Amp Block => " Depth " ...... I'm a bit confused about what it does ?

ben ifin

ben ifin

Experienced
Hi all

Can someone please explain in "dumbo" [ for me ] terms what this is meant to do (?) and what I should expect sonically to hear / notice as its rolled up from 0 -> 10 (?)

Many thanks,
Ben
 
Depth= Resonance

Wiki:

Peavey:
"Positioned in the amp's master section, Resonance alters the "damping factor" around the speaker's resonant peak—in effect, the amp controls the transient response of the loudspeaker. The higher an amp's damping factor, the more control the amp exerts over the speaker. Resonance reduces the damping factor at lower frequencies, causing dramatic changes to the low-end response and allowing the speaker to recreate the low frequencies with clarity and punch."​
 
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I will add, if playing through small speakers or headphones you will notice that it acts as a smoother to the higher frequencies. But what will happen at high settings is when played back on larger speakers you will all of a sudden notice a lot more pronounced low end. Small speakers can be very deceiving when using this parameter, so if you setup your live patches via headphones, be aware.
 
Depth works like presence (EQ in the power amp), only for low frequencies. Turn it up, and you get more bass response.
On Amps with a flubby low end, turn down bass completely and adjust depth... Works most of the time.
Will probably be affected by master volume setting (the higher, the lesser the impact) and might not work with all amps (some of them don't have negative feedback, consequently no depth or presence).
 
greiswig said:
Can someone explain the difference between this and the LF resonance peak on the speaker tab?
Click to expand...

Some amplifier manufacturers label the control resonance others call it depth.

The LF resonance in the speaker tab represents how the impedance of the speaker load changes based on frequency. I think of it as how hard the speaker "pushes back" at any one frequency. The LF resonance point is the place where the speaker impedance goes up, the power amp has to work harder at that frequency.

If my explanation is not correct, please ignore it... lol
 
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barhrecords said:
The LF resonance point is the place where the speaker impedance goes down, the power amp doesn't have to work as hard at that frequency.
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Impedance goes up ;)
At fundamental resonance (Fs) a reactive effect called Back EMF (Electro Motive Force), causes the speaker (Z) Impedance to rise many times.
 
kisslorand said:
Impedance goes up ;)
At fundamental resonance (Fs) a reactive effect called Back EMF (Electro Motive Force), causes the speaker (Z) Impedance to rise many times.
Click to expand...

Thanks to you and barhrecords for the replies. I guess I'm after less theoretical explanations, since these are really models of something that isn't happening in the AFX. Something like "depth will affect everything below 120Hz equally like a shelving EQ, but speaker resonance is more like a peaking EQ...yet they are both pretty much the same in their effect other than that. They are not EQ, but affect the way the circuit rings at the stated frequencies."

Yek's quote from Peavey helps, but I'm still confused. My explanation probably isn't correct...please ignore it.
 
greiswig said:
I guess I'm after less theoretical explanations, since these are really models of something that isn't happening in the AFX. Something like "depth will affect everything below 120Hz equally like a shelving EQ, but speaker resonance is more like a peaking EQ...yet they are both pretty much the same in their effect other than that....My explanation probably isn't correct...
Click to expand...
You're actually very close.

Depth affects a broad range of low frequencies. It only exists in amps that use negative feedback in the power amp. Negative feedback is a way help the power amp control the speaker more accurately by subtracting some of the power amp's output signal from its input signal. Depth works by EQing that negative feedback circuit. There is no way to explain this further without getting deeper into theory. But that's okay, because the first sentence in this paragraph is all you need to know.

Speaker resonance affects a narrower range of low frequencies. It simulates the way a speaker loads the amp differently at different frequencies and forces the amp to work harder near the speaker's resonant frequency. But speaker resonance also affects the amp's distortion characteristics, because frequencies that get amplified more will also distort at lower levels than other frequencies.

There are only two ways to move beyond the above explanations: either (1) you get more theoretical, or (2) you play with them to see what your ears can tell you about them. If you want to make effective use of these things, there's no way to move ahead without step (2), so you might as well jump right in with that. :)
 
barhrecords said:
The LF resonance in the speaker tab represents how the impedance of the speaker load changes based on frequency. I think of it as how hard the speaker "pushes back" at any one frequency. The LF resonance point is the place where the speaker impedance goes down, the power amp doesn't have to work as hard at that frequency. The apparent loudness at that frequency is higher.

If my explanation is not correct, please ignore it... lol
Click to expand...
It's mostly correct. But speaker impedance actually goes way up at the resonant frequency. This makes a tube amp work harder at that frequency.
 
... with FRFR (Cab block) I rarely don't use depth knob.
... with Poweramp/"Real Cab" I use both depth/dyn depth to get that thump that a real amp/cab feels like
 
greiswig said:
Something like "depth will affect everything below 120Hz equally like a shelving EQ..."
Click to expand...

There is a depth frequency knob in the advanced settings. You can choose where you want it to happen.
Lower frequencies than 200 Hz give a more hard and clear ooommphy bass, higher frequencies also affect the lower mids and can reduce some clarity there.
So what is it for? Metalheads could go for 150 Hz or around and rockers could go for 250 Hz or around to get some typical sounds.

Tweak it with a loud and big monitor or PA system or with the band. Small cabs are not able to show you how it translates with a PA.
 
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