Mondie

Mondie's speaker endgame: Lenard Audio 4-way active, high efficiency horn system development

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I am planning to Rab, and you would be most welcome. I have owned an active system for close on ten years and wouldn't have anything else, or at least haven't heard anything passive that would make me want anything else. Active high efficiency is on another level again

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Super Wammer

Having made some Diy active speakers (2 way only) and using Behringer active xover, along with 2 x A500 amps, and this simple, and cheap system has really blown me away, I am really looking forward to hearing this at Scalford, Simon.

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Progress :) The skeleton of my pair is shown against the prototype I heard and I am happy to see the slightly reduced height and the funky foot incorporating the port for the compound bass. I am struggling to choose a finish though. I like the idea of a funky colour for the horn on a black baffle but that is about the limits of my imagination. I am counting down the days until I have these in my room.

IMG-20170927-WA00011.thumb.jpg.a3b7d213406634abff84134d177d0607.jpg

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How about two tones darker than the room wall finish in your room. The speakers almost disappear  for ultimate waf factor. I think you have see this idea somewhere before.

R

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any colour of chalk paint of your choice , then finish with ...polyvine ... dead flat or silk finish.

all available on line ... not expensive and gives / leaves a pro finish.

simple and effective.

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24 minutes ago, rockhopper said:

How about two tones darker than the room wall finish in your room. The speakers almost disappear  for ultimate waf factor. I think you have see this idea somewhere before.

R

Hi Russell, did you think of that all by yourself, or did you have an 'advisor' 9_9 Your wife might like the shiny mirrored finish these will have on the sides that helps them blend into their surroundings, you can kind of see it on the photo of the black prototypes. Its only the front baffle that I really need to come up with some idea for. Would your 'advisor' have any suggestions?

Cheers

PS I will get back to you on your email, its still in my inbox :$

3 minutes ago, deggie said:

any colour of chalk paint of your choice , then finish with ...polyvine ... dead flat or silk finish.

all available on line ... not expensive and gives / leaves a pro finish.

simple and effective.

Thanks for the idea Deggie, never heard of the stuff so will do some googling :^

Edited by Mondie

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It’s time for a new year’s progress update on my final speaker system.
 
When the Symphony started development, the plan agreed with John was to use quad 12’s per side in a dual compound configuration for Fq < 90Hz. Back in October, John and Paul did a range of tests over a week to optimise the bass cavity design and volume using a test jig made to allow real time cabinet volume changes. Surprisingly, the testing showed that there was an audible difference between 2 x 12" single or 4 x 12" compounded configurations. This was totally unexpected as Paul explains:
 
"Johns work on the Sarabande many years ago revealed that using compounded drivers on the bass unit enabled the use of less expensive drivers with 100% reliability.  (2 voice coils, double cone, improved stiffness, linear movement). The main reasons for planning to use compounded 12" drivers, two pairs/side in Symphony were:
 
1. inexpensive, readily available drivers can be reliably used.
2. We knew we would be throwing considerable power and some eq at the bottom end in this system.
3. Marketing - People like the notion that system has 4 x 12” drivers inside it. (Regardless of the sound)
 
With only 4 x high power generic 12’s to start with and after testing the first prototype, we needed to test as a stereo pair. We ditched the compounding to be able to move on with testing and used only 2 drivers in each unit (non-compounded). An unexpected consequence was that an audible difference was detected in that the bass appeared to be deeper and flatter in response. (No Eq had been applied at this stage).
 
So, out came the testing Jigs and we experimented with different drivers, compound / non-compound, port lengths and chamber volumes.  Critically listening in the bandpass was undertaken followed by FR measurements for confirmation. Our testing revealed that indeed there was a difference between compound / non-compound but only when using compound pairs and not in the smaller Sarabande single compound / non-compound unit.  We have not yet identified the reason for this, but it’s kind of irrelevant given we simply use that which gives the best performance.
 
The results showed that chamber volumes/ratio, port length and area were in the ballpark. The compound pairs had a much larger peak in the FR whereas the single pair was flatter and went a little deeper.  (Reasons yet to be confirmed with more testing). With some fine tuning to the port area and length we got to a point that was not expected from a cavity drive bass system, requiring much less Eq to stitch it to the 15”mid. The end result in this application is that the non-compound pair wins! John reckons, backed by his fifty years of experience designing bass, that the final Symphony cavity design delivers bass energy equivalent to 2 x 15” high-efficiency drivers in a 500 litre sealed box. And it does!"
 
I have decided to use the saving in 12" drivers required (8 down to 4) and utilise the ultimate drivers we could find for this application. ( it’s endgame remember :) ) The non-compound design requires drivers with higher power handling & linearity, but offers more driver choice as they can be 8ohm, and not 4ohm as necessary for compounded pairs. The guys at Lenard had a long technical exchange with Acoustic Elegance, after which, we decided to go ahead and have them modify one of their 12" drivers specifically to suit this application. Around the same time, TAD let me down on the supply of 1601a's so I decided to go all in with AE and also order a pair of TD15m's with Apollo upgrade for the mid bass. My order of drivers arrived before Christmas, we now have all drivers in hand for the project with just the manufacture of the horns outstanding.. Finally, the Lenard team are ready to make a start on building the finished design in the coming months with just the final aesthetics to be decided. Fortunately, work has me returning to Oz in Feb, where I get another chance to hear the protos and check on progress. I cannot wait‼
 
For now I just have a few more driver pics from Paul to tide me over.
 
27681054149_f2aa5b6103_h.jpg
 
38749907064_16aa7381d7_h.jpg
 
27681054429_2e4debbe5a_h.jpg
 
38749907274_715d30874f_h.jpg
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Very nice and thanks for sharing the pics - I look forward to seeing more! 
I love my AE drivers and hope these speakers turn out well for you! :D 

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Super Dealer

I don’t recollect TAD having production difficulties with the dynamic drivers the compression tweeter was often in short supply.

Keith

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Think you are correct Keith, they ceased making the 4001 just recently, the 703 has been obsolete for at least a decade but the 1601a is still made in small batches. They just could not supply me with any in a timeframe that suited.

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Super Dealer

I hadn’t realised they have stopped the 4001, Ralph ( Cessaro) used to buy every 703 TAD made, he had a large unit full of them, they are nice drivers.

Keith

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John and Paul of Lenard Audio are back into final prototype optimisation. A new test jig has been constructed to allow comprehensive testing of the bass engine configuration and fully resolve its design. This will allow on the fly adjustment of parameters, both electrical and physical and comparison of various custom drivers in single and compounded configuration, final port tuning and reduce any requirement for EQ.  Results should be available next week. Some preliminary testing conducted with the existing Sarabande test rig, however, found anything up to 3dB in efficiency between different low-cost drivers. The big AE12's have the potential to be mega and take the systems bass dynamics and sheer visceralness to unimaginable levels based upon what I have already heard.

Paul linked me to this video of prototype open-air measuring and testing. They exhibit flat energy response across the entire frequency spectrum at these volumes in open air!

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Hi Simon,

Interesting reading, any updates ?

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Hi Joolz,

Slow progress, trying to source suppliers in Australia that are dependable and do good work is hopeless and this has slowed things down greatly. Paul and John of Lenard have also been quite busy sound treating local community halls and building & installing large-scale active horns systems. This has taken their focus for much of the year but they are back on Symphony and development of a much smaller 3-way active.  Its just a waiting game but I am hopeful the speakers will be done within the next four months.

I am more patient than I ever gave myself credit for!

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Looking forward to how this all turns out, it's an avenue I could see myself going down in the future.

Best of luck with these Simon, it often takes someone like you to start a seed germinating in others minds.

Aparently patience is a virtue......or so my wife tells me.

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