Hi/Lo Cuts in Cab Block quandry

J

joegold

Fractal Fanatic
Although I've spent most of my time with IRs of cabs with EVM-12Ls in them, as opposed to other drivers, I always find that for overdriven sounds, in order for it to not sound like ass, I have to use more hi-cut than I do for my clean tones using the same IRs.

Yet, when I use a power amp + cab rig with real 12L-loaded cabs, the same cab works great for both cleans and overdriven tones.

What is it about the way that audio is processed via an IR within the Cab Block that would cause this?

My goal, since getting an Ultra back in '09 and then my II in 2011 (I believe), has been to have one IR in one Global Cab Block instance that I can use across all my Presets.
These Presets are mainly tailored to my power amp + cabs rig.
The goal is to get a near identical sound via the Cab Block for FOH and/or recording.
But no matter what I do, no matter what IR I use, I always need different EQ in the Cab Block on my cleans vs my overdriven tones.

Why should this be so?
Do the rest of you, with whatever IR you like to use of whatever drivers, find you have to do the same?

All I can think of is the fact that 12Ls tend to let a bit more top end sibilance come through than most other guitar-priented drivers.
But there's never too much fizz on my gainy tones and my cleans can sparkle if I need them to when I use real 12Ls.
Why that doesn't map well onto an IR of a 12L I just don't get.

E.g.
I've got a decent sounding OH EV-Thiele IR that I'm using mostly nowadays.
With my EMG-SA equipped Strat through a bight hyper-clean tone (Doubleverb-based) I have to run the Cab Block's hi-cut almost wide-open (or around the 10k mark) in order to get anything like the bright tone I hear from my real EVs through my CLR.
But using that same IR with an overdriven tone (USA Lead-based) I need to lower the hi-cut to at least 6k or even lower, sometimes as low as 3500hz in order to get anything worth listening to.

I find it very perplexing.
 
IR are mic'd right up against the speaker, you dont listen to the cab wit your ears against it (one would hope not o_O), do you?
 
FractalAudio said:
He is.
Click to expand...

Well, while the differences between my cab sound and the way the IRs I've been working with sound definitely *is* part of what I'm asking about, I'm not really asking the typical cab-in-the room vs FRFR thing, per se.

E.g. When I put a mic on my real cab and find a good mic position and EQ to record with a bright or even a dark clean tone, I don't normally have to move the mic position or even change the EQ if I use an overdriven sound through that same cab/mic/mixer/EQ/monitors system, in my experience.
I.e. a single mic position and EQ normally works for both cleans and overdriven tones.
Yet when I use an IR, even with IRs I've recorded myself of that same cab (and admittedly I'm not very good at shooting IRs, so I usually stick to ones from OH that sound close), I *do* have to change the EQ.

All I'm asking here is why that seems to be so.

If there's something else about the nature of close mic'ing that I'm not taking into account, I'd be real happy if somebody would fill me in.
It'd definitely be better than the passive aggressive vibe I think I might be getting from you all now.
 
Molekiller said:
Maybe it's that you haven't found the IR that has the right mic placement for what you want to hear?
Click to expand...

Well, having the right IR is always going to be a big part of getting then tones you want but it's not THE issue that I'm asking about here, afaics.

My issue is that if I find an IR that's good enough for my cleans I have to EQ it differently for overdriven sounds, and visa versa.
In my experience mic'ing real cabs, once I find a mic placement and EQ that works for my cleans I don't need to reposition the mic or re-EQ the signal for overdriven tones.
I'm just wondering what makes working with IRs different in this respect.

Of course, if everybody else out there *does* re-position mics and re-EQ the signal when going between a clean tone and an overdriven tone then it is possible that my memory is not all that accurate.
I don't do a lot of sessions and quite often when I do we'll be using separate tracks for a clean part and then an overdriven part, etc., so the engineer may well be applying a different EQ to the mic on my cab and I wouldn't know.
But I've never had an engineer reposition the mic between takes of clean playing and dirty.
And I've also done sessions where both clean parts and dirty parts are placed on the same track with the same EQ and mic position.
And certainly, when I'm playing live into a FOH system, I don't nornally see the soundman run up on stage to reposition my mic when I take a solo.

So, I just don't get why it is that working with IRs should be different in this regard.
 
My provisional understanding is that an IR is a static snapshot of a speaker's performance. A convolution "engine" or algorithm will process the audio signal with this imprint. I expect IRs are made in a speakers' sweet spot with regard to tonal satisfaction. At least that's what I've done when I've made IRs. Everything makes some difference: cabinet, mic, distance, angle, space, volume level, etc.

IMO: A guitar speaker and cabinet system can not be regarded as "sound reproduction" (in the way FRFR or studio monitors are) because they are not a linear, low distortion, phase coherent reproduction of the audio signal. I think of a guitar speaker and cabinet as also being a sound generating device like the bell of a wind instrument, the body of a chordophone or whatever. It doesn't just reproduce the signal, it resonates, modifies, filters, and adds harmonics based on the audio content.

It's easy to test: Record a I khz tone through a speaker cabinet, and there is harmonic content added. A speaker that specs 70hz-4khz will not just produce its modified version of a signal in that range, but will be adding harmonics above 4khz (down many db) up to 16k or even 20k. The speaker will also perform differently with a loud, heavily saturated tone than with a clean one. Whether a sine wave sweep or burst is used in IR creation, It is not exactly reproducing a speakers' performance across a wide power handling range with a wide range of harmonic content. Of course, it will vary depending on the particular speaker. However, working in a sweet spot of speaker performance offers consistency that is; well, what's possible - and often desirable. How you say? Close enough for Rock'n'Roll?

Lucky for us, the cab block has a lot of adjustments to modify the cabinet response. The various cabinet resonance parameters can go some way toward balancing clean vs overdriven in a way EQ can't. As you've no doubt considered: there may be a different IR that works for both overdriven and clean tones without EQ with a particular amp. FWIW: I often use different cabinets (or one cabinet EQed differently) in the X/Y cabinet slots to optimize clean vs distortion settings. A real speaker may have more range (not much of which may be optimal) than an IR , but a real speaker won't have the versatility of two different dialed in X/Y settings.

I love turning off the cab sims and using one of my cabinets with vintage Fanes or Celestions as much as the the next guy (maybe more), but that has its limitations as well.

Lastly, let's not forget the significance of the quality of FRFR used: That is also a factor, I discovered by experience.
 
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artzeal said:
My provisional understanding is that an IR is a static snapshot of a speaker's performance. A convolution "engine" or algorithm will process the audio signal with this imprint. I expect IRs are made in a speakers' sweet spot with regard to tonal satisfaction. At least that's what I've done when I've made IRs. Everything makes some difference: cabinet, mic, distance, angle, space, volume level, etc.

IMO: A guitar speaker and cabinet system can not be regarded as "sound reproduction" (in the way FRFR or studio monitors are) because they are not a linear, low distortion reproduction of the audio signal. I think of a guitar speaker and cabinet as also being a sound generating device like the bell of a wind instrument, the body of a chordophone or whatever. It doesn't just reproduce the signal, it resonates, modifies, filters, and adds harmonics based on the audio content.

It's easy to test: Record a I khz tone through a speaker cabinet, and there is harmonic content added and attenuated. A speaker that specs 70hz-4khz will not just produce its modified version of a signal in that range, but will be adding harmonics above 4khz (down many db) up to 16k or even 20k. The speaker will also perform differently with a loud, heavily saturated tone than with a clean one. Whether a sine wave sweep or burst is used in IR creation, It is not exactly reproducing a speakers' performance across a wide power handling range with a wide range of harmonic content. Of course, it will vary depending on the particular speaker. However, working in a sweet spot of speaker performance offers consistency that is; well, what's possible - and often desirable. How you say? Close enough for Rock'n'Roll?

Lucky for us, the cab block has a lot of adjustments to modify the cabinet response. The various cabinet resonance parameters can go some way toward balancing clean vs overdriven in a way EQ can't. As you've no doubt considered: there may be a different IR that works for both overdriven and clean tones without EQ with a particular amp. FWIW: I often use different cabinets (or one cabinet EQed differently) in the X/Y cabinet slots to optimize clean vs distortion settings. A real speaker has more range than an IR, but a real speaker can't be optimized over the vast range possible with two different X/Y settings.

I love turning off the cab sims and using one of my cabinets with vintage Fanes or Celestions as much as the the next guy (maybe more), but that has its limitations as well.
Click to expand...
I agree with what you say about the difference between IRs and a real speaker but recently I've experimented a bit with speaker drive and motor drive parameters and those two if set right can give back most of what you experience with a real cab. Obviously they're "generic" controls and are not modelled against a specific cab or driver so we can't expect a 100% match, but they surely are a step ahead ;)

P.s.: maybe a little OT but yesterday I started this thread, someone that wanna discuss about it?
http://forum.fractalaudio.com/threads/amp-in-the-room-irs.120258/
 
artzeal said:
My provisional understanding is that an IR is a static snapshot of a speaker's performance. A convolution "engine" or algorithm will process the audio signal with this imprint. I expect IRs are made in a speakers' sweet spot with regard to tonal satisfaction. At least that's what I've done when I've made IRs. Everything makes some difference: cabinet, mic, distance, angle, space, volume level, etc.

IMO: A guitar speaker and cabinet system can not be regarded as "sound reproduction" (in the way FRFR or studio monitors are) because they are not a linear, low distortion, phase coherent reproduction of the audio signal. I think of a guitar speaker and cabinet as also being a sound generating device like the bell of a wind instrument, the body of a chordophone or whatever. It doesn't just reproduce the signal, it resonates, modifies, filters, and adds harmonics based on the audio content.

It's easy to test: Record a I khz tone through a speaker cabinet, and there is harmonic content added. A speaker that specs 70hz-4khz will not just produce its modified version of a signal in that range, but will be adding harmonics above 4khz (down many db) up to 16k or even 20k. The speaker will also perform differently with a loud, heavily saturated tone than with a clean one. Whether a sine wave sweep or burst is used in IR creation, It is not exactly reproducing a speakers' performance across a wide power handling range with a wide range of harmonic content. Of course, it will vary depending on the particular speaker. However, working in a sweet spot of speaker performance offers consistency that is; well, what's possible - and often desirable. How you say? Close enough for Rock'n'Roll?

Lucky for us, the cab block has a lot of adjustments to modify the cabinet response. The various cabinet resonance parameters can go some way toward balancing clean vs overdriven in a way EQ can't. As you've no doubt considered: there may be a different IR that works for both overdriven and clean tones without EQ with a particular amp. FWIW: I often use different cabinets (or one cabinet EQed differently) in the X/Y cabinet slots to optimize clean vs distortion settings. A real speaker may have more range (not much of which may be optimal) than an IR , but a real speaker won't have the versatility of two different dialed in X/Y settings.

I love turning off the cab sims and using one of my cabinets with vintage Fanes or Celestions as much as the the next guy (maybe more), but that has its limitations as well.

Lastly, let's not forget the significance of the quality of FRFR used: That is also a factor, I discovered by experience.
Click to expand...

Thanks for your input.
Assuming I actually understand what you wrote, which isn't a sure thing, I don't see how it addresses the question that I'm asking.

I'll ask it again yet another way...
If two instances of the Axe's Amp Block, a clean tone and an overdriven tone, sound good through a power amp + cab rig with the same cab and driver used for both tones, then why is it that an IR of a similar driver in a similar cab that's been EQ'd to work with the clean tone doesn't also work with the overdriven tone w/o needing to re-EQ that same IR in the Cab Block, and visa versa?
 
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DLC86 said:
I agree with what you say about the difference between IRs and a real speaker but recently I've experimented a bit with speaker drive and motor drive parameters and those two if set right can give back most of what you experience with a real cab. Obviously they're "generic" controls and are not modelled against a specific cab or driver so we can't expect a 100% match, but they surely are a step ahead ;)

P.s.: maybe a little OT but yesterday I started this thread, someone that wanna discuss about it?
http://forum.fractalaudio.com/threads/amp-in-the-room-irs.120258/
Click to expand...

I dunno about the current implementation of the Motor Drive parameter in the Cab Block.
It used to be basically a mild distortion knob, adding distortion to the signal as the signal coming into the Cab Block gets louder.
But several firmwares ago it became more like a compressor.
And it's not a very subtle type of compression.
E.g. Even at low Motor Drive settings, my Reverb, which is pre-Cab Block in most of my Presets (so I can use the FXL Block at the end for my power amp + cabs feed), goes nuts.
I.e. The Reverb tail is highly compressed and sounds way too loud.

And I normally don't mess with the speaker Drive parameter in the Amp Block because whatever it can do to make my FRFR feed sound more realistic will also affect my power amp + cab feed in a way that I don't want it to.

And I just want to reiterate that I'm not asking about how to achieve a cab-in-the-room tone here.
Those in the know tend to think this is impossible with the current state-of-the-art and at this point I have no reason not to believe them.
 
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joegold said:
I dunno about the current implementation of the Motor Drive parameter in the Cab Block.
It used to be basically a mild distortion knob, adding distortion to the signal as the signal coming into the Cab Block gets louder.
But several firmwares ago it became more like a compressor.
And it's not a very subtle type of compression.
E.g. Even at low Motor Drive settings, my Reverb, which is pre-Cab Block in most of my Presets (so I can use the FXL Block at the end for my power amp + cabs feed), goes nuts.
I.e. The Reverb tail is highly compressed and sounds way too loud.

And I normally don't mess with the speaker Drive parameter in the Amp Block because whatever it can do to make my FRFR feed sound more realistic will also affect my power amp + cab feed in a way that I don't want it to.

And I just want to reiterate that I'm not asking about how to achieve a cab-in-the-room tone here.
Those in the know tend to think this is impossible with the current state-of-the-art and at this point I have no reason not to believe them.
Click to expand...
In reality I was replying to artzeal and was considering his post as an independent topic, my bad.
You're right about the Motor drive, it's basically a compressor with a fixed threshold but it compresses differently the various frequencies (lows less compressed than highs) so It's normal that it messes up your reverb if it's placed before the cab. Maybe you can place it after just to try if it works or see if you can find a sweet spot where it doesn't mess up your reverb.
Anyway I don't find it that aggressive, IIRC the ratio when set at max is about 3:1, the threshold instead is set pretty low for the level coming out of the amp block but that's how it's supposed to be I think.
I like it mainly because I always found the amp models to have a bit too much dynamic compared to my experience with tube amps and for me is what works best to address this (surely better than output comp or cf comp).

Talking about the speaker drive instead I can see why you don't want it on your real guitar cab, that's one of the reason why after a couple of months I sold my power amp and cab to buy a Clr, too many compromises made to feed two different outputs.

Going back to your original question, I had a similar issue the first period I had the axe, it turned out to be the presence that I was setting too high because it has a different taper compared to most real amps. Now I always set it between 2 and 3 and haven't had that problem again (I don't play hi-gain stuff though).
What I can suggest is to try cutting that highs in different points of the signal chain and see if you find a setting good for both sounds
 
In all honesty, when I mic a real cab I most definetly will re mic when recording cleans and dirt. They naturally have different tonal characteristics that I want out of them. Dirty rhythms tones sound completely different then a nice warm clean tone, therefore I mic in different positions on the speaker that compliment each. But we all like different things so take that for what it's worth.
 
Pwrmac7600 said:
In all honesty, when I mic a real cab I most definetly will re mic when recording cleans and dirt. They naturally have different tonal characteristics that I want out of them. Dirty rhythms tones sound completely different then a nice warm clean tone, therefore I mic in different positions on the speaker that compliment each. But we all like different things so take that for what it's worth.
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I can see doing that on a recording where you want to have the ability to have complete control over your tracks, like on a pop tune for a well-known artist.

But there's still a lot of recording work done where speed is of the essence, because time is money, and the same mic position and EQ for both cleans and dirty's will get the job done satisfactorily.

And, as I've mentioned previously, in a live setting we don't normally see the sound man run up on stage between the guitar player's comping and soloing passages to reposition the mic.

So it should entirely be possible to find a single IR/Cab Block instance that is satisfactory for both types of tones as well, shouldn't it?

But I am slowly resigning myself to the fact that in order to do what I want to via an FRFR system I'm going to need at least 2 Global Cab Blocks programmed, one for cleans and one for overdrives.
I just really don't understand why that needs to be necessarily so.

Has anybody else out there found a single IR/Cab Block setting that works for both your cleans and overdriven tones?
Let's leave hi-gain out of it for now.
Hyper-cleans and mid-gain tones only please.
 
joegold said:
I can see doing that on a recording where you want to have the ability to have complete control over your tracks, like on a pop tune for a well-known artist.

But there's still a lot of recording work done where speed is of the essence, because time is money, and the same mic position and EQ for both cleans and dirty's will get the job done satisfactorily.

And, as I've mentioned previously, in a live setting we don't normally see the sound man run up on stage between the guitar player's comping and soloing passages to reposition the mic.

So it should entirely be possible to find a single IR/Cab Block instance that is satisfactory for both types of tones as well, shouldn't it?

But I am slowly resigning myself to the fact that in order to do what I want to via an FRFR system I'm going to need at least 2 Global Cab Blocks programmed, one for cleans and one for overdrives.
I just really don't understand why that needs to be necessarily so.

Has anybody else out there found a single IR/Cab Block setting that works for both your cleans and overdriven tones?
Let's leave hi-gain out of it for now.
Hyper-cleans and mid-gain tones only please.
Click to expand...
What are you using for overdrives? Different channel of an amp? Drive block? Boost switch?
 
DLC86 said:
What are you using for overdrives? Different channel of an amp? Drive block? Boost switch?
Click to expand...

My cleans are using Doubleverb sims and my overdrives use USAII+ Deep sims.
But sometimes I'll use a drive pedal sim on a clean Preset too, usually the BB.
 
Well can't you just change the eq in your dirty amp or pedal?

If that screws up your PA+cab tone the topic goes back to "guitar cab vs Frfr" that we discussed above..
 
DLC86 said:
Well can't you just change the eq in your dirty amp or pedal?

If that screws up your PA+cab tone the topic goes back to "guitar cab vs Frfr" that we discussed above..
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It would screw up my power amp + cabs tone.
But I don't see how this necessarily makes the issue revert back to a cab-in-the-room discussion.
Please elaborate.

My Presets, as currently conceived and programmed, are based on fine-tuning my power amp + cab tone.
When I use the Axe on gigs, that's how I use it.
I'm simply trying to find IRs, or ideally a single IR, that can be used with these same Amp Block instances, w/o too much compromise, to send to the FOH on live gigs and/or to use myself when recording demos or practice material at home.

I'm fully aware that if I just wanted to have Presets designed only for FRFR usage that the Axe is eminently capable of having a different Cab Block instance that would be quite suitable for each one of those Presets.
That's just not what I'm trying to do at this particular moment.
 
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