Orv's Frequency Response Thread

[Orvillain]

Thought I'd start a thread for my frequency response experiments.

So first up is ... the effect of different sweep lengths on the resulting plots.

The effect of different sweep lengths when capturing the frequency response of my recto. Settings for the amp are:

Dual Recto Red Modern:
Bass - noon
Mid - 2 o'clock
Treble - 2 o'clock
Gain - 2 o'clock
Master - 9 o'clock
Presence - 3 o'clock
FX Loop Bypassed
Bold
Diode
Load - Egnater Tourmaster 4x12 V30 16ohms

The super lows are quite interesting, but after about 10hz it is all a much of a muchness. So my advice would be, stick with the default 256k sweep length, in order to avoid pissing off neighbours. These sweeps are well within tolerance IMO.

 

[Orvillain]

So now I know to stick with a 256k sweep length, I thought I would check the response curves for a bunch of different loads I have. Here we go!

Same settings as above:

Dual Recto Red Modern:
Bass - noon
Mid - 2 o'clock
Treble - 2 o'clock
Gain - 2 o'clock
Master - 9 o'clock
Presence - 3 o'clock
FX Loop Bypassed
Bold
Diode

But the load changes: and nothing else.
Red: Egnater Tourmaster 4x12 with V30's at 16ohms.
Green: Marshall JCM800 Lead 1960 with T75's at 16ohms.
Purple: Marshall Mode Four with K100's at 8ohms.
Light Blue: Suhr Reactive Load IR at 8ohms.
Yellow: DIY Loadbox (schematic unknown) at 16ohms.
Dark Blue: Small 1x12 fully open backed cab with a T75 in it at 16ohms.

The three real life cabs are all quite similar. The two loads however, are quite different from the cabs and from one another.

Zoomed in version:

 

[Orvillain]

Here is the same test across loads, but with my Satriani JVM. Settings:

JVMJS OD1 Red:
Bass - noon
Mid - 1 o'clock
Treble - 2 o'clock
Gain - 10 o'clock
Channel: 9 o'clock
Master - 9 o'clock
Resonance - noon
Presence - 2 o'clock
FX Loop Bypassed

Dark Blue: Egnater Tourmaster 4x12 with V30's at 16ohms.
Purple: Marshall JCM800 Lead 1960 with T75's at 16ohms.
Red: Marshall Mode Four with K100's at 8ohms.
Green: Suhr Reactive Load IR at 8ohms.
Light Blue: DIY Loadbox (schematic unknown) at 16ohms.
Orange: Small 1x12 fully open backed cab with a T75 in it at 16ohms.

 

[Alex Kenivel]

I love grafs. Grafs be fun. People balk at grafs and be like "just play your stupid guitar" but some folks like to try to understand wtf is going on.

The three real life cabs are all quite similar. The two loads however, are quite different from the cabs and from one another.

IDK, the Suhr RL doesn't look that different from the cabs (especially the marshall) other than it looks smoother - compared to the DIY load?

And extra thanks for listing the color codded info. No way us plebs in phones can zoom in that easily in these pics.

 

[Orvillain]

Here is the same test across loads, but with my 2001 Diezel VH4 Silverface, channel 3. Settings:

VH4 2001 Ch3:
Bass - noon
Mid - 3 o'clock
Treble - 3 o'clock
Gain - 2 o'clock
Channel: 11 o'clock
Master - 9 o'clock
Deep - 1 o'clock
Presence - 3 o'clock
FX Loop Bypassed

Blue: Egnater Tourmaster 4x12 with V30's at 16ohms.
Orange: Marshall JCM800 Lead 1960 with T75's at 16ohms.
Green: Marshall Mode Four with K100's at 8ohms.
Dark Purple: Suhr Reactive Load IR at 8ohms.
Light Purple: DIY Loadbox (schematic unknown) at 16ohms.
Red: Small 1x12 fully open backed cab with a T75 in it at 16ohms.

 

[Orvillain]

Now here are an assortment of graphs. Each one shows each load with 3 amps. I've aligned each one of them to the lowest resonant peak.

Egnater Tourmaster 4x12 V30 16ohms:

Marshall JCM800 1960 Lead 4x12 T75 16ohms:

Marshall Mode Four K100 8ohms:

Suhr Reactive Load IR 8ohms:

DIY Loadbox (schematic unknown) 16ohms:

1x12 Open back combo T75 16ohms:

 

[Orvillain]

I love grafs. Grafs be fun. People balk at grafs and be like "just play your stupid guitar" but some folks like to try to understand wtf is going on.



IDK, the Suhr RL doesn't look that different from the cabs (especially the marshall) other than it looks smoother - compared to the DIY load?

And extra thanks for listing the color codded info. No way us plebs in phones can zoom in that easily in these pics.

I suspect that non-uniformity in the real loads versus the loadboxes hints at something 'extra' the cabs are giving us. Maybe that is where the liveliness and "3D" effect lives???

 

[Orvillain]

I really want to capture the impedance curves of all of these cabs. I know @DLC86 has posted a circuit diagram for a small box that you can use with your soundcard input and outputs. I may grab the bits and do that quite soon.

 

[SillyOctpuss]

I love grafs. Grafs be fun. People balk at grafs and be like "just play your stupid guitar" but some folks like to try to understand wtf is going on.

Absolutely. Graphs are much more useful to see what's going on vs 10 pages of anecdotal evidence, confirmation bias and arguments at TOP.

 

[Mongillo19]

What I've learned from this is that you have some tasty amps

 

[laxu]

So what do you plan to do with all this knowledge?

I found today that my Bluetone 4x10 cab has beam blockers on the angled top speakers after shining some light through its thickass grillcloth. I don't know what I will do with this newfound knowledge. "Thanks for not being harsh and piercing"?

 

[Orvillain]

What I've learned from this is that you have some tasty amps

I do indeed! In my kitchen no less!

Not pictured is a Laney VH100R, which needs a bit of love at the moment, and behind these is a Diezel Hagen which isn't mine, but may as well be for the time being!

 

[Orvillain]

So what do you plan to do with all this knowledge?

Well nothing really at the moment. It is just momentarily interesting to me, and I was curious what effect different loads had on the tone of amps at the same settings for each load.

Think the DIY jobby needs to go in the bin!

 

[Mongillo19]

View attachment 15502

I do indeed! In my kitchen no less!

Not pictured is a Laney VH100R, which needs a bit of love at the moment, and behind these is a Diezel Hagen which isn't mine, but may as well be for the time being!

I've been itching for a diezel (probably will have to be the VH2). I kick myself every day for selling my MW DR

 

[laxu]

View attachment 15502

I do indeed! In my kitchen no less!

Not pictured is a Laney VH100R, which needs a bit of love at the moment, and behind these is a Diezel Hagen which isn't mine, but may as well be for the time being!

 

[MirrorProfiles]

Makes way more sense to me to align to the dip around 600hz as each amp will have different amounts of depth and presence affecting the poweramp in the bass and top end.

 

[Alex Kenivel]

In my kitchen

Who needs meals anyway?

 

[Orvillain]

Who needs meals anyway?

I make the wife cook in the toilet.

 

[Orvillain]

Makes way more sense to me to align to the dip around 600hz as each amp will have different amounts of depth and presence affecting the poweramp in the bass and top end.

Yeah I was thinking about that based on our previous graph discussions. But I think if you move the graphs around too much, you kinda lose the differences in certain areas - ie; aligning one amp to another amps 600hz dip could then make it seem like the first amp was brighter than the second, when actually it was the other way around in terms of brightness... and the first amp had a balls-deep mid scoop that you've now erased.

 

[holoholo]