what are "Impulse responses " ?

Dominic

Somebody please educate me

TimmyO

Threads like this are shit!


^ that's one there 

TimmyO

:-) 

tone1

Something to do with deodorant I think ....like when a man smells a lady and gives her flowers after a chance meeting in a lift...

UnclePsychosis

Stolen from elsewhere:

"Technically, an Impulse Response, or IR for short, refers to a system's output when presented with a very short input signal called an impulse. Basically, you can send any device or chain of devices a specially crafted audio signal and the system will spit out a digital picture of its linear characteristics."

What this means in simple terms is that it's a way of measuring (and therefore recreating) the response of something to an input signal - in guitar terms it's commonly used as a way of modelling what a guitar cab would sound like. The idea is that someone somewhere measures the IR of a cab, then anyone else can use that IR to use a virtual version of that can in an amp model. 

Jonathanthomas83

Shameless plug...

https://medium.com/guitar-pedals-amp/how-to-get-a-great-guitar-tone-at-low-volume-without-a-speaker-cabinet-5bfd0371f9f6#.s2z32rold

I enjoyed writing this and hope it helps!

Sporky

An impulse is a short, wide-spectrum sound, or a physical knock on a thing.

For speakers it's the former. Basically very quickly from 0v to peak voltage as a spike, and you record the sound that makes, the convolve that sound with a guitar signal and it sounds as if you're playing through the speaker.

In practice it's not usually done with just an impulse; there are swoops and bursts of noise and even more clever maths to create the IR from what comes out of the speaker.

Dominic

I am interested to find out how this relates to a Helix
 Apparently early ones don't have this .....or is that wrong ???

UnclePsychosis

Dominic said:

I am interested to find out how this relates to a Helix
 Apparently early ones don't have this .....or is that wrong ???

---the Helix uses IRs to replicate different guitar cabs. You can also load third party IRs into it, if you want to. No idea what functionality is or isn't in specific helix versions though. 

My own take on it is that if you don't really know what they are then you don't need to worry about them. 

Bridgehouse

Ownhammer.

Download, install, enjoy.

Thats pretty much all you need to know about IRs and Helix

Sporky

Dominic said:

I am interested to find out how this relates to a Helix
 Apparently early ones don't have this .....or is that wrong ???

They all have inbuilt IRs, and they can all use third party IRs.

vale

Jonathanthomas83 said:

Shameless plug...

https://medium.com/guitar-pedals-amp/how-to-get-a-great-guitar-tone-at-low-volume-without-a-speaker-cabinet-5bfd0371f9f6#.s2z32rold

I enjoyed writing this and hope it helps!

thankq for the blog link Jonathan. not shameless at all. useful. i read it with interest when it came up a month or so ago in a 'dummy load' thread in the modding section.

i am thinking about making a basic regular non-resistive dummy load & trying to overcome the flatness with diy-on-vero cab sims & cab sim pedals (i don't have funds for a pro resistive load box).

is there any basic advice you would give to people who want to use their main amp (mine is class A 30w with 8 ohm celestion speaker) for silent (small flat) recording but have minimal means?

or maybe a modest modelling set-up better than a great amp through a flat non-reactive load?

i'd be interested to hear your thoughts.

Jonathanthomas83

@vale thank you. 

Heres a response I had on another thread

"Just one thing you might want to mention on there...the AMT PE-15 is a 15W reactive load box which works fantastically well. I've used it with my 20W and 50W Jet City amps - as long as you keep the volume reasonable and stay out of the red on the indicator, there's no danger at all. Even a 50W amp running at less than 15W sounds great like that. The main point here is the price - £110 or thereabouts, and about £100 if you use The Fretboard's discount on the AMT UK site"

This could be helpful. You don't need a pedal to import IRs onto, you can use software to load then into, if you have a computer and a soundcard that can take the signal from your load box.

I'll be writing another post to cover some cheaper options that the ones I discussed in my first post. :-)

vale

@Jonathanthomas83 thank you for the suggestion, Jonathan.

my class A combo is 30w 8ohm (with 8ohm jack out to a cab), so i would be wary of popping the amt if it is only meant for 15w. i'm just so scatty & absent-minded & i think i would forget the levels & turn it up without thinking.
i keep everything i use as foolproof as poss for that reason. even taking knobs off pedals to remind me not to change settings. i have tried but can't change my limitations so, i have learned to change my environment to deal with that. just me.

i will check out the demos & read reviews just to see, though. maybe it is very tough.

would be great to see a do-it-on-a-budget version of your orig article. will look forward to.

Jonathanthomas83

@vale apologies, I didn't read your requirements properly. I'll get on that article asap :-)