KM2

[pos]

Anti K, using a lowmid can be rewarding, but it is pretty difficult to setup correctly, especially the crossover with the woofer(s).
3-ways are specially tricky to get right when it comes to phase tracking.

Here are a few points to consider when choosing such a driver:
- choose the diameter based on the directivity and crossover frequency with the horn
- choose the highest sensitivity driver that still has enough excursion to go down to the woofer crossover at your target SPL and distortion.
- choose a cone that does not show any major breakup artifacts up to 1/2 oct above your horn crossover (more or less, depending on the slope there)
- choose a good modern motor *or*, better still, use a current drive amp (transconductance) to reduce distortion in the mids

[Robh3606]

Thanks! I feel I already looking a'bit that way, too...

Please advise - Your opinion. Below is 4367 graph - shortly, just ugly in mid-region.
Of cause, if active, it's not a question to EQ these drops.

/ I'm confused about D2430 driver, how bad they measure raw, without EQ.
It's like low end - when there is no capabilities, You can rise actively as much as You want, it its not capable...
it's like the story: You can feed the wolf as you want, bear's d*** is bigger anyway. /

How You feel, is that drop of 4367 becuse of 2216Nd-1 (not 2216Nd), or because of HF D2430 (not a smooth 4inch CD), or why? Just Your subjective thoughts.
I'm gathering this 'puzzle' together in my head.

When old-school, passive, then basically we 'pushed' all down to the lowest sensi part of whole system; then we got nice graph. By reduce.
Now, active, if some driver has -6dB drop, nobody starts to 'push down' all bandwith. Despite, we rise this driver's this region 6dB = kick in 2X more energy! And good, if the drop is only 6dB, not 12... and we ask, why this thing doesn't sound not as effortlessly and so on..

And one more thing: You name old-good 2123 mid cone.
What about newer designs 2262 , 2250, 2169 ?

I have both my passive M2 Horn 2216nd 476Mg system and my original 4 way mains in my HT system. My 4 way mains are quad amped 2235/E-145/2123 and 2453SL on PTH1010 waveguides. Subjectively they are very similar however one is much simpler to implement and has much better cost to performance ratio.

There is a reason JBL abandoned the 4 way in the studio decades ago. There is an argument to be made that they lost some of the dynamics and clarity moving away from the 10's when they introduced the 4430. A 2235 is simply not as articulate as a 10" or a 2216nd. And why have 2 HF drivers when you can get by with a single 2425 on a 2344. Seems to me cost and a CD horn were the drivers.

I don't have any issues with the smoothness of the 2216nd. It sounds fine in a simple passive set-up and also measures just fine. I would not try to fix this even if I had DSP.

The 2430 just doesn't have the same low end capability as a large format 4" driver. It's plain to see in the measurements. It is designed for maximum SPL and extends higher. Two different animals.

The older legacy drivers are all pre DSP so by nature they had to be network friendly and reasonably smooth over their bandwidth. The newer drivers are all in the DSP world so I would be looking at the DSP settings or at least try to get a measurement as there are a lot of sins that can be fixed.

Here is actual vs predicted over the woofers range and an old picture just for fun! The original system with Le14 subs 2035's 2122's and 2426's on 2344's

Rob

[Mr. Widget]

Anti K, using a lowmid can be rewarding, but it is pretty difficult to setup correctly, especially the crossover with the woofer(s).
3-ways are specially tricky to get right when it comes to phase tracking.

There is a reason JBL abandoned the 4 way in the studio decades ago.

I'll add my two cents here.

Adding additional drivers (three-way, four-way) makes it virtually impossible to design passive or analog active crossovers that will result in phase response, polar response and even on axis response (at the higher frequencies) that look good on paper.

As most of us know; a single full range driver is ideal, but beyond the use in headphones a full range driver is not practical due to a number of physical properties. This leads us to a two-way, or a three-way, or more... all of these are compromises.

I have experimented with all of the above. I have used full range drivers, augmented full range drivers, six foot tall electrostatic panels, multi-way cone and dome systems with DSP, with stepped baffles, and all had their strengths and their issues. At the end of this road, I have ended up with a four-way system with compression drivers up top. From an idealized perspective they are awful. They measure poorly in terms of phase response, and are not the most linear on axis or from a polar perspective... but I like them.

Beyond my liking them, which is the most important thing for the pair at my house, I have built two identical sets of these speakers. Over the years hundreds of people have heard the speakers. Average listeners, industry experts, and audio professionals have all heard the speakers and for the most part, the consensus is that the compromises made in the design are worthwhile.

The bottom line is that while spinorama, step response, waterfall plots, and basic frequency response plots are all extremely useful design tools, at the end of the day the speaker will either be pleasing or it won't be. My advice is to try to follow the best practices guidelines, and then choose your compromises based on your needs.


Widget

[Ian Mackenzie]

Thanks! I feel I already looking a'bit that way, too...

Please advise - Your opinion. Below is 4367 graph - shortly, just ugly in mid-region.
Of cause, if active, it's not a question to EQ these drops.

/ I'm confused about D2430 driver, how bad they measure raw, without EQ.
It's like low end - when there is no capabilities, You can rise actively as much as You want, it its not capable...
it's like the story: You can feed the wolf as you want, bear's d*** is bigger anyway. /

How You feel, is that drop of 4367 becuse of 2216Nd-1 (not 2216Nd), or because of HF D2430 (not a smooth 4inch CD), or why? Just Your subjective thoughts.
I'm gathering this 'puzzle' together in my head.

When old-school, passive, then basically we 'pushed' all down to the lowest sensi part of whole system; then we got nice graph. By reduce.
Now, active, if some driver has -6dB drop, nobody starts to 'push down' all bandwith. Despite, we rise this driver's this region 6dB = kick in 2X more energy! And good, if the drop is only 6dB, not 12... and we ask, why this thing doesn't sound not as effortlessly and so on..

And one more thing: You name old-good 2123 mid cone.
What about newer designs 2262 , 2250, 2169 ?

Your over thinking it in your head at this point.

It’s a trap to idealise the end result based on measurement or selection of drivers of another design.

Things like the measurement technique, the baffle size, driver layout are all sensitive to the midrange response. Your own physical design will be different so don’t worry about those details at this stage.

In a commercial product the actual published curves are magazine curves to make the consumer feel good. The design is ultimately a set of complimentary compromises in terms of cost, complexity, industrial design. The result in a consumers home is a lot less predictable than a pro recoding studio and this is why you need to set up your project to deliver a subjective result that you are looking for in your own room.

How it all hangs together is not something you can predict on paper. Some of the best most technically correct designs don’t always work out.

Getting it together is going to take some work and a lot of perseverance on your part.

Subjectively its not about a particular aspect of a driver but well it voices overall with actual
program material you are familiar with.

The dynamic attributes of a loudspeaker are not something you can determine from a frequency response graph.

In the diy space audio amateurs often buy used drivers and unfortunately these drivers are not necessarily in best working condition. They hear that and become dismayed because they don’t know what’s wrong?

I would tend to start off with a simple set up if starting from scratch and learn grow with it.

Classic woofers like to Great Plains Audio 416 are likely to put a smile on your face more quickly than some of the Jbl drivers which require some work to get a worth result This is because Jbl often takes a driver from one application and to make it work in another application they pay specific attention to the voltage drive of the crossover network. As an audio amateur you won’t know that unless you are familiar with that particular driver. Then you need specific skills and measurement equipment to figure it out like Rob did with his passive monitor project.

https://greatplainsaudio.com/wp-cont...Spec-Sheet.pdf

I have already mentioned the Joseph Crowe radial horns. Joseph can custom design the horn for a particular driver throat. These are next generation Tad horns. He can advise you on a driver as well.

And Jbl are conscious that the hifi loudspeaker market is not ready to accept a full dsp loudspeaker at this stage. A few players have put a toe in the water like Elac and Dynaudio. The industry mafia simply won’t let it happen because of the impact on other parts of the business.

[Anti K]

What we do here, if we DIY:
- we clone, or
- some saw some veneer when they get bored, and kick randomly some drivers in there, no finish (thats the lifestyle, OK, Peace), and then comment (what's the value of these comments - how to saw?)
- some know, the speakers in sales are all for business = one more compromise component, money. DIY often do not have to think about that.
Not because a lot of money (!) but because we do not have intention to sell them!
Another $500 driver is not a deal-breaker beacuse there is not a deal at all. Just one thing - does it improve things (potentially).

There are DSPs, dead-silent ncore and eigentakt amps modules (each driver gets personal block).
I did lot passive different systems and I'm tired of this. F*** tired. Do what you want, there is ALWAYS some BUT. Then, srewdrivers, iron, kick off all sofas, floor is full of s**t. Cords everywhere. Familiar? Listening room (often living room) is like old attic. And then You and Your relatives (if they didn't left You yet) have to live with that.
DO NOT LIKE THIS!
Was about 10y away from this because I mess up with another el.magnetic waves... for business.

Now is 2021.
I'll pick up potential NEW drivers (even do not listen them, what it gives me if I listen widely respected 2216Nd RAW), put together a nice puch of furniture and amps, switch and hide all cords.
AND THEN!
I sit down into comfy sofa, open my laptop, click deep slopes, not so deep slopes, delays and ... wirelessly, even every Friday evening if I want...
Anno 2021.

Your over thinking it in your head at this point.
In a commercial product the actual published curves are magazine curves to make the consumer feel good.

In the diy space audio amateurs often buy used drivers and unfortunately these drivers are not necessarily in best working condition.

And Jbl are conscious that the hifi loudspeaker market is not ready to accept a full dsp loudspeaker at this stage. A few players have put a toe in the water like Elac and Dynaudio. The industry mafia simply won’t let it happen because of the impact on other parts of the business

These are good comments!

I do not overthink. I just thin about one cone, left in my 'puzzle'.
Just one driver - Between crazy light Beryllium CD and huge 140 gram moving mass cone(s). Is there a point?

MrWidget made a 'very bad' 4-way; didn't just pair his very capable TAD_BE_CD with some 15'' bass and done.

Anti K, using a lowmid can be rewarding

Thanks! Finally!

3-ways are specially tricky to get right when it comes to phase tracking.

Yep. Considering a 4-way then...

I have both my passive M2 Horn 2216nd 476Mg system and my original 4 way mains in my HT system.
Subjectively they are very similar

You didn't consider first one is basically top-notch components/lens ; another feature way older parts, but active, so, what we compare?

As most of us know; a single full range driver is ideal

I've tried to figure out what the fans are find in there. OK, if You listen only (ONLY) a 'girl with quitar', while girl is mostly mute...better both.
There are brand new dead-silent amp-modules out there. Fullrange - seems to me - is a perfect choice to liten this complete silence IMHO
(Yes, I know all the phase theories and things behind...)

I have ended up with a four-way system with compression drivers up top. From an idealized perspective they are awful.

And how it was possible? Answer is quite simple. Because top-notch drivers. Am I right?
My theory is (sorry: look who's talking, two who...) that THESE drivers (I know now which ones) are able cover each other at quite wide area... and there was possibility to find out the subjectively best compromised points for cross.

[pos]

Thanks! Finally!

keep in mind the 2216 is tough to beat though...

Yep. Considering a 4-way then...

I guess that is a joke?
Adding a tweeter around 10kHz is easy, and you don't really care about phase coherency there as it is a lost cause anyway (nor is it a problem either, really).
But of course, it is in no way easier than a 3-way.
The hard part is the woofer to mid crossover in the 200-400Hz range: that range is tricky to measure with enough resolution and reliability, is not very forgiving (LF of vocals), and often interacts badly with the baffle size as well as the distance from the ground...

Good luck

[Anti K]

keep in mind the 2216 is tough to beat though...
The hard part is the woofer to mid crossover in the 200-400Hz range:

Good luck

Thanks!

I do not want beat 2216
(knowing reputation of M2 is even bit weird to talk about that for me)
but slide aside 2216 something with same motor (tough to beat!) but way lighter moving mass cone. This name is 2262.

I read Horn-Heads dispute: Whaaat, this driver has 42gram moving mass, did You really think this heavy brick is some kind a MID!?
(tey argued some 10'' driver)
And we talk about here 140gram cones pushing them as high as 700Hz...900Hz
(both 2216 and 1500AL weight)

We can find phase coherency point and make a cross there. But phase changes while low goes higher and mid goes lower. As we know.
So, theoretically, smalller the overlap, smaller the problem?
What about 96db/oct slope?

[Anti K]

I have just one question:


Did here, in the LH forum, the biggest community on planet of JBL nerds, somebody who messed around with
2169
2250
2262


?

[pos]

And we talk about here 140gram cones pushing them as high as 700Hz...900Hz

Other things being equal, a higher cone mass simply means a lower mass breakpoint frequency.
I doubt this is the only factor to consider when going from a 2216 to a 2262.
The 15" variant of the 2262 is the 2265 by the way. Same motor, but different VC and cone compared to the 2216.

We can find phase coherency point and make a cross there. But phase changes while low goes higher and mid goes lower. As we know.
So, theoretically, smalller the overlap, smaller the problem?
What about 96db/oct slope?

Phase coherency at and around the crossover point is paramount, there is no way around it if you want decent results.
Hiding summation errors with steep slopes is a recipe for disaster.

[Mr. Widget]

And how it was possible? Answer is quite simple. Because top-notch drivers. Am I right?
My theory is (sorry: look who's talking, two who...) that THESE drivers (I know now which ones) are able cover each other at quite wide area... and there was possibility to find out the subjectively best compromised points for cross.

Top notch drivers certainly helped and some have fairly wide usable frequency response, but as POS points out, picking the drivers that allowed me to pick more forgiving crossover points was also part of the design.

I experimented with a variety of JBL, TAD, PHL, and other woofers and drivers, and played with different alignments and crossover frequencies. Ultimately I landed on a 75Hz crossover, a 750Hz crossover, and a 12KHz crossover. The crossover between the 10" woofer and the compression driver is the fussiest, but I feel I was able to make it work.


Widget

[Kreativlos]

the most important thing is to plan the speaker properly before you build it...
Consider what are the specifications you need and with what compromises can you get along
Afterwards you make your choices and think of a 2,3 or 4 way. Then you ask, which drivers could get the job done best in the considered frequency range and from there the planning can go on. Imo best would be to start with prototyping at that point...
Good luck, wish you the best with the project

Best regards

[Ian Mackenzie]

the most important thing is to plan the speaker properly before you build it...
Consider what are the specifications you need and with what compromises can you get along
Afterwards you make your choices and think of a 2,3 or 4 way. Then you ask, which drivers could get the job done best in the considered frequency range and from there the planning can go on. Imo best would be to start with prototyping at that point...
Good luck, wish you the best with the project

Best regards

Post 71 sums it up.

The idea of coming up with a sensible diy system using best of class driver (available) in a modular format is going to be a more fulfilling audio amateurs journey than a painfully difficult attempt at an exact clone.

When l was in HK in 2019 l visited several local audio amateurs who had over a long period of time built larger than life diy systems. One was in a large photo shoot studio. The guy has changed his mind several times over the years with different configurations using Tad, JBL and other exotic drivers.
There were two 15 inch woofer per side.

But the thing is he was having a lot more fun than the guys who were tearing their hair out trying to accommodate the DD67000’s in less than ideal environments for practice reasons. They were at the point of blaming the design but frankly it was the circumstances and the belief that because it was the best Jbl system that’s how it should sound. Not so unfortunately.

The notion of making a clone or attempting a variation ramps up the risk considerably.

Giving yourself some flexibility and scope for change is far better approach.

Even Greg is busy with diy enclosures and horns to work in with his HT surround system.

[ivica]

.......
The 15" variant of the 2262 is the 2265 by the way. Same motor, but different VC and cone comparedto the 2216.

........

Hi POS,

Have You any more info about the VC differences between 2265 VC and 2216ND VC ?

Regards,
Ivica

[Ian Mackenzie]

https://reconingspeakers.com/product...r-for-lsr708i/

I would be looking to evaluate this 8 inch driver used in the 708 studio monitors.

According to Jbl engineers the motor has additional components for reduced distortion and extended cone excursion for a monitor application. It’s available which is a key thing. Given availability of high power ncore power amplifiers the relative efficiency of these drivers can balanced out. It could be used as a mid bass or midrange driver in a system with the LF augmented by a subwoofer and have a bandwidth up to 1.8khertz.

250+250 watts focused in the mid bass is ample for domestic situations where sound clarity is the primary goal over very high sound levels demanded in the Vertec systems.

That provides flexibility for smaller horns or wave guides and the physical layout more stealth which is generally a less complicated loudspeaker implementations for diy.

The other consideration is has the user assessed the space and location with any loudspeakers at this stage? With the typical surfaces in a domestic dwelling the reflected sound and the length of the building may demand a relatively closer listening distance to reduce interference masking the direct radiated sound to the listening position. The curtains won’t necessarily provide a low enough noise floor from interference caused by longer time reflections. This will reduce the spatial clarity of the system considerably and defeat the purpose of high quality playback. I recommend to conduct some tests before proceeding.

[Anti K]

GT's old 2123
10 inch / 101dB / 25gram MMS / 250W / 3inch VC
cannot find anything close ... or isn't just