Acoustic Guitar Impulse Responses

[Bill Phillips]

I recently purchased the Past to Future Martin D-18 impulse response files from here.  These IR's were recorded in Mono, Stereo, with 3 Mics and all with different mic positions. (All Vintage Neumann mics with Telefunken mic pres). Digital and audio tape versions are included. Here're clips of the acoustic guitar bridge pickup DI from a song I'm mixing with and without the digital stereo 3 IR effect in the MConvolutionEZ.

[Jacques Boileau]

How do you use these!?!?! You record any guitar, it goes through the IR and comes out sounding like a Martin?

[Bill Phillips]

7 hours ago, Jacques Boileau said:

How do you use these!?!?! You record any guitar, it goes through the IR and comes out sounding like a Martin?

I use them for mixing. I inserted the MConvolutionEZ IR player in the FX bin of a mono acoustic guitar bridge pickup track, auditioned several of the D-18 impulse response (IR) files and selected the one I liked best.

I don't know what the D-18 sounds like miced the way it was when  the IR file was produced but I doubt that the IR FX makes the track I recorded using the bridge pickup sounds much like the D-18. But I think it sounds a lot better than it does without the IR FX.

Edited February 25, 2020 by Bill Phillips
correction

[jude77]

20 hours ago, Jacques Boileau said:

How do you use these!?!?! You record any guitar, it goes through the IR and comes out sounding like a Martin?

It doesn't come out sounding exactly like a Martin, but it comes out sounding more like an acoustic guitar. 

[Tezza]

18 hours ago, Bill Phillips said:

I use them for mixing. I inserted the MConvolutionEZ IR player in the FX bin of a mono acoustic guitar bridge pickup track,

When you say "bridge pickup" are you referring to the under saddle piezo pickup on an acoustic-electric guitar?

[Bill Phillips]

4 minutes ago, Tezza said:

When you say "bridge pickup" are you referring to the under saddle piezo pickup on an acoustic-electric guitar?

Yes the piezio pickup under the bridge (saddle) of an acoustic guitar. The bridge is where the strings are terminated on the guitar body. I guess it might also be called a saddle.

[Jim Fogle]

@Bill Phillips,  Excuse my questions but I've never heard of impulse responses (IR) used in thae manner your describing so I'm trying to better understand your process.

So you're using the impulses to help your electric guitar sound like an acoustic or to make one acoustic brand sound like a Martin?  What plugin are you using the impulses in?

[user 905133]

34 minutes ago, Jim Fogle said:

@Bill Phillips,  Excuse my questions but I've never heard of impulse responses (IR) used in thae manner your describing so I'm trying to better understand your process.

So you're using the impulses to help your electric guitar sound like an acoustic or to make one acoustic brand sound like a Martin?  What plugin are you using the impulses in?

On 2/24/2020 at 10:53 PM, Bill Phillips said:

I use them for mixing. I inserted the MConvolutionEZ IR player in the FX bin of a mono acoustic guitar bridge pickup track, auditioned several of the D-18 impulse response (IR) files and selected the one I liked best.

I thought this is what he was doing.

[Bill Phillips]

10 hours ago, Jim Fogle said:

@Bill Phillips,  Excuse my questions but I've never heard of impulse responses (IR) used in thae manner your describing so I'm trying to better understand your process.

So you're using the impulses to help your electric guitar sound like an acoustic or to make one acoustic brand sound like a Martin?  What plugin are you using the impulses in?

Jim, User 905133 is correct. Let me know if you still have questions.

9 hours ago, User 905133 said:

I thought this is what he was doing.

Thanks @User 905133.

[Tezza]

This is really interesting Bill, I might also give it a shot. Generally, the piezo pickup on acoustic guitars sounds awful when recorded, scratchy, at best it is something that might be used at a very low level to add bite to to the microphone recorded acoustic track but I never bother with it. I use the piezo pickup when first sketching out a song simply because I can plug the acoustic in without worrying about background noise and because it's easier just to plug in. But that is just a guide track and is never used in the completed song. I'll muck about with it, see what happens.

 

[Jim Fogle]

@Bill Phillips & @User 905133, Again, I apologize.  I understand using an impulse response to recreate a space but I am not familiar with using an IR to recreate the sound of an instrument.  Thank you for your responses.

I missed @msmcleod post first go around so this post didn't make sense to me.  After checking out Mike's post, this post makes much better sense.

 

Edited March 8, 2020 by Jim Fogle

[msmcleod]

I did a post on this a while back with a video showing how to set it up:

The key thing with using instrument IR's is to crank up the gain, otherwise it's really quiet.

[rsinger]

2 hours ago, Jim Fogle said:

@Bill Phillips & @User 905133, Again, I apologize.  I understand using an impulse response to recreate a space but I am not familiar with using an IR to recreate the sound of an instrument.  Thank you for your responses.

I'm not a DSP guy; there are people on the forum who know a lot more about audio than I do, but I'll step in anyway. Two digital filters are FIR and IIR which are Finite Impulse Response and Infinite Impulse Response so impulse responses are used in filters. I think speaker IRs are basically filtering (EQing).

[mettelus]

On 2/24/2020 at 3:38 PM, Jacques Boileau said:

How do you use these!?!?! You record any guitar, it goes through the IR and comes out sounding like a Martin?

An IR essentially defines the reverberation characteristics of an environment (guitar body, room, et. al.), so it can turn the dry response of a lackluster environment/instrument into something more realistic. It would not change the timbre of the underlying source, so it won't "convert" electric string impulses to acoustic strings, make old strings sound new, etc.; but it would bring life to a piezo pickup so it could be blended to sound more like an acoustic recording.

To use them, you would need to load them as the profile in an IR Loader FX or Reverb FX that can import them. If you do not have such handy, MeldaProduction has a free MConvolutionEZ.  That is part of their MFreeFXBundle, so might as well get that while you are in there.

[user 905133]

I used to use Cakewalk's version of Voxengo's convolution reverb--not so much for simulating specific acoustic spaces, but more for experimental textures. Last time I tried the plug-in, it seemed a bit glitchy on my system; haven't tried newer/more efficient plug-ins; used to have links to IR fans that had massive libraries of IRs.** SONY even had some from the days when they owned Sound Forge.

Thanks for reviving these memories with the topic and for everyone chiming in with new-to-me ideas for using IRs.

**I seem to recall one IR fan that had most of his in Mac-based files, but wasn't too difficult to convert them to wav files (or whatever I used to do). That might have been the one with various Cathedrals.

 

[Robert Bone]

On 3/5/2020 at 8:30 PM, msmcleod said:

I did a post on this a while back with a video showing how to set it up:

The key thing with using instrument IR's is to crank up the gain, otherwise it's really quiet.

Yup, I appreciated that post a bunch, too.