Multiple-Degree of Freedom Cavity Resonator Diary

How are your holidays? New simulator is just released. Latest simulator runs a number of simulation cases at the same time. You can just add some volume to certain chamber or adjust duct size a little bit and estimate where the best design is. Just try. It is easy. Manual is included in the package. Windows 32bit executable, additional DLL file for non MinGW users, and sample input files are included. Visit http://mcap.web.fc2.com/software.html .

Do you enjoy Christmas holidays? I wish you Merry Christmas and a Happy New Year. I noticed that this blog has not been updated. I would like to resume Field Presenter Application in January. I have been struggling with the MCAP-CR simulator. It is a CUI version, but CUI version is more important simulator than GUI version. I added new feature to the DFT version simulator. Last one required users lots of executions, because it can handle only one simulation case. Next version will be able to handle a number of simulation cases. It made me easier to find effects of chamber volume, duct size variations to frequency responses. I am sure it will help designing not only MCAP-CR simulators but also double-bass-reflex.

I have been studying dynamics of moving masses for multiple-degree of freedom cavity resonator applications. It is interesting, because (I have seen) no study about multiple-degree of freedom model. It is not too much difficult like continuum mechanics. Therefore, I could have developed simulator programs of multiple-degree of freedom models. On the other hand, pipe resonator model is continuum mechanics model, so that it requires another technique to develop simulator models. It is true that just calculating characteristic frequencies of pipe resonator is easy; however, using calculation formulas, we do not know exact behavior of a cavity resonator application. I will not study pipe resonator model for a time being. The reason why I adopted pipe resonator for the field presenter application was not to compensate low frequency response, but to realize slim body. Slim body is advantageous for field presentation, because slim body does not sound field as much as big enclosure b...

Here is the concept of UP4D (UnParallel 4-Direction) field presentation loudspeaker system. There are four drivers in each channel and each driver faces different direction, and height of each driver is different each other. Left channel and right channel are symmetrical. First application was pipe resonator system. Pipe resonator is advantageous to configure slim shape. This "slim" structure may be the most important factor for field presentation system. Any way, this one realized unbelievable sound field. To be continued...

New field presentation loudspeaker system consists of 4 drivers per each channel. Price of one driver was just 200JPY. 200JPY corresponds to 1.74USD (1USD=115JPY). Size of the driver was nominal 7cm (smaller than 3 inches but greater than 2 inches). The reason why I chose this driver was that the price was reasonable enough. Fostex drivers cost ten times or greater. With these cheap drivers, the new field presentation loudspeaker system impressed enough. I felt it was more than loudspeaker system. It would be something else than being a loudspeaker system. Every acoustic source I chose made sound field if I were in a small concert hall..... I lost word. To be continued.

I recently tried an application of field presentation loudspeaker system. It was a lot more than I had expected. Some group of music mania will be amazed at performance of this application and will realize that traditional approach may have been somewhat wrong... I decided to concentrate on field presentation applications and continue reporting to my Blog. to be continued...

Hello. I am trying to analyze new architecture of multiple-degree of freedom cavity resonator system. It is proposed by my friend in France. My program code has been almost complete for single-case analysis. I will add automatic multiple-case simulator feature to the CUI version program code later. What I am interested in is how the new architecture. What I found up to now are Any multiple-degree of freedom cavity resonator system has advantages than traditional single or double bass-reflex systems. Most important advantage of multiple-degree of freedom system for small driver is that it adds considerable amount of pressure wave of low frequency range. Most important advantage of multiple-degree of freedom system for middle or larger driver is that it removes strong character of not preferred harmonics of low frequency range.  There are more advantages. I am interested in #3 advantage. My friend had already made commercial models of multiple-degree of freedom systems...

Hello dear, I seldom update my blog... I am now challenging for new multiple degree of freedom system with my friend in France. He will release some interesting systems. There have not been many updates of my research. I have some more updates in my native Japanese pages. I was convinced that my simulator model code003 can simulate the behavior of MCAP-CR system. It was demonstrated in the presentation of Research Institute of Loudspeaker and Related Technologies last year ( link in Japanese ). Here is what I presented in the meeting for dynamic simulation procedure below figure. My friend also presented electrical simulation model of the same system with measurement result in the same meeting: See the shape and frequencies of peaks. Measurement result, my simulation and electrical simulation matched. Now I am challenging for different architecture model, still I am now in the debugging process. The difference between the new architecture and MCAP-CR is just e...

Hello. It has passed 5 months since last update. There are more frequent updates in the Japanese pages, but not main page. Please visit the following page: SAMPLE DRAWINGS .