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Audiovisual Useful

Guide to Choosing Audio and LED Display Systems for Events

When it comes to organizing a successful event, the choice of audio and visual equipment can make or break the experience. In this comprehensive guide, we’ll explore the key factors to consider when selecting speakers, amplifiers, mixers, and LED displays, ensuring your event delivers an engaging and memorable experience for attendees.

Part 1: Choosing the Right Speakers

Speaker Type:

There are two main types of speakers: passive and active. Passive speakers require an external amplifier, while active speakers have a built-in amplifier. Consider the space and setup requirements of your event when choosing between the two.

Frequency Response:

The frequency response of a speaker determines the range of audio frequencies it can reproduce. A wider frequency range generally results in better sound quality. Look for speakers with a frequency response of 20 Hz to 20 kHz, which covers the entire audible spectrum for humans.

Power Handling:

The power handling of a speaker refers to the amount of power it can handle without being damaged. Ensure that the speakers you choose can handle the power output of your amplifier.

Sensitivity:

Speaker sensitivity measures how efficiently a speaker converts power into sound. A higher sensitivity rating means that the speaker will produce more volume with less power.

Impedance:

Impedance is the resistance of a speaker to the electrical current flowing through it. Most speakers have an impedance of 4, 8, or 16 ohms. Make sure the impedance of your speakers matches the output impedance of your amplifier.

Part 2: Selecting the Best Amplifier

Power Output:

The power output of an amplifier should match the power handling of your speakers. An amplifier with too little power may not provide enough volume, while an amplifier with too much power may damage your speakers.

Class of Operation:

Amplifiers are classified as Class A, Class B, Class AB, or Class D. Each class has its advantages and disadvantages in terms of efficiency, distortion, and heat generation. Class AB amplifiers are a popular choice for live events due to their balance of efficiency and sound quality.

Signal-to-Noise Ratio (SNR):

The SNR of an amplifier measures the ratio of the desired signal to the noise generated by the amplifier. A higher SNR means better sound quality. Look for amplifiers with an SNR of at least 90 dB.

Inputs and Outputs:

Make sure the amplifier you choose has the necessary inputs and outputs for your setup. This may include XLR, 1/4-inch, or RCA connections.

Part 3: Mixers and Their Role in Audio Systems

Inputs and Channels:

The number of inputs and channels on a mixer determines how many audio sources you can connect. Consider the number of microphones, instruments, and other sources you’ll need to accommodate when selecting a mixer.

Signal Routing and EQ:

Mixers allow you to adjust the volume, equalization, and routing of individual audio channels. Choose a mixer with enough control and flexibility to meet your event’s needs.

Effects and Processing:

Some mixers come with built-in effects and processing, such as reverb, compression, and delay. These can be useful for enhancing the sound quality and adding creative touches to your audio mix.

Part 4: LED Display Technology

Pitch Size:

LED pitch size refers to the distance between the centers of adjacent LED pixels. A smaller pitch size results in higher resolution and better image quality. The ideal pitch size depends on the viewing distance and the size of the screen. As a general rule, a pitch size of 1.2mm to 3mm is suitable for indoor events, while a pitch size of 4mm to 6mm is more appropriate for outdoor events.

Brightness:

LED displays should be bright enough to be visible in various lighting conditions. For indoor events, a brightness of 500 to 1,000 nits is usually sufficient. For outdoor events, a brightness of 2,000 to 5,000 nits is recommended.

Curvature:

Curved LED displays can provide a more immersive viewing experience and better viewing angles. Consider the layout of your event space and the desired audience experience when deciding between a flat or curved LED display.

Pixel Density:

Pixel density is a measure of the number of pixels per square meter. A higher pixel density results in better image quality and detail. For most events, a pixel density of 100,000 to 200,000 pixels per square meter is sufficient.

Choosing the right audio and LED display systems for your event is essential for delivering a memorable experience. Check out our dedicated site If you need technical help for your event in Japan.

Categories
programming Useful

Bash Infinite Loop raspberry pi

We are using a raspberry pi (with raspbian) to run a video file in a loop at www.dokodemoterebi.com, but this should work with any linux version.

Creating an infinite loop is very simple the following code will do the trick:

while true; do omxplayer /home/pi/myvideo.mp4; done

If you want it to run at start up, edit /etc/init.d/rc.local and copy the code above at the end of rc.local

Now you only need to power the pi and the video will run in an endless loop, log in or any input from the user is not necessary. Be careful as you will be locked out if you do this. If you need to change something in the future you can plug the disk into another linux machine or use ssh.

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Useful

Things that have helped me on my life in Japan

This post is a special post about repairs but I will list a few tools, places, etc. that have helped me as a foreigner. I hope those tips may be useful to the newcomers to Japan.

– If you are in Japan you will probably want to write in Japanese with your PC. To enable Japanese language go to “Control Panel” — “Language” and add the Japanese keyboard to your existing keyboard. ?You may also need to choose the option to install files for Asian languages. To?switch?between Japanese and?whatever?other languages you have installed you can click on the language bar on your desktop or the method I prefer press Alt+Shift. Even if you choose Japanese roman input is selected by default, to switch to hiragana you can go again to the language bar or do it faster pressing Ctrl+Caps Lock.

– If you use Google Chrome Rikaikun is a must, Rikaichan is the Firefox version. When you pass the basic stages of Japanese learning you may be able to understand many emails and information on websites but the problem is usually the difficult kanji. With Rikaikun and Rikaichan addons you can just hover the mouse over the words as you read to get the reading and translations for an almost real time Japanese reading. Of course you can also use traditional translation tools like google translate but I prefer to read the original as I may miss things because of a bad translation and it also helps on your learning.

www.jisho.org?is the other tool I use often. It is not only a dictionary but it marks common words, so that you can choose the right word if you don’t know which to choose from the provided translations. May words also come with example sentences that help to see the context where it is used and make sure it is the right meaning. Other interesting features are that you can get translations from japanese words in romanji, if you don’t know how to write it in kanji and also searching kanjis by radicals (useful if you don’t know how to read the kanji).

– I use www.hyperdia.com/en/ every day to plan my trips by train. They have a mobile phone version (paid) but you can also use the website version from free from your mobile browser.

– For banking most foreigners use Shinsei Bank, they don’t charge commissions for most operations and you can receive foreign bank transfers for free (other banks charge 4,000Yen or more). They also have English customer support and English online banking.

Softbank is the best carriers for foreigners, as they provide most of their information in English and they have english speaking staff in some shops in Tokyo. They also have prepaid phones that is useful for short stays. BMobile is the option if you want to use your own phone as you can buy only the sim with a prepaid or contract plan. Most of the info is in Japanese but they have limited information about one of their SIMs for visitors. BMobile ?rents Docomo network so most 3G foreign phones will work fine.

– If you want to learn Japanese without spending money you can check the website of your city council, they usually have free Japanese classes that are run by volunteers. I tried once when I was beginning to learn Japanese but I did not like that they did not have any teaching method it was just conversation, as I did not know much Japanese then it was useless for me, but it may be good if your level is higher and you need some conversation partners. This may not be the purpose of this classes but one of the teachers also invited me for dinner and some private lessons… If you want to spend some money I had a good experience at Human Academy, the classrooms where a bit cramped and the tables where small for my legs but the teaching method was reasonably good and I am quite happy with the knowledge I gained, it was money well spent.

– If you have a place in Japan and want to let family or friends watch Japanese TV, the best way is to check?www.dokodemoterebi.com?and install a TV transmitter. They will be able to watch TV as if they where in Japan, with many unique options such as recording, ?dual streaming, free mobile player and also a receiver. (Disclaimer dokodemoterebi.com is a LoreaTec group service)

– Last but not least at LoreaTec we offer the best computer repair service in Japan, mobile phone repair in Japan service and outsourcing services. You can get the lowest price if you send or bring your PC/smatphone to our office but we also provide on site support with English support in selected areas standard Japanese support?throughout?Japan. We are also the only specialist repairing not only iPhones but also Japanese smartphones, older Keitai and imported phones.

 

 

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Useful

How to display Japanese UTF-8 file names on your FTP

I have used FTP for a long time, I always created standard ASCII file names so I never had any problem. But I just started a list of PC models for loreatec and they contain Japanese characters on the file name.

http://www.loreatec.jp/pclist/パソコンメーカー/富士通%20FUJITSU%20パソコン.php

As you can see there are Japanese characters on the file name and on the folder name. So when I tried to upload the files using FTP it turned into gibberish once on the server. FTP is an old protocol so it does not always support UTF-8 characters.

Fortunately there is a solution, you can use SFTP SSH connection to your server. First you have to set up SSH access on your server, once it is done just choose SFTP connection on?Filezilla?and that is all. You will be able to see, upload and download all files with japanese characters, accents or any other non ASCII character. On top of that SFTP is totally encrypted and much safer than FTP.

This is not related, but I want to warn you all that I just found that Filezilla stores passwords in plain text. I decided to delete the saved passwords and from now on I enter the password every time I log in. This problem has been around for a while apparently, hopefully this issue will be fixed on future versions of Filezilla.