Sample rates and IRs

[rd2rk]

My Helix came set by default to 48k. Redwirez and (some) Ownhammer Impulses have folders of IRs at different sample rates, so I choose the 48k impulses. Rosen and 3Sigma don't have this option.

 

Anybody know what this is about?

[Guitarzman]

I'm pretty sure  3 Sigma does files for 44 k /  48 k / 88.2 and 96 sample rates... 

[WickedFinger]

I am new to the whole IR thing and I do not get the size either. Mine are 48 but 16 or 24bit, and the 16 is to not have any loss in fidelity. Beats me. Why use more DSP if it does not matter? 

[duncann]

It doesn't really matter because when you import them, they are converted to 16-bit 48kHz.

 

The 3 Sigma comes with different sample rates, but are all 24-bit. Same with Rosen Digital.

[rd2rk]

Sorry, my bad, 3Sigma does come with different sample rates, but the Rosen Custom sets I have just have the one non-specific set of 3.

 

The Helix automatically converts whatever you feed it to 16/48? I assume then that if I set the Helix at a higher rate, that it converts to that rate?

[duncann]

Sorry, my bad, 3Sigma does come with different sample rates, but the Rosen Custom sets I have just have the one non-specific set of 3.

 

The Helix automatically converts whatever you feed it to 16/48? I assume then that if I set the Helix at a higher rate, that it converts to that rate?

 

Have a look here: http://line6.com/support/page/kb/_/effects-controllers/helix/impulse-response-irs-r759

 

Even if you set the digital output of Helix to a higher sample rate, that's different from the IR sample rate, which would be 48kHz regardless.

 

I don't have any of the Custom sets from Rosen Digital, just the Carvin Legacy and Peavey XXX, which have the different sample rates for the three files located in a folder called 'S-Gear & Other'.

[rd2rk]

The user may choose a
1,024-sample version to save DSP, which fades out the IR halfway through

 

How does that affect the sound?

 

I'm guessing, then, that to use full 2048 samples, I should set up the amp and IR before adding other effects, while there's plenty of dsp available?

[duncann]

The first thing to go when you start chopping an IR is the low end. That's what I noticed when I tried this inside a DAW. But if I remember right, I didn't really start to notice anything until well below 1024 samples. So if you're having DSP problems, changing from a 2048 to 1024 sample IR would be a good place to look first, which won't have any significant effect on the tone.

 

As you use your Helix more and more, you'll start to figure out, or get a feel for, when you might run up against the DSP wall and some things you can to do. Probably one of the most important actions is to split things up between the two processor paths; if things won't fit on path A, move some stuff from that path to path B.

[rd2rk]

Thanks Duncann.

 

Amazing how much more dsp 2048 uses! Could be my imagination, but seems to affect sustain somewhat. Or my ears could be tired. Time for a break!