I want to manipulate/edit/wrangle audio recordings of one acoustic instrument -- let's say, an acoustic guitar -- so that it sounds like a DIFFERENT example of the same instrument. For example: Suppose I have only one guitar, but I want to produce a tune that sounds like two players, each with a different brand/model acoustic guitar, doubling the same part.

I have experimented with various techniques in the past, but the results always sounded like the exact same original single audio recording of one instrument but with different eq, reverb, fx, etc. Not REALLY like two different instruments.

Imagine two tenor saxophones: One is a brand new famous model X; the other is an old, cheap, but well-maintained Japanese thing. You know how it is: they sound both like tenor saxes, yet you can instantly tell them apart from the sound. THAT IS WHAT I WANT TO DO (with computer).

Technically of course, this results mainly from each instrument's individual timbre (or tone color or tone quality), which can be analyzed and even seen, so to speak, with various tools such as spectral analyzers.

I already know that one way to begin turning one sound into another in this manner is to fiddle with the formants, such as one may do with zplane Elastique Pitch. But that alone is not the complete answer.

It seems that I am blundering into the areas of physical modeling synthesis, wavetables, etc. Unfortunately I do not have a degree in physics! And I'm no rocket scientist!

So I am wondering where to turn for further tools, instruction, discussion.

Seems that Xfer Serum, Izotope Iris, Cubase Spectralayers, Celemony Melodyne, etc. are possibly useful in this regard, but absolutely nobody seems to be using them for what I have described above!

 

Last edited: Jun 29, 2021

-Record them using different mics, different mic positions. If your guitar has a pickup, record with that too. Then mangle all the different recordings.

-You can use something like Zynaptiq - Morph (or Melda's MMorph, if you don't mind using rip offs lol) to morph between two different recordings. If I'm not mistaken these plugins do spectral morphing, so the result is different than just eq'ing. Be careful though, when morphing between two similar sources, the little differences in transients etc. can make them sound shitty. In your case, morphing between two different mic's of the same take would be more appropriate.

-Try modding your guitar. I like to slide a little piece of acoustic foam under the strings near the bridge for a dampened-muted sound, and because I can hit open strings without palm muting it sounds different than actual palm muting. Another thing I sometimes do : when the fabric of my shirt on my picking hand slightly touches the string, it sounds eerily similar to a sitar. Not very practical musically, as you have to keep your hand at a very specific position and not move too much, but the effect is cool.

-If you don't mind going MIDI, Native Instruments have a couple of really good Kontakt libraries for acoustic guitar. As for physical modelling, you really can't go wrong with Applied Acoustics Systems : String Studio, Strum and Chromaphone are great. Not the most realistic sounds, but they can be made to sit perfectly in the mix.

edit : ok I see now I have not fully understood your question, you were asking more generally.

Check this out, although you may be left with even more questions lol

 

You should be able to do it with the tools you started with. Formant and Eq should make one sound different than the other. A very slight amount of modulation on one or both. Then you need to modulate the speed of one ever so slightly so sometimes it's a little behind, sometimes a little ahead. Two parts played seperately in real time are never exactly together all the time. Also, try turning one into a twelve string. Or try putting a virtual capo on one, so the strings are not the same notes. Ample Guitar M III does that.

 

Last edited: Jun 29, 2021

Two tools I've found that are quite effective at this are:

ReGuitar by Blue Cat Audio https://www.bluecataudio.com/Products/Product_ReGuitar/
and
the modeling portion of BiasFX2 by Positive Grid https://www.positivegrid.com/bias-fx/

 

How do I make one acoustic instrument sound like a different acoustic instrument of the same class?

 

Hello @ Maxxx0, great idea from you, nice that you are creative, I would use these tools:

CableGuys - ShaperBox
www.cableguys.com/shaperbox.html
FabFilter - Saturn 2
www.fabfilter.com/products/saturn-2-multiband-distortion-saturation-plug-in
Tonstrum - FRQ Shift
https://tonsturm.com/software/frqshift/

I would make an instrument 1 octave higher and use a Saturation plug-in like the 'FabFilter - Saturn 2' or 'CableGuys - ShapeBox' to add a bit higher with something "grainy, white noise, or use the ' Filter ' Lowpass Filter - BandPass Filter, Cutoff and Resonance.

 

Last edited: Jun 30, 2021

another old/free tool you may find helpful for this sort of thing is freakoscope. http://mdsp.smartelectronix.com/freakoscope/

 

Because altering timbre fucks up the sound granularly (fixed ratio). We are not there, yet. Maybe in the future. There are physical modeling synthesis being developed (MODO bass, Pianoteq, Chromaphone 2, etc). We've come pretty far since the first Karplus-Strong synths.

 

Last edited: Jul 1, 2021

Thank you all for your responses, some really interesting stuff here. It is true that I am inquiring about general-purpose techniques for any recorded instrument, not just guitar, but the guitar is after all a superb test case, isn't it? Just look a few different types, acoustic only, all with individual timbres:

-Steel string: Many subtypes, including such unique-sounding designs as the Selmer-Maccaferri (think Django Reinhardt), archtops, steel-body resonator (Dobro, National), and of course all the usual suspects, from parlor to dreadnought to jumbo

-Nylon string: Classical vs. Flamenco

"Additive Synthesis" indeed looks like very relevant theory/technology. I'll never understand the math and technical details, but I get the general idea: A real instrument sound is a bunch of different soundwaves combined, and so it should be possible to tweak any or all of these waves, add or subtract them, etc. I suspect I'll have to wait for more software to appear that can be used by people without university degrees =)

In the meantime I will try as many of the software suggestions here that I can get my hands on. Cheers!

 

formants are your first duty, followed by the "speed" and spectral content of the attack phase.

 

The experimental laboratory is open.
The company "Eventide Audio" www.eventideaudio.com, one should know.
Also the " Sugar Bytes - Tornado Multi-FX " and Sugar Bytes - WOW 2 Filter " .

 

All you need is a balloon...

 

I needed a different acoustic guitar to add to a track so I rented one from Long & McQuade.
Cost peanuts. I returned it early and got cash back
If you don't have somewhere to rent from make friends with someone who owns what you want

 

There's some practical ghetto tricks like: placing a Sponge, the Balloon,
or this one > Wooden Spoon for a quite convincing Sitar sound:

Or a Koto:

Triggerflipper gave you good advice on the Microphones,
you could try using completely Different mics, like old Ribbon vs modern Condenser..

Also you can try to (massively) EQ the instruments,
and Boost/Cut certain frequencies that you deem similar/fundamental to the instrument/sound you want to achieve..

For instance a Selmer guitar will have much more Mids or High-Mids in a very determinate area,
if you can isolate those freqs, and boost/cut appropriately, you're a small % closer to it..

However forget about radical transformations, with 100% Convincing results.


You cannot turn an Acoustic guitar into a 12-String guitar, or a Dobro/Resonator, with traditional means.
Not unless you're using very specific hardware/software made just for that..

For instance, 12-string pedals like digitech Mosaic,
or many multieffect pedals since the early 00's..

Or software like Bias-fx, where you can acoustify Electric guitars.

As for all the Software/Hardware that exists in this area,
or which one is the Best for your case/application, you'll have to do your own research..

There's a Ton of candidates, and few ppl will know/have tried them all,
specially from that perspective or goal in mind.. and even then, the results will differ from a 100% perfect transformation.

 

Last edited: Jul 3, 2021