Speaker Resonance page

V

vai777

New Member
Hi,

I am trying to understand the Speaker Resonance page, not to necessary tweak it, rather to understand what it is used for and how it works within the AxeFX.

I have read posts saying "when you audition IR's with the amp block, when you get to an IR where the SPKR page settings match closely the real cab it was shot from, you hear it as "better". So part of the "rabbit hole" is finding those matches. On the other hand, if you dial in the SPKR page and don't change IR's, I believe you also can get good results."

So My question is what exactly is the Speaker Resonance page for?

1. Is it for dialing in exact measurements of a cab sound when creating a IR?

2. Is it to dial in a IR to sound better when running through a real cab not FRFR?

3. Is it to dial in a IR that was not initially intended to be used with a amp, lets say a Mesa 4X12" with a fender twin ?

Thanks, Really trying to understand all this.
 
The Speaker Resonance page is there to make the amp simulation behave as if it were connected to a real speaker cab. Cabs have different impedance at different frequencies, and that makes the amp distort differently at different frequencies. That's part of the flavor that a cab provides.

Don't worry about picking an IR whose impedance curve matches the curve on the Speaker Resonance page. In most cases, you won't know what the cab's impedance curve is, anyway. Just pick the IR that sounds best to you — the one that sounds closest to the sound you're trying to get. The same is true if you decide to play with the controls in the Speaker Resonance page.
 
Last edited:
I was poking around on this page last night. I had to lower the resonance to tame some booming , just like someone else posted.
To be honest it's the first time i've really bothered with it. Someone a couple of years back told me not to bother unless I was using a real cab, I disagreed then and I disagree now. It's more for trouble shooting though.

I think I remember Cliff saying you don't need to mess with it because the default values are absolutely fine 90% of the time.
 
Each Real cab affects the amp sound in extra ways than what the IR does, therefore the SPEAKER page.
The speaker page is in the amp block, not the cab block, because it's more than just a filter on top of an amp sound. It affects how the amp itself reacts to the load.

Only if you get these settings correct, you get the closest to authentic sound of that particular amp with that particular cab.
However, there is no official list on what settings you should use with what cab, and you can only do it by ear.
There probably are tools to measure the correct settings if you have the actual cab though.
However, you don't have to aim for these to be authentic, it's all a matter of taste.

So, the answers to your questions are:
1. Is it for dialing in exact measurements of a cab sound when creating a IR?
No. It has nothing to do with IR creation.

2. Is it to dial in a IR to sound better when running through a real cab not FRFR?
No, these settings affect the sound of both.

3. Is it to dial in a IR that was not initially intended to be used with a amp, lets say a Mesa 4X12" with a fender twin ?
Yes. By default, these settings are dialed in for a typical cab used for that amp. For example, if it's the Mesa rectifier amp, the settings are dialed in to be authentic for a specific Mesa 4x12 cab.
 
Last edited by a moderator:
To get what resonance actually means is the first step.
Your guitar has a resonance. There are always notes where a guitar resonates way easier and notes where it is the opposite. In a worst case you have dead spots on the fretboard where the note sounds dull because the resonance don't exists at all at that certain frequency . Too much of a resonance can also be a problem when a note stands out and is way more prominent than others. Worst case is when parts swing together with the strings and add an unwanted high note.
With that example it is easier to understand that an eq can not fix this, at least not perfectly.

The resonant behavior of a speaker you took an IR of should already be part of that IR. A resonance at a certain frequency should lead to a higher volume there. Unfortunalty it's impact depends a bit on the speed of the frequency sweep when taking the IR...but that's another story.

What's not part of the IR is the resonance that happens because of the interaction of poweramp and speaker. So this had to be modeled.
You could add it everywhere where you don't have a natural interaction of a real cab with a tube poweramp (or a low damping valve state amp which works similar).
 
To put it another way, IRs capture the frequency response of a cab, but they can't capture its impedance curve — the way a cab's impedance changes at different frequencies. The impedance curve affects how the amp reacts to the cab's impedance. The Speaker Resonance page gives the amp model an impedance curve to react to.
 
In my opinion this page should not be ignored. I don't consider it an advanced parameter, but rather a needed link between ir and amp. I use it primarily to tame boom if needed, and to get my fr cab to have thump/knock like a real 4x12 would. I don't usually mess with the high resonance as I don't hear much difference.

Here is my 2 cents worth of procedure
1) narrow the low res q
2) crank the res amount up
3) sweep the freq for the sweet spot
4) back the q and res back down to taste.

With the q too wide the thump can start to sound too muddy like a sub woofer.
 
Thanks for all the information so far. It's getting clearer but still al little muddy in my brain not sound lol.

So I have one last question, my application for the axefx currently is to using it into a power amp (matrix) into (2) 2X12" Mesa cabs.

The dumb down for me question is the speaker page to fine tune (IR's) ? if i'm using the axefx with the cab block switched off into a power amp and real mesa 2x12" should i leave the speaker resonance page alone as this is a "Real" response into a real cab?
 
vai777 said:
Thanks for all the information so far. It's getting clearer but still al little muddy in my brain not sound lol.

So I have one last question, my application for the axefx currently is to using it into a power amp (matrix) into (2) 2X12" Mesa cabs.

The dumb down for me question is the speaker page to fine tune (IR's) ? if i'm using the axefx with the cab block switched off into a power amp and real mesa 2x12" should i leave the speaker resonance page alone as this is a "Real" response into a real cab?
Click to expand...

I believe, that the speaker page is most important when using a real cab with a solid state amp, such as the matrix.
For example, getting the low frequency response right will make your cab rumble just right...
Cliff has made a suggestion:
"One way to find the SRF is to put a Filter block after the amp block. Set the type to Peaking, Q to 5 or so and Gain to 10 dB. Start with a Freq. of 50 Hz. Play some chugga-chugga and slowly adjust the Freq. until you hear and feel the cabinet resonate. Make a note of the frequency. Remove the filter block and set the amp block SRF to match. 4x12s typically have an SRF of between 80 and 120. Open back cabs are typically a bit lower."
Click to expand...

If you were using a Tube power amp, instead of a solid state, and turned Power amp modelling off, this will also turn off the settings in the speaker page.
A tube amp does all this naturally.

If you were using FRFR, the effect wouldn't be felt as much as heard.

P.S. If you are using a real cab, I also recommend turning down "Speaker compression" to 0.
 
Last edited by a moderator:
Damn after reading this thread on the SPEAKER page I've realized how important that page is considering I'm using a real cab.
Haven't messed with the SPEAKER page much because I don't understand it and have loaded a crap ton of EQ in my preset already, Maybe I should set both amps GEQ flat and ditch the post-amps GEQ and PEQ and just start from scratch EQ wise AFTER i learn to tweak in the SPEAKER page because it may sound good now but I know it could be better, right?!?
 
Billbill said:
Damn after reading this thread on the SPEAKER page I've realized how important that page is considering I'm using a real cab.
Haven't messed with the SPEAKER page much because I don't understand it and have loaded a crap ton of EQ in my preset already, Maybe I should set both amps GEQ flat and ditch the post-amps GEQ and PEQ and just start from scratch EQ wise AFTER i learn to tweak in the SPEAKER page because it may sound good now but I know it could be better, right?!?
Click to expand...
Right. ;)
 
It is important when you’re using a real cab. The default settings sometimes work, but not always.

If you’re using a Mesa 2x12, try searching the forum, I think either Cliff or someone else has analysed the 2x12 and posted what the low res frequency and Q is. Might be a good place to start.

For my 2x12 Zilla cab I like having the low res frequency at 110hz (v30 / k100 combo). I think the resonant frequency might be a bit higher but it sounds a bit congested when I turn it higher.

I was messing around with a PEQ block the other day and I tried replicating the impedance curve with a peak filter at 110hz and a high shelf boosting a few dB (I do this sometimes when I use preamp pedals into a solidstate poweramp). I tried it on an amp model with the speaker page set flat, and it’s kinda cool.

I assume there is some dynamic element to the speaker page so replacing it with a passive PEQ made it feel stiffer, which was good for my metal patch.
 
mnemonic said:
I was messing around with a PEQ block the other day and I tried replicating the impedance curve with a peak filter at 110hz and a high shelf boosting a few dB (I do this sometimes when I use preamp pedals into a solidstate poweramp). I tried it on an amp model with the speaker page set flat, and it’s kinda cool.
Click to expand...
It's cool, but it's not the same. The impedance curve on the Speaker Resonance page isn't an EQ curve. The actual EQ curve of a cab looks very different from that. The effect of the impedance curve is likewise very different from EQ.
 
Rex said:
It's cool, but it's not the same. The impedance curve on the Speaker Resonance page isn't an EQ curve. The actual EQ curve of a cab looks very different from that. The effect of the impedance curve is likewise very different from EQ.
Click to expand...

That is true but the impedance interaction does affect the overall eq, to the effect of a bass boost and treble boost.
 
mnemonic said:
That is true but the impedance interaction does affect the overall eq, to the effect of a bass boost and treble boost.
Click to expand...
It does, but when you’re riding the edge of gain on the power amp (which is usually the case), the actual EQ effect of the impedance curve is minimized, and it’s all about what frequencies saturate when.
 
Doing some research and I've got a question for this thread if it's still alive.
So playing through my Orange PPC212 if I'm in the speaker page and play with the low res freq and I can hear it get thick and heavier what is actually going on there? I know it's not the same as throwing in an EQ and simply adding some low end.
 
paging @Ragdoll @2112 LeonTodd...

Leon has created a great video tutorial, where he shows how to use the synth block-generated signal that you alter frequency output of into a power amp and speaker Cab and thus "dial in" the right Speaker resonance frequency.

I am scouring his YouTube channel to find the link, but he has hundreds of videos and it is not popping up, but I have seen it - it does exist and really tells you what to do.

Leon could you post the link here for us??? THANKS!

Next week I'm going to to do it for my Bludotone 1x12 (closed) and 2x12 (oval back) to help get those dial in even further.
 
Last edited:
Billbill said:
Doing some research and I've got a question for this thread if it's still alive.
So playing through my Orange PPC212 if I'm in the speaker page and play with the low res freq and I can hear it get thick and heavier what is actually going on there? I know it's not the same as throwing in an EQ and simply adding some low end.
Click to expand...
Right. The Low Freq parameter changes the resonant frequency that the Amp block sees: the frequency where the speaker impedance is the highest. That causes the Amp block to have a stronger response at that frequency. It also makes that frequency distort earlier. Where you set the resonant frequency has an effect on the tone you get. And when it coincides with the resonant frequency of the actual physical cab you're playing through, it can get quite thumpy.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom