1" throat CDs comparison

[1hiep0]

here is.... FWIW
The BMS 4526HE-8 measurement was not included. It shown for size comparison sorry!
The amplifier output level was unchanged across.
it's about 12" from the horn mouth.
On axis "eyeballing" sorry.
Raw data.
The Faital and BMS were bought used, all others new

 

[Pano]

That's a nice collection - thanks for posting. Easy to see why the B&C 250 is so well liked on this type of horn. There are a couple of other good ones, too.

 

[kipman725]

I time gated the results at 7mS. Something seems wrong with the PSD2013-8. The smoothest response is from the DE250-8, BMS4550 and Tymphany DFM-2535R00-8. The smallest BMS seems to be missing from the results? the level is too low to get any harmonic distortion data.

 

[Pano]

The smallest BMS seems to be missing from the results?

The BMS 4526HE-8 measurement was not included.

Isn't it a 0.6" driver anyway? Not good for a 1" horn.

 

[1hiep0]

It's 0.63" throat so not included.
I re-measure the suspect PSD at higher input driver voltage here is what I got.

 

[1hiep0]

about the horn that I used for measurement
There is imperfect at the horn CD entry would its caused problem? It's about $20 per piece what i can ask for right!
https://www.parts-express.com/Dayton-Audio-H812-1-Exponential-Horn-100x60-2-Bolt-270-304

 

[Pano]

Is that the quantum phase alignment notch? 😛

 

[weltersys]

There is imperfect at the horn CD entry would its caused problem?

Any problem the "quantum phase alignment notch" caused should affect the response of all the drivers tested on it.
If it had much effect, there would be a similar peak or dip evident in the very high frequency response of all the drivers, but nothing stands out suggesting a common problem up high, though the horn's "ripple" response is evident up to around 3kHz.

 

[Pano]

Art - in your grand CD test, you tested at a fairly high SPL, didn't you?
https://www.diyaudio.com/community/threads/high-frequency-compression-driver-evaluation.212240/