Category: Boost volume

How to distinguish the sound quality of Mp3 songs?

How to distinguish the sound quality of Mp3 songs?

Mp3 quality

Factors that affect audio quality are the number of channels, the sampling rate, and the number of quantization bits.

Mp3 Quality

It’s not directly related to file size, I think friends who have used Audition or play more music will be more familiar with it.

-Number of channels

Channel count is easy to understand and is often referred to as channel count. Usually we talk about left and right channels, single and double channels, which refers to the number of channels.

The music that we listen to often in life is basically two-channel, that is, the left and right channels. Generally speaking, the higher the number of channels, the better the audio quality. Then the stereoscopic feeling of the sound will be stronger. It will feel more real. When a person speaks or an object makes a sound, the sound also spreads in all directions, and of course there are more than two channels. So, in fact, it is difficult for digital audio to achieve real sound realism.

-Sampling frequency

For example, when Audition exports audio files, there is a sample rate option. What exactly is this sample rate?

Sampling rate is explained in official words: the number of samples per unit of time (within 1S). The higher the sample rate, the more data it collects and the better the sound quality.

But you will find that music in real life is generally 44100HZ sampling rate, like the lossless music in the picture above. So there are so many miscellaneous sample rate options in the image below. What does this mean? The reason is that the audible sound range of the human ear is between 20 and 20,000 Hz. Even if you increase the sample rate, it will still sound the same to ordinary people, so there is no need.

-Quantization bits

This is also very understandable. It’s like the number of bits that people often say about the computer. Audio also has the concept of bits. A common number of bits for audio is 16 bits. Generally speaking, the higher the number of bits, the better the sound quality. The popular understanding of quantization is to digitize the sampled value, that is, in the binary form recognized by the computer.

The property display in Windows may not display these parameters intuitively, but you can see them with the help of tools. Sound quality is determined by the above three aspects. Instead of looking at the size of the file. Of course, the audio is basically compressed and transcoded when it is broadcast to the audience. After all, high volume digital audio is not conducive to broadcasting.

 

FAQ

How to distinguish the sound quality of an mp3?

It is important to look at several elements to distinguish its sound quality. Of course, first is the quality of the recording, then the bitrate and samplerate.

Your can improve the sound quality of an mp3?

It is possible, using Mp4Gain, to improve the perception of the quality of an mp3 or any other audio or video format. In addition to modifying the bitrate and sample rate, we can modify the “color” with an equalizer and even slightly modify the pitch and of course normalize the audio.

Volume Enhancer

Volume Enhancer

Volume Enhancer

When you have a good amount of mp3s or in any other format, you always wonder how you can improve the quality of the audio, as well as standardize the volume level.

volume enhancer

Mp3 Volume Enhancer

Although we are going to refer to mp3, this applies to many other formats since Mp4Gain is capable of compressing and converting into many audio and video formats and also normalizes the volume to standardize it so that they all have a sound or sound similar to each other. .

The operational part is very simple, since it will suffice to load one or more files in any format (Flac, OGG, mp3, m4a, etc) and convert them to any other. If you want (and it is recommended) at the same time, you can normalize the volume of all of them so that they sound at a fairly even volume level.

Audio & Video Volume Enhancer

As we already mentioned, Mp4Gain can operate simultaneously on audio and video files, managing to do volume enhancer on all of them one after another.

We can even choose to have them all, say, converted to Flac or any other format. Or each one can be processed and after normalizing its volume, a final file can be obtained from each one in the original format that the original file had.
As you will see, Mp4Gain is very versatile and allows us to choose exactly how we want it to work and it is very easy to operate, it does not need a learning curve.

Mp3 Increase Volume Part 2

Mp3 Increase Volume Part 2

mp3 increase volume

We talked in the previous chapter about the need to achieve an mp3 volume increaser, although the volume increaser is not limited to mp3s in Mp4Gain. You can actually achieve a volume increaser in all major audio and video formats.

mp3 increase volume

To better understand, we were talking about and analyzing how the compression of an audio file works.

Quantification encoding. Quantization encoding uses a three-layer iterative loop model for bit allocation and quantization. These three layers include: frame loop, outer loop, and inner loop. The frame loop resets all iterative variables, calculates the maximum number of bits that can be provided to each data slice, and then calls the external iterative model; the outer iterative model first uses the inner iterative model, which quantizes the input vector by incrementing The size of the quantization step allows the quantized output to be encoded within a certain bit limit. Huffman coding has a limit on the maximum quantization value, so it is necessary to judge whether all quantization values ​​exceed the limit. If it exceeds the limit, the inner iteration loop must increase the size of the quantization step and quantize again. Then determine the number of Huffman encoding bits such that the number of occupied bits is less than the maximum number of bits that can be provided by each encoding section computed by the frame cycle; otherwise, the size of the quantization step must be increased for requantization. When the quantization meets the requirements, store the final scale factor value, exit the outer loop, and compute the number of bits used to store each data section in the frame loop.

The relationship between frequency and bit rate, and the sound quality of MP3 Part 5

The relationship between frequency and bit rate, and the sound quality of MP3 Part 5

Sample Rate

The above is the fixed code rate compression ratio.

Sample Rate

 

In lame, this is called CBR (ie non-variable code rate). In fact, the most important feature of lame is that it provides users with a VBR variable code rate compression method. This method is a very good encoding method in some pauses, and the simple signal will automatically reduce the bitrate and reduce the file size. However, how to choose the lowest and highest VBR bitrate range to get the most appropriate file and sound quality? This is another problem that needs to be solved through experimentation. Considering 128kbps as the base value, we choose 96kbps to 160kbps as the compression range. The compressed file size is 3801kb which is just over 128kbps CBR. 387 kb, but the sound is definitely improved by a great deal. First, the high-frequency distortion is at least half as small. Although there is still a lot of noise in the details, the first listening sensation is much stronger than 128 kbps. The average code after compression speed is 147 kbps, which is also very space efficient. Then experiment with 96kbps to 192kbps, 96kbps to 224kbps, 96kbps to 256kbps, 96kbps to 320kbps, and found that they are very similar to the maximum CBR compression sound quality, i.e. 96kbps to 192kbps vbr sound is similar to 192kbps of cbr, but the former is 192kbps, 4481kb in size and the latter is 5123kb, so as a compromise method looking for higher quality sound and saving space, vbr is really useful. Of course, on the other hand, because the code rate changes, the stability is naturally slightly worse than cbr.

Fourth, in terms of mode parameters, there are stereo, J stereo, forced stereo, and mono. The comparison test shows that standard stereo has the best effect. Although the compressed file size is the largest, the file size difference is smaller, and the difference in sound quality and sense of hearing, I still think stereo is ideal.

Fifth, the compression method, there are vbr-old, vbr-new and two others in the software, but only the first two are easy to use. Comparing old and new vbr encoding methods, I found that the assumption is that in terms of sound quality, it’s still the old one. Delicate, but the compression speed of the old encoding is very slow, almost equal to 5 or 6 times that of the new encoding method. The production of a song is almost the same. in 3-4 minutes, which is very difficult to use, and the file size is also 10% larger, so it is recommended to use vbr-new for everyone, which is more convenient and easy to use.

Comparison of sound quality between AAC and WMA

Comparison of sound quality between AAC and WMA

AAC vs WMA

General description

AAC vs WMA

Comparison of AAC, WMA and MP3 sound quality. Since the difference in AAC is very large according to the encoder, we use two types, QAAC as a representative of excellent coders and VO-AEACENC as a representative of deficient coders.

QAAC 1.18, which borrows and encoding the Apple engine (Apple Support Software), which is also used in iTunes, wmaincode_0.2.9, encoding the Microsoft engine that comes with Windows XP or later, and the known open source encoder MP3 Lame We heard and qualify a total of 4 Visualon Vo-Aacenc 0.1.1 types, which recently became open source, 3.98.4, which also serves as a billing standard.

result
QAAC 192KBPS> WMA 192K> QAAC 128K ≒ LAME 192K ≒ WMA 128K> LAME 128K ≒ VO-AAC 192K ≒ VO-AAC 128K 128KBPS, VO-AAC 192KBPS, VO-AAC 128KBPS were the highest ratings.

evaluation
F: ID: Kamedo2: 20120124200328P: Image

Encoder QAAC VOAAC WMAE boring Qaac Voac Wmae boring
Year of launch 2012 2011 2011 2009 2012 2011 2011 2009
Version 1.18 0.1.1 0.2.9 398.4 1.18 0.1.1 0.2.9 398.4
CAA CAA AMM Format MP3 CAA CAA AMM MP3
Profile LC LC Standard —- LC LC Standard —-
Classification control CVBR ABR ABR CBR CVBR ABR ABR CBR
128K 128K 128K 128K 192K 192K 192K 192K 192K
41_30SEG percussion instrument 3.9 2.6 2.6 3.3 3.3 2.1 2.1 5.0 5.0 2.8 3.7 3.7 3.3 3.3
Final fantasy Rope repellent 4.4 4.4 3.4 3.4 4.0 4.0 2.9 4.6 3.9 5.0 5.0 3.7 3.7
A Train Jazz 4.6 2.7 2.7 4.6 2.3 5.0 5.0 2.9 5.0 5.0 4.5 4.5
Big Yellow Cups 3.8 3.8 2.8 3.1 3.1 2.3 4.7 3.2 3.2 4.2 4.2 4.0 4.0
Floor essence Tecno 3.4 3.4 2.5 3.4 3.4 2.5 5.0 5.0 2.4 4.1 3.4 3.4
Macabre orchestra 4.6 2.8 5.0 5.0 3.4 3.4 5.0 5.0 2.8 4.7 4.7
My blood is oxidized Rope instrument 5.0 5.0 2.4 3.9 2.8 5.0 5.0 2.4 5.0 5.0 3.9
Maybe Latin 4.1 2.3 3.6 3.1 3.1 5.0 5.0 2.3 4.3 4.5 4.5
Velvet Kingdom TECNO 3.8 3.8 2.5 2.7 2.7 3.0 3.5 4.5 2.6 2.6 3.5 3.5 3.2 3.2
Rain flowers Cups 4.0 4.0 2.3 4.4 4.4 2.8 5.0 5.0 2.3 4.7 5.0 5.0
Confidence Gossip 3.7 3.7 2.8 3.6 3.3 3.3 4.3 3.2 3.2 4.6 4.1
Wait Rock 3.8 3.8 2.6 2.6 3.7 3.7 2.8 4.2 4.2 2.7 2.7 4.6 4.0 4.0
Latin experience 3.8 3.8 3.8 3.8 3.7 3.7 3.5 3.5 5.0 5.0 2.8 5.0 5.0 4.0 4.0
Heart to Heart Cups 3.7 3.7 3.1 3.1 3.5 3.5 2.8 4.6 3.5 3.5 4.5 4.5 3.9
Female Voice Dining Room 4.6 2.7 2.7 3.6 3.3 3.3 5.0 5.0 3.0 3.0 4.5 4.5 4.1
↑ SOUND SOURCE Average score 4.05 2.74 3.73 2.85 4.78 2.83 4.47 4.00
Real Rate 136K 130K 135K 128K 208K 194K 203K 193K
All sizes (KB) 5803 5555 5782 5495 8894 8294 8674 8242
Encoder QAAC VOAAC WMAE boring Qaac Voac Wmae boring

Method
Eight eight audio files were shuffled using ABC / HR for Java 0.53A and MHP -A1 to listen and scoring with the brand face down so that the preconceived ideas on the brand will not affect it. 1.0 = I am very concerned about the deterioration of sound quality 2.0 = I am worried 3.0 = I am a little worried 4.0 = I can see the change in sound quality with respect to the original sound, but I do not care 5.0 = I do not know the Change in sound quality, I can not distinguish. If you want to grant a score of 4.9 points or less, perform the ABX test 20 times, answer 15 times or more (the likelihood of getting a higher rating in a coincidence is approximately 2%) and make sure you can listen to The difference before doing so (2.9 is omitted if it is less than or equal).
The same test was repeated in the SE-DIR800CII and the average was calculated. The score in this test is 15 (sound source) x 4 (BITS rate) x 2 (times) = 240 (times).

What is the best way to listen to music on your car smartphone?

What is the best way to listen to music on your car smartphone?

Bluetooth

Compare Bluetooth, USB, FM and more transmitters!

BLUETOOTH

How to listen to music on your smartphone by car?
Connect and play through Bluetooth
Connect with a USB cable and play
Connect and play with the voice entry (AUX)
Connect with the FM transmitter and play
What to follow, the best connection method for each person
How to listen to music on your smartphone by car?

The smartphone that most people use now. Smartphones are playing an active role not only in daily life and work, but also in driving, for example, providing cars a function that allows car manufacturers to be linked to smartphones.

In addition, many people use their smartphones such as music players and many people want to listen to the songs that they usually listen while driving. There are four main ways to listen to music on your car smartphone.

Listen with Bluetooth
Connect the USB cable and listening
Listen with voice entry (AUX)
Listen with FM Transmitter
Bluetooth is the mainstream now, but some people can say that their car is not compatible with Bluetooth or that sound quality can deteriorate if it is wireless. Therefore, we will present the advantages and disadvantages of each connection method.

Connect and play through Bluetooth
The first method that I will present is to connect your smartphone to a car navigation system (or stereo of the automobile) via Bluetooth. If your car already has a car navigation or stereo system with Bluetooth, this method is the most economical.

What are the benefits of connecting through Bluetooth and Listen?
In the Bluetooth case, once the pairing is completed, the smartphone and the car will connect automatically from the next time, and the music will be played automatically when the car is turned on. ..

The best part is that you do not have to buy additional equipment. Since radio waves are omitted and music is reproduced, it is not necessary to prepare wiring as cables, and the cables do not hang into the car. As it is not necessary to enter the cable one by one, although you connect a person’s smartphone in the rear seat, for example, the cable does not go through the inside of the car and is very smart.

What are the disadvantages of connecting by Bluetooth and Listen?
Since it is necessary to have a navigation and audio system for the car that Bluetooth admits, it will be expensive to install it if it is not installed. In many cases, rental cars and shared cars are not compatible with this.

It can also be annoying to play automatically.

Connect with a USB cable and play
Many of the latest audio and navigation systems for automobiles can be equipped with a USB terminal. In most cases, this USB terminal supports not only the load, but also the audio playback. If you prepare and connect a USB cable, you can listen to music while loading.

What is frame rate (FPS)?

What is frame rate (FPS)?

FPS

 

Did you know that there is a word “frame rate” in the term for video settings?

Frame Rate

The network video camera specifications also have this “maximum frame rate” item.

So what exactly does this frame rate mean?

This time, I will explain the frame rate in detail.

The frame rate is a picture from a flip book

Table of Contents
The mechanism of the video is the same as that of the flip book.
Frame rate is a factor that determines the smoothness of a video.
What difference is there in the value of the frame rate?
Frame rate doesn’t have to be high
What value should I set?
What is frame rate (FPS)? What value should I set? resume
Basic video knowledge
The mechanism of the video is the same as that of the flip book.
Video and still images may look different, but video is a collection of still images.

It seems to move by taking a lot of still images and displaying them continuously. This is a video.
For those who have a hard time imagining, I think it will be easier to understand if they can imagine a flip book.

In flipbooks, the greater the number of flipbooks, the smoother the movement, and the lower the number, the more uneven the movement.

A video is like a flip book with many images.

Frame rate is a factor that determines the smoothness of a video.
When making a flip book, you can expect the latter to be a smoother move between “viewing 50 images in 10 seconds” and “viewing 500 images in 10 seconds.”

The factor that determines this smooth movement is the “frame rate”.

“Frame rate” is the number of still images (frames) displayed on one movie per second. The unit is “FPS” (frames per second), which means “frames / second”.

If you express the book
animated in frame rate, you will see 50 images in 10 seconds … 5FPS (view 5 images in 1 second)
500 pictures in 10 seconds … 50FPS (50 in 1 second) See picture)

It will be expressed as such.

As you can see, if the value of the frame rate is large, the video will be smooth, and if the frame rate is small, the video will be hidden.

Frame rate is a factor that determines the smoothness of a video.

What difference is there in the value of the frame rate?
So how much difference does the smoothness of the actual video appear when you change the frame rate value?
For example, the world record for the 100m running is 9 seconds 9, but if you shoot at different frame rates,

・ When shooting at a frame rate of 1 FPS
⇒ 9 frames of still images at 100 m. The first and second images will be 10 meters ahead.

・ When shooting at a frame rate of 5 FPS
⇒ 49 frames of still images at 100 m. The first and second images will be 2 m ahead.

・ When shooting at a frame rate of 30 FPS
⇒ 297 still images at 100 m. The first and second images are 0.3 m ahead.

If you change the FPS value, this difference will appear.

In fact, I took a video.
What is the difference between videos based on frame rate (FPS)?

Frame rate doesn’t have to be high
If you read this far, you might think that “the higher the frame rate, the better.” But there are some downsides.

Frame rate doesn’t have to be high

A high frame rate means that a lot of still images are sent, so the amount of data sent is large.

Therefore, (
1) affects network equipment and line costs (
2) a large capacity hard drive is required to record
(when the number of cameras is large, the effect may be particularly large and the cost may be high) (
3) image quality when stopped deteriorates
(it is necessary to increase the size of the video data to improve the image quality)

There are also downsides like, so the higher the frame rate the better.

What value should I set?
The network camera’s frame rate setting varies depending on the purpose of use and the shooting objective.

For example …
・ If you want to confirm a series of movements ⇨ Approximately 24 to 30 FPS
・ If you want to emphasize confirmation of paused images ⇨ About 1 FPS to 5 FPS

Depending on the application, it may be necessary to verify the image from a security camera.

Is bass important in audio?

Is bass important in audio?

Bass Sound

High-end audio

Bass

What kind of sound does “good sound” mean in audio?
From a technical point of view, there are terms like “less noise” and “wide dynamic range”.
Dynamic range in audio is the range of strength and weakness of sound that can be expressed by audio, but it is an important concept when considering sound quality. There is no correct answer for
a good sound in which you can feel the delicacy that is well balanced in all ranges, an interesting sounding sound with something outstanding and a good sound.
Even if people say so, my sound is the cutest in the world! I think there are a lot of audiophiles who are deep in their hearts ^^

However, when listening to multiple audios, sometimes I feel that something is wrong even though the dynamic range is wide.
But I should have achieved numerically high sound quality, I did not feel carefree about the performance, I feel like, false, to reverse the treble and bass contour is too clear the
original music as a factor to be considered. means that there is some distortion between the harmony of the sound and the sound to be played.
It’s good to look for a clear sound, but I also want to look for a sound that fully conveys the feelings and emotions contained in the music.

In this article, I will talk about the essential and structural aspects of sound and how to enjoy audio using it.

Table of Contents

1 What is sound in the first place? From a scientific point of view …
1.1 What is sound? Air pressure change
1.1.1 Pure tone / complex tone / noise
1.1.2 Treble and Bass Characteristics
1.2 How humans recognize sound
1.2.1 How you listen depends on the frequency! Equal volume curve
1.2.2 Does sound control sound? Masking effect
1.2.3 Cocktail effect to select and listen to the sound you want to hear
1.2.4 Sound method
2 Enjoy an audio experience that takes advantage of the treble, middle and bass characteristics!
2.1 The midrange is easy to hear and compare even for beginners
2.2 Design concept of the loudspeaker unit
2.3 Here is the listening point where the treble and bass overlap
2.4 Techniques for adjusting the range by absorption and location of sound
3 Summary
What is sound in the first place? From a scientific point of view …
Sound waveform image

When choosing an audio device, engaging explanations of specs and word of mouth are helpful as well, but I think the actual display and the feeling of likes and dislikes are great too.
Also, if you can make a judgment that takes into account the universal nature of sound, you can make a decision that you won’t regret.
“Shuhari, Shuhari, and Shuhari” are common, and because there are basic concepts, you can feel the fun of chasing and playing by removing the form.
If you know the basics of sound and how to perceive human sound, you can approach audio from a different perspective.

What is sound Change in air pressure
For example, when you hit a drum, it makes a sound.
Although it is very slight, the membrane of the drum vibrates repeating a quivering movement like a spring.
This vibration causes a change in air pressure and the vibration is transmitted radially.
The vibration at this time becomes a sound.
Sound is transmitted through air as a medium, so it cannot be heard in a vacuum without air.
This change in air pressure is transmitted to our ears and is recognized as sound.

All musical instruments make sounds by vibrating the air in some way.
Audio speakers are often compared to musical instruments, but the principle is the same as for musical instruments because the interior is hollow like a drum and the air vibrates according to the transmitted electrical signal to produce sound.
In addition, the speaker is a delicate musical instrument because the sound becomes familiar with the shooting and use.

Pure tone / complex tone / noise
There are many types of sounds in everyday life, but the simplest is “pure tone.”
It vibrates with a regular waveform and the pure tones are like elementary particles of sound.
Pure tones rarely exist in musical instruments and everyday sounds, but pure tones include the beep tones used in television and radio weather reports and the tuning fork sounds used to tune instruments. musicals.

Compare the difference between bit, khz and kbps! High resolution doesn’t make sense? Part 2

Compare the difference between bit, khz and kbps! High resolution doesn’t make sense? Part 2

High Resolution Audio

If it is less than bit or kHz, it will not be high resolution.

High-Resolution Audio

However, if one of the values ​​is the same as the CD specification and the other exceeds the CD specification, it will be high resolution.

However, “96 kHz / 24 bit” and “192 kHz / 24 bit” are the main sources for high resolution audio.

Sponsorship

Over the limits of human hearing! High resolution doesn’t make sense?
What is the limit of the ability to discriminate human sounds?

Although there are individual differences, the human audible range is said to be 20 Hz to 20 kHz.

<Reference: Hearing-Wikipedia>

The sampling frequency of the CD is 44.1 kHz.

In theory, this value can be reproduced up to 22.05 kHz of the original sound, so it can sufficiently cover the human audible range.

In that case, the question arises that high-resolution sound quality, which has higher specs than CDs, may not be audible to the human ear.

Actually, there are many negative opinions from a scientific point of view, and it remains controversial.

<Reference: High Resolution Audio-Wikipedia>

However, the sound is highly dependent on experience, so if you are interested, you should give it a try.

Necessary environment to enjoy high resolution
Whether it makes sense or not, there are a few things you need to prepare for to enjoy high resolution.

The required environment is as follows.

High resolution sound source
High-resolution compatible headphones / earphones / speakers
High resolution compatible terminal
Let’s explain each environment.

High resolution sound source
There are various media for high resolution audio sources.

The easiest of these is probably the Hi-Res Audio source that is delivered online.

If you are a high resolution distribution site, you can get many sources of sound.

Note that listening with high-resolution headphones will not result in high-resolution audio.

High-resolution compatible headphones / earphones / speakers
In addition to high-resolution audio sources, prepare items such as compatible headphones and earphones.

It is quick to check if there is a high resolution mark on the product package to see if it is compatible.

Please note that most wireless headphones do not support high resolution playback because they compress data during transmission.

In the case of wireless technology, only aptX / aptX HD compatible items or SONY LDAC compatible devices support high resolution.

In any case, the high resolution brand is a milestone.

High resolution compatible terminal
In the case of the iPhone, it does not support the output of high-resolution sound sources.

Therefore, it is necessary to prepare a headphone amplifier equipped with a DAC that supports high resolution.

In the case of Android, there are terminals that support high resolution such as Xperia.

To enjoy high-resolution sound quality, you need to check whether the terminal that plays music is also compatible.