Zero Distortion: Leif's System with TAD 4003 based dual FLH

[kodomo]

His jmlc has rollback, so we are talking about evaluating autotech jmlc with rollback vs autotech minphase for the same cutoff

Ok, maybe I was not clear enough. JMLC and minphase each use a different function to get their respective curves and it has different effects. If you have the same cutoff for both, let's say 200hz, the jmlc mouth size will be slightly larger and the depth will be nearly twice the size of minphase. However the JMLC will load lower than minphase and minphase will have a slightly better off axis response. It all depends on what you need to achieve.

 

[christensenleif@msn.com]

min phase won´t happen here
next up is a huge K-402 inspired conical CD horn with tractrix roundoff, in which the 4003 behaves perfect with even dispersion over 75 degrees from 600 to 18K
no tweeter only hp filter...KISS
a prototype is finished and measured, already playing in friends system across the fjord...only waiting for complex CAD drawings for CNC
super precision specially 3D printed throat adapter
supersmooth, huge, even soundstage and growl like JBL2360
4003 is the only driver pulling this home without tweeter
all the rest have to low sens in the hights, breakups or both

here ´s a pick from measuring session in friends/designers basement:
the big to the left is 112cm wide...the one to the right 84 to better visually match the FLHs

 

[christoph]

even if someone decides they like JMLC, it is then resin vs wood,

Have you ever knocked on the Universums midhorn?
It is rather inert
Far from the flimsy plastic horns other manufacturers use

 

[Audiophile Bill]

min phase won´t happen here
next up is a huge K-402 inspired conical CD horn with tractrix roundoff, in which the 4003 behaves perfect with even dispersion over 75 degrees from 600 to 18K
no tweeter only hp filter...KISS
a prototype is finished and measured, already playing in friends system across the fjord...only waiting for complex CAD drawings for CNC
super precision specially 3D printed throat adapter
supersmooth, huge, even soundstage and growl like JBL2360
4003 is the only driver pulling this home without tweeter
all the rest have to low sens in the hights, breakups or both

Have you the frequency response data for this with 4003 versus JMLC yet, Leif. Presume you’ll lose acoustic gain with this conical/Tractrix hybrid?

 

[kodomo]

So when you draw the function according to formula and certain cutoff (cf) do not think all functions will behave and load in the same bandwidth. A conical would nearly load down to cf, a tractrix will be loading about half octave over cf and jmlc is close to that (they can however be reactance annuled and taken lower for midbass purposes), however the minphase would be loading higher than all those. Each function ahs certain qualities and they can all be used according to rest of the design.

 

[Audiophile Bill]

So when you draw the function according to formula and certain cutoff (cf) do not think all functions will behave and load in the same bandwidth. A conical would nearly load down to cf, a tractrix will be loading about half octave over cf and jmlc is close to that (they can however be reactance annuled and taken lower for midbass purposes), however the minphase would be loading higher than all those. Each function ahs certain qualities and they can all be used according to rest of the design.

Hi Kodomo,

Doesn’t one need to overlay the fact that the acoustic gain irrespective of *where* it occurs, which is different per profile, but also the amount of gain per se. So conical horn loading provides less acoustic gain full stop in all the data I have seen vs say Tractrix.

 

[kodomo]

Hi Kodomo,

Doesn’t one need to overlay the fact that the acoustic gain irrespective of *where* it occurs, which is different per profile, but also the amount of gain per se. So conical horn loading provides less acoustic gain full stop in all the data I have seen vs say Tractrix.

Yes, each has different qualities that would work better in different ways in different designs. Be it gain, lower loading, smoother response, better off axis response etc. That is what I was trying to say, it all depends on how it is utilized.

 

[Audiophile Bill]

Yes, each has different qualities that would work better in different ways in different designs. Be it gain, lower loading, smoother response, better off axis response etc. That is what I was trying to say, it all depends on how it is utilized.

Yes you are perfectly clear to me - thanks.

Did you test conical mid bass in yours at all?
I had assumed wrongly that Leif was using full horn loading in his mid bass not a conical horn. I note OMA and Sierra using conical mid bass too.

 

[christoph]

LV also mixes radiation patterns in different bands, which I don´t think is a good thing
that said, they were still among the best sounding systems when I attended Munich 2018
by rotating the TAD 703, they can in a certain way influence the perceived soundstage height, width and depth and minimize diffraction issues
I did the same when I rebuild my AG Trio to Quattro by adding a JBL 2405 ring radiator tweeter with a "slot horn"

The LV VO shouldn't sound as good as it IMHO absolutely does
And yet it is year after year my favorite room in Munich

 

[christensenleif@msn.com]

Have you the frequency response data for this with 4003 versus JMLC yet, Leif. Presume you’ll lose acoustic gain with this conical/Tractrix hybrid?

not available now
we´ll have to take down the 4003 by 7-8db to shave off lower range to match FLH, like shelving in a way
so net system eff will maybe be 107 instead of 112, but with simpler filter it´ll probably be compensated load wise
I´ll find out if it´s a JMLC replacement or not when I have it playing in my room with optimized new passive filter

 

[kodomo]

Yes you are perfectly clear to me - thanks.

Did you test conical mid bass in yours at all?
I had assumed wrongly that Leif was using full horn loading in his mid bass not a conical horn. I note OMA and Sierra using conical mid bass too.

If I get you right you have a point but now we are getting into more technical territories There is a very nice explanation here on this paper without getting too technical, it is a widely available paper.

 

[Audiophile Bill]

If I get you right you have a point but now we are getting into more technical territories There is a very nice explanation here on this paper without getting too technical, it is a widely available paper.

Yeah I read this one.

I haven’t decided on my mid bass geometry still although likely Tractrix based on my horn resp models. Will do some more tests.

Thx

 

[christensenleif@msn.com]

or you buy the "Norwegian Bible" by Dunker and Kolbræk

 

[kodomo]

Anyone who even has a slight interest in horns should get that book. I love it and check it quite a lot!

 

[christoph]

min phase won´t happen here
next up is a huge K-402 inspired conical CD horn with tractrix roundoff, in which the 4003 behaves perfect with even dispersion over 75 degrees from 600 to 18K
no tweeter only hp filter...KISS
a prototype is finished and measured, already playing in friends system across the fjord...only waiting for complex CAD drawings for CNC
super precision specially 3D printed throat adapter
supersmooth, huge, even soundstage and growl like JBL2360
4003 is the only driver pulling this home without tweeter
all the rest have to low sens in the hights, breakups or both

here ´s a pick from measuring session in friends/designers basement:
the big to the left is 112cm wide...the one to the right 84 to better visually match the FLHs

Very intriguing Concept/Design

 

[christensenleif@msn.com]

Anyone who even has a slight interest in horns should get that book. I love it and check it quite a lot!

Thomas lives 20km from me and wanted to come over with a copy and listen after Runes comments, but then came the Chineese bug.....

Thomas lecture at the ETF in Belleme last year was very interesting and entertaining

 

[Audiophile Bill]

or you buy the "Norwegian Bible" by Dunker and Kolbræk

Already bought that when it came out

 

[Alrainbow]

Not all servo are the same. Do not get hang up on the old servo approach what rythmik is doing is different. For more explanation on their approach: http://www.rythmikaudio.com/DirectServo.html

Servo control is an reaction to an event already passed , no matter who makes it and while i like and have servo’s myself its far from natural vs conventional done right , its nice but not as natural sounding IMO.

 

[Alrainbow]

Because open baffle bass seems to load my room better and they can be physically time aligned with the rest of the system which is another step forward in coherency.

I also think the room and the speakers as one unit so the bass to horns are crossed over according to my rooms schroeder frequency. Above the schroeder (about 115hz) my horns work where directionality is more important, below the schroeder, ob bass takes over where room loading is more important. I also have treatments according to my measurements, so I have both good frequency response and a very linear decay throughout the band.

Question ?

Doesnt OB designs have more distortion and suffer from nonlinearities in the bass vs enclosure type ..?

Is this why most choose to use boxes ..?

 

[Alrainbow]

I discussed these with Leif, whether to have bullet tweeter, a small compression driver instead of the bullet, inside, in between, or above.

He has an old one where it was inside

View attachment 68944

Ked ,

Are these systems mono or stereo setups?