for both midrange and bass, because the units can now be designed and placed optimally for the frequency range they cover.

Separate bass-system also provides flexibility. Bass-system is chosen according to room size and preferences, and can also be upgraded if the need or desire for more bass arises. The larger Compact Horn models can be stacked in multiple units to provide enough capacity for a live concert in large rooms, budget is the only limit.

The T6-A Compact Horn subwoofer with integrated amplifier turns F205 into an active speaker system. The 2-channel amplifier with DSP in the subwoofer does crossover and processing of the sound and powers both the subwoofer and F205.


Only as strong as the weakest link. There is no point in making one brilliant solution for one particular problem, if the rest of the design is just average.

The key to dynamics and realism is sound radiation control and sufficient capacity. Traditional technology requires large loudspeakers to achive this. But it can also be solved in smaller physical format, with the right solutions. As in the F205.

The radiation control is achieved using horn for higher frequencies, and acoustic ports on the side of the cabinet at lower frequencies.

Crossover is a combination of active and passive. The low cut-off is implemented active at 120Hz, where the bass-system takes over. This crossover is made so that flat phase is possible and no time discontinuity occurs in the important upper bass area.

Crossover between midrange and tweeter is passive, with extremely sharp cutoff and controlled phase and time behavior. This ensures sound never comes from different speaker drivers at different time in the same frequency range, and this is of great importance for perceived soundstage and resolution.

Choice of parameters and properties for the drivers is responsible for much of the sound in the F205. The HF driver in the horn is a medium-sized AMT, it has exceptionally low distortion and decent capacity. The LF drivers have very good transient reproduction and high sound pressure capacity, as well as covering their range completely without resonances from diaphragm or other moving parts. This is possible because they do not play bass, and they only work up to 1700Hz where the HF section takes over.

Sound from the rear of the drivers is acoustically filtered inside the cabinet, and radiates out through the holes on the side. This sound, combined with the sound from the front, creates radiation control down in the midrange and upper bass frequency range. To achieve this, there are three chambers inside, with four different types of acoustic damping material, there are acoustic ports inside the cabinet. The radiation pattern gradually widens downwards in frequency, like a normal large speaker, only slightly narrower so that less sound is sent backwards and out to the sides. In front of the speaker, towards listeners, the radiation is even.

AMT driver in horn is the ultimate solution for high frequencies. Transparency and airy highs similar to a ribbon, but also much lower distortion and higher output capacity.

The horn with the AMT driver is designed for a very precise radiation pattern, where sound is even over a large area forward into the room towards listeners, and sharp cut-off outside, across the entire frequency range from 1700Hz to the top. Horns can also be used for the rest of the frequency range downwards, but then the speaker will become very large, with dimensions close to 1 meter in width.

Development of such a loudspeaker is a combination of art and science.

An adjustable base can be delivered as an option.


F205 / F205-A Loudspeaker
Free-standing active (F205-A) or passive (F205) loudspeaker for music and entertainment in small and medium rooms, to be used in stereo pair, integrated with bass-system for low frequency reproduction.
Frequency range
120Hz - 20KHz
Rated impedance
4 ohm (Minimum 3.6Ω @196Hz)
Recommended amplifier power
5W to 400W
Power handling
300W AES (AES2-1984) / 600W Program (Normal music program material)
Output capacity
LF section
2x5" high output capacity drivers in small cabinet with damped acoustic ports and internal chambers
HF section
Medium-size AMT driver in controlled directivity horn
Crossover frequencies
LF section to HF section: 1700Hz controlled phase, very steep cutoff
F205 to bass-system: 120Hz active dsp-controlled
Recommended listening distance
1.6m - 3.2m
Optional base with angular tilt adjustment
Vertical adjustment 0° to 4° (default 2°)
Horizontal coverage
Cabinet Material
Birch plywood
949mm (floor-to-top)/162mm(cabinet baffle width)/182mm(cabinet depth)
Footprint 232mm(width)/204mm(depth)
F205 in Color
F205-A Active Version
Internal Hypex nCore FA251.
DSP functionality
Processing for bass-system crossover and integration, eq, delay, programmable.
Amplifier output power
Input Signal
Analog RCA 2.18Vrms,
Analog balanced XLR 6.15Vrms