Larsen version 4.3

Larsen version 4.3 was introduced in March 2021, after gone through an internal makeover. Two new drivers from the Danish company SB Acoustics and a new crossover brought the speaker to a new level. SB Acoustics have succeeded to improve their drivers in a way that agrees well with Larsen’s ortho acoustic philosophy and wishes.

What will you get with Larsen 4.3?

“A real audience-friendly bass and a much better discant is what we achieved”, says John Larsen.

“The new Larsen 4.3 has the same deep bass response, but noticeable lower distortion in the midrange and high frequency range. This manifests in an airier soundstage, not harsh at all, where you more easily can distinguish and follow details, as well as the core of the general presentation of the musical performance”, says Stefan Björklund, our Technical Advisor.

Improvements in depth

In an ortho acoustic loudspeaker, the baffle for the drivers is normally angled so that the driver’s axial direction is pointed upwards and inwards to help create the balanced sound energy distribution throughout the complete frequency spectra in a larger listening area than the “normal” sweet spot of a conventional loudspeaker. Counteracting the beaming of the high frequencies of the tweeter.

As a loudspeaker designer of ortho acoustic speakers, you need to prioritize the 30 ° off-axis radiation that is actually pointing towards the listener. Doing so in the crossover circuit design with a tweeter driver, like the one in figure 1, will result in a boosted on-axis response pointing towards the ceiling.

In a good (optimal size for that particular ortho acoustic speaker with optimum reflection/absorption) listening room, this extra on-axis acoustic energy in the high frequency can (as long as you sit down) enhance the positive effects of the idea of distributing high-frequency sound energy in a larger listening area.

In a not-so-good room/speaker placement, this extra energy might reach the listener in a way not intended and this can result in the loudspeaker sounding a little brighter than intended and even harsh with some musical material.

In designing Larsen 4.3, we got to resolve this issue by choosing a new tweeter that has sound radiation that is virtually identical in the 0 ° on-axis as well as the 30 ° off-axis direction. (Something like 3 dB down as high as at 18 kHz). Please look in figure 2.

With uniform sound radiation in all relevant directions, the perceived sound will not change in different rooms, if you sit down or stand up, not even if you go close to the loudspeaker and stand in front of it.

The principle of angled baffle sound energy dispersion in a larger area etc. is still fully implemented but in a more controlled way.

Figure 1 – Larsen 4.2

Response curve
Black : on axis, Green : 30 ° off-axis, Red : 60 ° off-axis

Figure 2 – Larsen 4.3

Response curve
Blue : on axis, Black : 30 ° off-axis, Red : 60 ° off-axis

Besides the obvious differences is frequency response curves the new tweeter also have a lower level of distortion.