Setting up my Source Audio Aftershock

[Alex_H]

I was looking for a mild overdrive and finally settled for an Aftershock by Source Audio.

While the presets were not bad at all, I just wanted to figure it out myself a little bit more.

One very interesting question for me was: What distortion engines are having no cut in the deep bass region?

To figure that out, I dialed in a setting with a very flat frequency response. I used these Settings:

Parametric Equalizer
Bass Freq: 42 Hz
Mid A Freq: 80 Hz
Mid A Q: 0.5
Mid B Freq: 442 Hz
Mid B Q: 0.5
Treble Freq: 1050 Hz
Type (cut only): High Pass
Shelving Slop: Low
Shelf Boost Rolloff: Minimum
Type (cut only): Low Pass
Shelving Slop: Low
Shelf Boost Rolloff: Minimum
Boos Maximum: +20 dB

Left (Channel 1) Controls
Drive: 127
Output: Maximum
Voice: Mitte (127)
Voice Frequency: Minimum
Drive Balance: Mitte (127)
Drive Max: Maximum
Clean Mix: Minimum
Bass: 42 Hz / 20.00 dB
Mid A: 80 Hz / 8.08 dB
Mid B: 442 Hz / 5.73 dB
Treble: 1050 / 11.37 dB

To get those charts I used two DI boxes. One before (blue graph) the pedal and one after (red graph). They are connected with XLR cables directly into my audio interface. A free VST host and two Spectrum Analyzer VST plugins are showing the signals. I feed the pedal pink noise, which I generated in Audacity, with the help of my Nux Core Loop pedal into the Aftershock.

38 Special

Bass Bender

Bass Big Pi

Bass Crunch Tube

Bass El Raton

Bass Fuzz Facade

Bass Gated Fuzz

Bass Metal

Bass Octave Fuzz

Bass Power Stage

Bass Smooth Tube

Bass TS9000

Bass Tube Drive

Bender

Bender II

Big Pi

Bigger Pi

Clean – No Distortion

Crunch Tube

Crunch Tube II

DS-1

El Raton

Foldover

Foldover II – Warped Drive

Fuzz Facade

Fuzz Face II

Gated Fuzz

Gated Fuzz II

Gated Fuzz III

Germanium Muffin

Grated Bass

Maestro FZ-1A

Metal

Metal II

Octave Fuzz

Octave II

OhSeeDee

Pepperface Fuzz

Power Stage

Power Stage II

Rat II

Smoked Glass C4L

Smoked Glass D5M

Smooth Tube

Smooth Tube II

The Klone

TS 9001

TS9000

Tube Drive

Vari-Screamer

After I had made all the effort, making those screenshots and so on, I thought I could share it here. Maybe it's usefull for someone too.

 

[crguti]

Good effort, however you missed some important details. What you should do is to divide the red curve by the blue curve (Output/Input) to get the Frequency Response of the system.
After that, add all the Frequency Responses in just 1 graph, so you can compare all the responses.

2 questions... in each graph I can see 3 curves, a thin line above, the color graph, then another thicker curve below. What are those?
and, How long time did you use to average the results?

 

[Alex_H]

Good effort, however you missed some important details. What you should do is to divide the red curve by the blue curve (Output/Input) to get the Frequency Response of the system.
After that, add all the Frequency Responses in just 1 graph, so you can compare all the responses.

True, that would be very useful. But I would have to use a different plugin for that. What I could have done, is putting both graphs onto each other with different colors. Maybe something I will do in the future. I tried it once in the FFT Analyzer mode, but it got to cluttered. The graphs are using the analog band analyzer with 4 bands per octave.

2 questions... in each graph I can see 3 curves, a thin line above, the color graph, then another thicker curve below. What are those?
and, How long time did you use to average the results?

Those are avarage minimum and maximums. The hold time is set to 3 seconds.

 

[Alex_H]

I further evaluated those screenshots, trying to find the distortion engines with the least bass cut. I noted down, the db values at 40 and 100hz. Subtracted one from the other and had a value describing the bass loss in that sub bass region.

Sadly there are none without any sub bass loss. But some distortion engines are having much less loss compared to others. Here are the ones, with not more then -6db loss:

• Grated Bass: -3 db
• Smoked Glass D5M: -3 db
• Bass Power Stage: -3,5 db
• Foldover II – Warped Drive: -4 db
• Smoked Glass C4L: -4 db
  
• Bass Tube Drive: -4,5 db
  
• Gated Fuzz II: -4,5 db
  
• Bass Metal: -5 db
  
• Bass Octave Fuzz: -5 db
• Gated Fuzz III: -5 db
  
• Vari-Screamer: -5 db
  
• Bass Big Pi: -6 db
  
• Bass Gated Fuzz: -6 db
  

 

[intrglctcrevfnk]

Perhaps because the bass eq is shelving and there is also a low cut/high pass filter? Most of these shots from the manual show a tail curve. There are also some options in the eq section for the knee of those shelves.

the screen shots you put up (and nice job BTW, I did a similar thing with Logic when I was making a Demon King clone with the OhSeeDee type) all show a characteristic bell curve to the configurable low cut filter I posted right above. Coincidence?

edit: also congrats to those that scrolled down and made it to this 4th post on the thread. You’ve come a long way!

 

[rsmith601]

Epic work!!!

 

[JasondeBass]

Any thoughts on how to get the aftershock to sound exactly like a blueberry overdrive?

 

[jam.majors]

I was looking for a mild overdrive and finally settled for an Aftershock by Source Audio.

While the presets were not bad at all, I just wanted to figure it out myself a little bit more.

One very interesting question for me was: What distortion engines are having no cut in the deep bass region?

To figure that out, I dialed in a setting with a very flat frequency response. I used these Settings:

Parametric Equalizer
Bass Freq: 42 Hz
Mid A Freq: 80 Hz
Mid A Q: 0.5
Mid B Freq: 442 Hz
Mid B Q: 0.5
Treble Freq: 1050 Hz
Type (cut only): High Pass
Shelving Slop: Low
Shelf Boost Rolloff: Minimum
Type (cut only): Low Pass
Shelving Slop: Low
Shelf Boost Rolloff: Minimum
Boos Maximum: +20 dB

Left (Channel 1) Controls
Drive: 127
Output: Maximum
Voice: Mitte (127)
Voice Frequency: Minimum
Drive Balance: Mitte (127)
Drive Max: Maximum
Clean Mix: Minimum
Bass: 42 Hz / 20.00 dB
Mid A: 80 Hz / 8.08 dB
Mid B: 442 Hz / 5.73 dB
Treble: 1050 / 11.37 dB

To get those charts I used two DI boxes. One before (blue graph) the pedal and one after (red graph). They are connected with XLR cables directly into my audio interface. A free VST host and two Spectrum Analyzer VST plugins are showing the signals. I feed the pedal pink noise, which I generated in Audacity, with the help of my Nux Core Loop pedal into the Aftershock.

38 Special
View attachment 3733357

Bass Bender
View attachment 3733358

Bass Big Pi
View attachment 3733359
Bass Crunch Tube
View attachment 3733360

Bass El Raton
View attachment 3733361

Bass Fuzz Facade
View attachment 3733362

Bass Gated Fuzz
View attachment 3733363

Bass Metal
View attachment 3733364

Bass Octave Fuzz
View attachment 3733365

Bass Power Stage
View attachment 3733366

Bass Smooth Tube
View attachment 3733367

Bass TS9000
View attachment 3733368

Bass Tube Drive
View attachment 3733369

Bender
View attachment 3733370

Bender II
View attachment 3733371

Big Pi
View attachment 3733372

Bigger Pi
View attachment 3733373

Clean – No Distortion
View attachment 3733374

Crunch Tube
View attachment 3733375

Crunch Tube II
View attachment 3733376

DS-1
View attachment 3733377

El Raton
View attachment 3733378

Foldover
View attachment 3733379

Foldover II – Warped Drive
View attachment 3733380

Fuzz Facade
View attachment 3733381

Fuzz Face II
View attachment 3733382

Gated Fuzz
View attachment 3733383

Gated Fuzz II
View attachment 3733384

Gated Fuzz III
View attachment 3733385

Germanium Muffin
View attachment 3733386

Grated Bass
View attachment 3733387

Maestro FZ-1A
View attachment 3733388

Metal
View attachment 3733389

Metal II
View attachment 3733390

Octave Fuzz
View attachment 3733391

Octave II
View attachment 3733392

OhSeeDee
View attachment 3733393

Pepperface Fuzz
View attachment 3733394

Power Stage
View attachment 3733395

Power Stage II
View attachment 3733396

Rat II
View attachment 3733397

Smoked Glass C4L
View attachment 3733398

Smoked Glass D5M
View attachment 3733399

Smooth Tube
View attachment 3733400

Smooth Tube II
View attachment 3733401

The Klone
View attachment 3733402

TS 9001
View attachment 3733403

TS9000
View attachment 3733404

Tube Drive
View attachment 3733405

Vari-Screamer
View attachment 3733406
After I had made all the effort, making those screenshots and so on, I thought I could share it here. Maybe it's usefull for someone too.

So much data!!! Thanks!

 

[jam.majors]

I further evaluated those screenshots, trying to find the distortion engines with the least bass cut. I noted down, the db values at 40 and 100hz. Subtracted one from the other and had a value describing the bass loss in that sub bass region.

Sadly there are none without any sub bass loss. But some distortion engines are having much less loss compared to others. Here are the ones, with not more then -6db loss:

• Grated Bass: -3 db
• Smoked Glass D5M: -3 db
• Bass Power Stage: -3,5 db
• Foldover II – Warped Drive: -4 db
• Smoked Glass C4L: -4 db
  
• Bass Tube Drive: -4,5 db
  
• Gated Fuzz II: -4,5 db
  
• Bass Metal: -5 db
  
• Bass Octave Fuzz: -5 db
• Gated Fuzz III: -5 db
  
• Vari-Screamer: -5 db
  
• Bass Big Pi: -6 db
  
• Bass Gated Fuzz: -6 db

That explains why most of those are my favorites!

 

[GMC]

An amazing and very conscientious piece of work!
With bass, it's important to understand that low sub audio is a tricky and complicated beast. Most 5/6/7 string basses do not produce a low B as clearly or at the same volume level as a low E. It's just physics...most of us pluck that string a bit harder to compensate. It happens...
Then there's the weird situation where the bass guitar's fundamental isn't very strong compared to it's 1st harmonic (at double the lowest frequency). So a low B with a 31hz fundamental actually doesn't produce much at 31hz, compared to it's 1st harmonic at 62hz and 2nd harmonic at 124hz. The Low E is similar, fundamental at 41Hz has very low output compared to the 1st and 2nd fundamental at 82hz and 164hz. This is why adding heavy boost at sub 60hz doesn't seem to add much "thunder of gawd" to the bass but oddly 120hz seems to add a lot more perceived sub bass. I tend to eq out anything lower than 40hz for the sake of my ears and my speaker cones. All my watts goes into that sub bass and isn't really heard...100-160hz has a far greater reaction for less ear damage and cone damage. If you add the complication that at high power levels, most drivers substantially drop off anything below 120hz any how (it's a perception thing as the mids get a projected with a much higher SPL level). 4x10 / 8x10's are particularly bad for this. Great a mid ot low power levels...start pumping a true 400w into them and only the mids get louder.
Anyhow...in my opinion...anything cut under 80hz isn't to be concerned about and is probably doing you a favour.
All of the EQ models in the Aftershock can be tweaked. I tend to replace the mix control to a bass control and I dial in 100hz for it's EQ centre. Far left of the dial is a 18db bass cut, far right is a 18db boost...that's your bass thunder right there...one knob...all that you could want. I tend to do the same for the Tone control, I remap it to a treble control cut / boost...works like a charm for old school tones (tone max left) and bright and zingy tones (great for driving other effects or synth tones) to the far right.
I tend to find most of the Aftershock's models to be a little dark, so for most of my patches, I have a little treble tweak. With the SA Ultrawave, which seems to be an inherently brighter pedal, I'm usually dialling down the treble end by quite a lot. I find with analogue grit, I'm often looking for some added top end sparkle that usually is cut off in the circuit design and is quite rare for the on board tone control to be able to get it back. The Dam Ezekiel is one of those rare pedals where the tone (treble) control is absolutely perfect for bass.
One of the things I love about the Aftershock and Ultrawave is the ability to take say a Tube overdrive, tweak the character of the EQ and swap out the tone controls for a true bass / treble options, save and use that patch ...all internally in the one box.
I guess that's why they are called "One Series" pedals?

 

[GMC]

Just to add...if you ever want to do the same for the Source Audio Chorus Modulation models...it would be very very interesting to see what's happening with the top end and low mids / upper bass regions. It would help me to build a truly bass specific EQ for Chorus. Lunar / Gemini / Mercury units. I think these models accurately reproduce the original unit's responses which is where the problem is for bass...they are guitar frequencies and not bass frequencies. I've flipped so many top tier chorus pedals over the years because I just wasn't getting what I wanted out of them...until I discovered boosting the 3Khz area for bass chorus. I'm using the SA Lunar and it's 4 band EQ section allows me to tailor in very specific adjustments. Way beyond the usual Guitar friendly (bass tawdry) tone knob found on most Chorus pedals...or worse...a mix knob. With bass Chorus...the mix knob is the kiss of death to any chorus wetness. Sure you retain the low end, but all your effected chorus top end gets massively diluted as well.