What type of EQ curve are XFormer LF and HF parameters?

[Deltones]

When you modifiy the value of XFormer LF and XFormer HF parameters in the amp block, what's the resulting eq curve? Shelving? Peaking? Low/High Cut?

 

[Deltones]

Anybody? This is not a trick question, I use those 2 parameters all the time on my higher gain patches.

 

[FractalAudio]

They control the magnitude of the LF and HF resonances. If you look up the impedance curve of a loudspeaker you will see what the shape looks like.

 

[Deltones]

They control the magnitude of the LF and HF resonances. If you look up the impedance curve of a loudspeaker you will see what the shape looks like.

Man... sometimes, I wished I was an electric/electronic engineer so that I could understand what you're talking about. A simple "Oh, when you change the parameter, it kinda looks like a shelving eq" would have been just dandy :mrgreen:

Alright, Google here we come: "What does the impedance curve of a loudspeaker looks like?"

 

[TheOtherDave]

Alright, Google here we come: "What does the impedance curve of a loudspeaker looks like?"

It depends on the speaker. Here's one for some unknown 120mm driver:

Here's one for a random two-way speaker:

The website that I found that picture on claims the dip around 1k is from a "poorly designed crossover". If that's true, then this one might be over-compensating for whatever was wrong with the first one:

I think it would be reasonable to guess that the three peaks in this one point to it being a 3-way speaker:

But it's not:

This particular speaker has an even stranger curve:

Anyway, the point is that what the LF and HF parameters do probably depends on which speaker you're simulating. Oh, speaking of which, if I'm not mistaken, the cab affects it as well.

 

[jlagana2002]

Wait a minute. Are you guys telling me, that I can look up my cabinets brand (Marshall 1960A) impeadance curve and adjust my HF and LF to correspond ???

Can someone teach me how to do this ?

This is important to me because i use 2 different cabinets in a stereo setup at home.

 

[AlbertA]

They control the magnitude of the LF and HF resonances. If you look up the impedance curve of a loudspeaker you will see what the shape looks like.

For the HF resonance, what is the frequency? Is it fixed to a certain value? Or is it certain percentage/offset from the low resonance frequency?

Thanks.

 

[FractalAudio]

The HF resonance freq varies with the model. I can't really say a lot about this because there are some secrets in there.

 

[Deltones]

This particular speaker has an even stranger curve:

Alright, let's take your last example here. Let's say I bring the value of the XFormer HF parameters down to about 1.3khz, what will happen to that big spike between 1k and 2k? Will it be diminished in level like if you were using a peaking EQ? Will it be abruptly cut off like if you were using a LPF? That's what I'm trying to understand.

 

[AlbertA]

Cliff was actually referring to the HF/LF resonance parameters.

I see your original questions actually refers to the Xformer LF/HF, in that case, you can think of it as the cutoff points of a bandpass filter.

http://axefxwiki.guitarlogic.org/index. ... _simulator