Multiple-Degree of Freedom Cavity Resonator Diary

This is the real giant. It is the first ever commercial product of multiple-degree of freedom cavity resonator type loudspeaker system! She is the president of DreamsounD where my friend devotes himself for true high-fidelity music presenter loudspeaker system. You will imagine how big it is!　She is not a dwarf. Once my friend wrote to me since he got interested in MCAP-CR. He had other multiple-degree of freedom cavity resonator project. I helped him for a little bit analysis part. He was really much impressed with the performance of the model. He wrote to me that he had never experienced such presence of music with the new system. I wish I could hear it. France is too far from Japan. Visit DreamsounD for more details. Ciao!

I recently noticed that the single file size is limited to only 250kB by FC2 free website. Therefore, some simulation program files were deleted by server. I have to find how to avoid this restriction. I know that standard paid service can avoid this restriction; however, I do not get any money from this research! I want to use free web service, unless there comes any sponsor... I feel sad research does not make money...

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.