About Speaker LF Resonance

Discussion in 'Tech Notes' started by FractalAudio, Nov 20, 2013.

  1. Waltdude

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  2. Rex

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    Cool calculator. I think it would get you partway there by giving you a way to figure out the resonant frequency of the cab by itself, but I'm not sure how you'd apply it to figure out the Fr of the cab-plus-speaker combination.
     
  3. ertan

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    Hi Rex,
    I made two changes because these are interchangeable (tube p.a. impulses also contain the lf/hf resonance data).
    So I think that I should use the lf/hf resonance of AF2 + ss p.a. impulses OR no lf/hf resonance plus tube p.a. impulses.
    Am I wrong?
    P.S. I also tried the tube p.a. and lf/hf resonance effect and the result is: it sucks imo! :)
     
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  4. Rex

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    They're not interchangeable. The IR contains frequency-response data only. The resonance controls on the amp block are impedance curves. They affect how the amp model distorts differently at different frequencies. IRs can't do that.
     
  5. #65 lauke-lux, Feb 9, 2014
    Last edited: Feb 9, 2014
    lauke-lux

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    Probably a stupid question, but howbeit :
    Should I conclude that standard definition for Axe Fx is based on 8Ohm speakers (DC resistance 6.7 Ohm) ?
    Dear all,
    How does this log rule apply for parallel speakers like in 4x12, or 2x12 cabinets where one can have different wiring methods, and generally there is made use of (examples) :
    - 4 x 16Ohm speakers in parallel (4 Ohms cab) or
    - 2x16 Ohms + 2x16 Ohms in series and parallel (16 Ohms cab) or
    - 2x8 Ohms + 2x8Ohms in series and parallel (8 Ohms cab)
    - or should I really go back to school ;-))
    Must I understand that such cabs have different LORES values depending on their wiring ? If so; what is the rule applied in Axe Fx 4x12 cabinets ?
    EDIT : of course this does not take into account the subject that output transformer impedance "normally" is balanced with cab impedance.
     
  6. KevGuitar86

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    So for LIVE i'm using a direct Signal to FOH and through Output 2 i'm going via a Mtarix Gt1000 into 2 Marshall 4x12 Cabs with V30 and G12T75 Speaker. When i am dialing my presets through my real Marshall cabs, is it just a matter of taste with these Parameters or are there specific settings explicit for Low Freq and Low Res for my Marshalls....I've found out that its real hard to find a perfect setting
     
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  7. ynor

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    When using an IR made with a tube power amp, should the Low Resonance and Hi Resonance be set to 0?
     
  8. Will Schut

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    My goto IR at the moment is factory IR 60, 4x12 Fractal GB M160. Any suggestions regarding the settings for this IR? I've tried to set them by ear, but the results are, depending on the amp used, very different so I'm guessing my dialing by ear doesn't really get me in the ballpark. Right now I have Low Res Freq around 90, Low Res Q at 1.8, Low Resonance at 7 and Hi Freq around 1000.
     
  9. antony71p

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    if i use output1 for FOH and output 2 for a real cab any changes at LF also affects the real cab ,so how do you handle that ?
     
  10. Rex

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    Any changes at all will affect the sound through the cab. That's part of having your sound up there on stage with you.

    If you care what you sound like in FOH, you optimize for that.
     
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  11. riktherude

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    Just been getting into this for the first time. Here are a few links which have helped me to understand the effect of the mechanical resonance. I've always wondered why more amps are not current sources (i.e. negative feedback so that the output current is controlled) as at the heart of it, the transducer relies on magnetism and hence current rather than voltage. Anyways, have at it...
    http://education.lenardaudio.com/en/05_speakers_3.html
    http://www.edn.com/design/consumer/...periority-of-current-drive-over-voltage-drive
     
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  12. #72 Perdikament, Mar 28, 2016
    Last edited: Mar 29, 2016
    Perdikament

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    An instrument that allows transmission that not only supplies inverse reactive current for use in unilateral phase detractors, but is also capable of automatically synchronizing cardinal grammeters.

    Basically, the only new principle involved is that instead of power being generated by the relative motions of conductors and fluxes, it is produced by the modial interaction of magnetoreluctance and capacitive directance.

    The original machine had a baseplate of prefabulated Amulite, surmounted by a malleable logarithmic casing in such a way that the two spurving bearings were in a direct line with the pentametric fan. The latter consisted simply of six hydrocoptic marzel vanes so-fitted to the ambifacient lunar wane shaft that side fumbling was effectively prevented.

    The main winding was of the normal lotus-o-delta type placed in panendermic semi-boloid slots in the stator, every seventh conductor being connected by a nonreversible trem'e pipe to the differential girdlespring on the up-end of the grammeters.

    Fractal Audio has now reached a high level of develement, and is being successfully used in the operation of nofer trunnions. Moreover, whenever a barescent skor motion is required, it may be employed in conjunction with a drawn reciprocating dingle arm to reduce sinusodial depleneration.

    It's available soon, wherever Fractal Audio products are sold!
     
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  13. #73 ∞Fractals, Mar 31, 2016
    Last edited: Apr 3, 2016
    ∞Fractals

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    I have V30s in Friedman cabs. I emailed Dave Friedman but he had no idea what his cabs plus Celestions might be doing in this regard. The Celestion published value for the V30s is 75 cycles but that didn't work out. Neither did 82. Will have to keep trying to find the sweet spot.
     
  14. #74 ∞Fractals, May 4, 2016
    Last edited: May 5, 2016
    ∞Fractals

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    So I heard a monster resonance yesterday playing a power "D" chord (@ the 5th fret, clearly the "D" on the A string) on the "Smokin'" preset - plain as day ... now, what's the best way to manage? Seemed to be the cabs resonating with a huge "woof".

    Tried the Low Resonance in the speaker page, but that didn't help (probably did it wrong, but was sweeping the LR freq and no difference (between 80 hz up to 135 hz)).

    Should I just look up that freq for the "D" and dial it out with an EQ? Or a harmonic/octave (down?).


    Update: 146.83 Hz is the "D" string, and one octave down is 73.42hz. Will play with these values and see what I can do.

    Halp!
     
  15. #75 Rex, May 4, 2016
    Last edited: May 4, 2016
    Rex

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    That may be a room resonance. Those are tough to resolve completely. Either reduce LF resonance, or hunt down the offending frequency and cut it elsewhere in your chain.
     
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  16. ∞Fractals

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    Yes, I thought of that, and I'll be changing rooms here in a few weeks (down to the basement - which I have the entire space ... much larger). We shall see. Sure did seem like cab resonance though ...
     
  17. yyz67

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    When Cliff says it I get confused. However, when you say it, it makes perfect sense.

    My grammeters are ambifaciently girdlespringing!
     
  18. yyz67

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    I am running my Axe-fx into an Atomic Reactor FR (tube power amp combo).

    Running CABs into it sounds good to great but I'm wondering how much the powered tube cab is FRFR versus. more like a guitar cab. It certainly punches like a real cab, and I imagine it does have an LF resonance (I don't think there is a DSP to keep the response perfectly flat).

    Anyone else running Reactor FRs or similar powered cabs?
     

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