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木吉他经典sol吉他乐句_吉他失真和超速如何工作？

时间：2022-01-23 01:44:14

木吉他经典sol吉他乐句

With so many musical genres, it’s no surprise there are plenty distortion pedals out there. But what makes them so different? Let’s take a closer look at what happens to audio signals as they pass through these relatively simple devices.

音乐类型如此之多，不足为奇的是，这也就不足为奇了。但是，什么使它们如此不同？让我们仔细研究一下音频信号通过这些相对简单的设备时会发生什么。

Distortion is a general term for any modification to an audio signal that provides a significant alteration. The world of music indeed has quite a few different types. But how does it all work? To answer that, we need to look at how sine waves are affected by volume.

失真是对音频信号进行任何重大修改的总称。音乐世界确实有很多不同的类型。但是，这一切如何运作？要回答这个问题，我们需要研究正弦波如何受音量影响。

削波和失真 (Clipping and Distortion)

Basic overdrive and guitar distortion can be visualized by the effect of clipping. We mentioned clipping in a previous article, HTG Explains: How Does Dynamic Range Compression Change Audio? Compression helps prevent clipping, but in this case, we want to emphasize it.

基本的超速和吉他失真可以通过削波的效果显现出来。我们在上一篇文章《 HTG解释：动态范围压缩如何改变音频》中提到剪辑。压缩有助于防止削波，但是在这种情况下，我们要强调它。

(Image credit: Wikimedia Commons)

(图片来源： Wikimedia Commons )

In the original signal, you can see that the sine wave exceeds the threshold of the device. Normal waves that are within the proper threshold sound smooth. As the playback devices can’t really exceed the threshold, what happens is the crests and troughs of the wave start to square off. This changes the quality of the sound. Why? Well it has to do with math.

在原始信号中，您可以看到正弦波超过了设备的阈值。处于适当阈值范围内的法向波听起来很平滑。由于播放设备无法真正超过阈值，因此发生的波峰和波谷开始趋于平缓。这会改变声音的质量。为什么？好吧，它与数学有关。

Let’s zoom in on a sine wave.

让我们放大正弦波。

Now, imagine we play another tone alongside this one, something with a higher frequency but that matches at the peaks. We’ll only introduce it at a low amplitude. Here’s what the result looks like.

现在，假设我们在此音色旁演奏另一种音色，该音色的频率较高，但在峰值处匹配。我们仅以低幅度介绍它。结果是这样的。

You can see that it starts to take the shape of that square-cornered wave from the clipping section. When you introduce an odd-numbered overtone, you’ll start to see this type of shape. If we increase the amplitude of that same overtone, you’ll see a more particular shape.

您可以从剪切部分看到它开始呈现出该方角波的形状。引入奇数泛音时，您将开始看到这种形状。如果我们增加相同泛音的幅度，您会看到更特殊的形状。

So you can see those sharp corners form a little more prominently. We can exaggerate this further with the addition of yet another odd-numbered overtone.

因此，您可以看到那些尖角形成得更加明显。我们可以通过添加另一个奇数泛音来进一步夸大这一点。

Having a lot of clipping changes the shape of the sine wave in a way that is mathematically represented by a different equation entirely, shown above as the addition of two sine waves. The harder the clipping, the greater the resemblance to a increasingly complex waves. Softer clipping won’t really affect the sound too much.

发生大量削波会改变正弦波的形状，其数学上完全由一个不同的方程式表示，如上图所示，是两个正弦波的加法运算。剪裁越难，与越来越复杂的波浪相似。较柔和的剪切不会对声音产生太大影响。

Let’s take a look at what a close up of some distorted waves in Audacity.

让我们来看看Audacity中一些扭曲的波浪如何闭合。

Here, I’ve highlighted a portion of the waves that match up. The second wave is a distorted sine wave, something that looks like it was clipped and then compressed down. It’s a square wave. Here’s a sample of a 440 Hz – middle A – sine wave, and a 440 Hz square wave.

在这里，我重点介绍了一些匹配的波浪。第二个波是扭曲的正弦波，看起来像是被裁剪然后压缩了。这是方波。这是440 Hz(中间A)正弦波和440 Hz方波的样本。

A 440Hz Sine (No Clipping) Wave

440Hz正弦波(无削波)

A 440Hz Square (Clipped) Wave

440Hz方波(剪切)

We’ve seen what happens with odd-numbered overtones. Even-numbered overtones do something different.

我们已经看到了奇数泛音会发生什么。偶数泛音的作用有所不同。

Compare this to the third wave in the Audacity screenshot above. This is referred to as a sawtooth wave, and sounds very different.

将此与上面的Audacity屏幕截图中的第三波进行比较。这称为锯齿波，听起来很不一样。

A 440Hz Sawtooth Wave

440Hz锯齿波

While we’ve skipped the math, we hope you see how wave addition simulates the effects of clipping in different fashions. Differently shaped waves change the quality of the sound in some very important ways. This is partially why distorted guitars have such a rich set of overtones and why there are so many kinds of distortion pedals out there.

在我们跳过数学的同时，希望您能看到波加法如何模拟不同方式的削波效果。不同形状的波以某些非常重要的方式改变声音的质量。这部分是为什么失真的吉他具有如此丰富的泛音集以及为什么存在如此多的失真踏板的原因。

超速行驶 (Overdrive)

There are many different types of distortion, one of the most common being overdrive. It works by applying an increase in gain, at specific outputs. Softer playing doesn’t really cause the telltale distortion to occur, but harder playing or a higher signal volume to the overdrive processor will cause the telltale clipping patterns to come through. Overdrive offers softer clipping, which helps keep the original timbre of the instrument more or less in tact, or else tries to make up for some of the loss.

失真有许多种，最常见的一种是过载。它通过在特定输出上增加增益来工作。较弱的播放并不会真正导致音色失真，但较硬的播放或给超速处理器的信号量较大，则会导致音色剪切模式通过。 Overdrive提供更柔和的削波，这有助于使乐器的原始音色或多或少保持完好无损，或者试图弥补部分损失。

Overdrive was originally found with tube amplifiers where increasing a voltage gain would “overdrive” the amp and produce the desired effect. Modern overdrive processors, such as those found in pedals, try to replicate this for amps that aren’t tube based. They require a higher volume from the amp to help create the effect in addition to some “color mixing” to help simulate the effect well. This last function is most easily seen in the tone dial. Overdrive preserves a good deal of dynamic range and can still produce some clean sounds, but can let some of those overtones come out shining with some push.

最初在电子管放大器中发现过驱动，在这种情况下，增加电压增益将使放大器“过驱动”并产生所需的效果。现代超速处理器(例如踏板中的超速处理器)试图将其复制为非基于电子管的放大器。除了需要一些“颜色混合”以更好地模拟效果外，他们还需要更大的放大器音量来帮助创造效果。在音频拨号盘中最容易看到最后一项功能。 Overdrive保留了很大的动态范围，并且仍然可以产生干净的声音，但是可以通过推动使某些泛音发出光芒。

失真 (Distortion)

Overdrive, while still technically distortion, is grouped separately because of its mild effect and it’s primary reliance on controlled clipping. More common distortion pedals, such as the grunge and metal stompboxes that are so common today, are more bold about their fluctuation. Instead of relying on gain fluctuations, they alter the shape of the wave in distinct patterns and do it in a way that isn’t dependent on the amount of gain. Overdrive’s “warmer” overtones are lost here, as well as a significant amount of the original timbre.

过载，尽管在技术上仍然是失真的，但由于其适度的效果并且主要依赖于受控削波，因此可以单独分组。更常见的失真踏板，例如当今非常普遍的垃圾桶和金属踩踏踏板，对其波动更为大胆。它们不依赖于增益波动，而是以不同的模式改变波的形状，并且以不依赖于增益量的方式来实现。 Overdrive的“温暖”色调在这里消失了，以及大量的原始音色。

Outright distortion really cuts out the dynamic range and adds some equalizer effects. Usually, the middle range is what we can hear best, so to make up for that the equalizer settings are set up to boost the high and low end. This is why the lower notes really drive metal, and why the pinch-harmonics which are barely audible normally really screech with distortion. Each type of distortion pedal has a particular shape it pushes its signal towards as well as specific EQ settings and some in-house special mixing thrown in, so it’s easy to be overwhelmed when looking at which to buy. Be sure to give each a listen and play with their settings to get a full grasp of what it can do.

彻底的失真实际上会切断动态范围，并增加一些均衡器效果。通常，中音是我们所能听到的最好的声音，因此要弥补均衡器设置的不足，以提高高端和低端。这就是为什么低调音符真正驱动金属，以及为什么几乎听不到的捏合谐波通常会失真地发出刺耳的声音的原因。每种类型的失真踏板都有其特定的形状，可将其信号推向特定的EQ设置，并提供一些内部特殊混音，因此在购买时很容易不知所措。确保让每个人都聆听并演奏其设置，以充分了解其功能。

绒毛 (Fuzz)

Another really popular and specific type of effect is fuzz, used widely in the industrial and metal genres and is often used for vocals as well as instruments. Fuzzboxes add a particular type of distortion that sounds just as its name implies. The original signal is wholeheartedly obliterated and turned into a square-waveform. It’s almost as if it hits a brick wall before continuing in a completely transformed shape.

另一种真正流行和特殊的效果是模糊，广泛用于工业和金属流派，通常用于人声和乐器。模糊框添加了一种特定类型的失真，听起来就像它的名字所暗示的那样。原始信号被完全消除，并变成了方波。仿佛在完全变形之前，它碰到了砖墙。

Fuzzboxes also add extra harmonic overtones to help give an artificially rounded out and warmer sound. This is done by an adjustable frequency multiplier, and if a harsher sound is desired, can yield inharmonic overtones instead. Actually, these artificially added overtones add a lot to string melodies and provide a good backdrop. Sitars bank on these same harmonics, and if you’ve ever heard one plugged into a regular distortion pedal, you’d swear it was in a fuzzbox instead.

模糊框还添加了额外的谐波泛音，以提供人为的环绕声和温暖的声音。这是通过可调倍频器完成的，如果需要更刺耳的声音，则可以产生非谐波泛音。实际上，这些人为添加的泛音为弦乐增添了很多色彩，并提供了良好的背景。 Sitars依靠这些相同的谐波，如果您曾经听过一个插入常规失真踏板的声音，您会发誓它是放在一个fuzzbox中的。

Now that you know why distortion does what it does, you should be able to alter it to help make your particular playing style more pronounced. You can even use your knowledge of equalizers to help the process. And, while we primarily discussed these effects in light of guitars, they can be applied to vocals and other instruments as well. Experiment and you break the ever-dissolving genre barriers present today!

既然您知道失真为什么会起作用，那么您应该可以对其进行更改，以使您的特定演奏风格更加明显。您甚至可以使用均衡器知识来帮助完成此过程。而且，尽管我们主要根据吉他来讨论这些效果，但它们也可以应用于人声和其他乐器。尝试一下，您就可以打破当今存在的不断消失的体裁障碍！