Join Scott Hirsch for an in-depth discussion in this video Navigating RX 4's new UI and Clip Gain, part of iZotope RX 4 First Look.
In RX Version Four, iZotope has really distilled the user experience down to be as efficient as possible, both graphically and from a workflow standpoint. In this movie we'll use RX4 in standalone mode to get rid of some unwanted noise in a guitar track. Along the way, we'll explore the improved new user interface and some new export options. First let's open the audio file we'll work on. going to go down and launch RX, and I'm going to go to File > Open, or Cmd+O, to open up this Wah_Guitar.wav file.
It loads into the viewer of RX4, and on first view, the RX window looks like we see here. In Version 4, you now have the ability to make the window full screen for a map by clicking on the green button on the top of the window. That is better. Now, graphically speaking, a lot of RX's power lies in the ability to move between the more traditional wave form view, which we see here, and the frequency spectrum view which we see here, or somewhere in between.
The frequency spectrum shows frequency from the lowest frequencies at the bottom of the screen to the highest frequencies at the top of the screen. The intensity of color reflects relative amplitudes within the frequency spectrum. The amplitude view, which we're used to probably if you use a lot of digital audio workstations, shows strictly amplitude over time. The higher the wave forms get, the larger the amplitude is, and time runs left to right. Let's take a listen to this clip.
It's a good sounding guitar track but some of the amp hum and string noise is getting in the way. Ultimately we will make it more emotionally impactful by removing some of the noise in the track. Here's a listen to it. First, let's look at the new clip gain feature in RX4. If I go over here to the right, I can see all of the modules available in RX4. If you're running just straight up RX4, you might see a few extras here that belong to the RX4 Advanced set. Let's start with the gain module, which is available in both versions.
We can always raise the overall gain of a clip by using the gain module. Let's raise it up ten decibels. Just type in the number ten here, or you can adjust the slider to however you want. And I'll select all of the audio in the clip by double clicking, and I'll click Process. As you can see, the wave form amplitude represents the new gain change, and if we take a listen we'll hear everything a little bit louder. It's now nice and loud, but unfortunately the noise floor rose up too, even more reason why we need to do some noise reduction.
A new feature in RX4 is the ability to also raise gain within portions of the clip. To do this we will go up to the View menu and choose Clip Gain or Cmd+G. Here we now have a gain rubber banding feature and we can select anywhere along the inside of the clip to raise the wave form. So I want this little note here to get a little louder. I made two break points, and I can simply drag that note up and you see the wave form shifting to represent the new gain change there. And you can do this anywhere you want along the clip.
I want this end to not fade out so drastically. I can do something like that. Now let's deal with some of the noise. There's a pretty audible hum here. Let's check out the Hum Removal tool. So I'll go up to Remove Hum. I open up that module and it looks like this. You basically have some very high queue EQs that are setup here. And the cool thing about the hum module is you can actually select just an area where there's only hum and not any of the guitar which is, I had here at the beginning of the clip. And I can click Learn, and it learns where the hum is.
In this case, it tells me the hum frequency is around 59.99 hertz, which is pretty typical place for a hum to be at around 60 hertz. And it adjusts the EQ to match that. And of course, I can change the number of harmonics we're taking out with this slider down here. And if I want to preview what it's going to sound like, I can now hit the Preview button and we'll hear it. And as it's previewing, I can click the Bypass button to hear what it's like with and without the effect. So this is not removing any hum, and here is removing some of that hum.
And once we are satisfied, we are going to select everything and click Process. Now notice just visually, when I click Process, some of these lines that band across the bottom. That's where the actual hum looks like in a frequency spectrum, so it's a continuous tonal range of frequencies that continue throughout the piece. And watch what happens when I click Process. See that, those went away, so the hum was actively removed. Now I can close this module, and we'll take a listen again just to confirm.
Great, that sounds good. And then the next thing I would do here is just to clean up a bunch of the other distracting noises, and I'll use Spectral Repair to do that. So we'll open up the Spectral Repair module, which is one of the more famous modules you'll find people using in iZotope RX4. And this is the Spectral Repair module. Now to do this let's see, I'm going to use it at first to remove this string noise we see here, we hear here. You can also see it visually, especially if I go into the frequency mode view a little bit.
You see that string noise. So I'm going to use the paint brush to select just that area there, and I can do Cmd+ to zoom in a little bit, actually get a better selection here. And I'll select just this area we see and hear the string noise. Okay, so there I have selected that area. So in this case I'm going to try the Replace tab. This tab searches around the area for similar sound, removes the unwanted sound, and fills in the blanks. I'm going to click Process, and visually we see that the string noise actually went away, but let's actually confirm this by hearing it.
So it's much better, and I can undo it just by clicking above that line item in the Undo history. I can hear before. Hear the string noise? And here's with the spectral repair. So once we're happy noise reducing our clip, we want to export the clip. And so I can do that up in the File menu here. So I have the option to click on Export, Cmd+E, and I have all the usual file types you might want. I can export it as a wave of varying bit depths. I also AIFF with varying bit depths, and I can actually even choose to dither the AIFF file as I export it.
And then we have Flack and Ogvorbis for some more unconventional file types, but that might be useful for some users. What i can also do in file menu is to go File > Save As an RX document. So if I do this, I can name it Wah_Guitar noise reduction one, and I'll go ahead and save that in the exercise files. And what we get when we do that, I'll just go and show you in the finder here. In the exercise files we get a RXDOC, and the RXDOC is cool because it'll bring us right back into this project we have here and we'll have the ability to see all of our undo history if we want to make a change later in the future.
So you can export the audio file, but you can also just save this as an RX Document that way and get back into the project at any time if you wanted to make a change. So there's a round trip look at one potential work flow using RX4 as a standalone app. In the next few movies, we'll take a look at how to use RX alongside a DAW host like Protools