Helix Live and The Fletcher-Munson Curve

[erniedenov]

My first several gigs with Helix have been going direct to the board. In that particular band, we use in-ear monitors. The band leader doesn't want to have amplifiers on stage, presumably to control the volume. It made sense to me to tweak my Helix using the same in-ear monitors I use live with the headphone jack. What I hear on the gigs is very similar to what I hear tweaking at home. But...

 

This past weekend, I played with a band I hadn't worked with before in a club and I used Helix with an FRFR powered speaker (Alto Truesonic TS 212) that I bought recently. In preparation, I did a bit of tweaking at home with the speaker turned up to what I guessed would be close to the volume I'd be using and immediately noticed that the lower and higher frequencies were much more prominent. I wasn't surprised, being aware of the Fletcher-Munson Curve (the theory of how and why we perceive frequencies differently depending on volume). I dialed the bass on my patches back considerably and the treble to a somewhat lesser extent. At the soundcheck, I found I had to dial the bass down even further, which I attribute to the hollow stage we were playing on. I ended up being pretty satisfied with the sound I was getting, though I know it would've been better if I'd had more tweaking time. But now I'm wondering about this:

 

Those patches that I initially made with my in-ears; what do they sound like at the gigs, given that they're going to be louder in FOH? I've never actually heard what it sounds like coming out of there and maybe I've just been blissfully unaware because they sound fine in my in-ear mix. I played with that band (that uses in-ears) the next night and asked the soundman if my sounds were too boomy and bright and he said "no," but I'm not sure I can just take his word for it. I saved the re-tweaked patches using the powered speaker in different banks; do you guys thing I'd be better off using them instead of the original ones I made using my in-ears?

[psarkissian]

Maybe standing waves, as a result of the venue lay out?

Room isn't as tuned as it could be?

[cruisinon2]

My first several gigs with Helix have been going direct to the board. In that particular band, we use in-ear monitors. The band leader doesn't want to have amplifiers on stage, presumably to control the volume. It made sense to me to tweak my Helix using the same in-ear monitors I use live with the headphone jack. What I hear on the gigs is very similar to what I hear tweaking at home. But...

 

This past weekend, I played with a band I hadn't worked with before in a club and I used Helix with an FRFR powered speaker (Alto Truesonic TS 212) that I bought recently. In preparation, I did a bit of tweaking at home with the speaker turned up to what I guessed would be close to the volume I'd be using and immediately noticed that the lower and higher frequencies were much more prominent. I wasn't surprised, being aware of the Fletcher-Munson Curve (the theory of how and why we perceive frequencies differently depending on volume). I dialed the bass on my patches back considerably and the treble to a somewhat lesser extent. At the soundcheck, I found I had to dial the bass down even further, which I attribute to the hollow stage we were playing on. I ended up being pretty satisfied with the sound I was getting, though I know it would've been better if I'd had more tweaking time. But now I'm wondering about this:

 

Those patches that I initially made with my in-ears; what do they sound like at the gigs, given that they're going to be louder in FOH? I've never actually heard what it sounds like coming out of there and maybe I've just been blissfully unaware because they sound fine in my in-ear mix. I played with that band (that uses in-ears) the next night and asked the soundman if my sounds were too boomy and bright and he said "no," but I'm not sure I can just take his word for it. I saved the re-tweaked patches using the powered speaker in different banks; do you guys thing I'd be better off using them instead of the original ones I made using my in-ears?

If you're sound guy isn't deaf, and actually knows what he's doing, then it was probably fine. He/she/it should have EQed away any problems....but one never knows. If you really want to find out, get a nice long cable (or wireless if you're so inclined) and go stand out in front of the stage during sound check, minus your in-ears...then you'll know.

[strabes]

This is something I really worry about too. One time I heard a recording of a live set and my guitar was just piercingly bright even though it sounded really good at home. After that I started turning up the mids a lot and cutting bass and treble a bit and the results have been a lot better. For live I really think you shouldn't have your amp set up as bright as you can in the studio. It's tough to know exactly how it sounds in a full band mix unless you have a wireless unit and can walk around during check. I just know I'd rather have it be too middy than too bright. 

[cruisinon2]

EVERY amp/modeler/profiler/whatever needs to be tweaked differently for stage volume vs. comfy home studio/living room volume. It's always been this way, and it always will. There will never, ever be any exceptions to this...unless we all wake up one day, and the human brain(s) collectively start perceiving sound differently. Don't hold your breath...

[DunedinDragon]

This is exactly the reason I use a FOH quality FRFR both at home and on stage, to avoid the surprise of what's going to be coming out of the front speakers.

 

It doesn't surprise me in the least that you found the lower and higher frequencies much more prominent once you went to a powered monitor.  And yes, chances are that's exactly what was coming out of the FOH in the case of your other gig where you were using in-ear monitors.  That's why many of us opt to use FRFR speakers so we can hear what the audience is hearing.  Can it be corrected at the board by a good sound man?  If the sound man is very experienced at dialing in guitar tone and has the right equipment to do so, then yes.  But in my 40 plus years of working in this industry I figure you have the same chance of that happening as you do of opening up your guitar case at a gig and finding your guitar case has been filled with gold bullion.

 

First, it's not really as much about the level of the bass as it is about the width of bass frequencies being produced.  That's why tightening up that bass by limiting that range through low-cut filters is so critical.  How much you need to tighten it up will vary based on the sound you're trying to achieve, the amp and cabinet, choice of modeled mic and it's modeled placement relative to the speaker, and will likely change from patch to patch.  The same is true of the high end.  On FRFR speakers typical of front of house systems, they tend to produce much more energy in the upper ranges particularly because they employ compression drivers and very often horns.  Again, it needs to be address by limiting the range of frequencies in that high range that you will allow to pass through using some form of high cut likely in conjunction with a graphic equalizer to gradually trim down that response on the upper end of the frequency range.  And once again this all works hand in glove with the amp model, cabinet, mic model and modeled placement of the mic on the cabinet.  In my experience tightening up the bass frequency range is simple in comparison to getting the high frequencies where you want them

 

You have plenty of facilities for doing every bit of this built into your Helix.  It's not very likely your sound man will have all of those facilities to dedicate to your guitar channel, nor will he be likely to spend the time to get it right.  That's why you're much better off doing it yourself with the Helix and just sending the FOH the signal you want sent to the audience.

 

The advantage of this level of effort is that the audience will hear EXACTLY the tone you want them to hear which, in my experience, has rarely ever been true even using a real amp with a mic or a direct out line for the same reasons.  But I can now say with a GREAT deal of confidence, because I have checked it out in real life by comparing my stage guitar tone to the FOH sound on various setups, that it's a very precise representation of what I designed that guitar tone to be.

[HonestOpinion]

This is exactly the reason I use a FOH quality FRFR both at home and on stage, to avoid the surprise of what's going to be coming out of the front speakers.

 

...

+1 My reasoning exactly! Using something similar to a PA speaker gives me that warm fuzzy feeling that my presets will sound close to the same to the audience as they do to me. Whenever possible I design the presets near performance volumes otherwise the Fletcher-Munson curve will ensure that the sounds I designed at a lower volume will sound very different live no matter how similar the speakers I used to design them with were to the PA. I find practice with the band to be a good opportunity to make the final adjustments to my presets as I am usually closer to stage volume than the volume I generally use to initially setup my presets. My advice, get a good pair of relatively neutral earplugs for setting up presets close to stage volume. I understand for apartment dwellers and the like that may not be an option but you may or may not find yourself needing to make some last minute adjustments, potentially to the Global EQ, when you play out.

[zooey]

+2.

 

I'd add that differences in venues, playback rig or volume, and other environmental factors, are exactly what the global EQ is for. If you have a small number of environments, and the time and inclination to build separate presets fur each of them, you can be more specific about it.

 

But it's not clear that's a better approach than compensating for the different frequency response of each playback system with different global EQ. If you have make last-minute adjustments, it's certainly easier to change your global low-end EQ than to edit all the presets you built for that situation.

[HonestOpinion]

...

 

But it's not clear that's a better approach than compensating for the different frequency response of each playback system with different global EQ. If you have make last-minute adjustments, it's certainly easier to change your global low-end EQ than to edit all the presets you built for that situation.

 

I agree, I prefer to get my presets individually EQ'd so as not to require a "blanket" EQ of all of them with Global EQ just to compensate for live volumes versus the volume I used to design my preset. With that said, as you point out sometimes the Global EQ can be the best option for compensating for a given room or PA without trying to go in and modify the presets individually on the fly at a gig.

[DunedinDragon]

I used to be a much bigger advocate of using Global EQ as a way of taming these issues across all presets, but the longer I study the problem I tend to opt more for addressing it on a patch by patch basis.

 

Much of this comes from more experience in learning how to better exploit different cabinets, mic's, and mic placement which can address a certain level of these issues and then refine the sound using a combination of minimal high and low cuts at the cabinet level and the 10 band graphic EQ to soften the abrupt cut-off on frequencies that high and low cuts provide.  I'm much happier with the results because I can get it a lot closer to the tone I'm wanting that way.

[rvroberts]

I've got my sound adjusted for stage volume with quiet a bit of low and high cut. I do it with globals and I'd be more happy if I could save a few rather than one, but to answer your question, you would need a really good FOH guy to get the type of sound you would dial in yourself if you are feeding him/her the type of heavy bottom/bright top you tend to create at low volume or through phones. Your average midrange desk doesn't even have very good EQ for thi type of thing and the adjustments they would have to make would start to look extreme from a normal mix. Generally they have a fixed bass ant treble frequency and maybe a sweepable middle. Some of the new digital desks have something similar to the Helix global EQ, but it would be very trusting to imagine the sound guy would make the rather drastic low and high cuts you really need.

Send them an EQ'd sound that is good for high volume and then they only need to make minor tweaks for the room.

Works for me. I'm getting compliments on my sound regularly now.

[erniedenov]

Thanks for all the replies, guys!

 

The consensus seems to be that it's best to tweak my patches using my FRFR powered speaker at a volume that's at least in the ballpark of what it would be coming out of the FOH. That makes sense, but here's my quandary: If I'm digging the way my guitar is sounding in my in-ears with the patches I created using the headphone jack, I'm afraid I'm going to be pretty unhappy hearing them after I've re-tweaked them for optimum tone in the FOH; they'll sound thin and dull in my in-ear mix. It's no secret that the happier you are with your sound, the better you're going to play. I don't think I'm altruistic enough to give the audience the best sound I can give them at the expense of my own enjoyment. Let's face it, though we obviously want the audience to like us, our top priority is to please ourselves. I think the gigs I've enjoyed the most in my career were when I was playing in a venue small enough where it wasn't necessary to mic my amp at all and everybody was generally hearing what I was hearing coming out of my speakers (taking into consideration the difference in proximity to those speakers). 

 

I realize this poses a more difficult question and perhaps the only answer is the acceptance of compromise. Thoughts?

[DunedinDragon]

I'm probably the wrong person to ask because I always side with giving the audience the best I have to offer them and pleasing myself comes second.  If not for them I wouldn't be there at all.  My job isn't to inspire me, but to inspire the audience.

 

Personally I don't think it's as big a problem as you're thinking it is.  I'm sure you will be able to tell a slight difference, but if you tweak your settings correctly it shouldn't be that much off.  Most of the tweaking you're going to be doing is going to be at at the very high end and low end of the frequency spectrum, which your in-ears probably don't replicate that well anyway.  And that's why you haven't noticed the issue, because your in-ears don't work that well in that range of frequencies.

 

As far as Fletcher-Munson you don't need to be in the ballpark of the FOH volume.  You should simply be at a reasonable stage volume somewhere around 80 to 100 db.  Just enough to hear all the frequencies and be able to notice the adjustments you're making.  In fact that's a pretty reasonable level to be sending your signal to the board.

[zooey]

I started out with Helix in the fairly decent studio phones I already had, AKG D240s. When I picked up a pair of Alesis Alpha 112 FRFRs so I could play with people, I basically had to start over. All my headphone patches sounded awful.

 

After much angst, I decided that ultimate-sonic-reality concepts aside, I should make myself happy with what I was actually hearing. I used the global EQ to compensate a little for excess mid-highs and a 100hz or so peak I heard, especially playing recorded music through them. I did that not so much because I think that's the only or right way to do this, but because practically speaking, I wanted to play along with tracks sometimes, and didn't want to need an EQ for that. Once I had that EQ set, I wrote it down (it's not saved in any current Helix file format), and built all my patches listening through it.

 

When I next played in a band context, using those speakers with that EQ and the patches I'd set up for them, I only needed to make a few minor adjustments, and I really was quite happy.

 

Moral of the story I think is that everything is different from everything, so live your life like you're actually going to live it, and build patches listening to the speakers you're going to use IRL.

 

If the whole band is using in-ears or other monitoring the players can control themselves, then it's simple -- make yourselves happy, and let the FOH person take care of the room. No matter what you do, you're not going to hear what they hear out there anyway, you need to trust them. Maybe talk w them about what you're going for, if you think that'll help.

 

If you're the only one with in-ears, then you need to figure out how the other players are going to hear you, who's going to control it, etc., and do what you can to have your tone in there match what you're hearing as best you can, again letting FOH do their thing.

 

And just to say it, I keep hearing people mention 80db stage levels. I don't know any drummers doing anything besides lounge stuff who play at a volume where that makes sense. No doubt it preserves your hearing, but you gotta get the music out in the first place.

[cruisinon2]

And just to say it, I keep hearing people mention 80db stage levels. I don't know any drummers doing anything besides lounge stuff who play at a volume where that makes sense. No doubt it preserves your hearing, but you gotta get the music out in the first place.

Never made any sense to me either...

 

For the sake of comparison:

 

http://www.industrialnoisecontrol.com/comparative-noise-examples.htm

 

Seems there are any number of household appliances louder than that. Personally, I've yet to meet the drummer who'd break a sweat drowning out a friggin' garbage disposal. And when was the last time you had to scream to be heard over the dishwasher? ;)

[DunedinDragon]

Never made any sense to me either...

 

For the sake of comparison:

 

http://www.industrialnoisecontrol.com/comparative-noise-examples.htm

 

Seems there are any number of household appliances louder than that. Personally, I've yet to meet the drummer who'd break a sweat drowning out a friggin' garbage disposal. And when was the last time you had to scream to be heard over the dishwasher? ;)

 

Actually the reference was 80 to 100 db to overcome the limitations of Fletcher-Munson.  And 100 db (averaged) is certainly a reasonable level for most of the instruments.  Peaks will naturally be higher on things like drums, but those are instantaneous so they don't really interfere with a fairly solid 100db from a lead guitar.

 

The fact is you can go higher, but that sound dissipates rather quickly across space because traditional cabinets (and particularly drums) drop off very rapdily due to the sound energy being lost in their unfocused output (into the ceiling, floor and off to the sides) unlike FOH or FRFR speaker which have much more confined and focused  energy in a much tighter sound projection scheme.  This typically ensures that if the instruments are too loud, the front few rows of people won't hear vocals very well, and if the sound guy compensates for this the back rows won't hear the instruments very well.

 

The theory that the sound man will be able to correct things like shrill highs and boomy lows is pretty much fantasy.  Although the newer digital boards have most of facilities one would use to correct such things, it's highly unlikely that most sound people in real life (who often struggle with the simple gain staging of all the inputs) would allocate the time to apply the hi and low cuts much less the graduated EQ slicing on the highs on your particular channel to get the guitar tone to to something reasonable.  Clearly on an analogue board most aren't even equipped with the appropriate outboard equipment necessary to do such things.  Most of those boards are equipped with a fixed low-cut, no high-cut, and a single sweepable mid with a fixed spread (Q) on each channel if you're lucky.  The may have a graphic EQ with can be used in final stage to correct all channels prior to being sent to the FOH speaker, but those adjustments would apply to everything (voices, cymbals, high hat, harmonica, etc.).

 

That's kind of like saying, "I don't need to use a compressor, or a delay, or a reverb on my guitar.  I'll just have the sound guy do it".  Good luck with that....

[cruisinon2]

Actually the reference was 80 to 100 db to overcome the limitations of Fletcher-Munson. And 100 db (averaged) is certainly a reasonable level for most of the instruments. Peaks will naturally be higher on things like drums, but those are instantaneous so they don't really interfere with a fairly solid 100db from a lead guitar.

 

The fact is you can go higher, but that sound dissipates rather quickly across space because traditional cabinets (and particularly drums) drop off very rapdily due to the sound energy being lost in their unfocused output (into the ceiling, floor and off to the sides) unlike FOH or FRFR speaker which have much more confined and focused energy in a much tighter sound projection scheme. This typically ensures the front few rows of people won't hear vocals very well, and if the sound guy compensates for this the back rows won't hear the instruments very well.

 

The theory that the sound man will be able to correct things like shrill highs and boomy lows is pretty much fantasy. Although the newer digital boards have most of facilities one would use to correct such things, it's highly unlikely that most sound people in real life (who often struggle with the simple gain staging of all the inputs) would allocate the time to apply the hi and low cuts much less the graduated EQ slicing on the highs on your particular channel to get the guitar tone to to something reasonable. Clearly on an analogue board most aren't even equipped with the appropriate outboard equipment necessary to do such things. Most of those boards are equipped with a fixed low-cut, no high-cut, and a single sweepable mid with a fixed spread on each channel if you're lucky. The may have a graphic EQ with can be used in final stage to correct all channels prior to being sent to the FOH speaker, but those adjustments would apply to everything (voices, cymbals, high hat, harmonica, etc.).

 

That's kind of like saying, "I don't need to use a compressor, or a delay, or a reverb on my guitar. I'll just have the sound guy do it". Good luck with that....

My only point was that 80dB is not particularly loud, and in all likelihood woefully inadequate to assess what you'll sound like at actual stage volume, which is likely to be a whole lot louder than 80dB....and for what it's worth, I've never been one to rely on the "sound guy" at the local gin mill for much more than "outlets are over there, here's your mic cable".

[WickedFinger]

Aside from all the tech argument. May I humbly suggest using a BBE unit on the Helix and or the PA which if you position it correctly as it was designed, level no more than 12:00 the phase correction it does to the frequency range really does improve live sound and makes everything more pleasing and less fatiguing to the ear.

Mine are so transparent to the overall sound you only notice when it is not there. 

[strabes]

RE: Global EQ. I just have mine set to an 80hz low cut, 10khz high cut, and a fairly narrow 3db cut at 4khz ("harsh" territory). Helps me get a lot louder before it sounds harsh. Works with all of my presets. 

 

Most of my presets I set to be very mid heavy with the bass and treble very low. Just playing through an FRFR and turning the volume up from conversation/bedroom level to gig level the difference in EQ in insane. The lows and highs jump out so much more, and it is shocking how a sound that was very dark at conversation level can be very bright at gig level. 

[WickedFinger]

EQ is tersely related to volume F&M demonstrates. 

You simply have to adjust preset levels and EQ on the gear you will be using live at performance volume. Any time the level changes the EQ changes as well. 

Just so you know: many gain pedals like my Seymour Duncan Palladium I have looped in has a bass EQ param adjust right at 80Hz, many pedals use low end 80Hz as the punch of the bass. Mesa always targets 750Hz as a notching point as seen in the Cali EQ and Mesa Amp models.

Guitar presence controls on most amps are around 8-9KHz. I have asked L6 in an on-going attempt to understand the param adjusts exactly what is the hi and lo cut on the speaker IRs doing. True to all guitar speakers they start roll off slope around 5K and the IR is supposed to track the actual speaker response so one wonders what the hi cut is really for as above 6K or so it is probably doing nothing anyway. So if we are IR modeling a particular cab and speaker then why would you want to hi and low cut it when it is reproducing what it was intended to do.

Cutting into the high end might darken things up but seems EQ and amp adjust are better tweak adjustments than killing the cabinet response. I have a hard time understanding the use of FRFR response while narrowing the frequency range of the tones. EQ on an IR is useful to notch the resonance frequency each cab has but drastically cutting the range of the cab IR seems counter-intuitive. 

That being said I sub sonic cut as I cannot find out if the Helix has a built in lo filter or not, I also cut ultra highs on the global but every else is flat left up to the preset to tweak the EQ per tone. 

[HonestOpinion]

I think this has been mentioned by someone else on the forum so I do not want to take credit for their idea but wouldn't it be cool if someone came up with a Fletcher-Munson EQ block or global setting that automatically compensated for volume by changing the EQ as the volume was cranked up. I can see how difficult this would be because there are so many variables to account for. You would probably need to have a reference mic attached to the Helix to monitor and inform the EQ changes (think that idea was suggested as well). The objective would be to keep the same perceived EQ for a given preset regardless of volume. Quite a challenge and unless you could do it with a fixed algorithm that did not require a reference mic I could see it requiring quite a bit of DSP.

 

 

Note: I suppose a "poor man's" method of doing this now would be to setup potentially multiple sets of EQ blocks you only use live that compensate for the added perception of lows & highs as the volume rises. For instance, if you know that the 2k range sounds as if it is 6 decibels louder when there is a 3db bump in volume you could kick in an EQ block(s) specifically for that volume setting. EQ blocks are inexpensive on the Helix and use up very little DSP.

[BINGEWOOD]

So if we are IR modeling a particular cab and speaker then why would you want to hi and low cut it when it is reproducing what it was intended to do.

 

IR modeling a cab and speaker and mic in a certain placement and distance from the speaker, stick your ear where the mic would be and close off your other ear while listening to a real amp/cab and see if it sounds closer to the results you get without the cuts.

[Thurston9]

 

Note: I suppose a "poor man's" method of doing this now would be to setup potentially multiple sets of EQ blocks you only use live that compensate for the added perception of lows & highs as the volume rises. For instance, if you know that the 2k range sounds as if it is 6 decibels louder when there is a 3db bump in volume you could kick in an EQ block(s) specifically for that volume setting. EQ blocks are inexpensive on the Helix and use up very little DSP.

 

This guy did just that and provides the patches:

 

https://www.youtube.com/watch?v=6c2723NVwNs

 

His video part 1 is a great explanation of how and why the fletcher munson effect happens:

https://www.youtube.com/watch?v=VTNhCRjKBec

[HonestOpinion]

This guy did just that and provides the patches:

 

https://www.youtube.com/watch?v=6c2723NVwNs

 

His video part 1 is a great explanation of how and why the fletcher munson effect happens:

https://www.youtube.com/watch?v=VTNhCRjKBec

 

Great links! Thanks for posting this.

[erniedenov]

Well this turned out to be a really interesting thread that generated a lot more discussion than I expected! And I'm impressed with the amount of knowledge around here, especially pertaining to sound engineering, something I'll admit that I know nothing about. I'm just your stereotypical dumb guitar player and I'm used to just turning knobs until things sound good.

 

So anyway, I got a chance to tweak my Helix with my powered speaker at a reasonably loud volume today. I hadn't previously used hi or low cuts until now and discovered that they come in pretty handy (I know, DUH!). I never had that option on the various tube amps I've had. Of course Helix is a whole different animal! So I'm pretty pleased with what I'm hearing out of my powered speaker now; it'll be interesting to find out what the sound guys I work with think when I use these patches direct to the board.

 

Again, thanks for the comments, everybody!

[lawrence_Arps]

...... I have asked L6 in an on-going attempt to understand the param adjusts exactly what is the hi and lo cut on the speaker IRs doing. True to all guitar speakers they start roll off slope around 5K and the IR is supposed to track the actual speaker response so one wonders what the hi cut is really for as above 6K or so it is probably doing nothing anyway. So if we are IR modeling a particular cab and speaker then why would you want to hi and low cut it when it is reproducing what it was intended to do......

 

There are several points in the chain (speaker, Mic, preamp) where high frequencies might be introduced.  Even if all the gain staging is clean the sum and difference harmonics will be present. (a signal with two frequencies present will generate harmonics at the sum and at the difference...so 2kHz and 3kHz will generate 1 kHz and 5kHz.)

These will be added to by the system you play though ending up in more HF than originally intended - so it does make sense to bandpass the IR.