Some speaker driver measurements...

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#244
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#247
I'd really like to see a motor (power handling) like that applied to their conventional dome (D2905/970000). (..I suppose the Revelator is similar to that.. but the 3rd harmonic discontinuity from 2nd at lower freq.s is not good.)


-what I find shocking is just how primitive the "enclosure" pathing/stuffing is - a BIG thanks for cracking-open that sucker! (..of course I'm not sure it had to be LITERALLY cracked-open.) 😀

You might try various foam ppi (grades) instead of that cotton (..I'm assuming it's cotton, maybe it's a ceramic or glass fiber). I'm pretty sure they use foam for the Ellipticore.

http://www.troelsgravesen.dk/OVAL-1/ellipticor-6-1800.jpg
 
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#248
ScottG said:
I'd really like to see a motor (power handling) like that applied to their conventional dome (D2905/970000). (..I suppose the Revelator is similar to that.. but the 3rd harmonic discontinuity from 2nd at lower freq.s is not good.)


-what I find shocking is just how primitive the "enclosure" pathing/stuffing is - a BIG thanks for cracking-open that sucker! (..of course I'm not sure it had to be LITERALLY cracked-open.) 😀

You might try various foam ppi (grades) instead of that cotton (..I'm assuming it's cotton, maybe it's a ceramic or glass fiber). I'm pretty sure they use foam for the Ellipticore.

http://www.troelsgravesen.dk/OVAL-1/ellipticor-6-1800.jpg
Click to expand...

Thanks for the advice🙂
It seems ScanSpeak do not long thinking just used in that beryllium model the motor from previous Revelator series tweeters - R2904/7000, D2904/7100, where it has special plastic supporting element for the aim:
- in the ring radiator version - to hold in place the bullet;
- in the dome version - to hold an underdome damping piece of felt.
In the 7140 there is no any of that elements, so, IMHO, the plastic "crab" was left there as a rudiment. It only inferes to the back pressure escape out of the under dome cavity.
In R2904, D2904 and all AirCirc tweeters are used the cotton pads, you are right.
In the Ellipticor ones it seems they use not the cotton but synthetic (maybe natural?) kind of felt. The back chamber cover in the Ellipticor made of a clear plastic and resonates very well🙂
 

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#249
..hmm, felt for the Ellipticore.

Yeah, I think you could get better subjective results with the right ppi foam (or even different layers of ppi foam). (..striving for similar damping/absorption but with much lower-loss/resistance (air-load to compliance) to the driver's motion.)

Are you sure that the 7140 isn't similar to the 7100? It looks like they both use the same outer-ring radiator design, and excursion is identical (..though mechanical resistance is half that of the 7100 - which is pretty awesome.)
 
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#252
ScottG said:
I'd really like to see a motor (power handling) like that applied to their conventional dome (D2905/970000)..
Click to expand...

I just read this and realized I didn't reference what I was referring to.. 😱

-the 714000's power handling/SCALING vs. non-linear spectrum to the 970000: where the 970000 "jumps" (for lack of a better term) from 4.5 to 8.8.

My *guess* is that it's a motor issue, because the 970000 is NOT a ring-type design (like the 714000, which is).
 
#253
ScottG said:
I just read this and realized I didn't reference what I was referring to.. 😱

-the 714000's power handling/SCALING vs. non-linear spectrum to the 970000: where the 970000 "jumps" (for lack of a better term) from 4.5 to 8.8.

My *guess* is that it's a motor issue, because the 970000 is NOT a ring-type design (like the 714000, which is).
Click to expand...

Not quite understood but if you mean the 9700's THD jump when going from 4.5 to 8.8 Volt then I think it is due the absence of HPF at those measurements. I made them a long ago when didn't come to my standard measurement procedure yet🙂
 
#260
Now here are some new SEAS drivers, and especially the tweeter (27TAC/GB) would be really interesting to see the distortion measurements.

F_Seas_Prestige_loudspeaker_tweeter_H1825-06_27TAC_GB.jpg


The woofer (L16RNX3) is using a 28L cab (VAS19L) which is close to Qtc 0.5 and in my opinion over damped. The dotted line is their calculated infinite baffle and hopefully much closer to Qtc 0.707-0.8. If so, then it is a good competition to Wavecor SW182BD03/04. Looks promising as woofer(s) in a 3/4-way system and below 500Hz.

F_Seas_Prestige_loudspeaker_woofer__H1869_L16RNX3.jpg


Prestige Titan Launch
 
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