I am actually build a 4345 Clone. I will use the 2447 H over 1000Hz ,without a super tweeter. I am looking for a 1000 -1200 Hz crossover build
with equalisation for the 2447H . Who can help?
Viele Grüße
I am actually build a 4345 Clone. I will use the 2447 H over 1000Hz ,without a super tweeter. I am looking for a 1000 -1200 Hz crossover build
with equalisation for the 2447H . Who can help?
Viele Grüße
I think l have that driver let me check. Yes l do and all the other drivers in my driver storeroom .
I do passive crossover designs off line for interested people.
If you send me an email in my signature I can go through it with you.
Ian
The special 3-way version of the 4345 works very good. The 2405 is not in work. A 2447 H works from 1000Hz - 17000Hz ,with a short horn.
The 2245H is activ, the 2123H + 2447H passiv with a Ian Mackenzie crossover. Many thanks to Ian.
Very nice!
Are you using the JBL 2311 horns? You really should put a pair of lenses on these horns.
Beautiful Studer/Revox!
Widget
It is a shortened 2309,with 1,5" connection .
Great to see a project come to fruition.
I am a firm believer in realising variations of these famous 43XX monitors for system owners. Being able to put your own signature on the subjective results is about what makes your own ears happy. There are subtle differences in the mid cone and compression drivers. Mixing the older and newer components can bring about individualised “custom” presentations. Each to his own.
Linear X Leap software enables realistic simulations using JBL specifications and even more accurate predictions of system performance with uploaded REW measurements of custom configurations. This takes the guess work out of inserting different diaphragms and drivers in these more complex multi way system. I can provide user defined driver adjustments with RC element values in 1.00 db steps for EQ and level matching. That way the user can accurately determine his / her preferences in his / her room.
Leap AFAIK has been unavailable for a couple of years at least. Do you know of a source now?
Hi Riley.Originally Posted by Riley Casey
The answer is no l don’t. Have a look at the freeware program Heather posted.
I look forward to you posting about a project you have put together.
The creator of Leap did his internship at JBL under Ed May as l recall.
Then later Peter Larson worked with Greg Timbers at JBL developing loudspeaker software.
I have a photo of Greg at a party with Peter with wearing a wig. Those were the good times at JBL.
Today Loudsoft owned by Peter Larson is recognised as the most advanced loudspeaker software available. It starts at around US$10,000 for the analyser. I thought about it but couldn’t justify it.
On that front Erin’s Audio Corner website who had a very costly Klippel analyser has gone belly up after his wife announced she is filing for a divorce.
Those who hold an existing Leap 5 licenses are it. The problems of getting it to run properly on more recent windows software are too numerous to discuss here. Leap 5 requires a Windows PC running XP Most legacy PCs that ran XP are long gone. I run Leap under a licensed virtual environment in a MAC Laptop l had built.
You are best to try your hand at one of the free diy loudspeaker programs if you want to have a go at this yourself.
Leap 5 is a specialised engineering program. It’s not a basic CAD program you can pick up and run with out of the box. The functionality is quite intricate and tedious. It took me a good five years to become proficient at a basic level with the program. There is a significant learning curve and you need to have a solid understanding of crossover network and loudspeaker acoustic design to use it efficiently. Otherwise you end up spending long hours night after night creating all sorts piece meal networks that don’t really work. You also need accurate measurement data or be able to create data for the program.
l recommend you first look at what your loudspeaker is doing using REW which is free.
Accurate SPL adjustments are possible inside your home with some practice. REW is free and has versions for both Mac and Windows. All you need as a mic with a calibration file. With some patience you dial in a cook book passive crossover with REW using an empirical approach. Greg Timbers has explained this is how he originally designed his JBL networks. Predicting a loudspeaker frequency curve with a simulator is a leap of faith (sorry). By varying the crossover R, C and L values you can iteratively work away at something that not only measures good but sounds good.
Something that measures good does not sways sound good because drivers have unpredictable personalities. Just because a new employee interviewed well and had a good resume does not mean the employee will work out. If they don’t fit in the team nothing happens properly. And so it is with developing a loudspeaker.
I've been a Smaart user since it arrived on floppy disks and I'm happy with it at version 7. A new and impressive option is Open Sound Meter https://opensoundmeter.com/ which is also cross platform Mac / Windows, a big sell for me as Win XP was the last version of Windows I was conversant with. Learning to run measurements on a TEF analyzer made Smaart seem very downhill. I was asking about LEAP simply out of curiosity as it's really a different animal entirely from measurement software. I rarely design passive networks as a lifetime of having my cake and eating it too with active crossovers is hard to back up from.
Measurements of the Purple People Eater speaker project are coming soon. Just need to run impedance curves.
Getting back on topic point of my commenting on the Leap 5 software is that with skill and a detailed understanding of the 43XX systems variations for users can be realised with a high degree of confidence. I have a growing portfolio of 43XX measurements using different drivers. I am also looking at different horns and uhf drivers.
Throughout the product life ownership people will at one point or another will want to explore their own ideas and why not. It’s all about enablement of an idea and making it work and realising the result. You don’t need to be an expert when you can get a helping hand when you need it. And you don’t need go down a rabbit hole looking for the software and then learning how to use for a one off change to your system?
For those who want to realise a 43XX variation or their own diy system l am available to offer support.
As to “full active” system it’s a niche and not something that justifies the complexity and investment unless in the hands of a highly skilled user.
Last sentence! Been there, etc. It gets beyond the hobby stage. Thing is, after some years, everything becomes unstable - connections, electronics degrade . . . and you don't realize it at first, the human brain tends to adapt. So, KISS is best philosophy in the real world. And, a well developed passive system sounds plenty good, to these ears, at least. In fact, better in some ways. No magic. I like your "down the rabbit hole" comment.
I run full active 4 way, bi-amp and passive set-up's. There is something to be said for the simplicity of a passive system but even they can have issues such as the dreaded Bi-amp switch and potentiometers. I have had more issues with the pot's in my old school L/R active crossovers. You really need to go into maintenance mode every couple of months to rotate and clean off the whippers as part of it. Plug and unplug connectors and so on.
I would avoid using pot's in new crossovers and use stepped attenuation instead like L250/9800 as examples.
I don't think that's big price to pay and with modern DSP it's not an issue no Pots! One thing for sure if you can take measurements good enough to do a passive crossover you can certainly use them to create DSP filters for an all active system.
The ease of which you can create filters using DSP is impressive so you can try and make changes almost on the fly. Simply can't do that with passive networks so if experimentation is your thing DSP has distinct advantages.
Either way active or passive it's all a fun time!
Rob
"I could be arguing in my spare time"
Looking over my shoulder
To the thousands of lurkers watching this thread try and interpret each post from your own perspective.
Everyone has has their own level of hands on experience, insights and accumulated technical understanding of active crossovers.
Context is a powerful thing in the face of ambiguity and rhetoric.
Putting the above paragraph into context it’s about where your starting from, your goal, your expectations and what information you have and what input you can obtain. This can be a make or break situation on it an active loudspeaker system working out.
In the real world
In the real word at one extreme as Rob comments he manages to dial in a dsp crossover without too much difficulty. But that is an individual perspective and we all exist in a different station in life.
Rob has years, decades of diy loudspeaker experience behind him and number of important skills he has picked up along the way. So Rob’s comments are valid in his situation. But if your curious with what this all about and new to the scene it’s not going to a walk up start. I have personally met people who spent a fortune on state of art jbl drivers and attempted an active system with a DEQX active crossover. They unfortunately ended up selling everything because they gave up trying to make it work. That’s right.
The key ingredients
But don’t let this put you off. Depending on exactly what you think your trying to achieve there can be merit in using an active crossover network. If you have or can obtain all the necessary data, expertise available and have the time to implement it correctly you were will succeed. A good starting point is to have a conversation with myself by going to the link below.
The playing field
Sometimes it’s about reaching an understanding of what’s possible and to de bunking some of the myths and over glorifications that seem to float around cyberspace about active loudspeaker systems.
Most contemporary loudspeaker engineers- designers with real qualifications would prefer to implement their products as active systems. Small active monitors are popular in the home studio market. They are great for getting a much bigger sound than you would expect out of a small bookshelf sized enclosure. But not in the consumer hifi home audio market that has a long heritage of separate audio components. In getting their passive loudspeaker designs to work and in fact sound any good the loudspeaker engineer - designer has to do a lot more massaging with a passive crossover than you might think.
What really goes on inside your loudspeakers?
The passive crossover, the drivers and the enclosure are carefully adjusted to work as a “system” to achieve an acceptable subjective outcome. A passive loudspeaker system must incorporate compromises including losses of system sensitivity, bandwidth, system placement and power handling. We put up with it because it’s what we know and we accept. A full active system can remove some of these compromises. But designing an active system from scratch or converting a passive system into an active system is not a piece meal exercise.
What you need to know when you remove the passive crossover
Referring back to my earlier comments what the loudspeaker engineer-designer did with the passive crossover is now completely removed. What you don’t know is how the system would have been set up if it was an active system in the first place? Passive crossovers general work on the basis of attenuation of sounds across the audio spectrum. Active crossovers generally work by boosting and attenuation of sounds across the audio spectrum.They sometimes pull a few tricks too. These modifications to the tonal balance exist to make the loudspeaker subjectively acceptable to listen to. This is worked out not only with paper graphs but with many hours of listening in real listening rooms and a lot of trial and error error.
Some myths debunked
Your ears are not just listening to a snap shot or a slice of the loudspeaker sound output. Your ears are also listening to the impact of the loudspeaker distributing sound energy into the listening room. The significance of this arises when attempting to obtain the correct tonal balance from the loudspeaker system.
It’s important to have the correct tonal balance at frequencies where your ear is particularly sensitive such as in the 2000 hertz region and at low and high frequency extremes for the system to sound tonally balanced. As mentioned above sound is being distributed into the listening room and does not just stop immediately after it arrives in the room. The sound decays according to the room acoustics. This is referred to the reverberation time and is measured by recording the time required for a sound to naturally attenuate to an inaudible level. Then arrival of the next sound will be masked if the first sound had not attenuated quickly enough.
These aberrations, artefacts are always there whether you are consciously aware of it if not. Depending on the room acoustics these artefacts might be perceived at slap echo, flutter, booming and or ringing resonances. The source or cause of the artefacts exist whether the loudspeaker is in the room or not. An active crossover be it dsp or analogue cannot remove the source or cause of the artefacts your ear hears in the room. It can only modify the apparent loudness or intensity of the artefacts. Attempting to remove these offending sounds can cause a loss of important program information all together.
What’s possible
The loudspeaker engineer- designer has no control over these issues. But adjustments can be introduced in the loudspeaker system to reduce the apparent intensity of certain frequency regions sensitive to your ears in the listening room. The loudspeaker does not exist in an infinity large space in the listening room. The shape of the loudspeaker and the size of the baffle will influence the frequency response and the diffraction of sound from the loudspeaker baffle. To repeat its important to realise that EQ correction & phase adjustments can only influence or modify the apparent intensity of what your ear hears in the room. Not remove the source of the problem.
Sometimes these tonal balance adjustments are permanent contours or they can be switched or variable adjustments with the passive crossover. It’s therefore a good idea to obtain some frequency response measurements of your passive loudspeaker system in your room before attempting to convert it to an active system.
If this is all new to you its best you obtain an active crossover with pre determined characteristics for your particular passive loudspeakers.
I'd be inclined to say just the opposite unless one is simply trying to recreate exactly an existing design as the R&D resources and skills required to iterate passive networks successfully are significantly larger than off the shelf DSP crossovers and a couple extra power amps but to each their own
Each to their own
You are right each to his own and l leave it to people to do as they wish.
But your perspective suggests a plug and play approach (in the absence of the requisite R&D which l have at my disposal).
The Facts
Without an understanding of the individual native driver response and other characteristics on an actual baffle an attempt to do otherwise ( without R&D ) is unlikely to yield a satisfactory result.
No loudspeaker driver has a perfect text book pass band frequency response or phase response. Placement of a driver on a defined loudspeaker baffle can make a significant difference to its native frequency response.
The science
The late Dr Linkwitz in his dsp active crossovers goes to great lengths to demonstrate that an accurate acoustic Linkwitz 4th or 2nd order filter from a driver is far from trivial with dsp. It’s in fact quite a complicated bit of design.
The Pass Analogue Active filter approach
What Nelson Pass explained to me was that he proved to his neighbour Dr Linkwitz that a close equivalent measured & subjective result could be obtained with a correctly designed analogue active system. Dr Linkwitz took some convincing but was so impressed with the Pass analogue active crossover that a kit has been made available at the Diyaudio.com shop for one of the Linkwitz loudspeaker systems.
It should be noted and respected that Dr Linkwitz was a leading scientist in the field of loudspeaker crossovers and in a number of other audio areas. He was also a fastidious advocate of high quality sound reproduction.
To my knowledge Neville Thiele’s patented TM crossover offers superior characteristics over all previous crossover types. However this is quite complex crossover to implement. Again it’s the drivers acoustic response we are referring to not the electrical voltage drive. Douglas Self has in a presentation devised analogue version of the TM crossover.
Perspective
If you are merely after a PA Wall of Sound or simply fun playing with an active crossover then of course none of the above matters too much. I think we have all been there. While such high powered sound systems may be impressive to an audience in an arena they are not designed for critical listening or monitoring in the recording or sound reproduction process.
Sometimes it’s easy to loose sight of the perspective on specific or discrete applications when referring to such technologies. For example Texas Instruments don’t just make a general purpose audio chip these days. They offer chips for a variety of applications from portable lifestyle consumer audio, automotive applications, to consumer hifi and professional sound applications. The environments are all unique as are the specifications.
https://bssaudio.com/en/site_element...ks-white-paper
As l have said previously let your ears be the judge of what you hear and that is a personal thing. The real science behind what you hear is however is well defined.
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