Acoustic Horn Design – The Easy Way (Ath4)

[mabat]

It looks huge on the pictures. Is it really 12" - didn't you scale it somehow?

[TNT]

Yes, put a CD beside for some reference ;-)

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[TNT]

Originally Posted by mabat

Because the mic response is the same in all the polars. It just subtracts away.

"frequency response of the driver and mic response are put out of picture by normalization"

?

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[maravedis]

Originally Posted by mabat

It looks huge on the pictures. Is it really 12" - didn't you scale it somehow?

its 15" = 390mm and 190mm deep. I'm pretty sure that's what you gave me. What on earth have I made!

[gedlee]

Originally Posted by maravedis

There seems to be something about how the horn loads the air that I recognise from live music that seems absent from CD waveguides. But perhaps it depends on what you want your playback to do.

How a system design interacts with your expectation is indeed a highly relevant factor. For example a lower DI is going to enhance the reproduction of live recordings due to its greater "spaciousness", but will degrade studio recordings because the low DI is going to degrade "image". These are tradeoffs that simply cannot be avoided and will play very much into your "expectation".

[mabat]

Originally Posted by maravedis

its 15" = 390mm and 190mm deep. I'm pretty sure that's what you gave me. What on earth have I made!

Oh, I should probably check again, I remember 12", but definitely you should check the bigger one before you start it! Something may be wrong somewhere

Edit: Yeah, it was really 15". My bad, sorry. Well, that's a nice piece of waveguide you have.

[mabat]

Originally Posted by TNT

"frequency response of the driver and mic response are put out of picture by normalization"

?

I don't understand the question.

Measured_SPL_at_0_deg = DUT_at_0 + MIC
Measured_SPL_at_10_deg = DUT_at_10 + MIC
Measured_SPL_at_20_deg = DUT_at_20 + MIC
...

Data normalized at 0 deg:

Normalized _SPL_at_0_deg = DUT_at_0 + MIC - (DUT_at_0 + MIC) = 0
Normalized _SPL_at_10_deg = DUT_at_10 + MIC - (DUT_at_0 + MIC) = DUT_at_10 - DUT_at_0
Normalized _SPL_at_20_deg = DUT_at_20 + MIC - (DUT_at_0 + MIC) = DUT_at_20 - DUT_at_0
...

You see, no MIC response in the normalized data.

[TNT]

OK!!

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[maravedis]

Originally Posted by gedlee

How a system design interacts with your expectation is indeed a highly relevant factor. For example a lower DI is going to enhance the reproduction of live recordings due to its greater "spaciousness", but will degrade studio recordings because the low DI is going to degrade "image". These are tradeoffs that simply cannot be avoided and will play very much into your "expectation".

Agreed. The most extreme example I can think of is playback of 1920s recordings. (seems that it's what I spend most of my time listening to these days). Through my mono 1m wide 1m deep exponential horn they can sometimes come alive in a quite spectacular way. Detail, fizz and pop and sheer pleasure of performance - makes you wonder about 100 years of progress. I don't need to be told that they would be 'better' through the Genelecs!
Of course, that's not the whole story, which is why we are here.

I do think there is an issue with what we expect 'entertainment' to be in the modern era. Music can be so meaningless and uncommunicative these days - and of course we can easily design, make, and are sold equipment to reflect that. Walking round Munich show last year was an eye opener. The very very few rooms that were listenable seemed to be reflection of the aesthetic tastes of their designer's passion for their love of music, culture and taste.

[mabat]

Originally Posted by maravedis

The most extreme example I can think of is playback of 1920s recordings. [...]. Through my mono 1m wide 1m deep exponential horn they can sometimes come alive in a quite spectacular way...

In other words they are best listened to on 1920s equipment... I suppose there can be some truth to that.