Preface


Yellowstone National Park, WY USA (Photo by Yuichi)



A-480 Horn

= Throat size : 1 in or 2.5 cm
= Cut-off : 480Hz
= Frequency range : 1200Hz to 20KS
= Material : a Chinese quince laminated lumber
= Finish : Two coats of oil based clear polyurethane varnish
= Color : Not applied


About sound measurement system

As I describe on the Front page, this Web site is for wood crafting and audio fans. I allocate many pages on how to make speakers. In parallel, I also allocate pages how to measure acoustic properties of the speaker systems and room acoustics.

Measurements are very important even in case we just buy completed speakers. After buying them, we install them in a room. Then acoustics show some behavior. But once we re-install the same devices in a different room, we will find them behave differently. It is because frequency changes, that is, echoes and standing waves characteristics change, and sound reflection from the walls also differ. This is why we need sound or acoustic measurement tools. We measure characteristics and record the data for the first step,. Then, do some adjustment work to find out better physical properties. Finally, we utilize our ears referring to the data we obtained in the first step. If we skip the first step, we get lost.

Somebody says that ears are the best measurement tools. Yes, the person is right, because the purpose of the speaker system is for listening music. It is true that ears are very sensitive to recognize differences. But in a sense, earfs sensitivity is not repeatable. They do not maintain the same sensitivity all though a day, week or season for instance. In this way, measuring the physical properties of a speaker system is imperative. For one example, TS (Thiele and Small) parameters drift during long term usage because compliance of surrounding circumstances changes. So once TS parameters change, vented box and vent size need to be adjusted to keep original characteristics of the system. Frequency response is identical to blood pressure in a human body.

For above reasons we need to have measurement system in order to have a good system, as well as good years. We do not need to have expensive measurement equipment. For good equipment, we can very easily find it in the Internet world. Some of the devices even do not require external hardware. Just only software can be downloaded into our PC. Then the PC becomes a good sound measurement system. I introduce some of these in this Web site.


About Wood Craft

Wood crafting is a very enjoyable world. We can yield beautiful works by choosing good materials. Sometimes it is a hard work cutting and forming them. But we can yield good ideas by fully utilizing our time and brains. It is so beautiful when it is completed. It also gives us great satisfaction. For wood materials, I strongly recommend laminated lumbers of cherry plywoods and Chinese quince. These are hard and heavy but very good for loudspeaker enclosures and horn speakers. I often use these materials. I have never had problems related to cracks or volume reduction on these materials. Red sandalwoods and ebonies are also very good and beautiful but are too hard to cut, but worthwhile to challenge. Maples are good too and relatively easy to get. Softwood such as cedars or pines is not recommendable because it shrinks, but is good for experimental purposes.


About listening Music

You guys are specialists in this domain. So, I have nothing to say. Please enjoy yourself!!

A-300E Horn

Driver throat size:
2in or 5cm
Cut-off : 300Hz
Frequency Range:
600 Hz to 20KHz

Material : a
Cherry plywood
A-290 Horn

Driver throat size:
2in or 5cm
Cut-off : 290Hz
Frequency Range:
600 Hz to 20KHz

Material=a Chinese quince laminated lumber
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