High Frequency Compression Driver Evaluation

[blakkshepeaudio]

Wow, it's going to take a while to assimilate all this info.

Big up for all the work and the serious attempt to provide a valid and meaningful set of tests. DIY to-the-max.

Rgds,
blakkisblakk

[keto]

Thats an amazing report! It looks like the BMS 4550 is a little bit more powerful than the BMS 4552 in the lowest part of the pass-band. For a Unity/Synergy horn, with a 4th-order effective high-pass (and 10-15dB of padding due to EQ) at 1200hz, and judging from all your measurements and listening, would there be much of a performance difference between the two drivers?

[weltersys]

Originally Posted by keto

Thats an amazing report! It looks like the BMS 4550 is a little bit more powerful than the BMS 4552 in the lowest part of the pass-band. For a Unity/Synergy horn, with a 4th-order effective high-pass (and 10-15dB of padding due to EQ) at 1200hz, and judging from all your measurements and listening, would there be much of a performance difference between the two drivers?

There would not be much difference at 1200 Hz, but the 3 dB difference below 1200 Hz is enough to make me favor the 4550 if the cones used below it were not flat to 1200 Hz.

Art

[keto]

All the graphs I've seen make the 52ND look a little "smoother" than the 50. Does it sound a little smoother?

[weltersys]

Originally Posted by keto

All the graphs I've seen make the 52ND look a little "smoother" than the 50. Does it sound a little smoother?

Keto,
The difference in “smoothness” is quite little as you can see in post #33, the 4552 having a slight peak around 5000 Hz, the 4550 two small dips around 6500 and 8500.
It could be argued that the 4550, with lower and upper response more equal in level, is “smoother “ than the 4552.

The recordings were posted for you to listen to and make your own decisions, please share which sounds “smoother” to you.

Art

[Hentai]

Art,

Thanks for this impressive effort. The uploads are sure of great value for diy community.
The B&C performed pretty well.

I have a question though. I'm trying to figure a DIY compression driver and what I've noticed it behaves quite differently when modeling is done with different types of horns.
So my question/concern is that the test are only conclusive on that type of horn. Could the results be different with another horn?
If this matter has already been addressed please direct me to it.

I have seen many agitated spirits here so don't take my question the wrong way, its just a concern i stated in another topic i opened on compression drivers.

[weltersys]

Originally Posted by Hentai

I have a question though. I'm trying to figure a DIY compression driver and what I've noticed it behaves quite differently when modeling is done with different types of horns.
So my question/concern is that the test are only conclusive on that type of horn. Could the results be different with another horn?

Different horns using the same driver will result in different frequency response, pattern control, sensitivity, diffraction effects etc.

The relative differences in the drivers in my test can be interpolated to how they would respond on other horns.

Good luck with your DIY compression driver project.