saemola

Acoustic modelling would be my next step. Pickups modifiers are exactly what I'm trying to achieve right now, but I sample FabFilter as it's simply a much better EQ than what's on the Helix.

Sascha, what a great idea! I tested your Dirac and it's as transparent as can be: if place it on a parallel path, raise the level by 6.2dB and flip phase, I get virtually complete cancellation. I'm gonna use this for all my EQ sampling needs. Thanks so much!

I can export the sweep from IRU, process the file in Pro Tools, but then I need to deconvolve it. I can't reimport it into IRU as it needs to be a .SDIR file, and for the life of me I can't find a way to convert .WAV to .SDIR (though I can find the other way around, which I'm currently doing with the XLD app). I'm giving Reaper a shot right now!

How do you mean exactly? The sweep happens in Impulse Response Utility, and needs to be recorded back into IRU. However, I can't load plugins in IRU, so I have to send the signal from IRU, to Logic to process it with the EQ, back into IRU to record and deconvolve it. Are you suggesting something else and I'm not getting it?

Thanks Ilya. The issue is I haven't found anything for Mac other than the Impulse Response Utility. For example, Voxengo is PC only. I'll keep searching. Thanks for the tip about the pre-transient bit!

Thanks for the reply Ilya. I did a test sampling the same signal chain, but with none of the EQ bands engaged. The result was a flat sounding IR. This is a screenshot of the IR giving me troubles. The cursor is at about 0.8 into the sample. If I can ask a few questions, in your experience: 1- Is there a correlation between IR length and frequency resolution? 2- Is everything before the transient "supposed" to be there? I sampled with a sine sweep. 3- Where would you trim the sample? 4- Is a minimal DC offset to be expected? Cheers!

After some experimenting, I realise that the shorter I trim the IR the better less mud I get. But there is a tipping point after which if I cut it too short I start losing the effect of the sampled IQ. That threshold seems to be 3 wave cycles. Is there a way to calculate how short I can go with the IR? Should I consider just keeping everything above a specific amplitude and trim the rest? Also, it sounds to me like fading in/out doesn't matter as long as I'm at zero crossing. I'd love to read something about this, so if anyone has references please send them over. I can't find anything online.

I'm dipping my toes into creating my own IRs for the Helix. It's mostly experiments with EQ curves, I'm not really interested in cabs right now. When loading my own IR, I'm finding an odd side-effect: my signal gets muddy. There is a noticeable boost in low end and I feel like something odd is happening with the phase (though I'm not 100% sure on that one). This is true even if I'm just sampling a flat eq with a notch at 6kHz. Is there something in the process of creating an IR that might create this side effect? I'm using Logic's Impulse Response Utility, sending the sweep out to Soundflower into a channel in Logic with an instance of FabFilter Pro-Q2. No linear phase is activated. I then convert the files to Wav, edit them in Pro Tools and bring them into the Helix. Another thing I'm noticing is that unless I use a hi-pass filter, I get some DC-offset. Anyone had similar experience?

Ok, so I understood correctly the first time around. My confusion was I thought USB Input was stuff that goes TO the computer and not having the Helix with me I couldn't test it. Thanks rd2rk!

Oh no, I did understand the part about headphones and I understand that that is not possible like you say. But regarding my first question: can I monitor Logic's output through 1/4" only (without having to go through blocks and using up a path) while monitoring my Helix bass path through XLR only? That I'm not sure I understood correctly.

I did go to the Global Settings, but I figured what I was looking for was USB Out rather than In. Thanks for that! I guess Headphones Out would share DAC with either 1/4" or XLR, so there is no way to have it completely isolated from the two. Thanks! Edit: or maybe I'm not getting your point and you are telling me that what I'm trying to achieve is not possible...? I don't have the Helix on hand now but will give it a shot tomorrow.

Hello folks, I want to use the Helix LT live to output my bass through XLRs and my Logic session with stereo synths through the main 1/4" outs. I know this can be done by creating a parallel path with the input coming from USB 1-2 and the output going to 1/4" while keeping the bass amp on XLR out only. However, both my DSP use parallel paths for my bass and I don't have a path to spare for the computer output. Since this is not a resources issue but rather a user interface one, is there a way to tell the Helix to output USB 1-2 to 1/4" only without going through paths and blocks on the Helix interface? I'll add: is there a way to do a similar thing to send Return 2 to Headphones Out? I'd like to use that as an in-ear preamp.

I can see how it might be cause for trouble, but I think it could be easily circumvented by automatically disabling certain I/O when selecting them from the Send block, much like the Path 2A+2B option is greyed out when the merge box is not brought on the B chain on Path by 1. The lack of extra paths per DSP definitely looks like it’s a simple design/interface decision, which I can understand on a basic level, but I don’t see why they wouldn’t give advanced users the choice to “mess up” their interface by choosing extra paths. It could even be an option that’s buried in some advanced menu for all I care. No point to have these arbitrary limitations. Fingers crossed for firmware 3.0.

You got it all right, but what I was trying to say is that I need parallel path 1B for some effects pre-DI split, hence the reason why I couldn’t use it as my DI chain. Yes it would. I’m pretty surprised this isn’t possible, but I’m not complaining. I discover new, incredible flexible ways to achieve things everyday with the Helix. When using the 2 send method I showed in the pic above, the delay was there obviously as they can’t account for DA/AD, but I was pleasantly surprised to find out that there is no phase difference when summing into an external mixer a signal coming from Path 1 with a signal coming from Path 2. Looks like this is it then: I either give up the parallel path on Path 1, or I keep using the unprocessed DI via the Send on Path 2. Thanks everybody for chiming in!

Thanks for taking the time. It might have not been too clear from the first post, but the problem is that path 1 is already split in A and B and I need the effects to come before the DI send, so I don’t have any other splittable paths. Unless there exist techniques that I don’t know of, the only options right now are: - Send 1 to DI box before amps in path 2 - Giving up the parallel path on DSP 1

My Helix LT bass setup is comprised of several effects on the first DSP, spread between Path 1A and 1B, going into the second DSP with a clean amp on Path 2A and a dirty one on Path 2B. After all the effects, but before getting to the amps, I use a Send block (that passes 100% of the signal through to the amps) to output a clean signal to Send 1, which then goes into a physical DI box and to FoH, so that it can be blended with the amps signal (both amps chains are coming out of XLR L). Pretty easy so far. What I'd like to achieve is: - have the clean "DI" signal coming out of XLR R instead of Send 1, so that I can avoid carrying a physical DI box and just provide FoH with the XLR output going into the mixer's preamp. - affect the DI chain with a SansAmp (the block is called ZeroAmp), but not having it affect the amp chain. For the first goal, I looked around and I seem to understand that it's not possible to have a Send block output to XLR. Since all my effects are on the first DSP, I thought I could at least have Path 1 to output both to XLR (which would be my "DI") and to Path 2 (which would be my amps), but that doesn't seem possible either. Please, correct me if I'm wrong. As far as the second goal goes, so far this is the only solution I have found (picture attached, for clarity): - after the effects blocks on Path 1, the chain goes into Path 2 ••• here it enters a Send 1 block, coming out of Send 1 physical out which is plugged straight into Return 1 physical in to bypass the DI chain - Return 1 block gets the signal and carries it to the amps, culminating in the XLR output ••• Send 1 block has Thru set to 100%, carrying the signal to a SansAmp block - the signal terminates into a Send 2 block with no Thru, leaving the amps unaffected - Send 2 physical out goes into a DI box, to the mixer The reason why I don't like this solution is that the amps signal goes out of and back into the Helix, adding extra latency (and D/A, A/D conversion), which messes up the phase when blended with the DI. There are ways to fix it, but it's just too much of a pain and too prone to errors. (Oddly enough I thought that sending the DI chain from a parallel Path 1 B would create a similar phase issue since that chain wouldn't be affected by the second DSP latency, but I can't hear such an issue. Maybe latency in the system doesn't work the way I think it does.) I thought that using Send and Return blocks without plugging anything into the physical outputs/inputs would create a virtual path that would normalize Send block 1 into Return block 1, but that's clearly not the case. Is there another way to "tap" the signal chain at any point and send it somewhere else into the chain virtually and without adding latency? Bonus question: does each block add latency or is the latency fixed in a Helix system (other then when outputting Path 1 into Path 2)? I'm wondering for all the parallel paths patched I create. Is anyone aware of any solution to my problems?

Thanks for the quick reply Phil. If it's below 1ms then that's clearly nothing to worry about. I realize I wasn't clear. I borrowed a friend's LT and I was splitting Path 1 into A and B. I wanted B to be an always on, parallel, overdriven amp and A to handle all the effects (before the split) but I'm told I can't have more than 6 blocks in that path, so the solution was to have the parallel amps in Path 2 A and B and have Path 1 handle all the effects before going to Path 2. So I thought I was gonna start building all my patches like that, but then wondered about the added latency.

Hello, I'd like to purchase a Helix LT, but I would need to use the Path 1 > Path 2 feature to get more than 6 blocks. Does going from Path 1 into Path 2 before coming out to the speakers increase the latency? I'd like to know the actual figures in milliseconds if nay from L6 can reply. Best!