DAN AGOSTO: Hi. I'm Dan Agosto with Gearwire.Com and you're watching Engineering 101. This is part four in our series about convolution reverb. And in this video, as opposed to the last video where we took an impulse response of this room, we're going to be taking impulses of things you wouldn't normally think of taking impulses of. The great thing about convolution reverb is that it just doesn't do reverb. It can also give you sort of the feeling of being in like a tiny space, for example. You can also put impulse responses through distortion pedals and things like that, and we'll see what that does and see if it actually in fact works, but first up let's try a very small space and this isn't really a reverb. It's actually more of a filter or a frequency response curve that the convolution does to it.

So what I've done is I've taken a shoe box, and I've put a little hole in it using a razor and stuck a microphone cable into it. So what I'm going to do is take our Earthworks microphone and just plug it in here. And what I've done is I've put some bubble wrap on the inside so that the mic doesn't jiggle around too much. I just put it in there, close the box, and actually just stick right in front. This is our Mackie HR824 speaker, and you just stick it right in front of that.

Okay. So once again, we see our sine sweep on track 1 and we're armed on track 2, that's where the Earthworks mic is. We're going to send out the sine sweep through our speaker right into the box.

[DAN AGOSTO RECORDING SINE SWEEP THROUGH SHOE BOX AND EARTHWORKS MIC]

For a lot of impulses, there's excessive amounts of low frequency energy, so what I've elected to do is before I export, I'm putting this linear phase EQ on here and just putting the filter around 100 Hz. That'll make sure you don't get any unwanted rumble effects when we load it into our convolution program. I'm going to call this one shoe box and save it in the same place I've saved all of our other sine sweeps.

So once again, in Space Designer, I'm going to hit deconvolution, choose my shoe box sine sweep, point out my test tone, and save the IR. Unlike the room response we made on the last video, with this type of effect, we just went and listened to the wet signal without any of the dry mixed in. So, let's take a listen first to our dry signal. We're going to listen to Ultra Beat again. I'll start that up.

[DAN AGOSTO PLAYS ULTRA BEAT IN LOGIC PRO DRY]

There's the direct signal, and now I'm going to start to turn up our effect.

[DAN AGOSTO PLAYS ULTRA BEAT IN LOGIC PRO WITH SHOW BOX IMPULSE RESPONSE]

So this is kind of giving that weird resonance that, you know, the shoe box frequency.

Okay, so next up we're going to take a response of the VOX Over the Top Boost from the Cooltron line of pedals. Okay, so now we're ready to record with the pedal. The only problem is I want the pedal at a setting that sounds good, so what I'm going to do is actually run the drums though it and find the setting before I run the sine sweep.

I'm going to find a setting that I like.

[DAN AGOSTO PLAYS ULTRA BEAT IN LOGIC PRO THROUGH VOX OVER THE TOP BOOST PEDAL]

Okay. That's pretty good. Now I'm going to run the sine sweep to it. I'd recommend turning down your monitors when you do this.

[DAN AGOSTO RECORDS SINE SWEEP THROUGH VOX OVER THE TOP BOOST PEDAL]

All right. So let's fast forward a little bit. I've already exported the IR and taken out some of the low frequency energy using that filter, and I've already deconvolved it and loaded it into Space Designer, so let's listen to our dry signal in Ultra Beat again.

[DAN AGOSTO PLAYS ULTRA BEAT IN LOGIC PRO DRY]

I'll take that down and bring up what's supposed to be our distorted signal.

[DAN AGOSTO PLAYS ULTRA BEAT THROUGH VOX OVER THE TOP BOOST IMPULSE RESPONSE IN LOGIC PRO]

Well, that's definitely not distortion. I actually kind of like what it's doing but unfortunately the convolution reverb cannot encode distortion. It's more of a filter thing to it really. Let's move on to something else that convolution actually can do.

Our next victim is the Ibanez AD-80 analog delay. This is a vintage pedal from the 70s so let's plug it in. All right, the pedal's plugged in and I have it on the long delay setting with a good amount of feedback.

[DAN AGOSTO RECORDS SINE SWEEP THROUGH IBANEZ AD-80 ANALOG DELAY PEDAL]

So since drums aren't the most appropriate thing to put through a delay pedal, I've chosen a guitar sample, and I chosen to set it up in a certain way. I have Space Designer first in the chain kind of like where you would have a guitar pedal, followed by a compressor, a guitar amp simulator, and then a limiter just to make sure we don't clip too much.

So now we'll listen to our guitar sample without any reverb.

[DAN AGOSTO PLAYS A GUITAR CLIP IN LOGIC PRO DRY]

All right, I'm going to turn up our reverb or delay as it is in this case.

[DAN AGOSTO PLAYS A GUITAR CLIP THROUGH THE IBANEZ AD-80 ANALOG DELAY IMPULSE RESPONSE IN LOGIC PRO]

All right. So the convolution did a good job in capturing the delay effect. The only problem is that the delay is way too long. Well actually, most convolution reverbs, all of them that I've worked with, give you an option to change the length of the sample so doing that will effectively change the time of the delay effect.

In Perfect Space, the sample length control is located right here on the left side of the plugin, and as you can see this displays our length. It's 1.770 seconds. So I'm going to turn that down a bit. Let's try turning it down to about 0.5 seconds. This is actually 0.496 but we can round that up.

All right. So now we're going to do the same thing. I'll start with the dry signal and I'll slowly turn up the delay effect.

[DAN AGOSTO PLAYS A GUITAR CLIP IN LOGIC PRO DRY]

Dry, and then here comes our delay.

[DAN AGOSTO PLAYS A GUITAR CLIP WITH DELAY FROM IMPULSE RESPONSE IN LOGIC PRO]

All right. So that's a lot more appropriate. So thanks for tuning in to these videos and make sure to keep checking back because we're going to make all of the responses that have been created in this series available for free download, and we might actually try to get a few extra ones in there for fun. So thanks for tuning in.