Sunday, August 29, 2010

Finishing cabinet

 Cabinet of the system was painted yesterday. It was tougher work than I expected.  Finishing work is always the most tough part of loudspeaker system assembly.
It looks nicer than I expected. I learned about painting recently by commercial DIY video by Loudspeaker Meister Mr. Oyama. It is available in his website. His video is more than excellent than anything else. I wish I could have bought this twenty years ago. I should not have spend hundreds of euros, if I had had this video.

 After finishing was done, I replaced speaker driver modified FE83E with FE83En, then I was disappointed at the sound. Therefore I made some modification to FE83En.

 Appearance became different from FE83E. Painting from back side made dirty stain in the front side, while same painting material was used.

 It seems material of membrane became somewhat different.

 Sound after this modification was made, impresses me a lot. High frequency does not annoy me as original FE83En. Problem was that low frequency at 50Hz became too strong so that membrane hit limit and made noise; however it is not problem for home use.

 I do not recommend any one to make same modification. It will spoil the speaker driver unless user love this result.

Multiple-Degree of Freedom Cavity Resonator Project

Monday, August 23, 2010

Remodeling speaker driver

 Modification of speaker driver was tested.

 Original speaker driver was FE83En. Before making change to this FE83En, FE83E was modified in order to know if modification works well.

 Purpose of this change was to make high frequency response lower and and to boost low frequency response.

 What was done was to make painting layer to back side of membrane. Painting layer has effect to increase mass of membrane and to reinforce stiffness of membrane. Former one will make F0 lower, so that response of low frequency will be boosted. Later one will work to reduce high frequency response, because higher vibration mode will become higher because stiffness will increase.

 I was not sure if there were any side effects. I am not Fostex sound lover, so that I decided to remodel Fostex original.

 My impression follows:

  1. No side effects were tangible.
  2. Distortion in high frequency seems to be reduced.
  3. Low frequency response was somewhat boosted.

 As a result, this modification seems to work well to "me". Please do not copy this modification. Success is not guaranteed at all.

Sunday, August 22, 2010

Impression and tuning of the new model

This new model was designed to demonstrate at Muse-no-hakobune loudspeaker craft contest which will be held in November this year in Tokyo. I named this new model as "CON GIOIA". "CON GIOIA" is Italian words that mean "with joy".

I think the most important objective of speaker craft is to enjoy, so that new model was named "CON GIOIA".

Approximately three week has passed since CON GIOIA was assembled. It has wide frequency range. Low end frequency is around 50 Hz or even lower. This may be enough for Fostex's 3" driver FE83En. Response of 80Hz - 100Hz does not sound high enough to me, so that I made some change.

I tried to reduce capacity of main chamber of the speaker cabinet stuffing clay into main chamber. Volume of main chamber of original design had little less than 4 litre. It was spacious, but I tried to reduce by 1.5 litre in order to tune some characteristic frequencies in order to compensate 80 - 100Hz small dip.

It did not make significant change. I will try some thing different later.

Wednesday, August 11, 2010

Structure of new model

This is internal structure of the new MDOF-CR model. This model has main chamber and two sub-chambers. All the chambers are connected through ducts each other.

Number of degrees of freedom of ducts is five. Much more complex than double bass-reflex cabinets.

Some more information will be uploaded later.

I will soon have vacation, so we will see at the end of August.

See you on the Blog!

Give me email if you have any questions. My email address is "mcapspeakers @". Please remove two spaces from the email address both sides of "@".

I have just begun Blog!


I have just begun Blogging my story of multiple degree of freedom cavity resonator (MDOF-CR) loudspeaker systems.
I manage web pages in the different place, but not frequently update them. I will write what some are interested in.

This is an application of MDOF-CR. I will later upload more details.

Please also review my pages.

Best regards,