About Speaker LF Resonance

Finally, just because real speakers behave like this doesn't mean we have to adhere to this behavior. Perhaps a better speaker has no resonance (Low and High Res are zero), or maybe the Q is a lot lower or higher. In our virtual world we can design a speaker that is impossible to construct in the physical universe.
I tried an amp with everything set flat, no Lo- or Hi-resonance.
I quite liked it.
 
Pretty disappointing that the biggest and best known guitar speaker manufacturer - Celestion - doesn't give more detailed info on its products. Still no success finding detailed impedance plots for Celestion (guitar) speakers. Anyone contacted Matrix regarding the Celestion Cenutry Vintage?
 
Pretty disappointing that the biggest and best known guitar speaker manufacturer - Celestion - doesn't give more detailed info on its products. Still no success finding detailed impedance plots for Celestion (guitar) speakers. Anyone contacted Matrix regarding the Celestion Cenutry Vintage?



Just buy your own woofer tester.
 
Don't these specs apply to speakers in 'free field', as opposed to being mounted in a cabinet?

PS I use the sweep method and get great results (with "real" cab).

From what I understand (I believe Cliff or someone else from Fractal posted something about this a year or two ago...), once a guitar speaker is mounted in an enclosure (cabinet), the resonant frequency will go up. More so in closed back cabs than open back. So, for example, the Celestion Vintage 30 has a resonant frequency of 75Hz. Mounted in an open back cabinet, that resonant frequency might be somewhere around 80Hz to 90Hz. Mounted in a closed back cabinet, that resonant frequency might be around 95Hz to 115Hz or higher. All depends upon the cabinet.

Great thing is, once you know the "free field" resonant frequency of a guitar speaker, you can start there and then use the sweep method to find the resonant frequency of that speaker in the cabinet you're using by listening and feeling with your ears.

This, of course, is all in the spirit of accuracy. Like Cliff eluded to, we can go nuts with this and try whatever we want without fear of breaking anything. :)
 
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Pretty disappointing that the biggest and best known guitar speaker manufacturer - Celestion - doesn't give more detailed info on its products. Still no success finding detailed impedance plots for Celestion (guitar) speakers. Anyone contacted Matrix regarding the Celestion Cenutry Vintage?

Do you mean like this? Classic - G12 Century Vintage - Celestion - Guitar, Bass & Pro Audio Speakers

Looks like the resonant frequency of the G12 Century Vintage is 70Hz. Shouldn't that be enough info to get you started? (sorry if I missed anything specific you were looking for in earlier posts)
 
I was referring to the acutal impedance at the resonance freq which a lot of manufacturers publish (often as a plot over the whole bandwidth). But Celestion doesn't for a lot of their speakers.

BTW I doubt that the cab has any influence on the impedance of a speaker. Of course, the cab has its own resonance frequency but we're talking about an electric phenomenon here between the speaker and the power amp. As I'm not a professional in this area this might be horribly wrong, though. :D
 
Just a quick question...

If a real physical cab has a known low resonance frequency will an IR shot of that same cab (or a similar cab) necessarily have the same low res frequency as the real cab?

E.g.
I'm pretty sure that my EVM 12Ls, in open back cabs, have a low res freq around 69.3hz.
If I'm using an IR of an EVM 12L in an open back cab will it still be best to set the low freq res in the Amp Block to 69.3hz as well?
 
BTW I doubt that the cab has any influence on the impedance of a speaker. Of course, the cab has its own resonance frequency but we're talking about an electric phenomenon here between the speaker and the power amp. As I'm not a professional in this area this might be horribly wrong, though. :D
The cab does influence the impedance of the speaker. A loudspeaker is a transformer, just like the output transformer in a tube amp. The only difference is that a speaker transforms an electrical signal into mechanical motion, and vice versa.

It also transforms impedances. The mechanical impedance of the speaker (which is affected by the cab) will be reflected back into the amp as an electrical impedance. The amp will see the impedance curve of the speaker/cab combination, including its resonance.
 
If a real physical cab has a known low resonance frequency will an IR shot of that same cab (or a similar cab) necessarily have the same low res frequency as the real cab?
Same cab? Yes. Similar cab? Depends on how similar.
 
once a guitar speaker is mounted in an enclosure (cabinet), the resonant frequency will go up. More so in closed back cabs than open back. So, for example, the Celestion Vintage 30 has a resonant frequency of 75Hz. Mounted in an open back cabinet, that resonant frequency might be somewhere around 80Hz to 90Hz. Mounted in a closed back cabinet, that resonant frequency might be around 95Hz to 115Hz or higher. All depends upon the cabinet.

yepp! Good point! :encouragement:

btw: the resonant frequency as more effect if the transducer has a higher impedance - which is also tied to the wiring in some big boxes. And it get's even more complex when putting two different speakers in one cabinet and wire them up in series - the resonance frequency of one transducer will react on the other ....so it could be a difference between serial or parallel wiring.....
Of corse this endless - let us play guitar instead...... ;)
 
Thanks Cliff for striving for such amazing accuracy with this black box. Simulating the interaction between the tube power amp and speaker is a great feature.

This brings me to a question about IR's that are created with Tube power amps:

If one IR was done with a SS amp and another IR of the same speaker is done with a Tube Amp, wouldn't the Tube amp IR have the resonant frequency response baked in and therefore be a little warmer, boomier sounding?
 
If one IR was done with a SS amp and another IR of the same speaker is done with a Tube Amp, wouldn't the Tube amp IR have the resonant frequency response baked in and therefore be a little warmer, boomier sounding?

Most definitely. You can clearly hear it in the Ownhammer IRs. The IRs made using a tube amp have a noticeably more scooped tone.
 
IIRC ,Redwire has speaker impedance irs in their library ,for mixing with cabs. Just remembered that haven't been into the Redwires for awhile
 
I came up with a number of 82.5Hz and 20db, for a 212 mesa cab. I think this is the correct calculation. Now where do you enter this value?
 
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After reading the topic, I decided to try the Mark IIC+ in two different presets with exactly the same settings except the LF/HF resonance and the cab.
In the first preset, I used the default resonance settings with the SS Ownhammer cab.
The second one was basically the same with both resonances set to zero and with the 5881 tube Ownhammer cab.
I was expecting that I would like the first one more since it has been mentioned that the LF/HF resonances will affect the power tube breakup.
In contrast to this, I found the second one much more useful. It sounded more natural to me. Please try and share your opinions.
 
After reading the topic, I decided to try the Mark IIC+ in two different presets with exactly the same settings except the LF/HF resonance and the cab.
In the first preset, I used the default resonance settings with the SS Ownhammer cab.
The second one was basically the same with both resonances set to zero and with the 5881 tube Ownhammer cab.
I was expecting that I would like the first one more since it has been mentioned that the LF/HF resonances will affect the power tube breakup.
In contrast to this, I found the second one much more useful. It sounded more natural to me. Please try and share your opinions.

Btw, I'm using the M-CB-75 R121 IR's (this is my new favorite speaker and mic) and with the 5881 tube impulse I saw a serious bump at 110 Hz. Maybe I have mistaken about the LF resonance while setting it to 90 Hz. Does anyone know the true LF/HF values for this speaker/cab combination?
 
After reading the topic, I decided to try the Mark IIC+ in two different presets with exactly the same settings except the LF/HF resonance and the cab...The second one was basically the same with both resonances set to zero and with the 5881 tube Ownhammer cab.
I was expecting that I would like the first one more since it has been mentioned that the LF/HF resonances will affect the power tube breakup.
In contrast to this, I found the second one much more useful. It sounded more natural to me. Please try and share your opinions.
You made two changes but only one comparison. There's no way to draw reliable conclusions from that. Try changing only one thing at a time and see which you like better.
 
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