Anyone Want to Test This Beta Firmware

17.04

This version adds a new method of capturing User IRs: “Mic + DI” method. The method used to capture IRs is set in the Global menu. Mic Only is the traditional method and uses a single input into Input 2 Left as the response from which the IR is derived. Mic + DI uses both Input 2 Left and Input 2 Right. The mic response (i.e. preamp output) is input into Input 2 Left as usual while the output of a DI box (or DI output on an amp) is input into Input 2 Right. Both responses are captured and the response from the Right input is used to correct the response from the Left input. This accomplishes the same thing as using Reference Compensation in Cab-Lab but is done at capture time rather than during post-processing.

The advantage to the Mic + DI technique is that it allows almost any amp to be used. A flat, solid-state amplifier is not required. Any amp, whether solidstate or tube, with or without integrated preamp can be used. For example a tube guitar head can be used as the “power amp”. You can even plug right into the front of the head (as opposed to using the power amp input or effects return), even if the head is set to heavy distortion. The unique capture technique of the Axe-Fx removes any distortion from the measurement and completely separates the amp response from the speaker response yielding a pure and accurate IR.

To use the Mic/Line + DI method do the following:
1. Connect the line output of your mic preamp to Input 2 Left.
2. Connect a DI box between the amplifier output and speaker input. Be sure
to use a DI box that is specifically designed to work with speaker level
signals and one that does not have any on-board cabinet emulation.
3. Connect the output of the DI box to Input 2 Right.
4. Connect Output 2 Left of the Axe-Fx to the input of the amp.
5. Set the IR Capture Method in the Global menu to Mic + DI.
6. Set the Input 2 Mode in the I/O->Audio menu to Stereo.
7. Capture the IR as usual either using the front panel or Cab-Lab.

Suitable DI boxes include:
Suhr ISO Line Out Box
Pro Co DB1
Whirlwind Director
Whirlwind Direct2
ART ZDirect
Behringer Ultra-DI DI100
Behringer Ultra-G GI100 (with cab emulator off)
Behringer Ultra-DI DI600P

You can also use a speaker attenuator that has a line out. Turn off the attenuation and connect the line out to Input 2 Right.
 
Awesome news. Hope I have a time this week when my wife and the children are off the house, so I can fill up the living room with gear.
 
respect!
never mind that this would be possible!
Would like to try it out but sold my last Amps on ebah before Christmas duhhhh...
well will test it with my friends Amp's. :)
many many thx to make this possible!
was the best decision to buy a Axe and not a K. ! :)

btw. the Big Hair sounds amazing. It's my favorite.
 
My Backstair Combo has a Speaker Emulated Output jack - anyone know if that would that suffice as a DI output to Axe Input 2R?
Wouldn't you then be getting an IR of the speaker emulation? Which... I mean... if that's your thing, that's cool.
 
May we refer to this as the "six cable method"?

I'm going to have a go at this, and might even confuse myself with all the cables and gear strewn around. Previously I've shot IR's of my cabs by isolating the cab in a seperate room (with the door closed), and the cables running under the door. This removes from the equation any noise emitted by the Power amp & Axe-Fx from spoiling the capture.
 
Hmm - I have Precision Instruments DI Boxes with an Instr/SPKR switch but I'm not sure I want to trust it and risk frying my Axefx. My Backstair Combo has a Speaker Emulated Output jack - anyone know if that would that suffice as a DI output to Axe Input 2R?

Don't think so, the idea is to capture the response of the power amp before it hits the speaker so it can be removed from the equation later. If you are adding a simulated speaker there will be more to cancel out later with the inverse signal.
 
It amazes me that we have been double coloring our ir's (once in capture and once in re-amplification) and no one but Cliff has offered a solution that I know of. This is cutting edge stuff!

If we could only do something similar and get rid of the mic coloration, which I have a Behringer reference mic I'll try if can find my DI interface.
 
You can really use anything.

I tested this using an EHX 44 Magnum power amp pedal, a Shure A85F (mic-to-line level adapter), a SM57, an ART DUALXDirect DI box and my 1x12 cabinet.

The "Mic and DI" captures gave me fine and clear IRs of the 1x12.

EDIT:
I used a HumBuster cable between Out2 Left and the Magnum's input.
I used an instrument (not speaker) cable between the Magnum's output and the DI's input.
 
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You can really use anything.

I tested this using an EHX 44 Magnum power amp pedal, a Shure A85F (mic-to-line level adapter), a SM57, an ART DUALXDirect DI box and my 1x12 cabinet.

The "Mic and DI" captures gave me fine and clear IRs of the 1x12.

Yek,

Not to derail the thread, but how does the 44 Magnum pedal hold up at band volumes? Does it stay clean and clear, or does it start breaking up? Also, could it run a 2x12 cab well enough for small gigs?
 
Thanks yek. I'm not really looking for a permanent set up out of it, but would be nice knowing it would work and save us in a pinch if we needed a backup in case we couldn't go direct FoH or we had other power amp issues and needed something to pull us through. I mean its small enough to stick in a rack drawer easily or a gig bag/case pocket. My concern is mostly that it would start breaking up and screw up my clean patches.
 
This is something I've been working on for a while.....the new version of Cab-Lab and if you've bought some of our new Cab Packs there are reference IRs in there. These reference IRs capture the response at the output of the amplifier and can be used to correct the IR for the imperfect response of the power amp.

I have Cab Packs 4,5,6, and 7, and am chomping at the bit for the new Cab Lab!

Soon?
 
No, this is for capturing IRs.

Thought as much. Would be nice to have something available for amp/cab users. Dont know if its possible - BUT, if you are basically capturing amp profiles/IRs at the amplifiers output, rather than at the speakers (which I assume you use to A/B your models), then this would be ideal to feed a real amp/cab.

Im probably way off track here though - Im assuming an amp model with cabs disables is basically what Im after already, in which case ignore my ramblings.
 
Our research has shown that even so-called "flat" power amps aren't all that flat and usually suffer from significant frequency response errors around the resonant frequency of the speaker and at the high frequencies.]

This was my test result also when doing these comparisons. The way I've done this is by using Mesa amps because they've got slave outs that have the power amp color in the signal. So I would remove the power amp color of the tube amp from the IR and this way that should be mathematically the cleanest capture. Essentially this is the "TEH" joke that I've been throwing around. Might be all in my head but I feel more satisfied when shooting IRs with tube amps. :)

If only I had known that I could've used any of my DI boxes to do this trick with any amp... I would've saved a lot of time. :lol
 
I'm dumb in these matters... That said, could this be done in the other side of tye speaker as well to remove any mic color?
 
Our research has shown that even so-called "flat" power amps aren't all that flat and usually suffer from significant frequency response errors around the resonant frequency of the speaker and at the high frequencies.

Does this mean that all of the current cabinet IRs that come stock with the Axe-Fx suffer from this?
 
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