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The two new Factory Cab 58 & 59

ML SOUND LAB

Cab Pack Wizard
if the guitar don't really do anything down there, I guess you could say then that I'm effectively dialling it out of the way
so maybe that'll have a similar effect as dialling the spike out with the low res's level control
Exactly. :)
 

clarky

Axe-Master
purely in the interests of science.. lol..
I'll try putting the spike back up to 110 [it's default] and dropping the level until there is no spike at all
and then see if that achieves the same effect, or if there seem to be some differences..

to be honest, I can't say I've ever fully understood what that spike represents
 

Anthony David

Experienced
I think it was 117hz according to my measurements for Cab Pack 8.

I might actually create a thread where I can share the impedances as IRs for all the Cab Packs. Is there something wrong with using an impedance IR and setting speaker resonances to 0?
Good idea, I look forward to this if you do make that post.
 

FractalAudio

Administrator
Fractal Audio Systems
Moderator
I think it was 117hz according to my measurements for Cab Pack 8.

I might actually create a thread where I can share the impedances as IRs for all the Cab Packs. Is there something wrong with using an impedance IR and setting speaker resonances to 0?
You don't want to do that. The amp block needs an approximate impedance curve to sound correct. If you set everything to zero then the interaction is all wrong. Furthermore using an impedance IR would be way off because the effect of the impedance is dependent upon the amount of negative feedback. IOW, that won't work right.

The LF resonance doesn't need to be exact. The default values are fine. I usually turn the amount of LF Resonance up a little because I like more bass when playing alone but in a mix it might be too much.
 

Gamedojo

Power User
E series JBL speakers have a low Freq Res at around 50-60hz... I've been setting my Low Res to 52hz on all my SRV patches.

I haven't tried that low but being an audio engineer I can safely state that there's no place for guitar at 40hz. Actually I doubt many sound systems can even play those frequencies properly. F.ex. most kick drums have their low end around 60-80hz. Guitars are usually around 125hz. However like you said it might sound cool and breaking the rules is okay. :)
 

RDH

Fractal Fanatic
Speaking of Low Res frequencies , If the low res setting on the amp page is the correct one for the model ,and that's based on the typical cab used with that amp . Why is the plexi 100 set at 114hz 2.000 Q , and the SLP 100 set at 72hz , 1.800 Q by default ? One would basicly use the same cab with either .
 

FractalAudio

Administrator
Fractal Audio Systems
Moderator
Speaking of Low Res frequencies , If the low res setting on the amp page is the correct one for the model ,and that's based on the typical cab used with that amp . Why is the plexi 100 set at 114hz 2.000 Q , and the SLP 100 set at 72hz , 1.800 Q by default ? One would basicly use the same cab with either .
I based the SLP on using it with G12H(55) speakers which have a resonance of 55 Hz. When mounted in a typical cab the resonance will be in the low 70s. There is no right or wrong. Whatever sounds best.
 

RDH

Fractal Fanatic
Thanks Cliff, setting it by ear is basically what I've been doing , I've leaned toward getting caught up in what is the correct frequency for a given amp and speaker ,but bottom line is what sounds best to an individual . I've noticed there is substantially more perceived difference when tweaking with a guitar in my hands ,as opposed to playing a loop and tweaking while listening . Much of it is about feel !
 

imrecs

Inspired
So the idea is to use a cabinet that's matched to the amp based upon it's low res setting, or otherwise alter the low res setting to fit the chosen cabinet?

So it's both the cabinet resonance and the speaker resonance that come into play here? How do you figure out what resonance to set the amp, based upon both cabinet and speaker information? And what about when combining IRs with different speakers? (I often use 3 different speaker IRs in one cabinet from Ownhammer)

What's the best way to figure out which cabinets pair best with which amps when auditioning combinations? Where can I find information on both the cabinet resonance and the speaker resonance?

Any other factors come into play when adjusting an advanced amp parameter to work best with a particular speaker? Or is it just this low frequency resonance? I rarely feel the need to adjust advanced parameters on the amps (just basic bass, mid, treble, presence, gain, etc.). If I don't like the amp, I chose another amp. But this one seems to be important when matching an amp with a cab.

An example: some advice to illustrate the proper method would help.

I use the Deluxe Verb / Tweed Deluxe as X/Y states into an Ownhammer Bogner 4x12 w/ 3 Irs.
Bogner 4x12 - can't find information on the resonant frequency of the cabinet - anyone?
Celestion Alnico Silver/Blue (57/121) - 75hz resonant frequency i believe
EV-L (421 mixed -6db) - 55hz resonant frequency i believe
Fane Purple Back (414 mixed -12db). - 60hz resonant frequency i believe

How would I calculate the proper low res setting for the Deluxe Verb and Tweed Deluxe?
 
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simeon

Axe-Master
I based the SLP on using it with G12H(55) speakers which have a resonance of 55 Hz. When mounted in a typical cab the resonance will be in the low 70s. There is no right or wrong. Whatever sounds best.
@FractalAudio - cliff i'm wondering how you calculated the low res frequency as "low 70's". i've been going on the premise that you take the resonant frequency of the speaker and then add on 10Hz - so a V30, which has a resonant frequency of 75Hz, will require a setting of 85Hz in the speaker page of the amp block. if that's true, then your 55Hz cone would need a low res freq of 65hz...not 70Hz and a bit. am i doing it wrong, or is there something different about the 55hz speakers?
i know i should be listening to find the actual lr freq, but i can't do it loud enough to figure it out at home, so i need a quick "method".
 

6stringscott

Inspired
Seems like the amount to add would vary based on how the cabinet is built: most importantly, how dense is the wood, how how thick are the panels, and the dimensions of the box. Think about what resonance is: one or more wavelengths reflecting within an object or space and losing little energy. The energy is retained because the waves are reflected at the perfect end of the wavelength so the reflections add up together rather than canceling each other out from being out of phase. So a bigger box will tend to have a longer wavelength that perfectly matches, which is a lower frequency. There is probably a lot more complication from stuff like how dense is the material to better reflect the wave (which might correspond with how high is the peak of the resonant frequency), and internal baffling that breaks up the resonance, and faces that are not parallel to each other which limits the peak of the resonance and might create some other weird standing waves based on multiple reflections of non-parallel faces.

One simple thing to experiment with might be using a lower resonant frequency for a 4x12 cab than for a 1x12 cab. But it's probably not that simple because maybe the 1x12 cab has an internal length measurement of "100" (just making a random unit for the sake of example), and the 4x12 cab has a linear measurement of "380" which sets up 4 standing waves of wavelength=95 whereas the 1x12 cab just set up a single standing wave of wavelength=100. Please disregard these actual values and units in this example- just using some made up numbers to illustrate the concept that a much bigger cab might still have a shorter resonant wavelength with higher resonant frequency. But if you compare to similarly sized cabs, the slightly bigger one should have a slightly lower resonant frequency.

I might be smoking crack in my interpretations, but that matches with what I remember from basic college physics almost 25 years ago.
 

simeon

Axe-Master
i also wonder why the default low res freq for most of the marshalls is set to 114hz, which again, doesn't work out if you assume greenbacks or v30's, which both have their low resonance at 75Hz. i'm wondering how cliff came up with 114...
 

HarrySound

Experienced
Which amps to use with these factory cabs(58 and 59)?
Try the FAS Lead 1.
Here is my tweaked preset. You'll notice I took time to get every parameter just right.


It's got a lot of gain I know but it bounces and sounds pretty amazing on my PRS. I think I'm definitely coming round to the stock IRs in this thing. I guess I just understand things better these days. I like these IRs a lot!
 

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