Acoustic Horn Design – The Easy Way (Ath4)

[mabat]

I can't recall what I used when I experimented with it. Use what Dkalsi used

[Dkalsi]

Originally Posted by mabat

Great. Do you know the details of the exit section of the driver used (angle and depth of the last conical section)?

Unfortunately, I do not. It's the Peerless DFM-2535R00-08. Googling did not yield the above info :-(

JSS - I thought the 30% infill was sufficient.

[Patrick Bateman]

Originally Posted by mabat

Great. Do you know the details of the exit section of the driver used (angle and depth of the last conical section)?

I'm too lazy to take mine apart. But I did some rough measurements, and the exit angle appears to be nineteen degrees. It's 20mm from the exit of the phase plug to the exit of the compression driver.

[mark100]

Originally Posted by Patrick Bateman

I've probably done a thousand measurements of various projects. And the moment I hear that pink noise sweep, I know if it's good or not.

Pink noise sweep ??

[Patrick Bateman]

Whoops.

I guess it's a sine sweep?

Whatever it is, my neighbors hate it. I literally have teenagers walking by and making the noise to clown on me.

Buwooooooooooop

Buwooooooooooop

The place I lived two years ago, the sine sweep would make the dog across the street freak out, and then the neighbor across the street would stand in front of her house and glare at me.

All of this and more can be yours, for the low low price of $1,700,000 in California. Living the dream!

[mark100]

Haha...i hate it too Patrick !

Whenever i run high level SPL distortion tests of CD's outdoors, there's always the risk of neighbors calling in air-raid sirens, or UFO's

BuwoooooooooooooP .....lol


But all kidding aside and a Segway, one of the beauty's of dual channel FFTs is how they are source-signal independent at making transfer function measurements.
I've never had a neighbor complain about pink noise, and if they did, I'd just switch to spectrally dense music which works just fine.

[Patrick Bateman]

Is pink noise as accurate? I suppose I should know this by now.

Pink noise is definitely way less obnoxious than sine sweeps.

One time when I lived in Oregon City, I did a sine sweep into a B&C woofer, didn't check the voltage level, and I think they literally heard it the next town over. It's a straight shot across the river and there's nothing to attenuate the sound between the two towns. People probably thought it was a Tsunami siren.

[gedlee]

Pink noise can never be as good as Sine sweep, but it can be done accurately that way. In the 'old' days when there weren't computer systems for analysis, I did use white noise. But I knew what you meant all along.

[mark100]

Technically, I've been taught that nothing is as accurate as sine sweeps.
But that is soooooooo much technicality, and not the least to do with anything that matters real world.

But even technically, another great thing about dual-channel using pink or music or whatever, is that it allows real-time temporal averaging, increasing accuracy beyond that of a single sine sweep.

But that said, you could average multiple sine sweeps as REW explains, and maybe achieve even greater technical excellence ....

And make everybody, including ourselves, even more ultra annoyed !!! LoL

[gedlee]

Listen Inc. use stepped sine and when I talked with an engineer about it, it made a lot of sense. Multiple averages of a several waves.