• We would like to remind our members that this is a privately owned, run and supported forum. You are here at the invitation and discretion of the owners. As such, rules and standards of conduct will be applied that help keep this forum functioning as the owners desire. These include, but are not limited to, removing content and even access to the forum.

    Please give yourself a refresher on the forum rules you agreed to follow when you signed up.

Can the Mic be eliminated by sum and difference?

dumbeat

Inspired
i am wondering if the Mic can be eliminated from the cab sim equation in order to be able to hear the axe fx as you would a real amp, using frfr.

This seems to be an issue that comes up here often, where there is no way to actually hear the axe fx without the Mic filter, which to me adds way too much coloring, compated to an amp in the room.

My thought is that the mic could possibly be phased out by means of sum and difference when IR’s are made, thus leaving the ir as if there was no mic on it, thus playing back on an frfr exactly what the original cab was delivering.

Any thoughts?
 
Last edited:

James Nash

Inspired
I think at absolute best the result would be a perfect representation of exactly what it sounded like in the *spot* where the original microphone was placed to generate the IR. In most cases, that will be a few inches off the speaker cone, which IMO sounds very different from the typical playing experience.

The Axe is generally used to replicate the tone of an amp on recording or through a PA system--i.e. through a microphone. There are some folks playing around with "distant IR" captures which you might find interesting ?

Good luck!
 

666was999

Power User
1st: No, it can't.

2nd: why should it. It's not a sound that you should send to a console, because techs are used to mic'd sounds. Also the audience don't knows how AITR sounds. When they hear an AITR sound, they'd say it's off from what they expect.
You could still be after the AITR for your own pleasure at home, but it's not something to play out. Advance and leave AITR behind?
 

bdrepko

Fractal Fanatic
i am wondering if the Mic can be eliminated from the cab sim equation in order to be able to hear the axe rx as you would a real amp, using frfr.

This seems to be an issue that comes up here often, where there is no way to actually hear the axe fx without the Mic filter, which to me adds way too much coloring, compated to an amp in the room.

My thought is that the mic could possibly be phased out by means of sum and diffrtrnce when IR’s are made, thus leaving the ir as if there was no mic on it, thus playing back on an frfr exactly what the original cab was delivering.

Any thoughts?
If you are looking for amp in the room you need just use a power amp and a cab.
 

chris

Legend!
hear the axe rx as you would a real amp, using frfr.
this is the same issue we've discussed in a previous thread.

the exact equivalent of using an IR is putting a real speaker cab in another room where you can't hear it at all, mic'ing it up and sending that signal to an FRFR speaker. that is the exact equivalent.

IR = real cab in another room mic'd up

you can't get the signal from a real guitar cabinet in another room into a FRFR speaker without a mic. there's no "direct output" on a speaker cabinet. it has to be captured somehow, and that somehow is a mic.

i understand the essence of what you want. but even with a real amp, there's no way to get a real amp and cab "into an FRFR speaker" without a mic. right? how would you get the sound of that speaker cab "into" the FRFR speaker?

what you want is for the signal coming out of the FRFR to be the exact same you'd hear standing in front of a real guitar speaker cabinet. but the way to do that is to use that real guitar speaker cabinet and listen to it in person. how can you capture the sound of that speaker without a mic? there's just literally no physical way to do that. it's the same way that you can't take a picture without a camera. something has to capture the image.

years ago, the IR capture method preferred using expensive "flat" mics that didn't add any coloration to the IR capture. from there, we could use the Mic simulations in the various gear to add a SM57 eq if you want.

although this sounds like exactly what you're asking for, in practice, it a) didn't sound like you were standing in front of the real speaker and b) took longer to mix because you had to add mic sims.

the industry pretty unanimously shifted to capturing IRs using the mics and positions you'd actually use in a recording session, and this is agreed upon by many as the superior method.

a big point you may be missing is this:

a microphone listens to one spot on one speaker, very close to the speaker. your ears are several feet away, listening to multiple speakers in the cab (assuming it has) at once, and also hearing the sound bounce off the room you're physically in at that exact moment. THAT is what "amp in the room" is. the physical space and actual volume perceived by both your ears at that moment.

a single FRFR speaker in front of you cannot make you feel like sound is coming from behind you. there's physically no way for a sound in front of you to appear like it's "bouncing off the walls" around you... unless it's actually loud enough to bounce off the walls around you. otherwise, now we're talking about Reverb effects.

this IS an issue that comes up often, but mostly because of the misunderstanding of how an IR works and what it is.

an IR must be captured by something, and that something is a mic.
it's been agreed upon by many that the mic to use is a mic you'd normally use (SM57, MD421, etc.).
a mic'd speaker cabinet is typically a single point on a single speaker - it is not an "amp in the room sound", therefore an IR typically cannot produce an "amp in the room sound." (far-field IRs exist, but still probably won't give you want you want.)

to experience the sound of a guitar cabinet, you must use a guitar cabinet. you can't model all 3-dimensional aspects of a multi-speaker device with an IR capture flowing through a single quiet FRFR speaker. the issue is not that a mic is being used. it's plain physics.
 

Shaw

Inspired
Amp in the room has been discussed at length here and is worth searching the forum for.

The quickest and easiest way to get amp in the room tones is to disable cab sims and hook the Axe up to a power amp and a guitar cab.
... and crank that sh*t up! To steal a phrase from the motorcycle world, there’s no replacement for displacement!
 

haffner1

Inspired
Amp in the room has been discussed at length here and is worth searching the forum for.

The quickest and easiest way to get amp in the room tones is to disable cab sims and hook the Axe up to a power amp and a guitar cab.
I have an Avatar 4X12 with K-100s and a SS power amp gathering dust in my living room because its use tends to damage the hearing of wives, children and dogs. I can't bring myself to sell it because they have gone up in price by at least 50% since I bought it! I only miss using it sometimes as I have been mostly going direct for the last 10 years or so.
 

sprint

Fractal Fanatic
Interestingly, I am a bit of a rare bird around here who has always preferred the Mic'd Cab sound (probably because I started playing guitar for individual leisure later in life with my whole idea of guitar tone being what I heard from commercial recordings and/or concert PAs).

Knowing nothing, for a long time I tried to get my modellers (Pods, then Axefx Ultra,2,3) to sound good to my ears through tube amps (combos and various head / power amp + Cab configs). I did not like the sound of AITR with or without a modelled preamp component (I went through a few good quality combos and head/cabs none of which I liked). It always sounded harsh and thin to me. After a couple of years struggling with guitar tone, I decided to plug my AxeUltra into my home stereo one day and turn virtual cabs on. Bingo! - That's what I wanted my guitar to sound like! - I had inadvertently discovered how the guitar sounds I had been listening to for decades actually get created. I then proceeded to waste many hours trying to get my modeller/tube amp/Real Cab setups to sound like what I had heard through my home stereo - fools errand indeed!

Fast forward 10 years which has included a 1000 hours of volunteer sound production at our local theatre, a college program in music production, lots of tinkering in my mancave, and lots
of reading here, I'm now much better informed and happier place:

- My Axe3 into studio monitors sounds great.
- My Axe3 (w PA modelling ON and Cab modelling OFF) into Mattrix Stereo SS Power amp into 2 112 Mesa cabs sounds great also in a different way; though it has taken me a long time to apprecuate the AITR sound. Based on my feeling on any particular day, I'll play one setup or the other but I've learned my lessons about trying to get one to sound exactly like the other. (I've not yet tried WDW).
 
Last edited:

shatteredsquare

Fractal Fanatic
I don't see how by the laws of consumer peasant logic, if you had a virtual power amp distorting the right frequencies, and you had some filtering applied to the signal to make up the measured difference between a V30 and the FRFR driver you're using, how the FRFR driver would not throw the exact same sound that the V30 would, so that when it reaches your ears in the far field (in your listening environment) the FRFR sounds just like the V30.

It would seem to me simpler to isolate the frequency response of a V30 speaker, it only puts out what it puts out...apply that filter to the FRFR, based on whichever driver you're using. Measure both, apply the difference to the FRFR driver. Turns it into a V30.
 

bdrepko

Fractal Fanatic
I don't see how by the laws of consumer peasant logic, if you had a virtual power amp distorting the right frequencies, and you had some filtering applied to the signal to make up the measured difference between a V30 and the FRFR driver you're using, how the FRFR driver would not throw the exact same sound that the V30 would, so that when it reaches your ears in the far field (in your listening environment) the FRFR sounds just like the V30.

It would seem to me simpler to isolate the frequency response of a V30 speaker, it only puts out what it puts out...apply that filter to the FRFR, based on whichever driver you're using. Measure both, apply the difference to the FRFR driver. Turns it into a V30.
If it were possible, it would already be available. There are people a lot smarter than us, that have looked at this issue.
 

shatteredsquare

Fractal Fanatic
If it were possible, it would already be available. There are people a lot smarter than us, that have looked at this issue.
Uhhh I don't believe that for a second. No one has tried it yet is all. JBL monitors come with that mic you put in the listening position, it does a sweep, and applies the applicable EQ curve to compensate for your room problems. An FRFR driver is just a speaker, supposedly full range, but capable of throwing the same freqs as a guitar speaker. You measure the FRFR response, you measure the guitar speaker response, apply the difference. What's missing?

IR meta data hasn't been tied to the amp speaker page yet, so that a certain IR loads up the right impedance curve to the amp. It's totally possible, just 1. Hasn't been asked for, 2. Hasn't been necessary, 3. Hasn't had the time or inclination. Straight up though, if you load up a 1960a IR with a Recto amp without adjusting the speaker page, it's not distorting right. The amp is still looking at it's (assumed, likely) V30 impedance curve that it loads as a default.
 

DLC86

Fractal Fanatic
I don't see how by the laws of consumer peasant logic, if you had a virtual power amp distorting the right frequencies, and you had some filtering applied to the signal to make up the measured difference between a V30 and the FRFR driver you're using, how the FRFR driver would not throw the exact same sound that the V30 would, so that when it reaches your ears in the far field (in your listening environment) the FRFR sounds just like the V30.

It would seem to me simpler to isolate the frequency response of a V30 speaker, it only puts out what it puts out...apply that filter to the FRFR, based on whichever driver you're using. Measure both, apply the difference to the FRFR driver. Turns it into a V30.
This is the principle behind the line 6 powercab and the new Kemper cab.
But don't expect them to sound really the same as the real V30 or whatever speaker they emulate. They're still completely different drivers, with different dispersion and different non-linear behaviours.
 

bdrepko

Fractal Fanatic
Uhhh I don't believe that for a second. No one has tried it yet is all. JBL monitors come with that mic you put in the listening position, it does a sweep, and applies the applicable EQ curve to compensate for your room problems. An FRFR driver is just a speaker, supposedly full range, but capable of throwing the same freqs as a guitar speaker. You measure the FRFR response, you measure the guitar speaker response, apply the difference. What's missing?

IR meta data hasn't been tied to the amp speaker page yet, so that a certain IR loads up the right impedance curve to the amp. It's totally possible, just 1. Hasn't been asked for, 2. Hasn't been necessary, 3. Hasn't had the time or inclination. Straight up though, if you load up a 1960a IR with a Recto amp without adjusting the speaker page, it's not distorting right. The amp is still looking at it's (assumed, likely) V30 impedance curve that it loads as a default.
It would be great if it could be done, but I don't it happening anytime soon.
 
Top Bottom