Great Balls of Prestige

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Founder of XSA-Labs
Joined 2012
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Maybe what is needed is a custom 3d printed horn with a rounded lip that smoothly transitions to the sphere? That would smooth things out significantly. A hard edge like that is just asking for diffraction. Is the horn removable via those screws? One could print a new one and screw back onto same holes.

VM752_1.jpg
 
X I think you are absolutely right! But it may bring its own downside with different loading of the dome and dispersion. Would I be able to tell the difference given the few dB of off axis blips and that is is already down 6dB at 2800hz and handing over to the tweeter? I just don't know. I suspect it is a non issue to be honest. But as an purely intellectual exercise and if you were chasing every last gram of performance it might be fun to try!
 
If the measured "anomaly" isn't audible, then your approach makes perfect sense.

I wonder what if any early diffraction the protective grill & 3-legged cover over the Yamaha beryllium midrange dome will cause?
mid-large.jpg

Recently acquired a pair & want to integrate them into a 4-way active system. I guess only way to really find out is to measure. Gotta get my test room finished... :( :rolleyes:
 
Bush, note that silent mike said "test room." Coming from him, that probably means something more like this. :)

Fess up, Mike! Are you building another anechoic chamber?
Oh-oh, I've been outed! :eek:

No, no more anechoic chambers. The computer noise measurement/analysis phase of my life is over, I haven't posted anything on my site for a couple years, it lives on in spite of my negligence.

I did use some of the batts to build some 4x8' one-foot thick broadband sound absorption panels on wheels. Imagine open office partitions on steroids. They're in my basement. This was then I thought I might continue some sound testing after moving out of the city a couple years ago... but that seems unlikely now.

I did recycle the Ultratouch batts to make a huge bass trap all across the back wall of my room -- where the ceiling meets the wall. Will post pics later... maybe elsewhere.

Sorry to go so off-topic, not intentional; this thread on prestige balls is great on its own!
 
Re-reading your post Badman - I think you may be referring to the transition from the horn lip to the sphere? Rather than a circular baffle edge as such - my apologies if I misread you initially!

Correct, the transition from the horn to the sphere is a worst-case termination for the horn/waveguide, except for perhaps free-air mounting. Again, not looking to be a downer and it doesn't look that impactful, just saying that a smoothed transition into the sphere would create a lower-diffraction performance.
 
Correct, the transition from the horn to the sphere is a worst-case termination for the horn/waveguide, except for perhaps free-air mounting. Again, not looking to be a downer and it doesn't look that impactful, just saying that a smoothed transition into the sphere would create a lower-diffraction performance.

You are right - but impossible to do this without changing the horn itself.
As stated previously (and demonstrated in above measurements) - the sphere has a much better measured power response than the volt VM752 did on the flat baffle of the prestige cabinet. So interestingly not the 'worst-case termination' it seems....:)
 
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