Cab block

Cab: in the owner's manual

• Axe-Fx II: 5.2 Cabinet [CAB]
• Axe-Fx II: 5.2.1 User Cabs
• Axe-Fx II: 8 Global Parameters
• Axe-Fx II: 10.5 IR Capture
• Axe-Fx II: 13 Backing Up and Restoring
• Axe-Fx II: 16.2 Table of Cab Types
• Axe-Fx II: 16.3 Loading User Cab IRs

Cab: in which products?

• Axe-Fx II: yes.
• FX8: no.

Cab: Amp & Cab Quick Reference Guide by jma

• Forum member jma provides an handy reference guide, covering Amp and Cab block parameters and descriptions, list of CCs, Drive block descriptions etc.

Cab: Impulse Responses (IRs)

• This page is about the Cab block and its parameters. The separate page Impulse Responses (IRs) provides information about IRs / user cabs and IR Capture.

Cab: factory cabs (stock cabs)

• Selected Red Wirez, OwnHammer and other IRs are included in the Axe-Fx II firmware as stock cabs. Also included are some farfield IRs by Jay Mitchell. Additional IRs are included as attachments with the firmware.
• All stock cabs are time-aligned, which means that you can mix these inside the Axe-Fx II using stereo cabs.
• The Axe-Fx II XL has 159 factory cabs, more than the previous Axe-Fx models.
• Cliff: "The factory IRs were hand-selected by me after auditioning thousands of OH and RW and other IRs. Some of the IRs are custom mixes of mine. My rule-of-thumb was to select as neutral sounding IRs as possible. However, what I like may be much different than what others like. Some people complain the Axe-Fx sounds too bright. Others say it's not bright enough. It's a no-win situation. This is why I've been harping on capturing IRs. It's personal preference. Producers probably spend more time perfecting mic placement than anything else when getting guitar tones to tape. An IR is the same thing, it's capturing the mic and placement." source

Cab: user cab slots for uploading external IRs

• If you are looking for something different than the factory cabs, try external IRs. The Axe-Fx II has 100 "user cab" slots for this purpose which you can use to upload external IR files, using Fractal-Bot, Cab-Lab, Axe-Edit or a MIDI librarian. The Axe-Fx II XL has 500 user cab slots.
• The Axe-Fx II and Axe-Edit will display the name of the IRs in the user cab slots. The name is contained in the sysex data of the IR file. IRs can be renamed using Axe-Edit, Cab-Lab or 3rd party utilities.
• Axe-Fx Mark I/II: the first 50 user cab slots are included in system backups (not on XL).

Cab: testing IRs in the Scratch-Pad

The Scratch-Pad is a dummy location (last user cab slot) which can be used to receive cabinet data but is not saved to non-volatile memory. This allows auditioning IRs without overwriting any of the user slots.

Cab: substituting an IR with a Tone Match block on an Axe-Fx II

• You can integrate an IR in a preset by replacing the Cab block with a Tone Match block, after having captured the tone of the Cab block. Here's how.

Cab: deleting all user cabs on an Axe-Fx II XL

• The Utility menu on the XL provides an easy way to delete all user cabs at once.

Cab: matching amps and cabs

• It’s a matter of personal preference which cab model you like to pair with an amp model. You can choose for traditional combinations. Or be creative and innovative. The differences can be huge.
• When comparing cabs, don't judge too quickly. Each time you select a cab, you may need to adjust the amp settings to dial in a tone.
• Common combinations of amps and cabs are listed here: Amp: all models.

Cab: position of effects and Cab block

• In the "real" analog world it makes a difference if you put effects before or after the speaker cabinet. It's different with the Axe-Fx II. 
• Javajunkie: "You can place the effects loop anywhere in the chain (just add the fx loop block). Unless you are running a stereo cab or 2 mono cabs panned hard L/R, you may want to place stereo effects after the cab. The cab is a linear time invariant effect (unless you add drive) so effects like delay and reverb will sound the same before or after it. As Cliff and others have stated on numerous occasions LTI effects can be placed before and after each other and they will sound the same. Only when placed before or after non-LTI effects (drive, amps, et. al) it really matters. The one caveat there is that some effects are mono, placing effects before and after that makes a difference."
• Cabinet blocks in parallel rows sound louder than a single Cabinet block. Here's the explanation. Bakerman: "It depends on how you're panning. Assuming a mono signal sent to cabs: Stereo cab w/ Pan L and Pan R fully left & right will be the same output level as 2 mono cabs w/ balance L & R. If pans/balances are centered the 2 mono cabs will be 6 dB louder. Balance elsewhere would be between 0 and 6 dB louder, and balance doesn't correspond 1:1 to pan L/R for the same placement. Balances will need to be further toward -50 or 50." source
• Cliff's comments:
  • "The difference in having the cabinet before or after the effects is usually subtle. It depends on how non-linear or time-variant the effect is. For effects like EQ, which are linear and time-invariant, it doesn't matter at all. For slightly time-variant effects like chorus and flanger the difference isn't very pronounced. For highly time-variant effects, like pitch shifting, the difference can be marked."
  • "Linear means that the output is related to the input by a straight line: y = mx + b. Filters are example of linear systems. A cabinet IR is a filter. Distortion is an example of a nonlinear system. Linear systems are associative and commutative. Associative means that a * (b * c) = (a * b) * c. Commutative means that a + b = b + a or a * b = b * a. Therefore you can do cab -> eq (a * b) or eq -> cab (b * a). The cab block is "completely" linear if motor drive is non-zero but it is "wide sense stationary" so you can treat it as linear." source
  • "The cab block is level-dependent if the Motor Drive is non-zero. So if you turn up/down the level out of the amp block you may need to compensate by doing the opposite with the Motor Drive." source
  • "You gain nothing putting it before the cab and risk collapsing the stereo image if the cab is mono." source

Cab: mono/stereo output

• Keep an eye on the mono/stereo configuration. When placing the Cab block at the end of the grid, the output signal will be summed to mono, unless the Cab is set to Stereo mode, or when using two panned Cab blocks.
• If the Cab block is set to Stereo mode, but it is followed by a mono effect such as Drive, the resulting signal is also summed to mono.

Cab: Hi/UltraRes, Normal Res, Stereo

• See Impulse Responses (IRs)

Cab: microphone models, Proximity parameter

• Don't underestimate the impact of a mic type on the tone. I.e. adding the R121 model (Royer 121, captured at 6", front) will add highs and lows to the tone. The 57 DYN (Shure SM57) works with almost everything and adds bite. Many studios and users like to combine the Royer and SM57. Cliff: "I almost always use a mic model on the non-mixed IRs. I'll typically use a 57 on one side and an R121 on the other." source
• The "None" and "Null" settings disable mic coloration. A mic is still involved though, because the IRs themselves are always captured with microphones. Even when a neutral mic was used to capture, such as an Earthworks mic. When capturing IRs, the mic is most often placed very close to the speaker, so the result is a close-mic'd tone. Still, selecting "none" is a good way to prevent adding additional eq-ing to the tone.
• The Proximity parameter simulates the proximity of the modeled mic to the speaker. Higher numbers translate to the mic being closer to the speaker (nearfield). Lower numbers translate to the mic being further away from the source, with the lowest number providing far-field coloration. Proximity only works when a mic model is selected, including Null.
• The Proximity Frequency parameter allows tuning the frequency range over which the proximity effect occurs.
• Cliff's comments:
  • "The mic models are actually IRs. The mic IR is convolved with the speaker IR to create a composite final IR." source
  • "The mic I've been most impressed with for recording guitar lately is the Beyer M160. I don't like SM57's alone for amps. They're too spikey and compressed but mixed with an M160 or R121 they add some nice sizzle." source
  • "The M160 is an awesome guitar cab mic. All the IRs we got with the M160 came out really nice." source
• There's useful about mics and mic positioning in the document Dialing in Your Tone by Red Wirez.
• Wikipedia:
  • Shure SM57
  • Shure SM58
  • Shure Beta 87A
  • Neumann U87
  • Royer R-121
  • AKG D112
  • Neumann U67
• More information about microphones:
  • http://en.wikipedia.org/wiki/Microphone
  • http://soundschematic.com/dynamic-ribbon-condensor/
  • http://www.recording-microphones.co.uk/index.shtml
  • http://www.barryrudolph.com/stellar/guitar.html
  • http://www.gearslutz.com/board/so-much-gear-so-little-time/201972-mic-standards.html
  • U 67
  • SM57
  • SM58
  • MD 421
  • U 87
  • D 112
  • Beyer M160, Beyer M160
• Additional information about microphones in this Wicked Wiki thread.

Cab: Input Select parameter

• This lets you control the signal that enters the Cab block. For example, if you wish to run two panned Cab blocks, you can use this parameter to force one side of the signal to go into one Cab, and the other side into the other cab.

Cab: room ambience parameters

• The Axe-Fx II provides room ambience parameters in the Cab block. This is a dedicated reverb effect, which also works well when using the Axe-Fx with headphones or IEM.
• Enabling the cab's room reverb will turn a mono signal into stereo. So the left and right sides of the signal can be different because of this.
• Also see Audio topics.

Cab: LowCut and HiCut Freq parameters

• The Cab block provides low-pass and high-pass controls. These make it easy to tame boomy or harsh sounds. You can also use similar parameters in the Amp block, or apply eq-ing through a PEQ, GEQ or Filter block. Common settings are 80-150 Hz for high-pass (cutting bass), and 5-7 kHz for low-pass (cutting treble), but YMMV.
• Cliff's comments:
  • "Using Low Cut in the Cab block is akin to what you would do in the studio to carve out room for the bass player." source
  • ""LOWCUT FREQ" in the cab block sets sets the -3dB point of a highpass filter at the output of the cab block." source
  • "The filter slope in the cab block is 6 dB/oct." source

Cab: Speaker Size parameter

• Cabinet Size Warping allows the user to change the relative size of the speaker. This parameter is accessible only when the IR is non-UltraRes and the Cab mode is mono.

Cab: Motor Drive parameter

• This models the effect of high power levels on the tone of the speaker. The Motor Drive parameter controls the relative drive level and, therefore, the intensity of the effect.
• Changing Motor Drive from 0.00 to 0.01 and above will cause an audible "click".
• When using two UltraRes cabs in a preset, don't use Motor Drive on only one of them, because this will cause a hollow sound.
• Cliff's comments:
  • "Motor drive isn't EQ. It models efficiency reduction due to thermal effects." source And: "What I have found is that thermal compression is somewhat noticeable and measurable. This is modeled by the Motor Drive parameter." source
  • "Motor Drive will cause compression if not set to zero (as it models driver compression). Otherwise the cab block is completely linear and will not cause any compression." source

Cab: Air parameter

• The Air parameter mixes some of the signal going into the Cab block with the signal leaving the Cab block. The Air Frequency parameter lets you adjust the cutoff frequency of the mixed signal. Increase the Frequency to its maximum value for a straight mix.
• If you want to listen to just the Air'd part of the signal, set the Cab to an empty user cab, and turn up Air.

Cab: Delay parameter

• Micro delay for stereo application. When running a stereo mode, or two cab blocks in parallel, delaying one cabinet relative to the other can achieve interesting comb filter effects. A common practice in studio recording is to use multiple mics on a speaker at different distances to intentionally introduce comb filtering.
• Cliff: "My secret to realistic cab sounds is Delay. Use two IRs in stereo or two cab blocks and put a small amount of delay on one (using the Delay parameter in the Cab block). I like around 0.06 ms. You may like more or less. Producers experiment with placing mics at different distances to enhance the recorded guitar tones. This is the same as using a small amount of delay. Adding a bit of delay introduces some comb filtering which creates notches and peaks in the response which, in turn, adds a sense of "space" to the tone. Try it." And: "If you have any cab packs try mixing the "Back" IR with one of the regular IRs. I use more delay when doing this, 0.1 ms or more. I lower the level on the back IR by a couple dB. This gives a nice "in the room" open-backed cab sound." source
• GM Arts: "This is about mixing 2 signals: one without delay, and the other with a very short delay. 0.06mS is way too short to be perceived as a repeat; the effect is filtering caused by mixing these two signals. To keep things simple, we’ll apply an equal mix of the same signal and another delayed by 0.06mS. An easy way to experiment with this in the Axe-FX is with a Flanger block, with depth and feedback set to zero, and mix set to 50%. Adjust the delay to 0.06mS (not 0.6mS) to hear the effect with a mono signal. This produces a notched frequency response with complete signal cancellation just above 8KHz, with the -3dB point one octave lower at just over 4KHz. The signal is restored over the next higher octave (8KHz to 16KHz), but bear in mind that most Cab IRs will not have much response there anyway, so this effect is mostly a blocking filter over the range 4KHz to 8KHz. So if you have a cab IR that has some response over this range, it will be perceived as a loss of some treble response. For many, this will remove harshness in a way that’s difficult to achieve with other filters. Others may find this effect too much. You can soften this effect by decreasing the delay and/or changing the mix ratio. Decreasing the delay raises the frequency at which this cut occurs. For example, a 0.05mS delay blocks response over the octave 5KHz to 10KHz. Lowering the mix % decreases the depth of the notch. Similarly, applying a delay to a different Cab IR than the un-delayed block will “jumble” and reduce the final response to some extent. If you increase the delay (typically from 1mS and above), you’ll hear the combing effects as multiple notches become low enough to hear in the range of “guitar frequencies”. This sounds like a flanger or chorus without modulation, which shouldn’t be a surprise given we’re experimenting with a Flanger block. So why does this delay sound produce a tone more amp-like? Most players prefer their amp tone off-axis, meaning that they’re avoiding the direct harsh sound directly in front of the speaker, where high-frequencies are beamed. This filter simulates that effect. It’s also similar to standing slightly off-axis when using multiple speakers. Sound travels at roughly one foot per millisecond, so there is a very short delay between sound from different transducers. As Cliff stated, it also emulates recording techniques with mics placed at different distances from the cab. How to calculate? To find the frequency where this rolls-off high frequencies at -3dB, it’s simply: Hz = 1000 / 4 /delay in mSec . So for 0.06 mSec: 1000 / 4 / 0.06 = 4167Hz. Complete cancellation occurs at double this frequency, 8333Hz, and builds back to -3dB a double this frequency again, 16666Hz. Bear in mind that with higher delays, there will be audible effects from additional notches above this calculated frequency." source

Cab: Preamp simulation

• Firmware 17: Added preamp simulation to Cabinet block. The simulations recreate the sound of overdriven channel strips, preamps, tapes, etc. The Drive parameter controls the gain of the simulation. The Sat parameter controls the ratio of even/odd harmonics. The Preamp Mode parameter (on Page 2) allows selecting between Economy and High Quality modes. In High Quality mode oversampling is employed to prevent aliasing but this results in higher CPU usage.
• Cliff's comments:
  • "The VU meter shows the level into the pre. Select a pre Type and turn up the Drive. As the VU approaches the 0 dB marker you will begin to overdrive the pre." source
  • "Probably not something you would use for clean sounds. A common technique for rock music is to push the pres, console, tape, etc. to varying degrees to get compression and "sparkle". The trick is getting just the right amount. Too much and it sounds raspy and nasty." source
  • "0 on the VU meter indicates onset of clipping. It's not the same as your plug-ins in that regard. The problem with plug-ins is that you don't know where the onset of clipping is since the headroom isn't specified. Our way is superior since 0 dB indicates the point where things are clipping. The other way you have no idea where things start clipping. So 0 dB on the Axe-Fx is NOT equivalent to 0 dB on a typical plug-in." source
  • "I've done a lot of testing with isolation cabs. The big thing that happens is that the mic distorts, especially when using an SM57. This adds some crispness to the high end and some compression. I've found that I can duplicate that effect very closely by using the FET I preamp type in the Cab block and turning the Drive up until the desired compression is achieved. I set Sat to zero." source

Cab: related parameters in the Amp block

• The Amp block has a couple of parameters which are closely related to the Cab block. Check the Speaker tab.

Cab: how to empty an user cab slot

• To empty an user cab slot on the hardware, use Cab-Manager in Axe-Edit.

Cab: actual speaker characteristics

• Here are some sources for information about common speakers:
  • Legendary Tones: G12M versus G12H
  • TGP: EVM 12L versus EVM 12S
  • Sound On Sound: Choosing guitar-amp speakers
  • Sound on Sound: Understanding and recording guitar speakers
  • Guitar Player: 15 12" speakers
  • Rivera: 15 speakers compared (YouTube)
  • Eminence tone guide
  • Fenderguru: Selecting speakers
  • Guitar Player: Alnico Taste Test