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Recording Impulse Responses - portable and easy

A3D2

Active Member
Does anyone have experience recording impulse responses quickly on the fly? I've tried recording impulse responses with a sweep from a small portable speaker but as you can guess it kind of makes your rendered reverb sound as if it was played through that tiny speaker. I know big speakers are better, but I'm looking for a portable quick solution.

I've read things about popping a balloon or using a clapperboard? Do you guys know if that could work for quick reverb sampling? :) Or does it not cover enough frequencies? I'm afraid it will have little bottom end frequencies...

Thanks for the advice
 
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Jaap

Yes, that's an alto flute
Done a whole serie of outside impulse recordings in fields and forests this summer and popping balloons did a great job.
 
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A3D2

A3D2

Active Member
Done a whole serie of outside impulse recordings in fields and forests this summer and popping balloons did a great job.
Nice, I'm going to give balloons a try then as well :). I just made myself a clapperboard from two pieces of wood so I'm also curious if anyone has tried this as well?
 
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A3D2

A3D2

Active Member
Done a whole serie of outside impulse recordings in fields and forests this summer and popping balloons did a great job.
@Jaap Did the balloon capture the entire frequency range? Or was the impulse response lacking some low end?
 

wst3

my office these days
Moderator
Balloon pops, starter pistols (not any more folks!), clapboards, hand claps - any impulse can be used, the length of the impulse will have an affect on the spectrum captured, and there are other considerations which I do not recall since I switched to a swept sine wave a while back.

A swept sine wave is very effective for capturing an impulse response, and done properly it can increase the signal to noise ratio of the IR. It does require a reasonably wide band transducer on both ends (loudspeaker and microphone), but corrections can be made for fall off at the extremes, as long as there is some information there to start with.

I may, or may not have mentioned that part of my day job involves acoustics, so I look at impulse responses a little differently - but the IR is the IR, and one can use it for predictions, measurements, auralization, and yes, music production!

I'm not sure how many of these links will be accessible (I logged out of my account before accessing them, and I could access them, so you may be good to go):
  • CATT Acoustic Gratisvolver - a free convolution tool (there is a "pro" version too)
  • The entire CATT Acoustic web site contains a wealth of information, check it out.
  • A Syn-Aud-Con article about Gratisvolver - mostly about convolution, but a good read.
  • The IR Process - courtesy of Syn-Aud-Con - written from the perspective of a sound system designer, but it still applies
  • Deconvolving - also from Syn-Aud-Con, and also geared towards acousticians and sound system designers.
  • Creative Field Recording published this article on IRs. (Paul is one of my favorite writers on sound, and this is definitely geared towards music production)
  • this article from Designing Sound is a little more academic, but still worth reading at least twice!
  • another academic paper
  • here's a better explanation of how we go back and forth between sweep and impulse than I could ever write.
  • lastly - don't overlook Voxengo's Deconvolver and Modeler if you can still run Windows x86 binaries.
Hopefully there will be something for everyone in there somewhere.
 
OP
A3D2

A3D2

Active Member
Balloon pops, starter pistols (not any more folks!), clapboards, hand claps - any impulse can be used, the length of the impulse will have an affect on the spectrum captured, and there are other considerations which I do not recall since I switched to a swept sine wave a while back.

A swept sine wave is very effective for capturing an impulse response, and done properly it can increase the signal to noise ratio of the IR. It does require a reasonably wide band transducer on both ends (loudspeaker and microphone), but corrections can be made for fall off at the extremes, as long as there is some information there to start with.

I may, or may not have mentioned that part of my day job involves acoustics, so I look at impulse responses a little differently - but the IR is the IR, and one can use it for predictions, measurements, auralization, and yes, music production!

I'm not sure how many of these links will be accessible (I logged out of my account before accessing them, and I could access them, so you may be good to go):
  • CATT Acoustic Gratisvolver - a free convolution tool (there is a "pro" version too)
  • The entire CATT Acoustic web site contains a wealth of information, check it out.
  • A Syn-Aud-Con article about Gratisvolver - mostly about convolution, but a good read.
  • The IR Process - courtesy of Syn-Aud-Con - written from the perspective of a sound system designer, but it still applies
  • Deconvolving - also from Syn-Aud-Con, and also geared towards acousticians and sound system designers.
  • Creative Field Recording published this article on IRs. (Paul is one of my favorite writers on sound, and this is definitely geared towards music production)
  • this article from Designing Sound is a little more academic, but still worth reading at least twice!
  • another academic paper
  • here's a better explanation of how we go back and forth between sweep and impulse than I could ever write.
  • lastly - don't overlook Voxengo's Deconvolver and Modeler if you can still run Windows x86 binaries.
Hopefully there will be something for everyone in there somewhere.
@wst3 Thanks for all this information Bill, really kind of you to gather all these nice articles, I'll definitely read them, awesome! :) I've also tried a sine sweep myself in a church some years ago, but maybe the speaker just wasn't loud enough... Since the resulted IR tended to distort easily in my DAW which was kind of weird. But apart from the result taking a speaker with me was a bit too cumbersome for me, so (after hearing Jaap's experiences) I'm going to give the clapperboard/balloon a chance and see what kind of results I can get.
 
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