Cab in an anechoic chamber

[Clive]

Hi,

Imagine I shot a cab in an anechoic chamber, would the resulting IR be different if I used a high res type instead of an ultra res type ?

Of course nobody does this but I could have used an Iso cab instead.

 

[aleclee]

As I understand it, the low end would be different.

 

[Jbmetal]

There would still be a difference between Ultra and High res, because even on close-miked IRs, it makes a difference, and it's not picking up a lot of reflections from the room when it's that close. But for distant-mic'ing, it would make a world of difference. The UR format captures more (more precisely it has more accurate) low end because it's a longer capture and low frequencies take longer to complete a cycle, meaning the longer the sample, the longer the low frequencies have to develop.

 

[AkakorMo]

But will it feel like a cab in an anechoic chamber?

 

[Jbmetal]

But will it feel like a cab in an anechoic chamber?

I would assume not. It would feel like a distant mic'ed cab without reflections, which doesn't require an anechoic chamber (as exemplified here: http://forum.fractalaudio.com/axe-fx-ii-user-cabs-irs/77246-some-far-field-irs-marshall-1960av-v30-4x12.html) Because, as far as my understanding goes, an anechoic chamber wouldn't feel like anything. It's more of a lack of feeling because there's no reverberation, meaning the only thing you'd be able to hear would be the dry cab signal. But it's a very interesting thought and I'd love to be proved wrong. Hopefully someone with the right connections could make it happen.

 

[antcarrier]

Hi,

Imagine I shot a cab in an anechoic chamber, would the resulting IR be different if I used a high res type instead of an ultra res type ?

You'd have to consider that anechoic chambers still contain low frequency reflections - and these would be captured in UR IRs. Reflection free IRs would make a better comparison if you want truly 'anechoic' IRs. In this case I doubt you'd hear a difference, but until I see the measurements I can't say for sure. Regardless, it would be nothing like when making the comparison when captured in a normal room. I've measured cabinets that need no more than 12ms (hires IRs are 42ms) to be captured entirely. Most cabinets need more than this though. I've never captured reflection-free IRs longer than 21ms, but by this time many cabs have been entirely captured, and the rest have been very close to entirely. Some cabs seem to want slightly more time, but I highly doubt they would ever reach, let alone exceed 42ms.

IME the main difference between UR and hires IRs is due to room reflections.