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

[bonzo75]

http://zero-distortion.org/tad-4003-dual-woofer-flh-leifs-system-norway/

The article covers a visit to one of the top 3 systems I have heard, based on a TAD 4003 dual woofer FLH, entirely DIYed. The article discusses the attributes of beryllium, of TAD 4003, Leif’s approach and philosophy and experience. I stay light on the nitty gritties of DIY to avoid turning this into a DIY post, and keep it sonics related. It has many videos and those who don't appreciate videos can make sense reading through, though the videos add to the context. Videos are for context to be read with the text, so judge by the written description. Thanks.

Apologies it is long and can be done in parts

 

[the sound of Tao]

Fantastic thanks Ked, so much great everything, love it. Great report and the insights are concentrated through out. Love Leif’s setup. This seems almost summative and is one of your best. 5 stars.

 

[Duke LeJeune]

Thank you Ked, thoroughly enjoyed your article!!

 

[Ron Resnick]

Thank you for this fantastic report, Kedar! Congratulations to you for having the interest, determination and perseverance to drill down to the bottom of all of these questions and alternatives and figure it all out from the outside!

I also like the way you described the "Yoda" aspects of these true experts who experimented and educated themselves and honed their knowledge for years to arrive at the music reproduction systems and implementations they now enjoy.

1) Why so you feel open baffle does not sound as good as FLH? Couldn't you add drivers to the open baffle (three or even four 15" drivers) to match the sonic weight of dual FLH?

2) Which commercially available, current production speaker do you feel most closely duplicates (even if it does so with a totally different design or different parts and pieces and different implementation) the sound you like from Leif's DIY system?

3) Are TAD 4003s a good investment?

 

[the sound of Tao]

3) Are TAD 4003s a good investment?

only if I can afford them... and like a Rolls... if you have to ask I’m thinking I better not ask.

I actually really got this time (from the videos) that essential difference between flh and OB... that added viscera and impetus in the lower mids... it would be ideal for expressing power in big orchestral works.

I think I may still prefer the coherence and scale of my 2 way OB in many ways for medium and smaller scale music but when the big scale orchestral forces are unleashed in large scale symphonic works or even opera or big band jazz I can see now just how compelling this approach with flh would be.

I’m even more signed on now to doing a big horn setup for the big music moments. Ked’s journey has made some considerable contributions to broadening horn system understanding and the videos are definitely helping to bring this to life.

 

[bonzo75]

Thanks Ron

1) Why so you feel open baffle does not sound as good as FLH? Couldn't you add drivers to the open baffle (three or even four 15" drivers) to match the sonic weight of dual FLH?

In some ways these horns sound OB though they have the benefit of horn loading, which increases db output, approx. 6db gain. Depending on design, the midbass horn cabinet can be open at the back, closed (open only in front), or like Leif's have a vented diaphragm at the back for a rear wave.

OB is more light weight than cones though more free. To add the same amount of weight as a cone you need to increase number of woofers. If you take 16 ohm drivers, every pair that you add in parallel, the impedance halves. So if you start adding more than two pairs, you start going below 4 ohms and you don't want to lose the SETs low grip advantage. Yes biamping SETs and SS is a possibility but that adds to complexity.

So I like to keep it to two pairs. Hence the dual.

Horns for acoustic gain, and front firing horns to match dispersion to the top horn. Hence dual front horns.

Google Nelson Pass' SLOB, that is an OB that can be done very inexpensive, the cost is the cost of the drivers used. I have never heard one, but the people who do it usually use a more full range driver like Lowther , Feastrex or AER

2) Which commercially available, current production speaker do you feel most closely duplicates (even if it does so with a totally different design or different parts and pieces and different implementation) the sound you like from Leif's DIY system?

Audioquattr's Cessaro Zeta is a dual FLH, and Tang's Cessaro Gamma also is all front firing except with a circular midbass horn. Crossover points are different, and they have three drivers for the upper half itself. Their upper half is all TAD, the issue I have is that they are tougher to drive and I can hear that. The TAD woofers used by them are also better known for box loading rather than horn loading, and I can hear that too. Also note that Leif's drivers are vertically much closer together than the Cessaro Gamma, this works for a better point source coherence unless you have very long distance to sitting position.

I think Volti is trying Altec type VOTs but not sure how good they are.

 

[bonzo75]

I think I may still prefer the coherence and scale of my 2 way OB in many ways for medium and smaller scale music but when the big scale orchestral forces are unleashed in large scale symphonic works or even opera or big band jazz I can see now just how compelling this approach with flh would be.

You can have two way in dual woofer FLH. The Altec 817 is two way, because the midbass horn cabinet has vents taking over for lower bass, so it is combined into one with only one crossover to the driver above. If you use the JMLC (the circular horn for those who don't know what JMLC is) for the midrange, you get beaming at higher frequencies, and have to add a tweeter or another compression driver above that, but if you use constant directivity or Markus Kulg's Altec multicell horn, you can go up all the way till the driver rolls off

 

[kodomo]

http://zero-distortion.org/tad-4003-dual-woofer-flh-leifs-system-norway/

The article covers a visit to one of the top 3 systems I have heard, based on a TAD 4003 dual woofer FLH, entirely DIYed. The article discusses the attributes of beryllium, of TAD 4003, Leif’s approach and philosophy and experience. I stay light on the nitty gritties of DIY to avoid turning this into a DIY post, and keep it sonics related. It has many videos and those who don't appreciate videos can make sense reading through, though the videos add to the context. Videos are for context to be read with the text, so judge by the written description. Thanks.

Apologies it is long and can be done in parts

First of all, I want to say that this is one of my favorite systems even though I have not listened to it.

This is very much what I was telling Graham to go for. I guess the jmlc horn is 270hz and not 350hz cutoff though. This horn would load lower but you will loose more vertical space. I would put the tweeter channel on the ear height but the rest is how I would do it too. The lower bass solution is original as he has a very good consultant so I would not comment on it but an alternative could be my aligned servo open baffle bass solution too. I have tried tapped horns and chose OB. Tapped horns look like this but Leif explained that this is not a tapped horn.

 

[bonzo75]

First of all, I want to say that this is one of my favorite systems even though I have not listened to it.

This is very much what I was telling Graham to go for. I guess the jmlc horn is 270hz and not 350hz cutoff though. This horn would load lower but you will loose more vertical space. I would put the tweeter channel on the ear height but the rest is how I would do it too. The lower bass solution is original as he has a very good consultant so I would not comment on it but an alternative could be my aligned servo open baffle bass solution too. I have tried tapped horns and chose OB. Tapped horns look like this but Leif explained that this is not a tapped horn.

Yes this is 270 but his friend who has a TAD 4003 dual FLH uses JMLC 350 as he has a smaller room and the vertical space is more important for him. For Graham space is not an issue. Radian in Universum is in a JMLC 200T, and Markus Klug Altecs iirc are 270. So with those FCs, all the crossovers between 500 to 700 are possible and equivalent TAD, Altec, JBL, Radian, etc can easily be rotated as long as driver impedance is the same, with using LPAD to attenuate for driver differences. Regarding bass solution, Leif's is too big, I will look at slotted open baffle or Bill Fitzmaurice's bass horn or Lab subs, which don't cost much unless you beautify them like Living Voice does

 

[the sound of Tao]

I can’t tell you how much you guys are helping... just gobsmacked at the quality of knowledge here.

 

[bonzo75]

I can’t tell you how much you guys are helping... just gobsmacked at the quality of knowledge here.

Actually, what I wanted to highlight in my article is that the knowledge existed starting 100 years ago to a few decades recently, then we moved from the likes of led zep in the 60s and 70s first to punk rock, and before you knew it spice girls and that Canadian kid were superstars, because people who listen to MTV top 20 can't see beyond that

 

[the sound of Tao]

Actually, what I wanted to highlight in my article is that the knowledge existed starting 100 years ago to a few decades recently, then we moved from the likes of led zep in the 60s and 70s first to punk rock, and before you knew it spice girls and that Canadian kid were superstars, because people who listen to MTV top 20 can't see beyond that

Well unfortunately I remember all of those things Ked except for the 100 years ago bit thank heavens. I love exploring the development of both music and audio. Music is living and breathing and so is audio... we need to look to all ends of the spectrum and then look to our hearts and our mid-ranges about where any truth can possibly be because I feel that is where it all starts... and where it all ends. We are blessed with riches in both. Everyone’s truth lays in their own places. For me it’s mid-range that is the heart of music. Then teasing that out to reach up to brilliance of the heavens and down below to the deep comforting darkness of earth. In these great poles we find truth in the musical centre.

 

[christensenleif@msn.com]

If it ain´t got that swing, it don´t mean a thing
just one thing;
it was first when I got horns in all "bands" that the sound snapped into focus and integrated 100%
BR, SLOB or even OB may have more fun factor, but my experience is that mixing principles in speakers, is/can be a suboptimal approach
the round alu amps in the first pic, are FW F5 with choke input psu...a pain to get working, but among the best ss amps I´ve heard

enclosed is link to my bassamps build
https://holtonprecisionaudio.com/bl...-power-hpa-nxv800-mono-block-tower-amplifiers

 

[bonzo75]

What happens if only the lower bass horn, below 75, is not FLH

 

[christensenleif@msn.com]

Yes this is 270 but his friend who has a TAD 4003 dual FLH uses JMLC 350 as he has a smaller room and the vertical space is more important for him. For Graham space is not an issue. Radian in Universum is in a JMLC 200T, and Markus Klug Altecs iirc are 270. So with those FCs, all the crossovers between 500 to 700 are possible and equivalent TAD, Altec, JBL, Radian, etc can easily be rotated as long as driver impedance is the same, with using LPAD to attenuate for driver differences. Regarding bass solution, Leif's is too big, I will look at slotted open baffle or Bill Fitzmaurice's bass horn or Lab subs, which don't cost much unless you beautify them like Living Voice does

my son has the Bill Fitzmaurice THT hornloaded sub with a single Dayton 15" and I really like it...can be used up to 250ish

 

[christensenleif@msn.com]

What happens if only the lower bass horn, below 75, is not FLH

won´t integrate as well imo
different speed, accelleration (start/stop) sound character

 

[bonzo75]

Yes but my question is below 75, more disturbing does that get sonically? Could you have lived with it

 

[christensenleif@msn.com]

Yes but my question is below 75, more disturbing does that get sonically? Could you have lived with it

that´s what I responded to above
I did with my dual custom Bert Doppenberg designed woofertowers for my Trio´s
4x15 per side in matrix BR/Onken style cabs
Trio owner who bought them is very happy
kept them till Rune volunteered to design some proper subhorns
one of his earlier projects

 

[kodomo]

What happens if only the lower bass horn, below 75, is not FLH

It already is not a front loaded horn in his system at least not a purely done flh. So I guess it is ok The last photo he put is flh bass horn.

I tried tapped horns, sealed woofers, bass reflex woofers and OB. OB bass with enough drivers, power, correct positioning in the room works very well with the horns and sound very well together. This also is not a new idea, however using rythmiks patented servo system with it like I do is new. I liked how it blends so much that I used it in my new design as well.

 

[bonzo75]

What's the size of your OB