LF Resonance Fix for Boomy FRFR

kruzty

Inspired
A while ago there was some discussion of CLRs being "boomy." I have a pair of wedges and never thought I noticed it. But, on some presets I started noticing a pronounced low end at or around the low G. It didn't happen with every amp model, though, so I ruled out the CLRs. Also, just lowering the Bass control in the amp block didn't help. After some investigation, I suspected the LF Resonance setting in the amp block. This setting is used to emulate the interaction between the amp and physical speaker cab and the user must manually match it (if the default is not sufficient and the user is using a real guitar cab). But, in one post Cliff stated that it is not desirable to match the LF Resonance to FRFR speakers when using IRs.

So, I'm not sure if the CLR has a resonant frequency around 100Hz (the default for the amps I was having the issue with and close the frequency of a low G) or if it would be the same for any FRFR, but lowering the LF Resonance (0 or a little above) took away the big 100Hz hump. It appears this is mainly an issue on amps with Hi Cut instead of Presence and is why I only noticed on some amp models. I found some things mentioned in the that say the LF Resonance is much more pronounced in amps with no negative feedback.

I was worried about it drastically changing the amps character, but lowering the LF Resonance didn't seem to make a difference in the amps tone/feel.
 
Speaker resonance is far more pronounced in amps with no negative feedback - this happens with real amps too. Some of these amps sound boomy on my system also, which like the CLR are reference level, coincident speakers. Bear in mind that the default settings on the speaker page are measured from a single speaker cab - in real life the speaker interaction with the power amp would change automatically depending on the cabinet plugged in. In that light, its not unusual to have to adjust the speaker resonance by ear. Set it to where it sounds good, and you're set!

BTW, a good starting point is to set the resonant frequency about 10hz higher than what a given speaker's specs quote (of the IR, that is) - this approximates for the resonance of the cabinet - then adjust the level to taste.
 
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As interesting as that is I just grab ether 63Hz and or 125Hz in the amp sim and pull them down to taste.
 
As interesting as that is I just grab ether 63Hz and or 125Hz in the amp sim and pull them down to taste.

Unfortunately (at least for me), that doesn't directly address the problem frequency. EQing those frequencies would remove too much of the surrounding frequencies before getting to the 100Hz area.
 
Amps with no negative feedback get flubby with high MV setttings.

It's hard to say because "boomy" means different things to different folks.

I associate boomy with the IR itself first, then with EQ second.

For example, is the same preset boomy using the 1x6 oval IR?

Richard
 
This is definitely not "flub." If you play a low E, it isn't there. If you play an A, it isn't there. But if you play a G, it is obvious. I used the term "boomy" because I thought that might be what others were using to describe the same thing I'm hearing, which turned out is a just big boost at a specific frequency (which happens to be the LFR frequency).

I didn't try the 1x6 specifically, but I scrolled through 10 or 12 IRs and the frequency spike was consistent. Using models with negative feedback with the same IR and LFR frequency/level don't have that spike. I'll check out the 1x6 just for fun, though. I'll also check it on a speaker other than a CLR.
 
This is definitely not "flub." If you play a low E, it isn't there. If you play an A, it isn't there. But if you play a G, it is obvious. I used the term "boomy" because I thought that might be what others were using to describe the same thing I'm hearing, which turned out is a just big boost at a specific frequency (which happens to be the LFR frequency).

I didn't try the 1x6 specifically, but I scrolled through 10 or 12 IRs and the frequency spike was consistent. Using models with negative feedback with the same IR and LFR frequency/level don't have that spike. I'll check out the 1x6 just for fun, though. I'll also check it on a speaker other than a CLR.

If it is only close to the low G on the low E string, I'm kinda surprised parametric EQ can't dial that out.

Whenever I seem to be fighting EQ, I almost always switch IR's.
 
If it is only close to the low G on the low E string, I'm kinda surprised parametric EQ can't dial that out.

Whenever I seem to be fighting EQ, I almost always switch IR's.

Oh, I'm sure a parametric EQ before or after the cab block would do the same thing. I was just trying to find the root cause and the LFR seems to be it. I guess I'm thinking I should fix the problem as close as possible to the source of the issue.

Reducing the LFR works for me, so I thought I would post it here with the possibility that:

1) It will help someone else that has a similar issue OR
2) Someone will tell me I have something else wrong

One of the models that exhibits this behavior is the Maz Sr. and I just didn't notice that dramatic of a spike at any low frequency on my real Maz Jr. with similar settings (I know, not exactly the same, but a non-negative feedback amp). So, I didn't know if what I'm hearing is specific to the LFR/IR/FRFR interaction or something else.
 
But, in one post Cliff stated that it is not desirable to match the LF Resonance to FRFR speakers when using IRs.

Maybe we have to understand that the way that if you change the LF Res and try to hit the resonance of the IR that is something that is not modeled and therefore will not work in any way. So he wanted to avoid that people start a search for frequencies for certain IRs and try to engage an effect that just will never happen no matter how long one searches.

If that's the right interpretation then, yes, what you do could work instead? When your target is to hit the resonance of the FRFR mon, then it would be the same frequency for all of your presets that gives the best results, right?
If so, I wonder how the LF resonance settings could affect the FOH system as well? We never know what the techs bring on for the next gig.
 
The difficult thing is that there can be any number of factors doing it. It's great that you figured out what was causing it for you, and it's helpful that you shared it. I've had quite a bit of luck doing the same.

I also was having quite a bit of trouble dialling things in on V10 - I had done something I knew better than to do - I changed a few huge things all at the same time. I plugged in my new GT1000FX for the first time as I finished upgrading to FW 10. On top of that, there were some huge changes in our practice space that changed the acoustics of the room. I basically lost my reference point or reasonable ability to go back and do 1 change at a time like I should have.

I got to a point where leaving the GEQ flat, I could have the preamp bass knob on '0' and the depth knob on '0', and I was still getting all kinds of flub. Even if those settings would have fixed it I knew something was wrong. As a rule of thumb, if it takes an extreme tweak to fix something, you're tweaking the wrong thing.

Anyway, I've found a handful of factors that have really helped me get back to a sweet spot. One of these was actually hanging my wedges like a PA rather than sitting on the floor like normal wedges. I think the way they were coupling in the room and the way they were angled in our acoustically piss-poor space was causing all kinds of bass trouble. As mentioned, the LF Frequency also helped a ton. As did the 'Definition' and the 'Character' knobs.

Bottom line, the hardest thing about trouble shooting is when you have multiple culprits, because a single process of elimination doesn't yield any results. Hopefully anyone else having trouble out there can find the right combo of solutions (many, if not most, of which lie outside the settings of the axe fx).
 
My fix was easy.

I returned the CLR and purchased an amp/FRFR solution which worked great with the Fractal Audio Axe-FX right out of the box.

No more "Boom"

Now I can spend my time playing and gigging instead of tweaking!
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I returned the CLR and purchased an amp/FRFR solution which worked great with the Fractal Audio Axe-FX right out of the box.


My CLRs have worked great right out of the box, for me. Maybe if this happened on every amp model type or program music (which it does not) I would think it had something to do with them.
 
My CLRs have worked great right out of the box, for me. Maybe if this happened on every amp model type or program music (which it does not) I would think it had something to do with them.

Glad to hear that!


What are the presets/amps giving you a hard time?
 
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What are the presets/amps giving you a hard time?

Well, the original post describes it in more detail, but it is basically amps (at least the ones I'm using) that have no negative feedback. Honestly, I'm starting to wonder if I don't have something else going on with how I'm setting those amps because it seems like others would be having this same issue or could reproduce it quite easily: pick an amp, say the Badger 30, add a cab and play a low G (around 100Hz) and compare it to the some other notes.
 
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