Is it possible to cover the whole spectrum, high SPL, low distortion with a 2-way?

Quote that may shed a light:

"One might ask why on Earth someone would do such a thing. Yet rest assured that there’s a number of perfectly valid reasons. As Vladimir explains, in terms of absence of an enclosure, it is almost obvious. Internal standing waves, reflections which interfere with driver cones, resonances, energy storage, compression, time domain (phase) distortions and so on are gone when the box itself is gone. The sound is radiated solely with drivers and not with enclosure or its baffles. The other important feature of a loudspeaker without a baffle is lateral radiation absence of it. One doesn’t have nearby walls, floor or ceiling radiation, which leads to less room resonances. Hence it’s for the best to picture Bespoke P15 as a somewhat OB alike design, yet pushed even further in the box-free direction. The downside? Since there’s no pressure built-up in a resonant chamber, bass drivers have to be big and there’s no way around it.
Reflector Audio Bespoke P15 is different from typical OB products not only because it doesn’t sport a baffle at all. Its four 15″ long-throw (18 mm of excursion from peak to peak) paper cone woofers aligned in a four-leaved clover shape are inverted. Yes, their membranes fire directly on a wall in front of a listener and that’s very unusual. Here Vladimir chimed in again. He explained that the inversion itself was done in order to more closely approximate all four big drivers’ acoustic axis. The specific angles of said transducers were introduced to focus sound radiation in space at 1.2m in the Bespoke P15 case and from that point their coherence is achieved. These angles translate to increased sound efficiency radiation forward, which yields improved adaptation and an acoustic system performance in problematic listening rooms. This is what Roland Janevich’s patented invention is all about exactly.

The manufacturer’s suggestion is that a minimum distance from a speaker to a listening spot should be no less than 2.2 m. As far as space behind our Latvian dish goes, 0.5 m or more is advised."


This here almost makes it sounds like OB has less issues than the opposite....yet there are no OB studio monitors?
 
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The 124A is a stunning woofer, provided the Alnico is recharged and the surrounds are fresh.
It's probably one of the best 12" woofers ever, as well as one of the best looking, if you ask me.
However, it's more akin to a hifi woofer than a pro woofer, which implies considerable attenuation of a horn/comp. driver.

You may consider an AMT or wg loaded dome tweeter.

Yes I guess you are right. the driver is only 91db sensitivity. It will be better paired with a traditional tweeter (with or without waveguide).


I'm still interested in building a high sensitivity 'simple' full-range 2-way.. the faital pro hf units look great (on paper anyway).

The Cornscala D 2-way design is certainly appealing. Easy to build too.
 
It's from an online hifi magazine, so I would suggest to read between the lines.

It doesn't say that it is or is not a coax. In essence it probably behaved more or less as a coax. It's not really too different from a Bullfrog: just a woofer with a horn squeezed in, only now it has 4. The fact that it's an OB is a separate design choice. The 2 woofer version is different of course. It will make an MTM and will probably have wider horizontal dispersion because of it.

Of source there is one big difference to a true coax, and that is that lobing behaviour will depend on the x-over point (als slope in the end). With a center to center spacing of less than 46cm for the 18" version, an x-over of than 700Hz should give a good result. Some more interesting stuff can be found in this topic regarding the two woofer version: Study of a Dipole/Cardioid Bass Horn , where a V-shaped dipole horn is simulated.

Just to be clear: personally, I am not excited about the concept.
However, it seems to have piqued the interest of my fellow countryman.

Guilty as charged :D . Probably most of you thinks it looks quirky and strange.. which is correct of course, but I kind of like it. I guess you can't argue about (bad) taste :rolleyes:
 
I heard that some seem to like Quad ESLs for monitoring. Those would would definitely be dipoles. But this would be for acoustic music and definitley not hip-hop !
Regards
Charles

After building many horn speakers I settled with original ESL57 (not ESL63). I enjoy every type of music.
 

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I heard that some seem to like Quad ESLs for monitoring. Those would would definitely be dipoles. But this would be for acoustic music and definitley not hip-hop !

Regards

Charles


Yes, a friend of mine sold ESLs to some studios in the past.


I think, the woofers out in the open turns many people of.
The Reflectors in that small Berlin club are probably subject to a lot of: finger tapping, moist, smoke, dust etc.
 
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What is the technical reasons against using open baffle config for studio monitoring? I thought it was because of how much it excites the room energy which is counter productive of only wanting to hear direct signal like the focus of near-field.
It seems that with some design engineering you could still create this objective with OB, by creating a room covered in sound absorption.
Also, the radiation not coming from the front of the loud speaker should be pretty accurate in comparison to enclosure radiation so that helps things along but that is probably already a know plus of the OB design.
Supposed less vertical dispersion? That’s probably not so true or insignificant in comparison to enclosed design. Speaking of.....I though enclosed designs are supposed to be free of baffle radiation....I thought 3/4” inch MDF was good for most? The other claimed benefits of OB I can understand.
So many questions....
 
ESLs are very good, unbeatable in some respects, but limited with regards to primarily bass and SPL.

I've listened to quite a few ESLs: 57s, 63s, 989s.
For jazz, vocal, chamber music and similar these are briljant.
But as soon as you'll start to listen to heavy rock, large orchestral works, hip hop etc. at moderately loud levels they collapse.

I remember visiting audio stores in my teens... We brought some tracks along that were perfect to get any electrostat to its knees within seconds.
The faces of the salesmen and their arguments were priceless.
 
Hi everyone and WOW ! Trying to acknowledge all the great information on this topic and my brain starts to overload after the 15th page.

So what did camplo decided at the end ? I have a similar problematic which is "how to build an high spl, full spectrum 2 way system" and I'm trying to find directions

Goal : max ~130SPL / Frequency range : 40Hz - 20Khz
Crossover cut : 700 / 800Hz
My driver choices :
Sub : RCF LF15N401 - 15" Woofer or RCF MB15N401 - 15" Mid Bass
Tops : RCF ND840 - 1.4" Compression Driver with Product Detail - RCF

The big question : which kind of enclosure should I build for the subs ? I was thinking tapped horn but it would limit them to 200hz maximum. So I believe vented is the choice, if so, any tip about the volume / tuning frequency ?

The little question : As the subs and the tops will be in 2 different enclosures, at which distance should I place them in order to "phase them" ? I am not so familiar with phasing and to make speakers resonate in order to get the best global SPL / sound experience, so any guide / tip would be welcomed !

Maybe someone who follows this topic (and whom have acquired much more information than me so far) could help me to decide. Here is the topic I have started :
2 similar drivers in 2 different enclosures ?

Hope this is not too off-topic ^^
 
camplo, OB's generally need quite a lot of space and are not really suited for nearfield monitoring.
In addition, you'll need cone area in order to have some bass.

The Reflector Bespoke P1805s shown in the studio (a few posts ago) are located :
1. in a fairly big control room
2. at least 1.5-2m from the desk
3. with space behind 'em.
 
Of source there is one big difference to a true coax, and that is that lobing behaviour will depend on the x-over point (als slope in the end). With a center to center spacing of less than 46cm for the 18" version, an x-over of than 700Hz should give a good result. Some more interesting stuff can be found in this topic regarding the two woofer version: Study of a Dipole/Cardioid Bass Horn , where a V-shaped dipole horn is simulated.

Well, I just tried fooling around with that AkAbak script a bit. Looks like the two woofer version might have lower beam width in the horizontal plane than the vertical MTM plane. I wasn't expecting that. The vertical beam actually matches quite well with the waveguide.
 
camplo, OB's generally need quite a lot of space and are not really suited for nearfield monitoring.

Not quite sure I agree- several of the disadvantages of OBs are mitigated through nearfield use. Max SPL goes up dramatically near vs. far field, and there should be less apparent LF loss (there are several mechanisms at work here, I won't pretend to know how they net out for a given scenario).

The other big one is LF EQ- with more SPL capability, come fewer driver requirements/limitations. You can push that 6" down to 40 much more comfortably OB nearfield than you can at 12ft.
 
Not being an OB expert either, I am quite sure about the less than optimal near-field qualities.
If the OB concept were the end to all loudspeaker concepts, it would dominate the market, I suppose.

Despite my doubts, I look for an opportunity to listen to the Reflector Bespokes.
Because, if you want to get rid of the box, why not get rid of all panels completely?
 
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