amsdenj

I filled out a support ticket letting Line6 know that there is a noticeable difference between how Helix processes an IR and how a number of different DAW plugins process the same IR. The Helix IR block processing is much brighter, more brittle and harsher than all the other convolution plugins I tried and requires a significant amount of high cut in the IR block to tame this high frequency boost. Line6 support's response was essentially "All I can say is that there is no hard and fast rule that they need to be exactly the same. If you would like to make suggestions for improvements, you can submit your ideas here: https://line6.ideascale.com/". Convolution is in fact a very specific mathematical process. IR producers like Rewirez, Ownhammer, Rosen Digital, 3sigma audio, Celestion and many others painstakingly capture IRs for speakers, cabinets and mics in order to faithfully capture the dynamic frequency response of the source. There certainly can be some art in how the IRs are captured, how they are mixed, and how they are processed to produce a product. That's what distinguishes these different vendors. And of course the speaker instances they are capturing are also different. So we shouldn't necessarily expect IRs from different vendors of the same speaker/cabinet configuration to sound exactly the same. The same can be true of convolution engines that process audio through the IR. These can be different too, adding features like Z or damping factor, phasing, delay, high/low cut, etc. However, these are typically subtle differences, not significant deviations from the sound the IR was intended to capture. Line6 should consider doing some testing of its own to verify whether the Helix IRs are working as intended or if there is something causing the output to be overly bright. If Helix is working as intended, then Line6 should provide Helix users some guidance in how to use the IR block to produce the output as intended by the IR producer. Otherwise we are not necessarily getting the intended value out of our IR purchases or creations (I've created a few myself). For example, I used my DAW and a convolution plugin to audition a large number of IRs to determine the set I wanted to include in Helix. But when I added those IRs to Helix and tried to use them at rehearsal, they were way to bright and didn't sound like they did when I auditioned them. This is what prompted me to do the testing described in this thread.

Helix sounds pretty good through a Roland AC90 acoustic guitar amp - other similar amps might work well. Can't gig with this with real drums. But its fine for rehearsal and quiet jams.

See https://jimamsden.wordpress.com/2016/01/04/using-helix-as-an-effects-pedal-board/.

Try adjusting your tone for the neck pickup. Then use the tone control on your guitar to fine tune for the bridge pickup, just to remove a bit of the ice pick. That should provide a good compromise.

Here's a simple solution. Change IR hi cut to hi shelf boost/cut. Fix the IR block so it faithfully reproduces the IR, not a brighter version of the IR. Set the hi shelf default to the boost in the current IR block so that there's no change to existing patches. Users can then adjust to taste. But the key point is that the IR block should not need any filtering to reproduce the intended sound of the provided IR. The filtering should be to adjust from what the IR was designed to do to support the user's taste, or target FRFR. In this case, a shelf would be more flexible because it could make the IR brighter or darker depending on the user's needs.

In case you're interested, here's what's going on in that patch. Going into the Bright input engages a bypass cap on the volume control on that amp. Now this doesn't do anything if the volume is all the way up. It has the greatest effect when the volume is turned down as the bypass cap has more gain cut to work with as well as the cutoff frequency changes with the volume setting. Why is this interesting? Because at low volume the amp is nice and bright. But as the volume is turned up, there is less and less treble boost, so when the amp is distorting, you're not getting a lot of treble boost which can make the dreaded icepick tone. Treble and Bass all the way down and Middle all the way up on Fender amps is basically running the amp flat. The Treble and Bass controls on Fender style amps are all boost, no cut. The Middle control just raises the set point of the boost level. Middle all the way down gives a lot more treble and bass boost possibilities. Middle all the way up, you've raised the floor upon which the treble and bass controls can boost, so they have less effect. So this isn't so much a middle boost as a flat response with no treble and bass boost at all, which will sound like a lot more midrange then adding any treble and bass. Now the presence control is interesting in this case. The presence control is actually a treble cut in the power amp's feedback loop. So its post any preamp distortion. However it behaves somewhat similarly to the bright bypass cap on the volume control. Turning the presence up will cut high frequencies from the power amp feedback loop which will increase the treble response of the amplifier. So if the power amp is running clean, you get a nice sparkle and a somewhat different interaction with the speaker since removing negative feedback decreases damping factor and the speakers will behave a little looser. A Fender Bassman can produce some preamp distortion because it has an extra gain stage. So if you're getting some preamp distortion, the presence control acts as a tone control after the distortion. That can again be useful for removing ice pick. But if the power amp distorts, then there's no gain left for the negative feedback and the presence treble boost very quickly disappears - just what you wanted to dampen that ice pick.

I would have to do this test over again, give it more time and care, before posting anything. I did this very quickly last night and could have made some mistake, but I don't think so. The IR block in Helix and the DAW are both set at 100%, so there is no user set bleed of the dry signal. Perhaps some other people can try this experiment and see if its something I did wrong, something unique to my Helix/DAW, or something wrong with my ears (or I got biased by what I heard referencing with real amps and the EON610). Independent verification of a quick observation might be more valuable than me doing it again.

I did some more quick testing tonight just to verify what I was seeing in the live setup with the EON610 - that the Helix IR is pretty bright and needs a fair amount of high cut. I wanted to verify the observation without having any FRFR speakers involved at all. I created a patch in Helix that had just a Deluxe amp model and IR block. Then I created threes tracks in Logic Pro X and recorded the same quick, short guitar part three times: Track 1: Deluxe block + Helix IR block with Celestion G12-65 212 C R-121 Balanced IR, with high and low cut off Track 2: Deluxe block only, but with a convolution plugin in Logic with the same G12-65 212 C R-121 Balanced IR, no high or low cut. Track 3: Same as Track 1: Deluxe block + Helix IR block with Celestion G12-65 212 C R-121 Balanced IR, but with high-cut set to 3kHz What I found was what I expected: Track 1 was quite a bit brighter, Track 2 sounded like I would have expected the IR to sound, and Track 3 was pretty close to Track 2. That is, the Helix IR block appears to be overly bright and high-cut somewhere between 2 to 4 kHz is required to reproduce the intended IR output. Now I don't know why this is. I suspect its because convolution algorithms are computationally expensive and can introduce latency. Line6 may have a 'optimized' algorithm that takes some shortcuts to save compute cycles, and this could result in the block not completely following the IR. Since guitar speaker IRs generally have a lot of high-end rolloff, perhaps an optimized algorithm would not completely follow the IR and would let some of the excessive highs or dry signal come through. Note that I also tried a number of different convolution plugins in Logic including SpaceDesigner, LAConvolver, NadIR Convolver and mixIR2. These all sounded a little different too. So Its not surprising that different convolution algorithm implementations might sound a bit different. This was a quick, simple, informal test; just to verify initial observations. More careful analysis using pink noise or a sine sweep and a spectrum analyzer would likely be more accurate than my old ears. But at this point, I don't need to do any more analysis for my purposes - which was to simply verify that I am getting the most out of the IRs I purchased, and the tone I'm getting from Helix references well with a real amp. It would be nice if Line6 could provide some additional analysis of what some of us are informally observing, and some recommendations on how to best use the IR block and its high-cut control.

I did another test this morning with my home-made FRFR (on the left). Its a Tremolux size cabinet with two Eminence Beta-10CX coaxial speakers with Eminence ASD:1001drivers. Its being driven by a Hafler Transnova P3000 stereo power amp, 150W/channel. The cabinet is ported in the rear. Here's what I found. The EON610 and my FRFR behaved pretty much the same, they both needed the high cut. My FRFR is pretty directional, and certainly 2x10s driven by that Hafler is going to sound different than 1x10 with a horn driven by a 1000W Class D amplifier in that EON610. But they were certainly in the ballpark and needed similar high cuts. I think the high cut on the Helix IR block is very gradual, and does not behave the same as an EQ block or Studio Pre with the same high cut. So the frequency numbers might not mean what we might normally expect for a typical 6-12dB (or more) low-pass filter. The Helix IR block appears to be overly bright. My favorite IR with Helix is still the JOOSTALNICO-G12M-R121-U67.wav Joost created that's a mix of a G12M and a Weber Blue close mic'd with U67 and R121. Its a very warm sounding IR and doesn't require nearly as much high cut. See https://jimamsden.wordpress.com/2015/12/30/analyzing-jazzincs-srv-little-wing-patch/ for details. But the Celestion, 3sigmaaudio, Redwirez and other IRs don't sound overly bright when used with S-Gear in Logic, while JOOSTALNICO-G12M-R121-U67 is too dark. So I don't think its the IRs or necessarily the two different FRFRs. Rather it appears the Helix IR block is just a bright block and needs taming with the high-cut filter. Further verification could be done by using recordings and headphones to eliminate the FRFRs. But at this point, I'm very happy with the tone I get out of the JOOSTALNICO-G12M-R121-U67 IR into the EON610 or my FRFR, and that was the point of the referencing. Frankly, Helix with JOOSTALNICO-G12M-R121-U67 into my FRFR sounds pretty good compared to that Showman. There's a transparency in the Showman that's not quite there with Helix, especially on the upper end. I suspect a small resonance bump in the IR high cut filter would fix that. That would tame the overly bright high end, but give a little bump right where the G12-65 starts to roll off quickly. JOOSTALNICO-G12M-R121-U67.wav

My goal with this reference exercise wasn't to make Helix sound just like the real amps, it was just to see if my gigging Helix tone through the EON610 monitor and FOH was doing what I expected or not. The motivation for this was last gig I switched from JOOSTALNICO-G12M-R121-U67 (which is quite warm) to the recent Celestion G12-65 Balanced IR. This sounded overly bright to me at the gig so I through maybe I should check against a reference to see if I was in the ballpark. I'm happy enough to turn down the high cut to whatever is needed to make the 610 sound good. I'm also OK with that being something unique about that speaker, and maybe something I'll fix in the speaker itself (if I could ever get EON Connect to actually connect so I can adjust the EQ!). I would just like to understand where all that brightness is coming from - the Helix amp models, the IRs, and/or the EON 610. I'm going to do some more testing today with a different FRFR so I can narrow down what's causing the overly bright tone. I'm suspecting that 610. If so, and I can get the EQ to work and roll off the highs in the 610, then that's fine.

Did some referencing today after repairing these two old Fender amps. The Tremolux on the Left is our bass player's old guitar amp. It needed an new bias filter cap. The Showman on the right is my amp from 1968. It needed a new output transformer, new tubes, new filter caps in the power supply and a new optocoupler for the tremolo circuit. The Temolux has the original Oxford 10K5's while the Showman has a pair of new Celestion G12-65's. That's an old Lexicon MPXG2 guitar effects processor on top of the Showman. Its still pretty interesting, but not used in this test. While testing the amps I thought I might not only compare the Tremolux and Showman, but also use them to reference my typical Helix patch, just to make sure I'm in the ballpark. I typically use that JBL EON610 as my vocal and guitar monitor so I used that to compare against the reference. The Tremolux and Showman certainly sound different, I think mostly because of the different speakers and the different tremolo circuit. The Tremolux is the older bias tremolo while the Showman is the newer optical tremolo. The difference is that the optical tremolo cuts some of the gain in the Normal channel, even if the tremolo is off. That doesn't happen with the bias tremolo. Although they sound different, they are clearly the very similar sounding amps. That Tremolux has a little magic going. Here's the surprise. I have the Celestion G12-65 IRs, and one I made myself of that exact cabinet with the Showman. I found using my IR and a Deluxe Vib amp model, I got an almost exact replica of that Showman amp coming out of Helix and that EON610. However, to do so, I had to turn the high cut on the IR way down to about 3.2 KHz. The Celestion G12-65 and all the other IRs I had were even brighter. I was very surprised that all the IRs seemed to be a lot brighter through that EON610 than either reference amp. I found that I had to turn the high cut down to between 2 and 3 KHz to match the tone, and to achieve a warm pleasant tone from the Helix. Have others noticed that the IRs tend to be very bright and need a lot of high cut in Helix? The 3sigmaaudio IRs were especially bright. They sound great with a lot of high cut, but I don't understand why this would be needed. I don't recall having this problem using the same IRs in S-Gear, but that's though different monitor speakers. It could be the EON610. The response curve doesn't look like there's a lot of high boost, and I have the EQ turned off in the speaker. But maybe that horn is adding a lot of hype to the high end. So the lesson is referencing real amps and then adjusting Helix IR low and hi cut to compensate for your FRFR can be a valuable and surprising learning experience.

The Leslie effect is a modeling a cabinet with a horn, but it is likely not based on an IR. Its impossible to know for sure, but the speaker modeling may be traditional passive EQ and not the dynamic effect of an IR. So you could try using an EQ after the Leslie to undo some of the high-cut, then go into a speaker model, or feed the speaker model into the Leslie. Although this might be "technically wrong", it still might sound better - sort of like mic-ing a guitar amp and feeding it into a Leslie speaker. You might also find that running the Leslie effect in a separate path in parallel with a speaker works well too.

Latency in a DAW depends on what plugins you have running, in the channel strip you're recording and the output channel strip. I common issue is with plugins that have to do adaptive lookahead, like some mastering plugins in Logic. You can customize the toolbar and add a button to switch to low latency mode. This reconfigures some plugins so they behave differently and produce less latency. Helix's strength is as a performance tool, not an audio interface. It does that, but there are others that do it better at much lower cost.

I think there are some quality problems introduced into the later versions of Logic. I've had 10.3 crash a couple of times too, mostly when creating controller assignments. The bug list on https://www.logicprohelp.com/forum/viewforum.php?f=42&start=35 seems pretty active a well.

Would you mind describing some of the use case you are doing that would require this? I suspect the community would benefit from this.

I use a single JBL EON610 as my vocal and Helix monitor. I can send one side of my stereo Helix through the PA monitor output to the bass player's EON610 which is right to my left. But I don't bother with stereo monitoring - too many other things to worry about on gigs. The power you would need in a guitar amp is a lot less if the speaker is in front of you and pointing right at you. Your monitor is also likely contributing to what the drummer hears. Our band has 4 EON610 monitors driven by specific monitor busses from a Behringer X32Core digital PA. Think about it, that's 4000 Watts pointing at that poor drummer! We really have to work at keeping stage volume down.

Just a quick reminder for those Helix users that are challenged by the DSP limitations. Remember that if you're going direct into the FOH PA, you have an opportunity to use some EQ, reverb and delays that are almost always available in any modern (digital) PA. You might also find that the reverbs in the PA are better than those in Helix in some cases. So why not use them? If you leave some delay on all the time, take that block out of Helix and put it in the PA. Use the reverb in the PA instead of Helix. That simplifies your patches, removes some blocks, and gives you more flexibility. Modern digital PAs have a lot of effects, and can often assign them as inserts to particular tracks. This can offload Helix in some cases, freeing up DSP and providing some after the amp effect options that might not be in Helix.

I'm guessing that's because we're use to having our guitar amps behind us and down low on the floor. This makes them sound a lot warmer since the speakers are very directional for high frequencies. If you're using a floor monitor with a horn, tipped up to point right at you, that's going to sound a lot different. Note that what you're hearing through the monitor is likely pretty similar to what someone is hearing from FOH unless they're pretty far off axes, or listening through the damping of a lot of people. So although Helix cab models and speaker IRs do reproduce the speaker tones pretty well, how you're monitoring them can be quite different than the typical guitar amp setup, and that can have a big impact on your perception of the tone.

Very true, but it depends on what you're trying to accomplish. If you're using a stage amp as your source of contribution to FOH, then it needs to be able to compete with the drums. If you're only using a stage amp for your own instrument feedback, and FOH is fed directly from Helix outputs, then you only need enough power to provide your stage level. You generally want to minimize this to preserve your ears, and avoid competing with the FOA with stuff reflected off back walls, etc. Since your stage amp isn't for the audience in this case, you can put it in front of you instead of behind you. This way you won't need nearly as much power to compete with the drums.

The thing thats different about Litigator is that its based on the typical Fender amp, but its not trying to model/recreate that amp. Rather its a design of a new amp in the digital world that doesn't have all the constraints an analog amp might have. This is a good new direction to see Line 6 taking since we'll start getting new amps instead of just reproductions of old ones.

Helix is not just about tone, its also about convenience, and easy live workflow. This is where I think a dedicated acoustic guitar preamp would be useful. Yes, with a combination of EQs you can find the right frequencies and boost/cut your way to a good sound. But acoustic instruments are more sensitive to the environment in which they are played, the amplification system they are going though and where you are standing relative to walls, monitors and FOH speakers. There are lots of dedicated acoustic guitar preamps on the market, and what they have in common is someone has gone through the research to find the typical frequencies, Q, slopes, etc. that work well for an acoustic guitar and make it easy to quickly adjust the tone and phase for a particular guitar and situation. The LR Baggs Para Acoustic DI is a great and simple example. So although you could achieve the same results with EQ, something like the Para Acoustic DI might be more convenient, making it easier and quicker to dial in tones. There are other things that are unique for acoustic guitar too like EQ notch filters for feedback control and shape switches for various pickup types. Ultimately acoustic IRs make these acoustic specific preamps less critical, but they could still be useful.

Reaper makes a very good and flexible host for plugins. You can use the mixer view and create tracks just like any regular digital mixer. Its cross platform, inexpensive, has an active community and is one of the best software values ever. I have used Reaper for exactly this purpose, to create a simple computer based digital mixer for rehearsals. I also have used Logic Pro X and MainStage for similar purposes. Reaper being cross platform, light-weight and with a fast startup time is a plus. Logic/MainStage has a lot of great software instruments that are also very useful. Helix Native gives us a great opportunity to exploit modern DAWs and live performance tools that can incorporate our preferred guitar and bass tones. I'm very much looking forward to Helix Native.

I don't remember why I bought that gold-top. I didn't really like the sparkle. And I didn't want the small humbuckers. It was probably quite a bit cheaper and those were dry days for me. In fact, that guitar was the first thing I bought on time. Had to limit food in order to make the payments. But its still here after all these years. Me too I guess.

I have never experienced an issue with freezing when booting up. All my freezes are either immediate when switching to a corrupt patch (easily fixed), or intermittent while playing with a patch I very commonly use - but that has only happened once. I am using EXP 1 to control a volume block, and noticed the freeze occurred after turning down the volume pedal.

I spent some time this weekend organizing and auditioning my collection of IRs. I used S-Gear as a plugin in Logic Pro X, and used Logic's Space Designer to audition the IRs. This made it easy since I could drag and drop from Finder into Space Designer and the IR would take effect immediately. Here's may overall approach: 1. Find some convenient means of adding and removing IRs very fast on your system. Drag and drop from the file system is best as it allows you to quickly audition IRs from different providers without having to load them into a plugin or hardware device. Its easiest to do this in a DAW like Reaper than on Helix because of the ability to quickly try different IRs. 2. Record a few loops with different levels of complexity and drive settings so you can try different things free-hand. Keep the loops very short so you're hearing the same musical phrase over an over. That makes it easier to compare things. 3. Decide on what kind of speaker you generally prefer, perhaps based on what your favorite guitarists use. For many of us, that's Celestion. 4. Decide on what kind of cabinet you generally prefer, 1x12 open back, 2x12 open back, 2x12 closed back, 4x12 closed back, etc. 5. Decide on what kind of mic you generally prefer, SM57 for more aggressive highs, LDC for more natural reproduction, ribbon for a warmer sound. 6. Decide on where you typically like to place the mic - say cap-edge, 2" The purpose of 3, 4, 5 and 6 is to establish a common comparison point that you think is close to what you might end up with. You'll compare different speakers with the same recorded loops, cabinet style, mic and mic position. This way you are focusing on just the difference in the speakers, keeping everything else as constant as possible. 7. What I do is create an "audition" folder for auditioning a bunch of IRs, and another folder called "Favorite IRs". Go through all your available IR folders from different vendors and create links in your audition folder to each of the speakers you want to audition, choosing the variation that matches your cabinet style, mic and mic position above as closely as possible. Don't worry about whether you got all those things right, we'll deal with that later. What you want is a folder of IRs of different speakers with everything else the same, that you can get to quickly and easily, add to your auditioning system (DAW, standalone-amp modeler, or Helix). 7. Start with the clean, chords and some clean leads loops. Turn on loop playback and drag and drop each IR from your "audition" folder into your DAW convolver plugin (e.g., Logic Space Designer) and listen to the loop. 8. Move any IR's you really like into your "Favorite IRs" folder so you can remember them. 8.1. Repeat the process with different gain levels in your recorded loops so you can compare the IRs at different distortion levels. Some speakers that sound good clean are too bright for distorted tones. 9. Repeat the process with your Favorite IRs until you have the ones you really like, maybe even in priority order. 10. Now go back to the vendor's IR folder and repeat the same process, but this time with different cabinets. Then do it again with different mics. And then finally again with different mic positions. You're starting with the things that most impact the tone, then zeroing in on the things that may have somewhat less pronounce impact on the tone. The idea is to narrow down a selection of 100's of IRs into a small set that you will actually use and that help you get your preferred tone. After I did all this, I sort of came back to one of my original favorites, Redwirez BasketweaveG12M25s. using a Royer R121 at cap-edge, 2". I also like the Celestion 4x12 G12-65s, especially since I have a pair of those in an old Fender Bassman 2x12 Cabinet. Frankly, many of the IRs sounded great, just different. And many of the differences were pretty subtle. For example, I made my own IR of my 2x12 cabinet with the G12-65s, and it sounds pretty close to the one created by Celestion in a similar cabinet. At this point I'm satisfied that I can pick a few out of my favorites, load them into Helix, start playing, and stop worrying that I might be missing something if I just buy another 100 IRs.