Just a question of curiosity around tweeters

[imahawki78]

I happened to notice when looking up my old speakers (RF-82 II) that Klipsch literature claims those speakers have a "1” (2.54cm) Titanium diaphragm compression driver".  The new RP-8000f however claims a "1” Titanium LTS Vented Tweeter with Hybrid Tractrix® Horn"

 

I believe neither tweeter is a true compression driver.  If I look up the RF-82 II tweeter to buy a replacement, it looks like its just a horn-loaded titanium dome tweeter with phase plug.  Compared to the RF-7 tweeters which are actual compression drivers.

 

It matters not to me, but I'm curious if my observation is correct.  A horn loaded tweeter is not necessarily a compression driver.  You can horn load a traditional dome / cone driver, correct?

[moray james]

if you want to design a compression driver the diaphragm will need to withstand the compression. there are low compression drivers for example some with poly or Mylar diaphragms.

[glens]

If considering a "compression driver" to only have the appearance of something you'd see in an old Altec, JBL, EV, etc. catalog where it appears to be just the magnet structure with a dome, but emitting sound off the back of that dome out the back, then this question would make great sense.  But if you consider a 15" "standard" woofer mounted to a board with just a slot opening (much smaller than the area of the cone), like you'd have in a LaScala, for example, or a dome tweeter with an inverse dome mounted just in front of it (which is what it appears is in my Forte III), then it's easy (er?) to understand there are alternate ways to produce compression with a driver.

[imahawki78]

Sorry,  I thought this question was more simple, or maybe I'm just dense.  I figured a compression tweeter would have specific design elements that were inherent to a "compression driver" and throwing a dome tweeter in a horn wouldn't make it a compression driver any more than a waveguide would.  

[moray james]

3 hours ago, imahawki78 said:

Sorry,  I thought this question was more simple, or maybe I'm just dense.  I figured a compression tweeter would have specific design elements that were inherent to a "compression driver" and throwing a dome tweeter in a horn wouldn't make it a compression driver any more than a waveguide would.  

throwing a dome tweeter into a horn makes it a horn loaded dome tweeter. The profile and length of the horn will establish the amount of compression and what the load will be. Say you used a one inch dome tweeter and you placed a short conical horn with a one inch entrance on that tweeter it would act more like a wave guide in that dispersion would be controlled but there would be limited compression and little to no gain. Some times it can be confusing where one design stops and another starts. Perhaps for now accept that what looks to you like a dome tweeter with a horn can in fact be a compression driver. There are a few compression drivers with as much compression as a diesel engine ie:10:1 ratio. I am not a compression driver designer perhaps someone with compression driver design experience would explain this better than I have.