Waveguides and horns

[Tytte71]

Looks like a nice improvement with the Aquaplas, needing less correction and better time domain performance (wonder if distortion figures improves as well). Have you done any listening comparison?
Also, how much Aquaplas did you add?

[454Casull]

Originally Posted by gedlee

It was 6 or 6.5° (I don't remember the decimal places) - half angle.

6.5 degrees half angle would make it 13 degrees included angle as I mentioned.

[jzagaja]

Originally Posted by Tytte71

Have you done any listening comparison?
Also, how much Aquaplas did you add?

Will send sample diaphragms to Autotech for evaluation. Hard to say how much Aquaplas - just to cover diaphragm completely with white coating. About 7-10 layers.

[noah katz]

The sensitivity takes a big hit from the extra mass of the Aquaplas.

Standard application recommendation for optimum damping of diaphragm resonances is to cover the center 25%, as that is where amplitude is greatest.

If you wanted to get fancy you could effect constrained layer damping by adhering a small disk, or maybe two crossed strips for less mass, of aluminum foil to the center of the diaphragm.

[jzagaja]

Applying Aquaplas using table top fan:

https://docs.google.com/open?id=0ByP...05GWmhoN2huaEE

[jzagaja]

First day of using Bruel Kjaer 2012 Audio Analyzer - setting up Mummy crossover (12BR70+D800Ti). I would like to contact anyone familiar with this nice machine.

[jzagaja]

Intermodulation distortion with and without Aquaplas.

[jzagaja]

Interesting isn't it? Both ends are nicely lowered but waveguide modes region is not. I need to change base frequency and check again - maybe I hit a HOM

[jzagaja]

D800Ti when equalized (2 notches) has dip at 2.6kHz - Aquaplas may help.

[jzagaja]

Problem with stiff suspension drivers like D800Ti is crossover point below 1kHz. Higher is problematic due to driver/waveguide resonance. Don't be afraid of 12BR70 higher midrange distortion - it's not a problem as seen on below picture.