V6 firmware: Time to Release the Monster - Speaker Resonance Page

[iaresee]

Suddenly I am kind of annoyed I can't turn up my monitor! Kids are already in bed.

It's sounding...interesting...in headphones and on the studio monitors at low volume. I'm really looking forward to trying this out loud tomorrow morning. Not sure if better yet, but definitely different.

 

[VegaBaby]

I've tried everything I could imagine and keep coming back to the mix I have presented. It just sounds and feels right at volume.

But... if you are a hardcore NF only sorta guy... trust me, this formula will still be essential (in fact, maybe even more so).

very interesting indeed. I just had a look around a different speaker reso curves on the net, and you're right, they all look very similar to the one you posted, just with the peak at slightly different points. couldn't find much on Celestions though. will definitely give it a try...

 

[Scott Peterson]

Great post Scott but I was wondering if this will help at all for those like me that play thru guitar speakers & not FRFR?

I do not know.

Try it and let me know. I'd guess that if you followed the same thought pattern and used your own cab's resonance in the settings that it would be absolutely ideal... but I don't know.

If you actually have the cab, then you could measure the actual impedance curves exactly. I have to think that'd be a 'best practices' approach to this.

 

[Scott Peterson]

very interesting indeed. I just had a look around a different speaker reso curves on the net, and you're right, they all look very similar to the one you posted, just with the peak at slightly different points. couldn't find much on Celestions though. will definitely give it a try...

I could not find anything official from Celestion. There were some done by some folks to be found out there, but I cannot vouch for their accuracy. The curve though, was *remarkably* similar in shape and character. I spent a lot of time looking around; once I settled on a method that worked, I just then went with what my ears told me.

 

[notalemming]

I do not know.

Try it and let me know. I'd guess that if you followed the same thought pattern and used your own cab's resonance in the settings that it would be absolutely ideal... but I don't know.

If you actually have the cab, then you could measure the actual impedance curves exactly. I have to think that'd be a 'best practices' approach to this.

I figured I would try to find the curves for my speakers & see what happens. I use that page all the time but to tweak the tone. It works great for me to take out a little high end or clean up the low end in a subtle but effective way. It seems that without the cab sims that half the equation would be missing but still worth checking out.

 

[THX]

Scott, great post! Thanks for the information. I haven't had a chance to dive into these settings in detail, but certainly will.

From your research, is the speaker resonance curve in the AxeII strictly modeling the acoustic (mechanical) impedance / resonance of the speaker / cabinet or is it the electrical impedance of the speaker(s)? Or is it a combination of the electrical and mechanical impedance / resonance?

The only reason I ask is that most of the speaker impedance curves I've seen are showing electrical impedance. The speaker's impedance varies with frequency; ie an 8 ohm "nominal" speaker may have a 4 ohm impedance at one frequency and 12 ohms at another frequency, and varies greatly inbetween. The "average" (and I use that term loosely) is 8 ohms, so that's how it's rated. Granted, most of the curves I've seen are for multi-driver systems where the "spikes" in the impedance curve usually represent the crossovers between drivers, so I may be off base here for a guitar cabinet :roll.

 

[Fro]

So, I use the 1960A G12M as the NF in my NF/FF cab mix. I found the following on the Celestion web site for the G12M.

Chassis typePressed steel
DC resistance, reAvailable 6.7Ω or 13.1Ω
Frequency range75-5000Hz
Magnet typeCeramic
Magnet weight35oz, 0.99kg
Nominal diameter12", 305mm
Nominal impedanceAvailable 8Ω or 16Ω
Power rating25Wrms
Resonance frequency, Fs75Hz
Sensitivity98dB
Voice coil diameter1.75", 44.5mm
Voice coil materialRound copper

So, my Low Res Freq should be 85Hz?

Does this also have anything do at all in any way, shape, or form with the fact that I always seem to get a little more oomph out of my real Marshalls than I do with the Axe? Or that the bass control specifically on my Axe Fx II doesn't always seem react the same way as my real Marshalls do? I know this isn't really an EQ thing. I guess I should just shut up and try it!

At any rate, thanks for the post, and all of the effort to get to this point. I'm going to dive into it now and see what happens.

As I'm rereading my post... is it strange that the resonance frequency is also the lowest frequency that the speaker does? I probably just don't really understand any of this. Again, Fro, shut up and go try it. Sheesh.

 

[Patzag]

Thanks For sharing these findings, Scott.
On tour right now so it's not a good time to experiment but I will as soon as I can.
The NF/FF mix tip your provided a few months ago is what brought the Axe into the realm of "reality" for me and made it 100% usable. So I'm definitely looking forward to this approach.

 

[Scott Peterson]

Scott, great post! Thanks for the information. I haven't had a chance to dive into these settings in detail, but certainly will.

From your research, is the speaker resonance curve in the AxeII strictly modeling the acoustic (mechanical) impedance / resonance of the speaker / cabinet or is it the electrical impedance of the speaker(s)? Or is it a combination of the electrical and mechanical impedance / resonance?

The only reason I ask is that most of the speaker impedance curves I've seen are showing electrical impedance. The speaker's impedance varies with frequency; ie an 8 ohm "nominal" speaker may have a 4 ohm impedance at one frequency and 12 ohms at another frequency, and varies greatly inbetween. The "average" (and I use that term loosely) is 8 ohms, so that's how it's rated. Granted, most of the curves I've seen are for multi-driver systems where the "spikes" in the impedance curve usually represent the crossovers between drivers, so I may be off base here for a guitar cabinet :roll.

You are confusing the Ohm rating for the Resonant Frequency Curve. Different beasts. Celestion does not release the speaker impedance curves for their speakers, but most every other manufacturer does. I added two links that broke this down here:

Two good sources of information on this (though aimed at car speakers, you'll get the drift) as the resonant frequency in free air is related to how it changes in an enclosure:


Speaker


Speaker Box Calculations

So, I use the 1960A G12M as the NF in my NF/FF cab mix. I found the following on the Celestion web site for the G12M.

Chassis typePressed steel
DC resistance, reAvailable 6.7Ω or 13.1Ω
Frequency range75-5000Hz
Magnet typeCeramic
Magnet weight35oz, 0.99kg
Nominal diameter12", 305mm
Nominal impedanceAvailable 8Ω or 16Ω
Power rating25Wrms
Resonance frequency, Fs75Hz
Sensitivity98dB
Voice coil diameter1.75", 44.5mm
Voice coil materialRound copper

So, my Low Res Freq should be 85Hz?

Yes, to *start* from. In most cases for me, I've ended up at +10Hz from that number most of the time.

Does this also have anything do at all in any way, shape, or form with the fact that I always seem to get a little more oomph out of my real Marshalls than I do with the Axe? Or that the bass control specifically on my Axe Fx II doesn't always seem react the same way as my real Marshalls do? I know this isn't really an EQ thing. I guess I should just shut up and try it!

IMHO - YES!!!!!!!! Exactly.

At any rate, thanks for the post, and all of the effort to get to this point. I'm going to dive into it now and see what happens.

As I'm rereading my post... is it strange that the resonance frequency is also the lowest frequency that the speaker does? I probably just don't really understand any of this. Again, Fro, shut up and go try it. Sheesh.

Have fun! And read the links I quoted above again. Speakers are weird science for sure.

 

[Hotplate]

Very interesting Scott- thanks for taking the time to share this and break it down (and thanks to Jay as well). I'll try to dig into it and learn some things asap.

 

[groovenut]

Great post Scott! I have spent a good deal of time with this part of the amp block and have found it to be very powerful in getting the feel of the amp correct. Thanks for the formula as well! Now I have some more experimenting to do

 

[winger]

Cool stuff Scott! Like many others I'll be spending some serious time getting my head around this concept and experimenting.

 

[CodePoet]

Awesome - I love when there's a new Scott post.

Scott - much thanks for your efforts to keep pushing forward and breaking new ground. Your presentation and attitude towards it all is great.

A few questions:
- Since only the Low Res Freq setting is speaker-dependent in your method above, am I to take it that these are catch-all settings that work best for all speakers? Is any further tweaking on a per-speaker basis warranted, or do you feel these values work really good regardless of the speaker used and it's not worth the tweaking time to worry with doing more?

- What differences in sound compared to the stock settings should I be listening for? I've only been able to work on it with headphones so far. Is it mostly a "feel thing" at full volume? On the patch I was working with, your settings seemed to sound a bit smoother/less harsh in the high end than the stock ones, but I haven't spent much time to really compare yet.

- I'd assume Cliff went through a lot of work as well to arrive at the default Axe settings - what are your thoughts on the differences in your settings vs. the defaults? Just a personal preference or do you think yours make more sense for defaults for certain reasons? (Not trying to start anything up with this question - just thought your answer here would provide some additional insight).

(I see your NF is at -6db now - maybe soon you'll be like Jay and dial it out of there altogether).

Thanks again Scott - you're the man!

 

[immortal_soloist]

Thanks Scott will definitely try this when I go back home from my holidays. Another 2 months or so without the Axe FxII.
Oh well enjoy guys

 

[Fro]

- What differences in sound compared to the stock settings should I be listening for? I've only been able to work on it with headphones so far. Is it mostly a "feel thing" at full volume? On the patch I was working with, your settings seemed to sound a bit smoother/less harsh in the high end than the stock ones, but I haven't spent much time to really compare yet.

Exactly the same thing here. I wasn't able to spend much time with it yet, and only with headphones. My wife says that apparently normal people actually sleep at night. Who knew? At any rate, smoother, less harsh, and a feel thing is what I got so far. I'll crank it up tomorrow and see what happens then. So far I'm digging it.

 

[rudomat]

thanks scott,
would you maybe share some of your now in this sense tweaked fender, vox, marshall, and higher gain presets for all of us, who feel too stupid to do it themselves...;-)?
thanks!

 

[Diego]

THanks Scott, very useful as always.

 

[dsl]

...I'd assume Cliff went through a lot of work as well to arrive at the default Axe settings - what are your thoughts on the differences in your settings vs. the defaults? Just a personal preference or do you think yours make more sense for defaults for certain reasons? (Not trying to start anything up with this question - just thought your answer here would provide some additional insight)....

+1

 

[GiRa]

Great post Scott but I was wondering if this will help at all for those like me that play thru guitar speakers & not FRFR?

A lot!
If you are playing thru a SS power amp (a SS PA doesn't interact with the speaker so much) you'll get a more realistic response from the Axe and much more "balls".

To find you cab's low res freq play (or loop) some single note chuggha chugga at volume and slowly turn up the low res freq, at a certain point you will hear that the cab starts to "shake" the room. You are there.
A closed back 4x12" usually has a low res freq between 105Hz and 115Hz.

I don't have a scientific method for the mid and hi resonant frequency, just use your ears or compare the axe and a real tube amp behaviour with the same cab.

 

[GiRa]

- What differences in sound compared to the stock settings should I be listening for? I've only been able to work on it with headphones so far. Is it mostly a "feel thing" at full volume? On the patch I was working with, your settings seemed to sound a bit smoother/less harsh in the high end than the stock ones, but I haven't spent much time to really compare yet.

You need volume to really understand whats' going on.
You will get a different response at certain frequencies and those will also feed back to your guitar, so the headphones are killing some of the benefits.

- I'd assume Cliff went through a lot of work as well to arrive at the default Axe settings - what are your thoughts on the differences in your settings vs. the defaults? Just a personal preference or do you think yours make more sense for defaults for certain reasons? (Not trying to start anything up with this question - just thought your answer here would provide some additional insight).

Cliff words: ""There are certain aspects that simply can't be modeled and require user intervention." source.