The Acoustic Guitar Forum

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Acoustic Amplification

Reply
 
Thread Tools
  #31  
Old 12-04-2021, 02:23 PM
SpruceTop SpruceTop is offline
Charter Member
 
Join Date: Jan 2006
Location: Rochester, New York
Posts: 10,168
Default

Quote:
Originally Posted by guitaniac View Post
Very cool. That's a good way to have plenty of blend options to accommodate different situations.

I have the original Aura acoustic imaging blender and it has a similar setup. For each sound image you have a choice of nine different dry pickup/sound image blends: 100/0, 87.5/12.5, 75/25, 62.5/37.5, 50/50, 37.5/62.5, 25/75, 12.5/87.5 and 0/100.

PS. On the subject of the original acoustic imaging blender, its interesting to note that its similar to the Optima Air in that it has five sound images (IRs) which were created using mag pickups. They hadn't yet decided to discourage the use of mag pickups with Aura technology back then.
Gary, I had the original Aura Blender and always heard it as sounding the best of any of the Aura devices. I now have an Aura Spectrum DI and a ToneDexter that I never use. I now prefer to use only pickup/preamp systems along with some EQ here and there, and I prefer the amplified tone without using other enhancements. I now only play at home so my experiences may not be that of other players.
__________________
RainSong BI-DR1000N2
Martin HD-28 Sunburst/Trance M-VT Phantom
Martin D-18/Ultra Tonic
Guild F-212XL STD
Adamas I 2087GT-8
Huss & Dalton TD-R
Taylor 717e
Taylor 618e
Taylor 614ce
Larrivee D-40R Sunburst
Larrivee D-03R Sunburst/Ultra Tonic
Larrivee D-40M Legacy/Dazzo
Larrivee C-03R Tommy Emmanuel/Trance M-VT Phantom
Emerald X20
Ovation Elite Plus
Republic Duolian/Schatten NR-2
Reply With Quote
  #32  
Old 12-04-2021, 03:43 PM
guitaniac guitaniac is offline
Registered User
 
Join Date: Jan 2004
Posts: 6,089
Default

Quote:
Originally Posted by SpruceTop View Post
Gary, I had the original Aura Blender and always heard it as sounding the best of any of the Aura devices. I now have an Aura Spectrum DI and a ToneDexter that I never use. I now prefer to use only pickup/preamp systems along with some EQ here and there, and I prefer the amplified tone without using other enhancements. I now only play at home so my experiences may not be that of other players.
Ken,

The IR thing continues to fascinate me, although I certainly had my problems with an overly ambient sound, at times, when gigging with ToneDexter.

One of my best gigging rigs was using an onboard Aura-equipped little OO-size Cort guitar with the Aura Spectrum preamp. I was actually modeling with that guitar, since I would turn off the onboard Aura and use one of Spectrum's OM models which sounded much better (than the Cort's model specific sound images) to my ear. I never had feedback problems with that rig because it was a small guitar to begin with and I only needed around 35% sound image from the Spectrum. I'm still kicking myself for selling that guitar because the string spacing was a little too narrow for my taste.

Analog systems like the Anthem SL and iMix have also been good for live performance, but I doubt that I'll ever stop chasing the digital rainbow. Its been part of the fun for me.
Reply With Quote
  #33  
Old 12-06-2021, 04:49 PM
JackB1 JackB1 is online now
Registered User
 
Join Date: Nov 2017
Posts: 2,746
Default

Quote:
Originally Posted by guitaniac View Post
Ken,

The IR thing continues to fascinate me, although I certainly had my problems with an overly ambient sound, at times, when gigging with ToneDexter.

One of my best gigging rigs was using an onboard Aura-equipped little OO-size Cort guitar with the Aura Spectrum preamp. I was actually modeling with that guitar, since I would turn off the onboard Aura and use one of Spectrum's OM models which sounded much better (than the Cort's model specific sound images) to my ear. I never had feedback problems with that rig because it was a small guitar to begin with and I only needed around 35% sound image from the Spectrum. I'm still kicking myself for selling that guitar because the string spacing was a little too narrow for my taste.
Agree. Aura Spectrum PLUS a decent pickup (anything but a Sonitone) will yield excellent results live. I have never been happy with any IR playing live and you lose the immediacy of the attack. I think IR's are more suited for studio and recording work.
__________________
Gear: Martin SC13e, Martin GPC16E Special, Acoustic Flyrig, TCH Harmony GXT
Reply With Quote
  #34  
Old 12-08-2021, 07:12 AM
shufflebeat shufflebeat is offline
Registered User
 
Join Date: May 2016
Posts: 1,091
Default

Quote:
Originally Posted by jonfields45 View Post
My latest code generates a selection of blended IRs (100/0, 75/25, 60/40, 50/50, 40/60, and 25/75, IR/Bypass).

https://drive.google.com/file/d/1YoM...ew?usp=sharing
Time has been a precious commodity recently but am looking forward to exploring this.
__________________
Give a man a fishing rod... and he's got the makings of a rudimentary banjo.
Reply With Quote
  #35  
Old 01-02-2022, 03:52 PM
Cuki79 Cuki79 is offline
Registered User
 
Join Date: Feb 2012
Location: France
Posts: 2,550
Default

Hi guys,

For my second trial, I made a short video of the experiment. The goal is to overcome the "distant" feeling of acoustic IRs to make just a solid string sound for LIVE use without quack.

The guitar is a Martin 00-18V with an undersaddle piezo transducer plugged straight into a Torpedo CAB M+ remotely controlled by my computer.

All the processing is done by the pedal. The output is recorded direct into a focusrite 2i2.

3 cycles (Fingerstyle, Strumming, G chord)
1) Piezo (Martin Thinline a.k.a. Fishman Matrix)
2) 2048 pts homemade IR
3) EQ from Torpedo CAB M + a super short IR (64pts) (This time it is not noise, it is computed for my 00-18V and its pickup)


n°2 is definetly distant although a realistic aocustic image of the guitar
n°3 has still some high end artifacts but is dry and very responsive (you can not hear/see that in the video)



It's a work in progress.
__________________
Martin 00-18V Goldplus + internal mic
Martin D-18 (2012)
Martin HD-28 (2014) Trance Audio Amulet M-V T+ DIY IR
Eastman E6OM (2019) DIY Pickup v8 + internal mic

Gibson Les Paul Standard 1958 Reissue (2013)
Fender Stratocaster American Vintage 1954 (2014)
http://acousticir.free.fr/
Reply With Quote
  #36  
Old 01-03-2022, 10:07 AM
jonfields45 jonfields45 is offline
Registered User
 
Join Date: Jun 2011
Location: Allentown, PA
Posts: 4,166
Default

#3 is clearly the best, but might #2 with some bypass mixed in be similar?
__________________
jf45ir Free DIY Acoustic Guitar IR Generator
.wav file, 30 seconds, pickup left, mic right, open position strumming best...send to direct email below
I'll send you 100/0, 75/25, 60/40, 50/50, 40/60, and 25/75 IR/Bypass IRs
IR Demo, read the description too: https://youtu.be/SELEE4yugjE
My duo's website and my email... [email protected]

Jon Fields
Reply With Quote
  #37  
Old 01-03-2022, 10:20 AM
Cuki79 Cuki79 is offline
Registered User
 
Join Date: Feb 2012
Location: France
Posts: 2,550
Default

Quote:
Originally Posted by jonfields45 View Post
#3 is clearly the best, but might #2 with some bypass mixed in be similar?
Aha no. If you blend some raw signal, you will still have a 2048 pts tail… long but still there.
__________________
Martin 00-18V Goldplus + internal mic
Martin D-18 (2012)
Martin HD-28 (2014) Trance Audio Amulet M-V T+ DIY IR
Eastman E6OM (2019) DIY Pickup v8 + internal mic

Gibson Les Paul Standard 1958 Reissue (2013)
Fender Stratocaster American Vintage 1954 (2014)
http://acousticir.free.fr/
Reply With Quote
  #38  
Old 01-03-2022, 10:35 AM
Cuki79 Cuki79 is offline
Registered User
 
Join Date: Feb 2012
Location: France
Posts: 2,550
Default

When you make a 42ms IR (2048 pts at 48kHz), one could ask himself the tail comes from:


1) Propagation in air
2) Resonance in air (Room)
3) Propagation in wood
4) Resonance in wood (structure)

42ms at 340m/s gives around 14.3 meters... So obviously it can not be straight propagation. If your tail reaches 42ms it must feel like a small room with few reflections (the wet feel).

Here is the ongitudinal spruce velocity... of course it's the shear velocity that counts... it will be lower by a factor.

from Source link

42ms at 5000m/s makes 210m... So obviously the sound can not propagate straight along the guitar, it means that the sound must resonante and bounce between the limits of the box/top. The energy is confined into the top.

For me it means that a FIR filter which can not "store signal" like a IIR filter (EQ) might not the best.

Reducing the IR to 64 pts, we only get 1.3ms that is to say 6.6 meters of wood and probably much less if you consider shear velocity.

Using EQ (IIR filter that have a memory) to do most of the jobs and add just a super short IR to account for the sound spreading over the top should work.

... to be continued...
__________________
Martin 00-18V Goldplus + internal mic
Martin D-18 (2012)
Martin HD-28 (2014) Trance Audio Amulet M-V T+ DIY IR
Eastman E6OM (2019) DIY Pickup v8 + internal mic

Gibson Les Paul Standard 1958 Reissue (2013)
Fender Stratocaster American Vintage 1954 (2014)
http://acousticir.free.fr/
Reply With Quote
  #39  
Old 01-03-2022, 02:28 PM
jonfields45 jonfields45 is offline
Registered User
 
Join Date: Jun 2011
Location: Allentown, PA
Posts: 4,166
Default

If I open one of my IRs in a viewer, the tail looks pretty trivial to me compared to what I would expect in a reverb. When I listen to your second sample, I hear what I don't like about 100% of some of my IRs. Generally 75/25 clears that up. I think my last demo shows a similar improvement going from 100% IR to 75/25 IR/Bypass. Also, truncating the second half of that IR (2048 truncated to 1024), made absolutely no difference to my ear. If the tail is a problem for making something sound "distant" then that should at least improve it.

https://www.acousticguitarforum.com/...d.php?t=634568

Here is the 100% IR from my last demo post. I moved it a little later in time and gained it up to make the first coefficient equal to 1 and easier to see.

__________________
jf45ir Free DIY Acoustic Guitar IR Generator
.wav file, 30 seconds, pickup left, mic right, open position strumming best...send to direct email below
I'll send you 100/0, 75/25, 60/40, 50/50, 40/60, and 25/75 IR/Bypass IRs
IR Demo, read the description too: https://youtu.be/SELEE4yugjE
My duo's website and my email... [email protected]

Jon Fields

Last edited by jonfields45; 01-04-2022 at 07:25 AM.
Reply With Quote
  #40  
Old 01-04-2022, 01:05 AM
Cuki79 Cuki79 is offline
Registered User
 
Join Date: Feb 2012
Location: France
Posts: 2,550
Default

You are looking in linear scale. The tail looks insignificant but it is not. Also you can clearly see a pseudo period corresponding to the main low frequency resonance. (About 5ms which is 200Hz)

You don’t hear the difference because:
long IR only matters for the low end. If you don’t focus on the low end you might not notice. Remember long IR enables to resolve long periods which correspond to short frequency. For example 100 Hz has a period of 0.01=10ms. With a 40ms IR you basically allow 100Hz to ring 4 times before vanishing…

Most people are deaf at 100Hz.

The more you blend the closer to the pickup. My goal is to alter the most the pickup without actually increase too much the actual impulse response of the system.

When you use FIR filter, you basically trig the IR. In order to have a resonance at 100 Hz, you need 40ms Tail with those 4 periods. It means that every time you hit the note, these 4 periods will be added

I think it does not work like that in reality. In reality, my guess is that the top and the air inside the box store mechanical energy. Like the swing on the play ground. As they are excited they accumulate more energy that enable some frequencies to ring longer. That « memory » of the energy stored can not be modelled by a FIR filter without adding unrealistic tail. That is why Fishman, from day one, used IIR filters to model the low end.

Note that however we join somehow at some point. The more you let IIR do the job (EQ) the flatter the Short IR frequency response will be.

PS: I am not advising against « blending »: to this day it is the best way to use our IR in a Live context. I am just trying another path.
PS2: Jon when one blends interferences might occur between the IR convoluted and original signals. Check the spectrum for 10 blend settings. Peaks or notches can appear in your spectrum when the two contribution are balanced in amplitude and opposed in phase.
__________________
Martin 00-18V Goldplus + internal mic
Martin D-18 (2012)
Martin HD-28 (2014) Trance Audio Amulet M-V T+ DIY IR
Eastman E6OM (2019) DIY Pickup v8 + internal mic

Gibson Les Paul Standard 1958 Reissue (2013)
Fender Stratocaster American Vintage 1954 (2014)
http://acousticir.free.fr/
Reply With Quote
  #41  
Old 01-05-2022, 07:41 AM
Cuki79 Cuki79 is offline
Registered User
 
Join Date: Feb 2012
Location: France
Posts: 2,550
Default

Quote:
Originally Posted by jonfields45 View Post
#2 with some bypass mixed in be similar?
Jon, I tried with another guitar and recordings and I have to admit I am not competitive yet with blending with a 2048 pts IR...

To be continued...
Cuki
__________________
Martin 00-18V Goldplus + internal mic
Martin D-18 (2012)
Martin HD-28 (2014) Trance Audio Amulet M-V T+ DIY IR
Eastman E6OM (2019) DIY Pickup v8 + internal mic

Gibson Les Paul Standard 1958 Reissue (2013)
Fender Stratocaster American Vintage 1954 (2014)
http://acousticir.free.fr/
Reply With Quote
  #42  
Old 01-06-2022, 04:07 PM
Cuki79 Cuki79 is offline
Registered User
 
Join Date: Feb 2012
Location: France
Posts: 2,550
Default

New experiment

The goal is not to reach the mic tone but to get a better pickup tone. Still dry and direct but with less quack.


I use HX native (Line 6 Helix plugin version) to correct to the maximum the tone with parametric EQs & Shelfves. (5x3 PEQs + 1 shelf EQ)

The goal is that the IR carries the less correction, mostly do phase correction and remain short.

I added a crossover. Everything above 1Khz gets a shorter IR (512pts), in order to have less high frequency spikes and metallic tail. Everything under 1 KHz gets a standard 1024 pts IR.



Guitar: Martin 00-18V + Goldplus pickup (a.k.a Fishman matrix)

1) external mic SM57
2) raw Pickup
3) Pickup + 2048 pts IR (my current go-to process very mic-like)
4) New process: EQ + IR + crossover (512pts IR > 1KHz, and 1024pts IR < 1 KHz)
5) raw Pickup



4) is the new process. It's string focus and less quacky than the pickup.

I know Jon will say that I found a very very complex way to imitate his recipe combined with a high pass filter... (which is very dry thanks to its hidden blend).

At least this complex way is mine
__________________
Martin 00-18V Goldplus + internal mic
Martin D-18 (2012)
Martin HD-28 (2014) Trance Audio Amulet M-V T+ DIY IR
Eastman E6OM (2019) DIY Pickup v8 + internal mic

Gibson Les Paul Standard 1958 Reissue (2013)
Fender Stratocaster American Vintage 1954 (2014)
http://acousticir.free.fr/
Reply With Quote
  #43  
Old 01-06-2022, 04:11 PM
SpruceTop SpruceTop is offline
Charter Member
 
Join Date: Jan 2006
Location: Rochester, New York
Posts: 10,168
Default

Cuki, #4, the New process: EQ + IR + crossover (512pts IR > 1KHz, and 1024pts IR < 1 KHz), sounds VERY GOOD!
__________________
RainSong BI-DR1000N2
Martin HD-28 Sunburst/Trance M-VT Phantom
Martin D-18/Ultra Tonic
Guild F-212XL STD
Adamas I 2087GT-8
Huss & Dalton TD-R
Taylor 717e
Taylor 618e
Taylor 614ce
Larrivee D-40R Sunburst
Larrivee D-03R Sunburst/Ultra Tonic
Larrivee D-40M Legacy/Dazzo
Larrivee C-03R Tommy Emmanuel/Trance M-VT Phantom
Emerald X20
Ovation Elite Plus
Republic Duolian/Schatten NR-2
Reply With Quote
  #44  
Old 01-06-2022, 04:20 PM
Cuki79 Cuki79 is offline
Registered User
 
Join Date: Feb 2012
Location: France
Posts: 2,550
Default

Thanks Ken

It took me 3h to tune it… and I knew what to do. I have been working for few days on the idea, with different guitar.
__________________
Martin 00-18V Goldplus + internal mic
Martin D-18 (2012)
Martin HD-28 (2014) Trance Audio Amulet M-V T+ DIY IR
Eastman E6OM (2019) DIY Pickup v8 + internal mic

Gibson Les Paul Standard 1958 Reissue (2013)
Fender Stratocaster American Vintage 1954 (2014)
http://acousticir.free.fr/
Reply With Quote
  #45  
Old 01-06-2022, 04:36 PM
martingitdave martingitdave is offline
Registered User
 
Join Date: Feb 2014
Location: Chicago
Posts: 9,720
Default

Quote:
Originally Posted by Cuki79 View Post
New experiment

The goal is not to reach the mic tone but to get a better pickup tone. Still dry and direct but with less quack.


I use HX native (Line 6 Helix plugin version) to correct to the maximum the tone with parametric EQs & Shelfves. (5x3 PEQs + 1 shelf EQ)

The goal is that the IR carries the less correction, mostly do phase correction and remain short.

I added a crossover. Everything above 1Khz gets a shorter IR (512pts), in order to have less high frequency spikes and metallic tail. Everything under 1 KHz gets a standard 1024 pts IR.



Guitar: Martin 00-18V + Goldplus pickup (a.k.a Fishman matrix)

1) external mic SM57
2) raw Pickup
3) Pickup + 2048 pts IR (my current go-to process very mic-like)
4) New process: EQ + IR + crossover (512pts IR > 1KHz, and 1024pts IR < 1 KHz)
5) raw Pickup



4) is the new process. It's string focus and less quacky than the pickup.

I know Jon will say that I found a very very complex way to imitate his recipe combined with a high pass filter... (which is very dry thanks to its hidden blend).

At least this complex way is mine
It sounds very good. Perhas the issue is less to do with the IR process and more to do with the recording process. I think the distant sound may be a result of the room where it's recorded? The mic is still picking up reverberations from the room, no?
__________________
Martin D-28 Custom Authentic '37
Martin D-28 Marquis
Guild F-512
"Lift your head and smile at trouble. You'll find happiness someday."
Less clicking, more picking.
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Acoustic Amplification

Thread Tools





All times are GMT -6. The time now is 09:16 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
Copyright ©2000 - 2022, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=