A fun little experiment with IRs

A fun little experiment with IRs

G’day everyone. This video caught my attention the other day, so I decided to try it out:

That one was pretty brief, so I checked out this longer form example:

In any case here is a comparison of the impulse response I captured compared to the real amp mic’d up:

Sample “A”:

Sample “B”:

Let me know your thoughts, and which one you think is the real deal, and which one is the IR.


They sound pretty much the same to me. I imagine if I went in with headphones and turned things up really loud I might be able to find echos or sounds in the background, but just doing a simple A/B they sound close enough that I can’t tell.

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Jeez, I’m having a hard time discerning the differences between the two. :thinking:

Judging by these two samples, I would say that the IR is totally capable of accurately simulating a real cab.

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Thanks for the responses!.. Any guesses as to which is which?

FWIW, they definitely don’t null.

Hard to tell the difference. Clip A seems to have more “room sound” by just a little bit, so I guessing that’s the mic’d cab.

Pretty cool stuff.

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They both sound pretty similar. B sounds a little scratchier to me. I’m not sure if that makes it the real or the IR though. I’d guess that B is the IR. I’m surprised a single impulse like that worked as well as it did.

Also, a quick note, not that it really matters. There’s no need to use white noise when it’s just a single sample. Once you bring it down to a single sample, it’s called an impulse (surprise!) not white noise.

Another trick, although I’m not sure it’s really necessary. Run the impulse through a few times and add them all together, making sure they are time aligned. That will cut down on the noise and isolate the impulse response better. If my guess is correct and B is the IR, then cutting down on the noise would probably cut down on the scratchiness. If A is the IR, then I’m full of BS.

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My guess is B. I might be hearing nuances of normalized noise or on more close listening to it feels as if a dither or noise shaping filter is applied.

Certainly hard to tell in a blind casual listen, you only catch hints of the noise shaping on a looped sample. I guess that is the goal isnt it?

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Yesterday I listened through my headphones via laptop but today I’m listening through my crappy iPad speakers. I couldn’t discern any notable differences yesterday through the headphones, although I had a few moments when I thought I heard differences, but I think that may have been just my imagination. Today, listening through the iPad I can hear a difference! :flushed::hushed:. I would have expected that the difference would be much easier to hear through the headphones because of the detail that a decent set of headphones tends to reveal….and I listened at a higher volume level through the headphones….I’m listening at quite a low volume level through the iPad. It’s possible that my state of mind is different today and/ or my ears are “fresher”. I don’t really know.

But anyway……

Sample A sounds brighter than Sample B. The second sample seems less cutting. Now, hearing that doesn’t reveal which one is the IR and which is the real cab. Yesterday I was going to say that sample B was the speaker cab, but I really can’t say without ever having heard what the real cab sounds like in the first place. Even then, I think it would be difficult to guess. I’d have to be very familiar with the cab sound to know for certain.

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well, I need answers now. I just listened on monitors. I’m sticking with B as the IR. I’m 52% positive.

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This is great - excellent responses! It reminds me of our infamous “Audio Skeptics Society” “squinting” discussions back in the days of RR!

Keep those guesses coming - I shall reveal all in due time!

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Any more guesses on this?

Nobody wants to guess because they’re so unsure. It’s a difficult choice to make, but there’s a good chance 1/2 of us would choose the correct answer. :smile:

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I can’t tell, but that’s the point isn’t it? If anyone could tell these things wouldn’t be very popular would they? I’m probably missing something, I don’t hear well anyway.

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Aww… you’re no fun! :laughing: I’ll count that as a pass/no vote

True enough, I’ll grant they are very close. I was really surprised myself - That is why I posted the results here. So, I’ll count that as another pass?

Ah! Finally! A vote! Ok, that’s one for “A” as the real cab

[quote=“JayGee, post:5, topic:5939, full:true”]
Pretty cool stuff.

It is, isn’t it. I was blown away at how easy it was to do, and how great the results were.

Excellent - another decisive voter!

Now that is interesting! So what else can you use - any sound?

That is great to know. I just did one.

That sounds like a very convincing theory, and because you’re…well…Boz… I’d be inclined to believe you…we’ll see…

Awesome! I love that confidence :wink:, and that you committed to something :beerbanger: Ok, so another vote for “A” as real, “B” as IR

Haha, for a guy with your moniker, I would have thought you’d be a little less cautious! :wink: C’mon, not committing is no fun!.. Ok, so this is another definite maybe/ no vote. :frowning_face:

Ah Yes! Another confident vote! I have no idea what “nuances of normalized noise” actually means (or sounds like), or how you can actually listen to a loop of a sample.
I can hear a slight difference in overall eq, and distortion, but that’s about it.

In any case… great to have another vote … Wait, so are you voting for B as the real amp… or the IR?

Let me know - thanks.

I was certain someone was going to come along and confidently predict the answer due to some clear “tell” that I’m not across yet… oh well…

Yes, I guess it does kind of prove that they are an excellent alternative to the inconvenience of a very loud mic’d up 4 x 12 Marshall cab! Vote nicely dodged, Mr Ingo! :laughing:

Answer coming soon.

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I have a synesthesia gene in my family. As in some physical experiences connected with sounds.
Colors, sensations and actual physical senses. While it may not relate to the actual answer of this riddle, when I heard the samples, in one of them I felt water coming out of a faucet as a hard stream vs a feeling of a spray hitting the skin. It is hard to explain :upside_down_face:

I associated the “spray” feeling at the periphery of the water stream with likely white noise, that has been leveled or processed to some degree. I have that same feeling whenever I apply any kind of noise shaping algorithm for example L2 Type 2 limiter to certain tracks. I am not sure if the spray feeling has anything to do with the riddle though but based on that experience I voted for B as the Ir

Most can relate to this sort of thing by more stronger examples like sort of like getting goosebumps when someone scratches a rough surface of some kind.

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Eureka !:bulb:

A = IR
B = Cab

Super Ears has spoken! :partying_face::smile:

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Cool, so a vote!


Thanks for your explanation, but you still haven’t told me what you are guessing “B” is… Is “B” the IR or the cab?

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Michelle is very crafty. She’s playing to win! :smile:

Just playing around, Michelle :partying_face::rofl:


always! lol just kidding.
I did say earlier, B is the IR

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Ah, so you did! I missed that in your last post… my apologies!

Ok so let’s tally the votes:
Pass Votes (too close to call): @Chandler @ingolee = 2 Votes
Votes for A = IR & B = amp: @Wicked = 1 Vote
Votes for B = IR & A = amp: @JayGee @bozmillar @FluteCafe = 3 Votes

Click to reveal the answer

A = IR; B = Amp

Thanks for playing, everyone!