The JBL 4435 is one. You can ask Speakerdave why they choose that path
The JBL Everest 2 (DD65/DD66000/DD67000) is another contemporary example (although not a monitor, but absolutely top notch).
If they ever decide to do two-woofer version of the their current top-of-the-line M2 monitor it will most probably be a 2.5 way as well.
The JBL 4435 is one. You can ask Speakerdave why they choose that path
when saying:
I was referring to the idea of a 2.5 way monitor that uses two smaller woofers instead of one 8'' or 10''
something very different from JBL 4435 and the likes of it
BTW JBL 4435 is another very illustrative example of the point that I make in this thread
after all it's a 2 way with a 15'' crossed at 1 kHz 12 dB/Oct - this is what a 4430 is (and an integrated subwoofer added to 4435 doesn't change the picture)
and it is both an audiophile's and diyer's big no-no to cross such a big woofer that high, letting it handling the midrange, right? Moreover with 2nd order low pass. And I wonder why.
What about break-up? What about beaming? What about phase coherence? All diyer's nightmares.
Interestingly the basic idea of JBL 4430/4435 is not very far from - let's say - big studio Tannoys with 15'' woofers like System15DMT (can be considered an equivalent to JBL 4430 in this perspective) or System215DMT (an equivalent to JBL 4435), actually 215DMT is more like 2.5 way then 4435 with its lower crossover frequency set to 250 Hz
That's my point. All this reference level studio loudspeakers use big woofers to handle the midrange or at least the most of it.
Oh well, they probably are not on the reference level of Jay and others...
I wonder what is then?
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Instead of "And I wonder why." why don't you explicitly ask a technical question? It's easier than if you don't want to put yourself in "I don't know" position and keep wondering about many things.
"Balanced performance cost effective".
The most critical issue with smaller woofer is higher fs. But many larger woofers have higher fs than smaller woofer. So it is mostly about part availability. I have PL18 and XT25 in a waveguide. But I don't like the critical midrange handled by poor driver or by relatively good one (scan speak revelator) struggling with too low frquency. Of course, if we can find suitable drivers, it may be best to have 10 or 8" crossed to tweeter at 1k or 1.5kHz. What we can find is a "cost effective" solution not "ultimate" solution. Waveguide, XT25, are examples. I have better 9" woofer but don't have matched in quality tweeter.
I'm keeping an eye to Jeff's kairo and joachim's kalasan.
No I don't know that.
I don't want to go far off from 8"+1" topic. May be there isnt any reference level. Goods speaker is a function of driver quality and designer capability. How to choose the driver combo is part of designers' expertise. Jeff Bagby and Joachim Gerhard are designing with Satori drivers. When I decide to build similar project, I would consider the same drivers, and I would build both designs along with my own. The best of the 3 (plus any other candidates) is my "reference with those drivers.
My current speaker is using stiff cones which outperforms my scan-speak reference which outperformed other scan-speak reference of other good designer.
so now You know
in my opinion both a typical audiophile and a typical diyer is a very misguided person because both audiophila and diy are mainly fashion-driven activities
look quite nice, though I wonder
...why the tweeter has no neodymium magnet?AlNICo would be even nicer, in the woofer too
CCAW is nice, ribbon would be even nicer
but they surely look nice
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Polar Expedition:
Attached two polar plots that Dr. Geddes uses to illustrate directivity problems in typical 8" + 1" designs. 1) wide BW 8" midbass + good dome at too-high Xover; 2) limited BW 8" woofer with poor polar + modest dome.
A few example lobing plots for 8" midbass, and 8" midbass +1" naked_dome at different Xover frequencies using Xdir.
Naked_Dome vs. Waveguide_dome is one controlled directivity design decision for 8"+1" speakers. At what frequency do you start to narrow the polar response?
Curvilinear cone 8" shows modest beaming at 1,200-1,400Hz, such that with a steep LR6 Xover a robust naked_dome creates a "medium" polar pinch-in over about +/- 200Hz around the Xover frequency. FIGs. 8" polar at 1200 --> 8"+1" polar at 1400 --> tweeter polar at 1600 --> dome's natural physical width sets high frequency beaming for the upper polar response.
A controlled directivity wavguide_dome is crossed at a frequency where the 8" midbass beaming creates a smooth, but narrower polar response to match the
waveguide and then lets the dome's natural physical width set high frequency beaming for the upper polar response.
Attached two polar plots that Dr. Geddes uses to illustrate directivity problems in typical 8" + 1" designs. 1) wide BW 8" midbass + good dome at too-high Xover; 2) limited BW 8" woofer with poor polar + modest dome.
A few example lobing plots for 8" midbass, and 8" midbass +1" naked_dome at different Xover frequencies using Xdir.
Naked_Dome vs. Waveguide_dome is one controlled directivity design decision for 8"+1" speakers. At what frequency do you start to narrow the polar response?
Curvilinear cone 8" shows modest beaming at 1,200-1,400Hz, such that with a steep LR6 Xover a robust naked_dome creates a "medium" polar pinch-in over about +/- 200Hz around the Xover frequency. FIGs. 8" polar at 1200 --> 8"+1" polar at 1400 --> tweeter polar at 1600 --> dome's natural physical width sets high frequency beaming for the upper polar response.
A controlled directivity wavguide_dome is crossed at a frequency where the 8" midbass beaming creates a smooth, but narrower polar response to match the
waveguide and then lets the dome's natural physical width set high frequency beaming for the upper polar response.
Attachments
I
I think it has not been mentioned that active crossover easily allow for steep slope. The Orion uses LR4 with 8" Seas Excel at 1k4 I think.
I think it has not been mentioned that active crossover easily allow for steep slope. The Orion uses LR4 with 8" Seas Excel at 1k4 I think.
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MarkK has this 8+1" speaker, it is well documented and it was done almost 10 years ago. xo around 1400Hz LR8.
Dayton Reference RS225
Dayton Reference RS225
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Careful examination of T/S parameters and SPL/freq plots illustrates that very few 8" speakers are great candidates for a 8"+1" design. Very, very few if you want to match the 94db @2.83V sensitivity of the better dome tweeters. Accepting a sensitivity below 90db @2.83V provides many more good options.
I use a 93db/watt Tang Band W8-1808 without a whizzer cone which can reach 80Hz -3db in a 2cuft sealed box, or -3db 37Hz in a 4cuft MLTL. I keep watching for similar full'ish range 8" speakers. Troels Gravesen, Denmark DIY Loudspeakers website worked with ScanSpeak on a custom high efficiency 8".
The new Lambda TD8M with 20g Mms and 76Hz Fs does not catch my interest. AES forum stated this speaker has shipped to OEMs.
Attachments
well, again
when saying:
"I know no such 2.5 way studio monitor, perhaps because it would be worse by design anyway"
I was referring to the idea of a 2.5 way monitor that uses two smaller woofers instead of one 8'' or 10''
something very different from JBL 4435 and the likes of it
BTW JBL 4435 is another very illustrative example of the point that I make in this thread
after all it's a 2 way with a 15'' crossed at 1 kHz 12 dB/Oct - this is what a 4430 is (and an integrated subwoofer added to 4435 doesn't change the picture)
and it is both an audiophile's and diyer's big no-no to cross such a big woofer that high, letting it handling the midrange, right? Moreover with 2nd order low pass. And I wonder why.
What about break-up? What about beaming? What about phase coherence? All diyer's nightmares.
Interestingly the basic idea of JBL 4430/4435 is not very far from - let's say - big studio Tannoys with 15'' woofers like System15DMT (can be considered an equivalent to JBL 4430 in this perspective) or System215DMT (an equivalent to JBL 4435), actually 215DMT is more like 2.5 way then 4435 with its lower crossover frequency set to 250 Hz
That's my point. All this reference level studio loudspeakers use big woofers to handle the midrange or at least the most of it.
the concept of UREI is basically the same as JBL 4435 - it's a 2 way with an 15'' midwoofer and an integrated subwoofer
it's not like anything I was referring to
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