Trying FRFR... Not Digging It

[tnolanjr]

A miced signal is a bit like a video clip. It's not the same thing to watch a video than actually experiencing the thing with your own eyes. A mic only takes one spot out of a speaker just like a video doesn't have a wide view like your own eyes.

This is another poor example. Clearly you've already found what works for you, but if you are interested in expanding your technical knowledge then read up more on far-field IRs and their use.

Would I like to own all of those 40 amps? Hell yes but I'd only use 5. How many different IRs am I using with the Axe-Fx? 1 or 2. How many cabs would I really need? 1 or 2. So is the IR+FRFR useful to me? No. What about the Axe-Fx? 5 amps = 15 000€ when Axe-Fx = 1600€ and I get pretty much the same tones in one little box. AND I don't have to buy any effect pedals.

I think we all bought the Axe-Fx because it's extremely handy and an easy rig. Is FRFR somehow handier than a real cab... naah don't think so.

I'm not picking a fight. This is my opinion and you are entitled to disagree.

I'm not trying to pick a fight either. I'm glad you have something that works for you, regardless of what it is. The problem I have in this thread is the belief, backed by pure anecdotal evidence, that FRFR and IRs absolutely cannot accurately sound like a 4x12 speaker cabinet. Whether the effort and cost required to do so is worthwhile to an individual is entirely up to them, and not for me or anyone else to decide.

 

[Scott Peterson]

Cleaned thread up, deleted a lot of non-essential personal tit-for-tat that was off-topic at best.

Let's please all refrain from turning this into a trainwreck.

 

[Stratoblaster]

I'm still having problems with harsh high end though. When I use the PEQ, set to blocking at everything from 3.5k to 5.5k, I either kill too much top end or I still have the harsh stuff in there, I can't find the middle ground.

A lowpass ("blocking") filter is the wrong tool for that job. Set a PEQ filter to "peaking," Q to a moderate value (say 2), and Gain to minimum. Sweep the frequency value while listening for the harshness and identify the value that most effectively eliminates it. Once you've done that, increase Q and repeat. This will enable you to hone in on the exact frequency range that is causing the harshness and to only eliminate those frequencies with minimal effect on the surrounding ones. After 2-3 passes of this procedure, begin reducing the amount of cut (increase the Gain) until you only have enough to clean up the harshness. That will leave your overall tone least affected by the cleanup filter.

marshall2553 Jay's tip above is a very useful one in getting the high end under control. I do exactly that; finding the narrow band of objectionable high end and surgically removing it while leaving as much as you can intact. I find that range to be centered at around 4.1KHz to 4.3KHz, in general, for my ears and rig. You can then bracket the absolute low and high end and shape the tones using Radley's blocking EQ tips found on this forum to get things further refined.

 

[marshall2553]

Back to the original topic... I had boxed up the QSC and was ready to ship it back to MF but decided to break it back out and give it a few more days. I tried some of Scott's latest Redwire concoctions (simple 50/50 mixes) and was instantly much closer than I had been with my more convoluted mixes using farfield and close mic'ed IR's. The mic positions he's using helped the most, I just switched up some of the speaker choices to taste. Now I'm pretty close to hearing exactly what I want. All I'm doing is cutting some of the lows in a PEQ and for some patches I'll cut some top end or add a little AIR. I haven't completely made my mind up but I'm leaning towards keeping the K12 now.

And a warning for anyone out there like me with no experience mic'ing guitar cabs and a slight case of OCD. The Redwire IR's are a very powerful tool but there is a huge learning curve and you could spend days or weeks uploading IR's to your AxeFx, listening to all the mics and positions available, and tweaking IR mixes to find your sound.

 

[marshall2553]

marshall2553 Jay's tip above is a very useful one in getting the high end under control. I do exactly that; finding the narrow band of objectionable high end and surgically removing it while leaving as much as you can intact. I find that range to be centered at around 4.1KHz to 4.3KHz, in general, for my ears and rig. You can then bracket the absolute low and high end and shape the tones using Radley's blocking EQ tips found on this forum to get things further refined.

I'll give that a try, though after trying some of Scott's IR suggestions I am hearing less of the harshness. The weird thing is that like you I'm finding the frequencies I don't like to be around 4.0-4.5kHz but that is also the same frequency range that I'll go back and add some AIR at to open things up a little.

 

[Jay Mitchell]

The weird thing is that like you I'm finding the frequencies I don't like to be around 4.0-4.5kHz but that is also the same frequency range that I'll go back and add some AIR at to open things up a little.

This has a different effect than you're thinking. The frequency of the "air" parameter is the upper cutoff frequency of a lowpass filter. When you increase "Air," you're adding frequencies that lie below the selected frequency. In addition, when you add air, you may - in fact, probably will - be cancelling some of the frequencies contained in the added direct signal (which is what this parameter mixes in with the cab sound). IOW, dialing some "air" with the frequency set to, say, 4kHz, may reduce, rather than increase, the level at 4-4.5kHz.

One of the complications with some of the available parameters is that the results they produce are counterintuitive. Air adds low frequency direct signal to the signal that has been processed by the IR. "Addition" of two time-varying signals does not uniformly increase the frequencies contained in the signals. Depending on the phase relationships between the two signals, "adding" may involve the addition of a negative number, i.e., subtraction.

If you want to identify the frequencies that are causing "harshness," the technique I suggested is the easiest and most reliable way to do so. Once you have identified them, you can decide how best to deal with them.

 

[marshall2553]

This has a different effect than you're thinking. The frequency of the "air" parameter is the upper cutoff frequency of a lowpass filter. When you increase "Air," you're adding frequencies that lie below the selected frequency. In addition, when you add air, you may - in fact, probably will - be cancelling some of the frequencies contained in the added direct signal (which is what this parameter mixes in with the cab sound). IOW, dialing some "air" with the frequency set to, say, 4kHz, may reduce, rather than increase, the level at 4-4.5kHz.

One of the complications with some of the available parameters is that the results they produce are counterintuitive. Air adds low frequency direct signal to the signal that has been processed by the IR. "Addition" of two time-varying signals does not uniformly increase the frequencies contained in the signals. Depending on the phase relationships between the two signals, "adding" may involve the addition of a negative number, i.e., subtraction.

If you want to identify the frequencies that are causing "harshness," the technique I suggested is the easiest and most reliable way to do so. Once you have identified them, you can decide how best to deal with them.

That explains a lot, I thought air was letting direct signal pass through at just the selected frequency and didn't even take into account that it may cancel out some of the cab sound. As someone with a MS in computer science I had my fair share of math, physics, some signal processing, etc in school. Maybe I need to pull out some of my old textbooks and brush up on this stuff...

 

[dk_ace]

The weird thing is that like you I'm finding the frequencies I don't like to be around 4.0-4.5kHz but that is also the same frequency range that I'll go back and add some AIR at to open things up a little.

This has a different effect than you're thinking. The frequency of the "air" parameter is the upper cutoff frequency of a lowpass filter. When you increase "Air," you're adding frequencies that lie below the selected frequency. In addition, when you add air, you may - in fact, probably will - be cancelling some of the frequencies contained in the added direct signal (which is what this parameter mixes in with the cab sound). IOW, dialing some "air" with the frequency set to, say, 4kHz, may reduce, rather than increase, the level at 4-4.5kHz.

One of the complications with some of the available parameters is that the results they produce are counterintuitive. Air adds low frequency direct signal to the signal that has been processed by the IR. "Addition" of two time-varying signals does not uniformly increase the frequencies contained in the signals. Depending on the phase relationships between the two signals, "adding" may involve the addition of a negative number, i.e., subtraction.

If you want to identify the frequencies that are causing "harshness," the technique I suggested is the easiest and most reliable way to do so. Once you have identified them, you can decide how best to deal with them.

Thanks for posting that. I've not used the AIR parameter in my patches to this point. I misunderstood how it works in the same way that Marshall2553 did. I need to play with it some after the 9.03 update (I'm holding off on FW upgrades and patch tweaking until that release).

D

 

[Mike Snider]

The weird thing is that like you I'm finding the frequencies I don't like to be around 4.0-4.5kHz but that is also the same frequency range that I'll go back and add some AIR at to open things up a little.

This has a different effect than you're thinking. The frequency of the "air" parameter is the upper cutoff frequency of a lowpass filter. When you increase "Air," you're adding frequencies that lie below the selected frequency. In addition, when you add air, you may - in fact, probably will - be cancelling some of the frequencies contained in the added direct signal (which is what this parameter mixes in with the cab sound). IOW, dialing some "air" with the frequency set to, say, 4kHz, may reduce, rather than increase, the level at 4-4.5kHz.

One of the complications with some of the available parameters is that the results they produce are counterintuitive. Air adds low frequency direct signal to the signal that has been processed by the IR. "Addition" of two time-varying signals does not uniformly increase the frequencies contained in the signals. Depending on the phase relationships between the two signals, "adding" may involve the addition of a negative number, i.e., subtraction.

If you want to identify the frequencies that are causing "harshness," the technique I suggested is the easiest and most reliable way to do so. Once you have identified them, you can decide how best to deal with them.

Thanks Jay- you have turned on another lightbulb. I had misunderstood that parameter before now as well.

 

[joegold]

OK.
I obviously don't have the acoustical engineering chops/education of Jay and I'm sure he'll find all sorts of holes in what seems like common sense to me below but...

Isn't a big part of the way we experience the "in the room" sound of a 4 X 12 cabinet due to the fact that sound is emanating from 4 separate sources?
And these 4 drivers are usually not all aimed in the same direction so the sound spreads out in a way that is much more complex than it would be from a single driver, no?

Well, if the above is even partly true, then it would seem to me that the only way to get a FRFR speaker cab to excite the air in a room in a way that is as close as possible to the way a 4 X 12 cab excites the air in a room is to use a FRFR speaker system designed with 4 drivers that are aimed more or less in similar ways to the drivers used in a 4 X 12. I think that to be as accurate as possible you'd probably need to take IRs of each of the 4 X 12's drivers and have a quad amp of some sort deliver audio to all 4of the FRFR system's drivers.

In other words, isn't it safe to say that a single FRFR speaker can not spread the sound out in a room in exactly the same way that a 4 X 12 speaker does?
I think that a monaural IR played through a single monaural FRFR speaker can at best capture other aspects of the sonic characteristics of a 4 X 12 cabinet than it's "in the room" projection pattern and ultimately its feel.

Again, the question of whether the Axe through a FRFR system is giving you the "in the room" feeling is really about how much you're willing to live with slight differences between the way that feels and the way a real 4 X 12 feels. They will never be exactly the same experiences.

But you might find that the Axe through an FRFR system feels even *better* to you than the Axe feels through your favourite real-world cab.

Certainly, for me, and I'm using a real guitar cab in my rig, the Axe's amp sims feel better and sound more musical to me than any of the Mesa and Fender and Marshall and Traynor and Music Man and Mosvalve and ADA and Acoustic and Lab Series and Dean Markley and Roland and Polytone and Acoustic Image amps (did I leave any out?) that I've ever owned.
I don't really care if the Axe can sound *exactly* like any one of those amps because the Axe does their *job*, which is making me sound good and play good, better than they do.

Meanwhile, a local store is carrying the K12s. I think I might try to rent one for a while and check it out. The best FRFR systems I've tried so far have been the Yorkville Elite speakers. I didn't have much time with them and I was an Axe newbie at the time, but I was not really impressed with the feel when playing through them. The idea of using the Axe through an FRFR system is pretty appealing though, if I could get used to it.

 

[goodwill559]

Deduction from logical truths alone is insufficient to explain complex phenomena, or as Ivan Beaver once posted, "Any complex question can be easily answered with a simple easy to understand WRONG answer."

Due to its reliance on propositions rather than esoteric knowledge or study or research, common sense often leads to wrong answers, e.g., heavier objects should fall faster than lighter objects.

This is not a dig at any individual in our community, but a caveat against turning our board into a debate about beliefs.

 

[Jay Mitchell]

Isn't a big part of the way we experience the "in the room" sound of a 4 X 12 cabinet due to the fact that sound is emanating from 4 separate sources?

It is true that a big part of the characteristic sound of a 4x12 cab as heard at any one playing/listening location is due to the fact that there are multiple sources. This will be equally true if there is no "room," i.e., on an outdoor stage. A 4x12 cab, whether "in a room" or not, produces radically different sounds depending on where you stand when you listen to it, and the multi-source nature of the cab is a primary contributor to these differences. Not all of those sounds will be perceived as equally good, and almost every guitar player has a preferred position (or range of positions) in which he will tend to place himself relative to the cab. If you want to do the best possible job of reproducing the sound in this preferred position, you need to acquire an IR of the speaker with the mic placed in the general position of the player's ears when (s)he is in a preferred position.

And these 4 drivers are usually not all aimed in the same direction

The difference in aiming angle ranges from zero in a flat front cab to something less than 15 degrees in an angled-front one. This makes a relatively small difference in the sonic character.

so the sound spreads out in a way that is much more complex than it would be from a single driver, no?

This is equally true of flat front or angled-front cabs. The primary lobe ("beam") of any 4x12 is much narrower - less than 5 degrees at some frequencies - than the beam from a single 12" speaker, and very much narrower than the primary lobe of a well-designed FRFR system, which can be as wide as 90 degrees. In my experience, very few guitar players will voluntarily place themselves in the "beam" of a 4x12, because the sound will be very harsh. Unfortunately, it is possible for audience members to find themselves in such a position.

Well, if the above is even partly true, then it would seem to me that the only way to get a FRFR speaker cab to excite the air in a room in a way that is as close as possible to the way a 4 X 12 cab excites the air in a room is to use a FRFR speaker system designed with 4 drivers that are aimed more or less in similar ways to the drivers used in a 4 X 12.

"Exciting the air in the room" in the same way is not necessary in order to realize the goal here. Producing the effect of the sound that arrives at the player's ears directly from the cab is the most important attribute of a successful FRFR-based emulation. The effect of reflected sound is secondary. You are correct that the nature of the reflected sound cannot be made identical between a 4x12 and a typical FRFR speaker, but the nature of the reflected sound also varies tremendously from room to room, as well as with simply moving or re-aiming the cab. If you get the characteristics of the direct sound close enough - which is possible - then you can create the reliable sonic illusion of playing through a 4x12 cab.

Stratoblaster has described one technique - tweaking an existing IR with the target cab on hand as a reference. Another equally viable technique - the one I use - is to acquire an IR of the target cab with the mic in a representative listening position.

In other words, isn't it safe to say that a single FRFR speaker can not spread the sound out in a room in exactly the same way that a 4 X 12 speaker does?

Yes, in a manner of speaking. Actually, a single FRFR speaker "spreads the sound out in a room" quite a bit more uniformly than is possible with a 4x12. Ergo, the sound will change far less with different playing/listening positions with an FRFR system than with a 4x12. Technically speaking, this means that the FRFR is not perfectly true to the behavior of a 4x12. Practically speaking, it would usually mean that behavior of the FRFR system is preferable to that of the 4x12.

But you might find that the Axe through an FRFR system feels even *better* to you than the Axe feels through your favourite real-world cab.

Good point. I agree completely.

I don't really care if the Axe can sound *exactly* like any one of those amps because the Axe does their *job*, which is making me sound good and play good, better than they do.

I think we're on exactly the same philosophical page here.

 

[grOOvadelic]

LOL - I just logged in to check out this topic and the first sentence I read was "Deduction from logical truths alone is insufficient to explain complex phenomena"

:?

:arrow: Next topic!