amsdenj

If you use Flat/LF Raw, the tweeter is turned off and you're just using the raw woofer with no EQ. That's a guitar speaker that won't really handle the high frequencies required to reproduce an acoustic guitar tone. Flat/FRFR is probably more typically used for acoustic guitars. Of course different songs/styles may benefit from different configurations.

Since convolution is linear, it probably doesn't make much difference for most effects like EQ, reverb, delay, modulation or other linear effects that might typically go after the amp in a live or recording situation. However, compression would be different. Since convolution is a linear time varying system, the compressor input would see different signals depending on whether it was before or after an IR block. This is similar to the discussion about EQ before and/or after compression. Both are valid and do different things. However, if the block is non-linear, than positioning before or after the IR block could make quite a difference. But typically we wouldn't put distortion or amp blocks after an IR.

I purchased a bunch of Ownhammer IRs from the Helix store. I find these can't be loaded into Powercab because it has no way to login to check for a license. Is there another way? If not, will this eventually be supported? Another issue I noticed is that on MacOS, I can only import 48 kHx 24 bit IRs. I get an error with 32bit IRs that says they must be 16, 24 or 32 bit. Anyone else noticed this?

Running IRs into Flat/LF Flat mode is adding some additional EQ you might like, but will be changing the IR's natural tone. Flat/LF Raw also turns off the tweeter, but doesn't add any additional EQ processing, retaining the natural frequency response of the Eminence speaker. Speaker Model/Natural is similar, but has the option of sending a mic model through the XLR output. LF Flat voicing is intended to provide a base, flat speaker voicing upon which the speaker model processing is based. Try using a bit if high cut in Flat/FRFR for your Helix IRs. That's typically required for other FRFR solutions too.

Sounds like your tweeter isn't working.

Not sure if this is clear yet or not. I just got a Powercab this afternoon and think I'm beginning to understand the difference between the three modes: Flat, Guitar Speaker and User IR. First Powercab is primarily intended to emulate various guitar speakers in a room, that is, speaker models without mic models, mic position and mic depth. It accomplishes this by using a coaxial speaker that can have the tweeter turned off in order to actually be a guitar speaker in the room. The woofer is a custom Eminence speaker, similar in construction to a Beta-12CX coaxial speaker, but likely using a cone material and construction to more close match a typical guitar speaker rather than a fuller range PA speaker. When you run Flat/FR Raw, or Guitar Speaker/Natural, you're using just that woofer with no EQ or any other processing - its literally a 1x12 guitar cabinet in the room. The tweeter provides additional flexibility for other purposes, that hopefully are explained below. Flat mode has three voicings: FRFR, LF Raw and LF Flat. Flat/FRFR voicing uses the woofer and tweeter in the coaxial speaker with no EQ for a full range, flat response. Use this if you're using Helix (or HX Stomp) to provide the cab model or IR for the speaker model. Powercab just acts like a typical PA or monitor speaker in this mode. Flat/LF Raw voicing simply turns off the tweeter, and makes Powercab similar to any other 1x12, closed back guitar cabinet. Use only amp models in Helix or HX Stomp, no cab, or IRs for this mode/voicing. This should sound pretty close to a typical closed-back guitar combo amp, with the specific characteristics of that custom Eminence speaker providing the speaker tone. Flat/LF Flat is a special voicing that also only uses the woofer, but uses an EQ to establish a consistent starting point for the guitar speaker models. All the speaker models are built off Flat/LF Flat, using different EQ and perhaps other custom processing to make the Eminence woofer sound like other speakers. There's no tweeter for these models, and no mic model or mic position. This is what can't be produced by Helix cab models or IRs and what makes Powercab unique. Helix cab models and IRs all involve mics, but Powercab speaker models are variations on a guitar speaker, not impulse responses of a mic'd guitar cabinet. The Guitar Speaker models provide additional EQ on the Flat/LF Raw base voicing to model or mimic other speakers. The mic models and mic distance have no effect on the sound coming from the Powercab speaker, they only effect what's sent to the FOH or PA from the Powercab XLR output. Contrast with Helix where the cab models are sent to your FRFR monitor and FOH and all include mic models. Powercab XLR output needs additional mic processing that's missing from the speaker models to send to the FOH. What this means is that the guitar speaker models don't include any mic modeling in the Powercab speaker itself, making it sound more like an amp in the room. Speaker model/Natural is similar to Flat/LF Raw - the output from the Powercab speaker is the same, the Powercab tone is determined only by the Eminence woofer. But the Natural speaker model has the option of sending a mic model through the XLR output. In User IR mode, Powercab is essentially set to Flat/FRFR voicing with additional processing provided by user IRs. In this case, the tweeter is on, and the IRs will include mic models. Use this mode if you're using HX Stomp, want to user your own IRs and need to save a block. There's probably less reason to use User IR mode if you're using Helix floor since its probably easier to just include the IR or cab model in Helix.

Have you updated Mac OS? I'm using 10.14.2 with Helix floor, HX Edit and HX stomp and have never had any connectivity problems. Apple has made some recent updates that had impact on USB. For example, my old M-Audio Fast Track Pro stopped working for a few releases and now is working fine.

I could be wrong, but I don't think Helix guitar input sees the output impedance of the guitar in Auto mode. Rather it sets the guitar input impedance to the input impedance of the first block in the signal path. This loads whatever pickups your guitar has as the real effect would have and is typically important for fuzz effects. Note however that auto impedance does not change the guitar input impedance when the block is off. This can result in some unexpected loss in tone when the effect is off.

I'd recommend being careful about cleaning the piezo pickups on a Variax. I have found that my Variax Standard's clang tone has reduced somewhat over time. I'm thinking that's because the pickups are seating differently in the bridge, and maybe dirt and moisture has helped fill voids between the pickup and the bridge that I think contribute to clang tone. This is why I use the soft toothbrush. It gets the dust and dirt off the top, but doesn't put liquid of any kind down between and under the pick and the bridge. Something to consider...

I use a very soft toothbrush to clean them every time I change strings.

My JTV-69S with SVL Daytona single coil pickups is my main gigging guitar. I also replaced the neck with a Warmoth with stainless steel frets. This should indicate the value this guitar has for me. My Les Paul and Strat both stay at home, and I use a black Epiphone Sheraton II Pro as my backup guitar. I use a few open tunings, including some for acoustic guitar. Using a Variax with Helix makes this so easy its hard to imagine any other solution.

My HX Stomp USB center block broke too. My Helix is 3 years old and no problem. HX Stomp broke within a few days, with limited use. Maybe there was a bad batch.

9 blocks total, not including input and output. If you don't need to send path A and B outputs to different devices, then you can share common stereo blocks like delay and reverb on both paths.

My HX Effects is stored at the moment, but HX Stomp may be similar. HX Stomp has a L/R input, like HX Effects. In order to get two separate inputs, you use a split block first in the signal chain, and set the L and R levels hard left and right so the signal is split between the two paths.

They could be like the split and merge blocks, in between blocks, not blocks in their own right. This would be useful on HX Effects and HX Stomp because of the limited number of blocks.

If everything seems ok, I'd suspect power fluctuations.

I like running stereo, so I'd need two Powercabs - a bit too expensive and a bit too heavy. I'm currently using two JBL EON610s for gigging. I can't say these are stellar and wonderful, but they certainly get the job done. I've used them in different configurations depending on how much stage space I get (often not much in small pubs): side by side, stacked, and only one/mono. I think you can get good results from a lot of different FRFR options. But you'll need to create your patches for your FRFR, no matter what it is.

Acoustic body IRs work great, but they make a lot of assumptions and compromises. The IRs are essentially the subtraction of the piezo IR and the body IR with the same impulse. This is often done by using a bass drum foot pedal or other device to tap the body of the guitar and record the output of the piezo and mic's body at the same time. Then the body IR is convolution of the subtraction of these two signals. So the reason an IR might not sound right for your guitar is that your piezo pickup might not be the same as the one used to create the composite IR. You can try different body IRs in this case. Don't expect the body models to sound as you would expect because you are feeding them a different input then what they used on generation. You'll just have to listen and find one that works for you. Its best to keep the tone controls on your guitar piezo pickup as flat as possible when going into an acoustic body IR. This helps ensure your feeding the IR a similar signal to the one used to create it. Doing all the tone shaping after the IR instead of before might provide more predictable results as you're feeding the IR a signal closer to what was used to create it.

There's also a case for placing the looper in the "middle" especially for HX Stomp. Summarizing: 1. All looped parts go through the same signal path: place the looper first in the signal chain, and run it mono. The problem with this is you can't use any distortion because every loop part goes through the same distortion and the loudest part will duck all the others and you'll get a lot of intermodulation distortion between the parts. This is only useful for very clean tones. This is best for using the looper while adjusting patch parameters. 2. All looped parts have their own signal path: place the looper at the end of the signal chain. This makes sure all the parts are independent and can have their own distortion and effects. The only down side is you need to use a stereo looper to retain stereo effects, so the loop tine is cut in half. 3. Looped parts use different front of the amp effects, and distortion, but the same after the amp effects (modulation, delay, reverb, etc.): place the looper right after the amp, cab or IR block and run the looper in mono. This is a great compromise because it keeps the loop length longer, and everything in front of the looper is controllable for each loop. Each loop part shares the same after the amp effects and retains stereo. That's probably ok for delay and reverb, but might not be great for modulation effects. But its another option.

I do the same thing. The exp pedal has two purposes, one is to control the wah (in those patches that have that block) and the other to control max and min drive. This gives me two gain stages with one distortion/overdrive block. This isn't quite a flexible as two distortion blocks because the drive control doesn't have any voicing or tone control to adjust for different levels of distortion. But it works pretty well.

Right: as long as 1) the boost is really a clean boost and doesn't have a tone of its own and 2) the amp drive has enough gain to meet your needs. The need for clean boost pedals stems partly from Fender amps like a Twin or Super Reverb, or especially a Showman, that didn't have that much gain. I have a HX Effects that I use in front of may old Showman amp and it works great. That amp really needs a clean boost.

I'd actually recommend the opposite of this. Start with the guitar pickup and its tone set neutral/flat. Then go into Helix with just the IR block, nothing else. Then find the IR that best suites your guitar, playing style and FRFR. This provides the basic guitar tone starting point. You'd do something pretty similar if you were recording an acoustic guitar. You'd start with the right guitar for the song, with good setup and strings. Then you'd find the best mic position that fits the song and the role the acoustic guitar track plays. This again provides the basic starting point. In both cases, you're "getting it right at the source" before doing any other tweaking. Now think about compression, EQ, distortion/exciter, and other effects as required to tailor the basic tone to craft what you need. This is similar to what you would do when mixing an already recorded acoustic guitar. These changes further adjust how the guitar fits in the context with the rest of the parts, and is similar to playing in a live situation. You can of course repeat this process. If you can't get what you need from compression, ET, distortion, etc, then go back and adjust the IR or pickup preamp controls. The point is, the "source" of an acoustic guitar is the guitar pickup + body IR as the IR is attempting to convert the piezo pickup output into what the guitar body would have sounded like mic'd. You want to get this source as close as possible before making other changes. You may find the result will sound more natural this was as you are minimizing processing after the basic guitar tone.

I use the VDI cable with my JTV-69S and Helix all the time. Yes, I do think it's a little brighter than the 1/4" output, but that's probably because VDI is digital from the guitar to Helix and therefore doesn't have the high end drop from cable capacitance. I compensate by turning the presence down a little, or adjust the high cut on the IR. That is, I don't really care that the VDI and 1/4" sound different. I just adjust to produce the tone I need, just like you would with any gear. I'm not hung up on things being the same.

Fender amps have quite a bit of mid scoop. The bass and treble controls are all boost, turn them all the way down and turn the middle all the way up and you have a mostly flat tone. That's how you can get rid of that mid scoop - keep bass and treble down, keep mid up. But that still won't provide bass and treble rolloff, the mid control really just sets the flat set-point above which the base and treble controls can boost. This is why Tube Screamers work well with Fender amps. They provide an actual mid boost that helps compliment the mid scoop of the amp.

Depends on what you're trying to accomplish. Putting boost before distortion lets the boost help shape the saturation and sustain from the distortion. Putting boost after distortion provides a volume boost, but doesn't otherwise change the tone (assuming its going into a clean amp - otherwise its just part of a multi-part gain staging).