How can you EQ to account for non-FRFR?

[JRod4928]

Problem: People with cheaper FRFR rigs may have difficulty setting up presets because of the color added to the tone by the cheap FRFR rig. (such as myself Behringer K3000FX ).

Question: An EQ could be used to counter-act the non-flat response using superposition to make the EQ curve more like a high-end FRFR rig. But what's the best way to determine the actual frequency response? I understand that room size/prep, microphone location/type etc. have a huge impact on the frequency response readings, so is there another way?

I could use the line-out of the Behringer back into the AXE FX and perform a tonematch, but that will only account for a portion of the behringer circuit, it wouldn't account for the speaker response itself. Infact, I'm not 100% how useful doing that would be...

Ideas?

....maybe I could buy a mic and a high-end FRFR speaker and do a tonematch against the K3000FX

 

[Sixstring]

Not sure if I'm explaining this correctly so please take it was a grain of salt but you need to have a snapshot response of the speaker to make a corrective EQ. How ever it will not fix any phase issues there might be. Merlin did this with the FTB Verve 12ma a few years back and for those with the powered version of that speaker it worked pretty well. Maybe shoot him a PM and see if he can help out.

 

[JRod4928]

Not sure if I'm explaining this correctly so please take it was a grain of salt but you need to have a snapshot response of the speaker to make a corrective EQ. How ever it will not fix any phase issues there might be. Merlin did this with the FTB Verve 12ma a few years back and for those with the powered version of that speaker it worked pretty well. Maybe shoot him a PM and see if he can help out.

I understand your point, and I see the need for the snapshot. If I don't have it, I guess the best I can do is tweak the EQ by ear.

I don't understand the phase issue.

 

[clarky]

Problem: People with cheaper FRFR rigs may not be achieving a true flat response (such as myself Behringer K3000FX ).

Question: An EQ could be used to counter-act the non-flat response using superposition. But what's the best way to determine the actual frequency response? I understand that room size/prep, microphone location/type etc. have a huge impact on the frequency response readings, so is there another way?

I could use the line-out of the Behringer back into the AXE FX and perform a tonematch, but that will only account for a portion of the behringer circuit, it wouldn't account for the speaker response itself. Infact, I'm not 100% how useful doing that would be...

Ideas?

in truth, non of the so called FRFR monitoring systems are truly flat.. even studio monitors..
so just EQ to taste and don't worry about it

 

[JRod4928]

in truth, non of the so called FRFR monitoring systems are truly flat.. even studio monitors..
so just EQ to taste and don't worry about it

very true. The problem is that if I set up an awesome tone at my house, it might not translate to the venue. I've had this happen in the past, and I'm left EQing on the spot on my rig, or I'm left relying on the sound guy. I'd rather get it close on my own so the sound guy doesn't have to do as much work. Any preparation done at home that can make life at the gig easier is worth it

 

[zenaxe]

very true. The problem is that if I set up an awesome tone at my house, it might not translate to the venue.

So you think that accounting for subtle EQ differences between your home monitor's specific EQ curve and flat response will somehow also account for subtle differences between some live venue's completely different response curve and flat? And also that the audience hears these differences and they are the primary source of deviation between your tone @ home and @ the venue?

I'm with clarky on this one: You're probably better off accounting for things that are gross sources of error like Fletcher Munson effect, learn how to use the global EQ on site and just letting it rip.

 

[selta]

Soundguy will always have to do work. Your room, the rehearsal space and so on are not the venue in many ways (size, temperature, reflection surfaces, bodies of people and so on). There are always adjustments, which is why IMO it's more important to get a good soundguy and work with them on everything. Especially since he/she is at FOH and able to slice out the ranges for each instrument and make things sound truly good.

 

[selta]

very true. The problem is that if I set up an awesome tone at my house, it might not translate to the venue. I've had this happen in the past, and I'm left EQing on the spot on my rig, or I'm left relying on the sound guy. I'd rather get it close on my own so the sound guy doesn't have to do as much work. Any preparation done at home that can make life at the gig easier is worth it

Often times what sounds good in a solo setting sounds like complete ass in a band setting. Typically, people like a scooped tone when working by themselves... which is the easiest way to get totally lost in a mix. I'm not suggesting that is your case, but it is something to keep in mind. At home practice can sound like anything, but your primary tone shaping should take place together at rehearsal with the full band. In my opinion, anyway

 

[JRod4928]

I understand what you're all saying and I agree to some extent. I'm just saying that if a cheaper FRFR rig is nowhere near a flat response, and nowhere near the response of the speakers at the venue I'm playing at, then it'd be nice to account for it with an EQ so that I'm setting up better patches at home. With that said, I'm not expecting some magical EQ to fix everything, but I'm sure you guys can see my point.

 

[selta]

From how I'm reading your OP and your latest response, you're talking two different points:
1) Make "cheap" "FRFR" speakers sound like high-end "FRFR" speakers.
2) Make "cheap" "FRFR" speakers sound like the equipment used at various venues.

#1 is fairly easy to tackle, though futile (IMO). You'd simply (simple != easy) measure the response of the system as-is, in the room it is in presently, and make as much adjustment as you can to get a reasonable graph. I don't see a benefit of doing this. You'll have to add another EQ curve on top of the correcting one then to get your tone, and you'll still yet have to adjust once at a venue or rehearsal space.

#2 is difficult, if not impossible and equally futile. You'd need to know the specific venues general response, which is very dynamic. Each venue will be very different. Then you'd need to EQ for that, once again stacking your own EQ on top of that in order to get started. Then, once you get the the venue and fill it with a few hundred people, find out that it's way different and need to adjust .

I understand your want, I just don't see any potential payoff from it being worth it. Venue sound systems are not FRFR to begin with - then you dump them in rooms with people and straight lines / 90* angles and all goes to hell. In an ideal world, we could have true FRFR systems at home, and venue systems would be FRFR no matter what in every square inch of the venue.

Not to mention, the soundguy is going to have to tweak even if the "ideal" above is true, as he/she will have to make sonic space for each instrument, so you're band sounds good and not a mushy mess.

 

[lqdsnddist]

A venue with 50 people vs 500 people vs 5000 all will sound vastly different via the same sound system. Its just one of a number of variables.

Basically you just want a fairly flat system to dial in your patches, so that it will translate as well as possible, with some tweaks by the house sound guy as needed.

FRFR isn't some magic bullet, but it simply provides a fairly neutral starting point opposed to dialing in patches on something like a PC multimedia speaker system, that is designed to produce very hyped up low end (as that is how people often like listening to music) so then if you created patches on that, your "real" tone would sound super thin on other systems.

 

[JRod4928]

From how I'm reading your OP and your latest response, you're talking two different points:
1) Make "cheap" "FRFR" speakers sound like high-end "FRFR" speakers.
2) Make "cheap" "FRFR" speakers sound like the equipment used at various venues.

#1 is fairly easy to tackle, though futile (IMO). You'd simply (simple != easy) measure the response of the system as-is, in the room it is in presently, and make as much adjustment as you can to get a reasonable graph. I don't see a benefit of doing this. You'll have to add another EQ curve on top of the correcting one then to get your tone, and you'll still yet have to adjust once at a venue or rehearsal space.

#2 is difficult, if not impossible and equally futile. You'd need to know the specific venues general response, which is very dynamic. Each venue will be very different. Then you'd need to EQ for that, once again stacking your own EQ on top of that in order to get started. Then, once you get the the venue and fill it with a few hundred people, find out that it's way different and need to adjust .

I understand your want, I just don't see any potential payoff from it being worth it. Venue sound systems are not FRFR to begin with - then you dump them in rooms with people and straight lines / 90* angles and all goes to hell. In an ideal world, we could have true FRFR systems at home, and venue systems would be FRFR no matter what in every square inch of the venue.

Not to mention, the soundguy is going to have to tweak even if the "ideal" above is true, as he/she will have to make sonic space for each instrument, so you're band sounds good and not a mushy mess.

You're right, after I wrote it, my goal changed... i'm probably going to edit so I don't have people responding to the OP and ignoring this discussion... anyway...

#1 is what I'm interested in. #2 is impossible IMO.

Your answer to #1 is what I figured I'd need to do... aside from having the Behringer factory printout of the frequency response for my K3000FX, there's no other way to determine the actual frequency response....right? (aside from micing it which has its own set of problems)

As far as the part in bold. I'd rather have my tone, before the sound guy has to tweak to match the venue. That's what I'm trying to accomplish see post below.

 

[JRod4928]

A venue with 50 people vs 500 people vs 5000 all will sound vastly different via the same sound system. Its just one of a number of variables.

Basically you just want a fairly flat system to dial in your patches, so that it will translate as well as possible, with some tweaks by the house sound guy as needed.

FRFR isn't some magic bullet, but it simply provides a fairly neutral starting point opposed to dialing in patches on something like a PC multimedia speaker system, that is designed to produce very hyped up low end (as that is how people often like listening to music) so then if you created patches on that, your "real" tone would sound super thin on other systems.

Exactly.

 

[brianv4]

if you're looking to get a flat response, out of whatever speaker, in any venue, use an RTA to find the offending frequencies then use the AxeFX global EQ to correct.

 

[merlin17]

What I did back then with the Verve was "measure" it with the equipment I have in my studio. That was NOT totally scientific, but it worked well.
I sent white noise to the monitor and recorded what came out of the Verve with a Behringer ECM-8000 and a Neumann KM-86 from ca. 1m away on axis. I then EQ'd it with Fabfilter Pro-Q to look (and sound) flat and made an IR out of that curve.
If your monitor is as bad as the FBT was then I'd suggest you correct it. The Verve was TERRIBLE and of course never sounded right to me nor did it translate to any PA system at all.
If you have a speaker you know sounds good you can of course eq your Behringer to sound similar by ear, too.

 

[barhrecords]

I have used cheap wedges with the Fractal for inclement weather shows.

First try to make the wedge dedicated to GTR only. Running VOC or a band mix makes the problems worse.

Checkout the specs for the wedge and pay attention to the crossover freq. This is usually a mess in cheaper wedges. Put a PEQ at the end of your chain with a fairly broad Q at the crossover freq and experiment with boosts / cuts to see what sounds better.

Take a piece of gaffers tape about 4" long and place it on the wedge grill directly over and centered on the throat of the wedge horn. The HF horns in cheap speakers are so harsh you will fight the high frequencies like mad.

Use a lowshelf (highpass) to roll off the lows as much as possible.

 

[kevinerror]

I've experimented with this quite a bit. I've use the built in tone matching block to do this, and I've had great results.

I start by using a reference mic to capture the sound of pink noise going through my cab. That goes into the 'local' section of the tone match. Then, I feed pure pink noise into the 'reference' section of the tone match. I then let it correct, and smooth it out a little bit. It might take a few tries or different mic positions to get right, but this method can correct almost any cab/speakers frequency response to be nearly flat. It won't be perfect, there's still a bunch of other things this doesn't account for (like cabinet resonance or differences in frequency response at different volumes), but it's totally usable as a flat response cab after using this method - meaning you can use other cab IRs with any non flat response cab!

 

[JRod4928]

I've experimented with this quite a bit. I've use the built in tone matching block to do this, and I've had great results.

I start by using a reference mic to capture the sound of pink noise going through my cab. That goes into the 'local' section of the tone match. Then, I feed pure pink noise into the 'reference' section of the tone match. I then let it correct, and smooth it out a little bit. It might take a few tries or different mic positions to get right, but this method can correct almost any cab/speakers frequency response to be nearly flat. It won't be perfect, there's still a bunch of other things this doesn't account for (like cabinet resonance or differences in frequency response at different volumes), but it's totally usable as a flat response cab after using this method - meaning you can use other cab IRs with any non flat response cab!

I just checked out your thread where you did a similar thing with a guitar cab. that's basically what I'm trying to do...cool stuff!

I think I have the resources to give this a shot, with a little help from friends

 

[kevinerror]

Someone asked me for a tutorial on how to do this, so here's what I came up with

What you'll need:

- Some kind of reference mic - I just used a cheap $50 Dayton Audio calibration mic. The goal is to be as close to flat as possible, but it doesn't need to be perfect.

- A mic preamp / interface

The first thing you'll want to do is send pink noise through your cab - I assume that you can figure our how to do this using whatever methods you choose. I chose pink noise instead of white noise because I felt that the pink noise was more prominent in the frequencies that guitar actually takes up. Probably doesn't matter too much if you use white noise.

Set up your reference mic so that it's picking up a clear signal from your cab. This is the tricky part and might require lots of time to get right. You'll have to find a position/angle/distance that 'sounds' like just the tone of the noise coming through your speaker, no reflections or phasing issues. For me, this was right up against the cab on a speaker cone equidistant from the dustup and speaker edge. You'll have to experiment and see what sounds the most like your cab in the room to your ears. I recommend recording this into a computer (4 or 5 seconds will do) and listening back while the cab is off to really hear it.

Once you get a good sample of your 'cab noise', you'll want to send this to the 'local' section of the tone match block. You can do this a number of ways - I just set the input to USB and played back my sample into the Axe FX.

Next, you'll want to send the same pink noise you used going into your cab and send it to the 'reference' section of the tone match block. Again, I just set the input to USB and sent that original pink noise through.

From there - have the tone match block do the matching, and you're off! I find that a little smoothing and some backing off of the 'amount' really helps. It won't be perfect by any means, but neither are most 'flat' branded speakers anyway.

Some things to keep in mind:
- Your ears quickly adapt to colorations of tone based on expectation, so it's important not to lose context here. I recommend doing this at a not-so-loud volume to keep your ears fresh, and to find some kind of 'reference material' to pump through your cab that you can compare to a set of flat headphones or monitors. I used a song, actually. Just something you can hear back and forth from a 'known flat' set of speakers and your 'corrected' cab to see how close it is.

- This isn't perfect, and every time I post about this people like to call me out on it. I KNOW it's not perfect. But no system is truly perfect, and this is very close - measurably so.

Hope this helps!

 

[JRod4928]

Someone asked me for a tutorial on how to do this, so here's what I came up with

What you'll need:

- Some kind of reference mic - I just used a cheap $50 Dayton Audio calibration mic. The goal is to be as close to flat as possible, but it doesn't need to be perfect.

- A mic preamp / interface

The first thing you'll want to do is send pink noise through your cab - I assume that you can figure our how to do this using whatever methods you choose. I chose pink noise instead of white noise because I felt that the pink noise was more prominent in the frequencies that guitar actually takes up. Probably doesn't matter too much if you use white noise.

Set up your reference mic so that it's picking up a clear signal from your cab. This is the tricky part and might require lots of time to get right. You'll have to find a position/angle/distance that 'sounds' like just the tone of the noise coming through your speaker, no reflections or phasing issues. For me, this was right up against the cab on a speaker cone equidistant from the dustup and speaker edge. You'll have to experiment and see what sounds the most like your cab in the room to your ears. I recommend recording this into a computer (4 or 5 seconds will do) and listening back while the cab is off to really hear it.

Once you get a good sample of your 'cab noise', you'll want to send this to the 'local' section of the tone match block. You can do this a number of ways - I just set the input to USB and played back my sample into the Axe FX.

Next, you'll want to send the same pink noise you used going into your cab and send it to the 'reference' section of the tone match block. Again, I just set the input to USB and sent that original pink noise through.

From there - have the tone match block do the matching, and you're off! I find that a little smoothing and some backing off of the 'amount' really helps. It won't be perfect by any means, but neither are most 'flat' branded speakers anyway.

Some things to keep in mind:
- Your ears quickly adapt to colorations of tone based on expectation, so it's important not to lose context here. I recommend doing this at a not-so-loud volume to keep your ears fresh, and to find some kind of 'reference material' to pump through your cab that you can compare to a set of flat headphones or monitors. I used a song, actually. Just something you can hear back and forth from a 'known flat' set of speakers and your 'corrected' cab to see how close it is.

- This isn't perfect, and every time I post about this people like to call me out on it. I KNOW it's not perfect. But no system is truly perfect, and this is very close - measurably so.

Hope this helps!

Real cool man, thanks!

I'm not expecting perfection, nor am I looking for it, but like I mentioned before, if this helps at a live show, I'm willing to give it a shot. Everything gets changed so much at the main board that the minute differences in the FRFR is negligible. What I'm trying to do is make those difference minute. If nothing else, the tonematch will give me an eq curve that I could program in as a PEQ as opposed to merging all of my CAB IR's with my 'correction' IR in CAB LAB (maybe)

Thanks for the input man!