2019/09/19

MarkAudio "OM-MF519" Speaker assembly Part 7 - frequency characteristics

OM-MF519_DB_1.jpg

After painting, I played a lot of music with this speaker for sound aging.

My personal impression is that the bass sound is very loud despite the 8cm full range. This is probably due to the bass enhancement effect of the double bass reflex.

# frequency characteristics (distance 1m, Pink noise, measurement by RTA app "Audio Frequency Analyzer"j
OM-MF519_DB_freq.png

However, looking at the frequency characteristics measurement above, it seems that the elasticity and tightness are retreating compared to a general bass reflex type, probably because 125-200Hz is slightly depressed. In a sense, 100Hz or less is too high.

Next, I adjusted the length of the second duct and examined how the frequency characteristics changed.

# Original duct (15cm)
duct-original.png

duct-original.jpg

I prepared a paper pipe with a slightly smaller diameter and measured it in units of 2cm.

The level of 100Hz decreased in the duct +2cm. It may be the effect that the duct area is slightly reduced.

# Duct +2cm
duct-2cm.png

duct-2cm.jpg

After that, the length of the duct was increased by 2cm, but no significant change was observed. It is also possible to pick up ambient noise.

# Duct +4cm
duct-4cm.png

duct-4cm.jpg

# Duct +6cm
duct-6cm.png

duct-6cm.jpg

# Duct +8cm
duct-8cm.png

duct-8cm.jpg

# Duct +10cm
duct-10cm.png

duct-10cm.jpg

# Duct +12cm
duct-12cm.png

duct-12cm.jpg

As a trial, I changed the length of the upper and lower ducts extremely. But, it did not be much different from closing the duct.

# Duct +2cm, +10cm
duct-10cm-2cm.png

duct-10cm-2cm.jpg

These results was not clear, so I have to try several times with different dates. I try listening with a duct length of + 4cm for a while.
posted by toons at 03:20 | Audio

2019/09/18

MarkAudio "OM-MF519" Speaker assembly Part 6 - external painting

DB“h‘•(1).jpg

As usual, the back and top plates were painted with black spray. To change the taste a little, I started to paint blue to the side plates, but the gas ran out during spraying on both sides.

DB“h‘•(2).jpg

I gave up and overlaid with black from above. After all, it doesn't look good in the surrounding black.

And then I found the remains of the cork sheet!

DB“h‘•(3).jpg

If the front baffle is cork-lined, I expect a retro feel. The baffle surface is where the woodworking bond is diluted and bonded, and the surface is coated with a thin aqueous varnish to increase strength.
The baffle edge was not able to be processed well and it floated a little around the middle.

It was made by cutting out round to fit the unit.
The sound absorbing material was inserted with the weight of the left and right channels matched.

DB“h‘•(4).jpg

DBŠ®¬Œ`(front).jpg

Finally, the speaker was completed by tightening the duct screws!

DBŠ®¬Œ`(rear).jpg
posted by toons at 00:17 | Audio

2019/09/17

MarkAudio "OM-MF519" Speaker assembly Part 5

MarkAudio OM-MF519 Double bass reflex speaker is almost completed.

OM-MF519-DBŠ®¬Œ`(5).jpg

However, the entire box is still under consideration for external painting.

OM-MF519-DBŠ®¬Œ`(6).jpg

For trial, I painted only the duct part of back side.

OM-MF519-DBŠ®¬Œ`(7).jpg
posted by toons at 01:50 | Audio

2019/09/16

MarkAudio "OM-MF519" Speaker frequency characteristics, part 3

MarkAudio OM-MF519 Double bass reflex speaker is being adjusted.

The characteristic (1) was the result of adjusting the sound absorbing material to match my listening preference.

This was a measurement result at 1m above the unit axis (tilt about 15 degrees to the front of the baffle). The peak at 250Hz dropped, and the characteristics seemed to shift to 200Hz or below.

The characteristics of the second duct seemed to be concentrated around 60-100Hz. Then this area may not change unless the duct length is changed.

(1) Frequency characteristic of adjusting the sound absorbing material
“Á«(1)_1ch_‹z‰¹Þ3_4(20190816)-2.PNG

Incidentally, the characteristic (2) was measured on the front axis of the unit. The peak of 12k-16kHz which is the high frequency characteristic of this unit was appeared.

(2) Frequency characteristic on the front axis of the unit
“Á«(1)_1ch_‹z‰¹Þ3_4(20190816)-Ž²ã.PNG

The characteristic (3) was the result of distance from the baffle to 2m.
Although a peak was seen at 100Hz, I thought that it was possible to get around 50Hz as a low frequency characteristic.

(3) Frequency characteristic from the baffle to 2m
“Á«(1)_1ch_‹z‰¹Þ3_4(20190816)-2m.PNG

As for my impression, I could hear the profound feeling of the bass and strings with the feeling of adding a subwoofer.

However, the feeling of tightness in the low frequency area will be reduced, so the rhythm may be lighter in jazz and pop music. I don't know if this is a characteristic of the box, or if the work accuracy or adjustment is insufficient.

Since the internal adjustment is over, I will consider finishing the box surface.
posted by toons at 02:54 | Audio

2019/09/15

MarkAudio "OM-MF519" Speaker frequency characteristics, part 2

“Á«(1)_1ch_‹z‰¹Þ(20190814)-1.PNG

I tried putting the sound absorbing material into the first and second cabinets. It was shifted to the low side, 40/50Hz level up, dipped occurs at 160Hz.

And I reduced them for the first cabinet a little more. Adjustment was troublesome. Although it got more sense of volume in my hearing, the sound response was declining.

I will try to make a sound with this for a while.
posted by toons at 09:29 | Audio

2019/09/13

MarkAudio "OM-MF519" Speaker frequency characteristics, part 1

Attached the MarkAudio "OM-MF519" unit to the double bass reflex speaker box, so I made sound test.

I measured the frequency characteristics at the begining of playback and after aging for 1 hour. It was tested by the RTA app "Audio Frequency Analyzer" with pink noise.

# Begining of playback
“Á«(1)_1ch(20190814)-1.PNG

At the start of playback, there was a dip at 125Hz, but the level increased a little in about an hour.

# After aging for 1 hour
“Á«(1)_1ch_1ŽžŠÔƒG[ƒWƒ“ƒOŒã(20190814)-3.PNG

The original high frequency peak of 12-16kHz has disappeared. This is probably because the baffle is slanted and the measurement point is about 15 degrees off the unit front axis.

In addition, when blocking to tape one duct as a test, the 63/80Hz sound level was dropped. The second cabinet duct was seemed to have worked well.

# Blocking one duct
“Á«(1)_1ch_ƒ_ƒNƒg1ŒÂ(20190814).PNG

It wasn't the final sound because there was no sound absorbing material yet in the box, but the sound resolution was very good. The bass range did not drop to the lowest sound, but it had enough low-pitched feeling unlike a simple bass reflex.
posted by toons at 00:12 | Audio

2019/09/12

MarkAudio "OM-MF519" Speaker assembly Part 4

‘g—§Š®.JPG

I scraped off the gap between the baffle and the side plate. I found that it had a little off, but I'll try sanding again even before final painting.

The duct plate was temporarily fixed. I'll measure the frequency characteristics with no sound absorbing material by attaching the speaker unit once.
posted by toons at 01:15 | Audio

2019/09/11

MarkAudio "OM-MF519" Speaker assembly Part 3

‘g‚ݏグ(2)-1aJPG

I attached a terminal plate and routed the wire through the first duct. The surplus plate was reinforced by adhering it appropriately to the large area plate.

When attaching the remaining side plates, it felt a little floating, so I made a fine adjustment by sanding the protruding part.

“à•”\‘¢2.JPG

I glued the side plates and waited about half a day with a weight on top.

The inside of the speaker is only accessible from the speaker unit hole and the back plate duct. It can be the adjustment of the duct length and the addition of sound absorbing material.

I will make the appearance better by shaving the protruding part with a file when the adhesive is dry.
posted by toons at 00:21 | Audio

2019/09/10

Introducing TOON's free iPhone apps!

TOON offers free apps of various genres.

You can see more detailed information by clicking the icon below.

There are many apps with the same functions as the paid version, so please try the one you are interested in!

# Environmental measurement support Apps

Sound Level Analyzer Lite
icon-slalite_v400.png

"Sound Level Analyzer Lite" is a free sound level meter app that has simplified the sound measurement analysis function of the "Sound Level Analyzer"


Vibroscope Lite
icon-vslite_v300.png

"Vibroscope Lite" is a vibration measurement app by using the iPhone's acceleration sensor in real-time. It is a free app that has simplified the measurement analysis function of "Vibroscope".


Magnetscape Lite
icon-magnetscape_lite_v200.png

"Magnetscape Lite" is a new measurement app that observe invisible magnetic fields by using a built-in iPhone magnetic sensor. It is a free app that is simplified the magnetic analyzing tool, "Magnetscape"


Tilt Scope
icon-tiltscope_v100.png

"Tilt Scope" is a new inclinometer app by using iPhone's acceleration sensor.
You can easily measure the slope of a variety of locations, such as the distortion of the floor, the inclination of buildings.


# Life & Health support Apps

Hearing Analyzer Lite
icon-hlalite_v210.png

"Hearing Analyzer Lite" is a hearing check app that can be easily measured the frequency characteristics of your hearing. It is a free app that has simplified the hearing analysis function of "Hearing Analyzer"


# Audio & Sound support Apps

Audio Tone Generator Lite
icon-atglite_v400.png

"Audio Tone Generator Lite" is a reference Audio test signal generator app for iPhone. It is a free app that has simplified the sound generator function of "ATG - Audio Tone Generator" app, which creates Sinewave, Sinewave Sweep, White Noise and Pink Noise.


Colored Noise Generator
icon-cng_v300.png

hColored Noise Generator" is a new noise generator that can be used to as the sound source for a variety of acoustic measurement.


# Music Apps

Timbre16 Player
icon-t16p_v100.png

"Timbre16 Player" reproduces the favorite music with your sound image.
It is equipped with the high quality audio enhancer that allows the adjustment of various sounds.


# Healing Apps

Synthetic Healing Sounds
icon-shs_v120.png

"Synthetic Healing Sounds" is a new healing app that has the right relaxing sound on your living, bedroom and working space. It can be produced "Binaural Beat" sound with base relaxing sound at the same time.
posted by toons at 23:56 | News

MarkAudio "OM-MF519" Speaker assembly Part 2

First of all, I filled up the shortage of the duct back plate with a 23mm plate from the bottom plate.

’ê”Â.JPG

And the duct back plate was assembled. The duct is a 150 mm long paper pipe.

ƒ_ƒNƒg•”.JPG

The top plate and upper back plate were bonded.

“V”Â.JPG

I assembled the part that would become the first cabinet, but there was a slight gap.

‘æ1ƒLƒƒƒr.JPG

The first cabinet was glued to the baffle plate and fixed with a surplus plate sandwiched so that the duct width was 12mm.

ƒoƒbƒtƒ‹.JPG

This completes the assembly of the main components. And the parts were fixed to the side plate.

‘g‚ݏグ(1).JPG

It seemed that the reinforcing material of each corner and the bond were attached too much.
Before attaching the side plate on one side, it is necessary to route the terminal plate and wiring cord.
posted by toons at 01:55 | Audio