INTERVIEW

Interview with JANUSZ ROGOŻ. Finale platform BBS

Wojchech Pacuła’s interview with JANUSZ ROGOŻ,
owner, chief designer
„High Fidelity”, nr 185, 1 września 2019]

WOJCIECH PACUŁA: What is the symbol of the new platform?
JANUESZ ROGOŻ: The platform doesn’t have a symbol, but rather a name – the Finale / BBS. BBS is the acronym for our proprietary anti-vibration system. It started with a series of racks called Trio / BBS, Quartet / BBS, and so on.


So from now on all platforms will have names instead of symbols?
For sure, product lines that already have names – such as the latest racks – will be continued. The names of the last series of racks referred to the number of musicians in a band. In the case of platforms, their names will be referring to a part of a music piece – in this case it is Finale. I don’t know yet how we will call the next models.
It might be difficult to trump Finale…
(Laughing) Yes, it is not going to be easy, but I will come up with something 🙂 It does not mean that we will never have an even better platform, but for now it is our top model.


How does Finale differ from previous Rogoz Audio models?
It differs primarily in the fact that the BBS system is doubled. It consists of independent elements – each feet is also independent. The middle board is placed on those feet and it is already movable. In turn, this board is the basis for another BBS system – it is a work top. So there are two levels of lateral movement. The thing was that the previous top platform featured only one level, as in the racks. And while in racks one doesn’t need more, it is quite sufficient, because the top shelves are high above the vibrating ground (floor), in the case of a platform the top shelf might be sitting quite close to the ground/floor.
It’s not really that two BBSs are better than one. But the specifics of the platform’s operation required smoothing its resonance characteristics. As I say, this is not an issue for racks, because the tops are placed far away from the source of vibration (floor), but the platform does not have this first “stroke” buffer from the surface on which it is set. When we measured the racks and compared them with a platform in an extreme situation, i.e. when the platform was placed on the floor, close to full-range speaker capable of producing dynamics at the level of 100-110 dB for low frequencies of 16-20 Hz, it turned out that the rack tops were a bit less energy-laden with vibrations generated by the speakers than platforms.
The use of the second BBS system does result in twice as small load distribution, but it is more important that the phase characteristics of the resonance response changes. Both tops move horizontally, but depending on which one receives the vibrations – i.e. stroke – first it will move in a different phase than the second one. The phases of these vibrations will not match, thanks to which we get even greater smoothness of the resonance rise edge. And this is, in fact, the only difference between a single BBS and a dual one.


What do you measure in anti-vibration platforms?
We measure each rack and platform during standard tests using accelerometer – it is about measuring the acceleration of vibrations. Each material has its own resonance response characteristics. In the measurements we can see it as a main resonance, for example in the range of 500-800 Hz, which looks similar to the measurement of the impedance of loudspeakers as a function of frequency – there is one peak and a slight peak and then fall. Wherever there is a flat characteristic, within 5 dB range, there is the most effective damping and vibration dissipation by the platform. Where the material’s own resonance is activated, we can see a reduction in its effectiveness.
Individual materials differ from each other in the resonance response spectrum. The shape of the resonance build-up curve changes, which can be presented on a frequency graph as a function of volume level. The higher the curve and the sharper its shape, the more narrow the band and the more annoying it gets for a listener. However, if the vibration amplitude is relatively low, more widely distributed in the band and with a gentle slope inclination, then the vibrations interfere less in the musical signal and interfere less in the physiological sensitivity of the listener – they simply get less tiring.
The point is that the build-up of the resonance should be as smooth as possible, i.e. the characteristic should not be full of by peaks and „holes”. This is related to the vibration phasing, i.e. how they are distributed in the structure of the material and in the whole structure of the product. These are many variables that need to be combined in a project.

Are you more of a technician or a music lover?
When I work I become a scientist – methodology is the most important for me, both in terms of measurements and in relation to listening tests. I am a fan of a methodology that is called 'well-established methodology’. It was invented in the 1960s by Anselm L. Strauss, and in Poland it was Krzysztof T. Konecki who introduced it to the humanities.
It is an induction methodology. The point is that we don’t develop a project and only then wonder why it sounds one way or the other and using deduction we find out what contributed to it, and then we go back and change the parameters to improve the final result. In grounded methodology, we come to the effect by induction. In small steps, slowly. At each stage there are auditions and measurements, as well as falsification of projects and this way we reach the final product. We build a „house” not from prefabricated elements, but from foundations, layer by layer.
This is what grounding is all about – if you put a foundation, it needs time to fix, then you build a brick wall, which again needs weeks and months to dry, etc. Falsification is carried out on many levels. I am the author of the project and I can say that it is a process of long and arduous listening and testing. The deduction method is easier and faster, but it doesn’t give you confidence, you can’t use it to build over a longer distance. The effect is obtained quickly, but is individual.So, to answer your question: I like to think of myself as a scientist, but I surely am a music lover.


So first comes idea, then measurement and finally listening sessions?
The measurement stage is only for checking the results of our work. Only a few basic parameters can be measured, and there are many times more variables that we do not know. These are things that don’t get measured. Of course, you need to make measurements at each stage to see if you stick to the assumed parameter, but then there is time to work on it – this is just grounding the theory.
Due to the fact that we have been operating this way from the beginning, projects that were created several years ago are still good, we can still be proud of them. I have withdrawn three or four early projects, but that’s it. Sometimes we introduce some changes and the product get upgraded to the „MkII” version, but these are cosmetic changes. Since our working method is time consuming, we introduce new products very rarely.