Use Impulse Response to Make Logic's Guitar Amp Pro Sound Great
In this tutorial we will be looking into getting a little bit more out of Logic Pro's Guitar Amp Pro plugin. We are going to bypass Guitar Amp Pro's speaker cabinet and then load an impulse response (IR) for a different cabinet using Space Designer. If you've ever wondered what a Marshall amp and a Mesa Boogie cabinet recorded using a C414 in a great room sounds like, you're in luck.
The first thing to check is to make sure we have Software Monitoring enabled so we can play through Guitar Amp Pro. To do this, go to Logic>Preferences>Audio and make sure the Software Monitoring box is checked.
Let's set the input for our guitar. On audio track 2 make sure you have the right input selected. I have my guitar connected to input 3 of my RME interface.
Insert the Guitar Amp Pro plug-in on audio track 2. To do this click and hold on the first insert of track 2 until the pop-up menu appears. Then from the pop-up menu choose Amp Modeling>Guitar Amp Pro>Mono. The Guitar Amp Pro Plugin will now now appear on screen.
Choose a preset from the library. To do this click and hold at the top of the Guitar Amp Pro window and choose: 03Distorted>Modern UK Stack (Bright).
This preset is a little over the top for me, so let's modify it a bit. I have reduced the gain, bass, mids and also the treble. Please see the screen shot for my settings.
Let's record some guitar with these Guitar Amp Pro settings before we replace the cabinet with an IR. This way we have something to compare to when we change the cabinet.
Set audio track 2 to Record Enable. To do this, click on the R button at the bottom of audio track 2 and it should turn red. You will now be able to hear your guitar with the Guitar Amp Pro settings applied to it. If you have a good signal coming into this channel, hit the record button on the transport control, wait for the count in and record away.
The sound so far
So far so good. We are getting closer to replacing the cabinet with an IR, but there is just one more thing we have to do. We need to bypass Guitar Amps Pro's speaker cabinet. To do this click and hold on the pop-up menu for the speaker, and then choose DI-Box. This bypasses the speaker and the mic for the preset we used in step 5.
In order to use an IR we need a plugin that can read one. Logic has a plugin called Space Designer that can read IRs. Insert a mono Space Designer plugin on audio track 2, insert number 2.
Let's load an IR into Space Designer. Click and hold on the IR Sample button until the pop-up menu appears, and then choose Load IR.
When the dialogue box appears select the .wav file called Sperimental01.wav that you will find in the Play Pack.
You should now see the IR name Sperimental.wav loaded in the Space Designer window. Let's change a couple of settings in the Space Designer Plugin. Change the slider Dry to zero and the slider Rev to around -11.0db.
Hit the Zero key on your keyboard to move to the beginning of the time line, then hit the space bar. What you are now hearing is a Marshall amp with a Mesa Boogie cabinet recorded by a C414 off axis, and in a great room.
The sound with IR applied
Let's add a little reverb for good measure. We will do this with a bus. On audio track 2, click and hold on the first send until the pop-up menu appears, and choose bus 1.
Logic will automatically create a bus for you called bus 1. In the first insert for bus 1 insert a Space Designer plugin. We do this the same as we did in step 8 but this time simply choose stereo instead of mono.
With Space Designer open choose the preset 0.7s Recording Stage. To do this click and hold on the pop-up menu at the top of the Space Designer plugin. Choose 03 Small Spaces>01 Rooms>0.7s Recording Stage.
Let's add a bit of reverb by increasing the send amount on audio track 2.
The final sound
I hope you can see the possibilities with using IRs to create something a little different with Logic Pro's Guitar Amp plugin. A quick search on the net will find you dozens of IRs to play around with. Just about any cab can be found with different mics and mic placement and a ton of different rooms.
I have to say my favorite plugin to do this has to be Amplitube 2. You can get brilliant results with this plugin.
- Impulse response file