Another Squawker Shootout

[mboxler]

Although this is for my own benefit, I thought others might be interested. Any suggestions ae welcome. All measurements are with the horn mounted in a La Scala and the microphone a foot away from the mouth. All drivers are connected straight to the amplifier.

First is the K55V solder lug mounted on a K400.

SPL & Phase

I believe the bump in SPL around 4200hz is the result of the dual phase plug design.



Distortion.

I limited the plots to 2nd and 3rd Order distortion to keep it cleaner.



If I'm doing this right, that's a lot of distortion beginning around 4200hz. Coincidence? Tempted to measure a K55V Push Pin to verify.
I designed the 4500x to eliminate any squawker distortion after 4500hz and let the newer tweeters take over at that point. This is the first time I actually plotted the distortion I aimed to eliminate.

 

[mboxler]

Next is the DCM420.

All SPL

DCM420 is Yellow, compared to the K55V Solder. Impressive frequency response!



SPL & Phase



Distortion. Yikes! Gonna have to do more testing.

 

[Deang]

Yikes. That’s nasty. Looks like a nice place for a notch filter.

 

[mboxler]

I decided to start fresh this morning, and discovered something interesting, at least to me. I use a laptop to measure, backup the measurements, and reopen them on my desktop. I noticed that the distortion plots looked better on my laptop, and researched Distortion settings. Sure enough, they were different.

Back to the K55V solder. The top right setting panel contains the settings on my laptop. Looks much better.



This is the setting on my desktop. Use harmonic frequency as reference is turned on. Looks worse.



Next, I turned on Plot harmonics at the harmonic frequency.



Next one is same as above, but I hid the settings panel. I'm not smart enough to comment, but I think this means that the frequencies between 5200hz and 6200hz are generating second order harmonics between 10400hz and 12400hz. And, since that harmonic is beyond the frequency range of the driver, can it be ignored???

 

[DirtyErnie]

Harmonics at Harmonic Frequency moves them to where they actually happen. If you have a 4KHz spike in 2nd order, that setting will move it to the 8KHz where it actually happened.

Even though it's still the 2nd harmonic of 4Khz.

It's handy to separate actual harmonic distortion from a resonance. If you use that setting, a resonance will show up in all the traces at the same frequency.

 

[FastlaneDave]

Very nice work! I’m tempted to send you a FaitalPRO HF200 for testing because I’ve been so impressed with its sound and overall performance. My only concern is that you’ll like it as much as I do—and I’ll find out it has taken up permanent residence under your pillow!