Loudspeaker using MarkAudio "OM-MF4-MICA" - part 1

MarkAudio "OM-MF4-MICA" is a 6cm unit, so I decided to make a small bass-reflex system.

To make it small enough to be placed on a desk, I designed it to be 12 cm wide, 15 cm deep, and 20 cm high.


The small number of boards made cutting easy, and production was not difficult since the boards are laminated to the side panels one after the other.


At the time of temporary assembly, the duct direction was toward the unit, but I wanted to increase the duct length a little more, so I changed the direction to face the back plate.


The bottom plate had a 12 mm gap to allow the bottom duct to exit to the back plate side.


The bottom plate had a 12mm gap and the content area is about 1.9L. The duct frequency (fd) calculation assumed about 170 Hz.

A little sound-absorbing material was added to the top board side, and the side panels were attached to complete the project.



I waited a day for the adhesive to dry and measured the characteristics. The measurement location changed from before, so I made a comparison with my standard FOSTEX FE83N SP system.


With pink noise playing, amp volume at the same position, and measurement 100 cm on the iPhone axis,
The frequency response measured by the "Audio Frequency Analyzer" app was shown below.



The mid-high frequency characteristics of the OM-MF4-MICA were wonderfully flat, and above 16 kHz was the character of Mark Audio.

That would be expected to be flat with a frequency response at a 30 degree angle.

The duct frequency was probably around 160Hz based on this characteristic, and it looked 100Hz-12.5kHz flat.

The FE83N system seemed to have a slightly higher level at 1k-2kHz.

My impression of the OM-MF4-MICA system was that it did not have the typical papery sound. The high frequencies of cymbals and flutes were nicely diffused, and the graininess of the piano was also apparent.

However, the fundamental sound of the double bass and orchestral tutti reproduction were tough. If the speakers were installed closer to the wall, a little more low end extension might be expected.

So, I guess the only work left to be done is painting.

To be continued in the next article.
posted by toons at 21:29 | Audio