Summary slide.... might help others with future Eminence selection decision.
For a modest volume studio room, sound quality is more important than Max SPL.
For an SEOS12 tweeter, clean high frequency SPL extension over 2Khz is important.
Sealed F3=80Hz. The 4.8mm Xmax, smaller gauage 250W voice coil wire on DeltaliteII 2512, plus conductivity of NdFeB magnet keeps Le=0.43mH with good high frequency extension. Rising SPL above 1Khz complicates Xover.
Sealed F3=100Hz. The Delta Pro 12A reduces Mms to 48 grams with a modest 4.9mm Xmax, Le=0.57 from inside/outside voicecoil winding helps smooth frequency extension and simplify Xover.
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The Definimax 4012HO is a good canidate for inductance reducing shorting rings on the pole steel because of the high 1.17mH inductance created by the long, heavy copper voice coil requried for Xmax=6.2mm at 600watts. The 86g Mms also limits high frequency.
For a modest volume studio room, sound quality is more important than Max SPL.
For an SEOS12 tweeter, clean high frequency SPL extension over 2Khz is important.
Sealed F3=80Hz. The 4.8mm Xmax, smaller gauage 250W voice coil wire on DeltaliteII 2512, plus conductivity of NdFeB magnet keeps Le=0.43mH with good high frequency extension. Rising SPL above 1Khz complicates Xover.
Sealed F3=100Hz. The Delta Pro 12A reduces Mms to 48 grams with a modest 4.9mm Xmax, Le=0.57 from inside/outside voicecoil winding helps smooth frequency extension and simplify Xover.
---------
The Definimax 4012HO is a good canidate for inductance reducing shorting rings on the pole steel because of the high 1.17mH inductance created by the long, heavy copper voice coil requried for Xmax=6.2mm at 600watts. The 86g Mms also limits high frequency.
Attachments
You are forgetting that all 12inch cones including
the Definimax have narrowing response on axis.
Its a simple fact of that cone width.
Rising SPL does not complicate crossover. Its just
as fair to say the definimax has drooping SPL off-
axis as suggesting the weight helps it remain flat.
Either way does not mean your can extend the
crossover point above what is right for 12" and
still expect uniform coverage. You cross under
or at that point, there is not so much difference.
You take any of the "risers", and allow the baffle
to obscure the right and left edges. Dispersion to
a higher frequency will flatten them out.
the Definimax have narrowing response on axis.
Its a simple fact of that cone width.
Rising SPL does not complicate crossover. Its just
as fair to say the definimax has drooping SPL off-
axis as suggesting the weight helps it remain flat.
Either way does not mean your can extend the
crossover point above what is right for 12" and
still expect uniform coverage. You cross under
or at that point, there is not so much difference.
You take any of the "risers", and allow the baffle
to obscure the right and left edges. Dispersion to
a higher frequency will flatten them out.
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Go survey some Faital and Selenium 12" spec sheets.
Not cause of anything wrong with Eminence, just because
those other brands show both on-axis and 45deg off axis.
What you discover is that all 12" cones will sound different
on-axis vs off-axis beginning gradually around 900Hz.
So any 12" (including Eminence) would properly cross to
SEOS at or not much above that frequency.
Lets say your SEOS won't go that low, probably doesn't.
What can you do to make this work? You make the 12"
speaker less wide by covering the edges. Just like what
is often seen in midbass horns, only without the horn.
With an opening 10" wide, you get even dispersion to
1200Hz, at expense of losing some rising response.
With an opening 8" wide, you get even dispersion to
1800Hz, at even more expense of rising response.
Of course it takes a 12" woofer with rising response
to be able to make this trade-off. If already rolled off
flat with mass, then you got drooping response both
on axis and 45 degrees, once you spread it out.
I'm not going to suggest narrower than 8", cause
probably not any 12" with enough rise to do that.
And tuned cavity in front may become obnoxious.
Not cause of anything wrong with Eminence, just because
those other brands show both on-axis and 45deg off axis.
What you discover is that all 12" cones will sound different
on-axis vs off-axis beginning gradually around 900Hz.
So any 12" (including Eminence) would properly cross to
SEOS at or not much above that frequency.
Lets say your SEOS won't go that low, probably doesn't.
What can you do to make this work? You make the 12"
speaker less wide by covering the edges. Just like what
is often seen in midbass horns, only without the horn.
With an opening 10" wide, you get even dispersion to
1200Hz, at expense of losing some rising response.
With an opening 8" wide, you get even dispersion to
1800Hz, at even more expense of rising response.
Of course it takes a 12" woofer with rising response
to be able to make this trade-off. If already rolled off
flat with mass, then you got drooping response both
on axis and 45 degrees, once you spread it out.
I'm not going to suggest narrower than 8", cause
probably not any 12" with enough rise to do that.
And tuned cavity in front may become obnoxious.
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Farfalle. Is that better than straight edges,
or just JBL being unique for pasta sake?
RJ and Karlson had even weirder apertures.
Not trying to disperse 12" full range, just
trying to meet up with a SEOS. You would
definitely not fail by cloning JBL's aperture.
But are straight edges really all that bad?
or just JBL being unique for pasta sake?
RJ and Karlson had even weirder apertures.
Not trying to disperse 12" full range, just
trying to meet up with a SEOS. You would
definitely not fail by cloning JBL's aperture.
But are straight edges really all that bad?
I thought about this issue allot before buying the complete Eminence Delta Pro 12 a, SEOS kits, mainly to get the J. Bhagby XO design.
They do sound very good, at 20 watts as well as 200 watts, once you get them toed in enough they are spectacular.
In retrospect, I kind of wish I had spent the extra money and bought AE TD12M's.
I have heard that they have 10 dB lower distortion levels than almost any other 12, and they are supposed to sound very clear.
I would have had to XO them with my Beheringer DCX2496 to get it right.
I have heard so much good stuff about the Acoustic Elegance drivers.
Here is a thread about a SEOS 12-AE TD12M
SEOS12 and AE TD12M design
Dave
They do sound very good, at 20 watts as well as 200 watts, once you get them toed in enough they are spectacular.
In retrospect, I kind of wish I had spent the extra money and bought AE TD12M's.
I have heard that they have 10 dB lower distortion levels than almost any other 12, and they are supposed to sound very clear.
I would have had to XO them with my Beheringer DCX2496 to get it right.
I have heard so much good stuff about the Acoustic Elegance drivers.
Here is a thread about a SEOS 12-AE TD12M
SEOS12 and AE TD12M design
Dave
Would removing the dust cap reduce the peak?
Buying a house! Will be moving my speaker parts from storage (several years!) to the basement - and I will need to build speakers again. I want to do a Klipsch Heresy sized two way in the living room. Any suggestions?
Godzilla
Buying a house! Will be moving my speaker parts from storage (several years!) to the basement - and I will need to build speakers again. I want to do a Klipsch Heresy sized two way in the living room. Any suggestions?
Godzilla
I've only heard Klipschhorn in person, and that was on light jazz, trumpet, string bass, drums. So I couldn't really tell how good they were. Salesmen were all wearing suits & ties, the amp was MacIntosh, so the salesmen never spoke to me wearing jeans, or even looked in my direction. I couldn't afford any of that in 1975. Bought used dynaco ST70 and LWEIII speakers. Nearest Klipsch Heresy on demo is probably Boston.
I'm building or buying a 2 way soon, and I'll be crossing over @ 1200 hz. Which totally avoids the beaming effect of 2000-4000 hz out of the Deltapro woofer mentioned above .
I had a pair of Peavey SP2-XT and they were IMHO very nearly superb in my 14'x10x'33' living/dining/kitchen area. Speakers high on poles on narrow end, pointed slightly at my sitting position on couch on side of room 12' away. Very heavily damped room with carpet, couch+easychair, book & recordshelves, 2 organs + 2 organ speaker cabinets in the room. Used the SP2-XT at 1/8 W base level with 70 W peaks. Could sound very like the Steinway console piano I own, which is very rare for a speaker. Never owned a speaker close before, piano is hard to reproduce. Then 9/14 the SP2-XT were stolen. No SP2-XT available on used market so far nearer than LA. I don't have a car to go pick any up, either.
I've managed to score a pair used of Peavey RX22 drivers with horns for $130, and being 2" instead of 1" they handle down to 1200 hz very well. Sounded pretty good, not quite bassless, on the radio the day they got here. SP2-XT were crossed over @ 1200 hz.
Will be buying 15" woofers to go down to 54 hz, as that is low enough for my music listening habits. Will be buying probably Eminence DeltaPro15 per this thread, the Peavey 1505-8KADT is now made somewhere I don't care to support financially. Eminence is assembled 50 miles from here. Where Fatal is assembled, you are allowed to know when you open the box.
Will probably build 2 drivers in 2 boxes, because I can't lift an 83 lb speaker onto the pole over my head. So separate skeleton box for the horn tweeter. Tweeter box doesn't even need sides, does it? Lowes will deliver the plywood for $60, so don't need a truck.
Crossover design is tbd, massively complicated by my not having Windows computer. May have to buy a speaker book. First approximation, a 7.7 mH coil blocking the .8 mH woofer is 8 ohms @ 1200 hz. a 2.1 uf capacitor series the tweeter is also 8 ohms @1200. But those are only 6 db/octave crossovers.
I may put a 1157 brake light bulb series the tweeter to block excessive current in it. 1.2 ohm the DVM reads, cold. At least 4 ohms hot, maybe 6.
I'm building or buying a 2 way soon, and I'll be crossing over @ 1200 hz. Which totally avoids the beaming effect of 2000-4000 hz out of the Deltapro woofer mentioned above .
I had a pair of Peavey SP2-XT and they were IMHO very nearly superb in my 14'x10x'33' living/dining/kitchen area. Speakers high on poles on narrow end, pointed slightly at my sitting position on couch on side of room 12' away. Very heavily damped room with carpet, couch+easychair, book & recordshelves, 2 organs + 2 organ speaker cabinets in the room. Used the SP2-XT at 1/8 W base level with 70 W peaks. Could sound very like the Steinway console piano I own, which is very rare for a speaker. Never owned a speaker close before, piano is hard to reproduce. Then 9/14 the SP2-XT were stolen. No SP2-XT available on used market so far nearer than LA. I don't have a car to go pick any up, either.
I've managed to score a pair used of Peavey RX22 drivers with horns for $130, and being 2" instead of 1" they handle down to 1200 hz very well. Sounded pretty good, not quite bassless, on the radio the day they got here. SP2-XT were crossed over @ 1200 hz.
Will be buying 15" woofers to go down to 54 hz, as that is low enough for my music listening habits. Will be buying probably Eminence DeltaPro15 per this thread, the Peavey 1505-8KADT is now made somewhere I don't care to support financially. Eminence is assembled 50 miles from here. Where Fatal is assembled, you are allowed to know when you open the box.
Will probably build 2 drivers in 2 boxes, because I can't lift an 83 lb speaker onto the pole over my head. So separate skeleton box for the horn tweeter. Tweeter box doesn't even need sides, does it? Lowes will deliver the plywood for $60, so don't need a truck.
Crossover design is tbd, massively complicated by my not having Windows computer. May have to buy a speaker book. First approximation, a 7.7 mH coil blocking the .8 mH woofer is 8 ohms @ 1200 hz. a 2.1 uf capacitor series the tweeter is also 8 ohms @1200. But those are only 6 db/octave crossovers.
I may put a 1157 brake light bulb series the tweeter to block excessive current in it. 1.2 ohm the DVM reads, cold. At least 4 ohms hot, maybe 6.
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I bet it will reduce the peak!
No. Not yet. But stoked to hear fom you later. I am in the process of doing a speaker Alpha 15A, LilBuda, 1" compression driver, possible more modern than DE 250 like you published it...
Godspeed!