1" dome tweeter vs. 1" compression driver on same size horn / waveguide, SPL & nonlinear distortion comparison

[stoneeh]

Hello, audio science community.

Over the last couple of years, I evaluated a lot of measurements of high frequency speakers - from dome tweeter over ribbons / AMTs to compression drivers etc. Some observations about dome tweeters in waveguide vs. compression drivers in horn struck me, so I wanted to formalize my findings via an objective comparison between the two concepts with focus on SPL vs. nonlinear distortion, with all other variables evened out as much as possible. I've recently managed to do that, and made the results public on my Youtube channel.

The measurement program was as follows:

- sensitivity 1w / 1m 4pi
- horn / waveguide gain vs. driver in free air
- decay behavior
- power compression
- harmonic distortion with filtered frequency response
- multitone (IMD) distortion with filtered frequency response
- various bonus measurements

As is the academic standard, the comparison comes with full documentation, for full reproducibility if needed.

I do not want to abbreviate my data or take it out of context. If you are interested, please watch the comparison in its entirety. Enjoy.

Regards
Stoneeh

 

[SDC]

To be specific, nd350 has 1" throat but 1.75" diaphragm. Compared to the 1" of dome tweeter.

Still, nice work!

 

[alex-z]

I assume when you say 1 watt you really mean a fixed 2.83 volts?

 

[stoneeh]

To be specific, nd350 has 1" throat but 1.75" diaphragm. Compared to the 1" of dome tweeter.

Still, nice work!

1,75" refers to the VC diameter, as far as the manufacturer declares it. The effective membrane area, one can only guess. Compression drivers are normally referred to by their exit throat diameter, which is 1" in this case. I guess I could/should have specified that directly though.

Thank you!

I assume when you say 1 watt you really mean a fixed 2.83 volts?

2,83Vrms for the 8 ohm compression driver, 2Vrms for the 4 ohm tweeter. These voltages calculate to 1 watt on the respective nominal impedance values.