Janszen Model 1 (New ESL & Woofer Arrangement)

[bolserst]

I just noticed one of the pictures on the Janzen website for the Model One looks quite different than the pictures in the Whitepaper and those I'd seen elsewhere on the web and in magazines.

In particular:
1) the ESL panels now seem to be aligned vertically rather than being canted over an angle which had been done to minimize diffraction effects. The ESL is still looks to be a monopole rather than a dipole as is typical for an ESL

2) the one large woofer at the bottom has been replaced with two 8" woofers...one top, one bottom. The two woofers appear to be different, the one on the bottom having a phase plug, the one on top a regular dust cap.

I've seen W-ESL-W arrangements before, but usually the woofers are the same.
Interesting....
my guess is that the lower woofer crosses to the ESL. The upper woofer perhaps is used to provide more uniform low frequency response (30hz-100Hz) at listening levels above the middle of the panel.

[MJ Dijkstra]

The canted esl of the former esl looks irrational to me.
The latter (with two woofers on opposed sides) makes me think of a dutch hybrid design by E. Fikier. He put a woofer on top to improve bass response in room. However in case of Janszen this is (at least partially) spoiled by a second woofer at the bottom...........

[Capaciti]

Hi,

if i look to the (animated ?) picture of the speaker, i am wondering about low frequency performance. If the ESL is covered from the back, consuming some housing volume, there is nothing significant left for the woofers.

I doubt a few gallons volume for the woofers will enable low frequency performance correlating to the product pricing.

Capaciti

[bolserst]

Originally Posted by Capaciti

Hi,

if i look to the (animated ?) picture of the speaker, i am wondering about low frequency performance. If the ESL is covered from the back, consuming some housing volume, there is nothing significant left for the woofers.

I doubt a few gallons volume for the woofers will enable low frequency performance correlating to the product pricing.

Capaciti

I believe the woofers have built in amplifier and equalizer, so cabinet volume is not as much of a concern as for a passive woofer. But, two 8 inch woofers , even if they had a clean Xmax(peak-to-peak) of 1 inch would still not be capable of significant output below 40Hz. Perhaps there is a larger external subwoofer, or one hidden on the back side.

It is a bit hard to find now, but here is the link to the whitepaper I found...

http://www.janszenloudspeaker.com/4s...aper%20web.pdf

[JeffL]

Could be David JansZens ESL answer to the ORION++ .
.
AudioPhiles trying to analize the sound difference , would make fascinating fiction ( wide range of String Instruments playing at same time , might satisfy my curiosity ) .
Close recorded Acoustic Guitar on my old ESLs were fabulous .
.
Only my Sennheisers gave a simular sound .SENNHEISER HD414 DIST% hd414 "classic" headphones
.
We all had these Sennys , before HiFi Speakers , in the early 70s ... JeffL

[DavidJanszen]

There are two woofers, one above and one below the ESL line, to better match the cylindrical shape of the ESL's sound front, to reduce excitation of room modes, and so that sound arriving from the woofers is in phase with itself and with the sound from the ESL's when one is seated. It also gives us the opportunity to use dissimilar woofers, so that the inevitable cone coloration is reduced, not that there is much when the upper cutoff is set at 225 Hz.

The woofers are not powered in the standard version, and the case is sealed, yet the in-room response extends to 30 Hz.

I do not believe that exceptional bass authority is what warrants a high price, but exceptionally clean, clear and natural sound reproduction combined with striking industrial design does. If someone wants more bass, subwoofers are widely available, and even we will have one available pretty soon, too.

The tilt on the ESL module in the original, fully powered version was to distribute the diffraction interference frequencies so that none dominates. In fact, there is very little diffraction interference in this design to begin with, and the small improvement was far outweighed by audience aversion.

[Capaciti]

Hi Davidjanszen,

certainly you put some right thougts on the design of this speaker.

My experience tells me that the upper woofer will put a lot of movement in the construction when playing 30 Hz with extended excursion. The distance to the bottom is long and the standing area just limited.

The only way to handle this waste of stability is to set a second woofer on the back side in order to compensate the impulsenergy of both woofers to zero. But this doesnt work with crossover frequency at 225 Hz.

On the other hand a calcuation ot wavelength at 225 Hz indicates that the distance between the lower and upper woofer is too long. As a result the woofers are not working as a common source but will interfere frequency response depending on listening distance


Capaciti

[MJ Dijkstra]

The design of E. Fikier (published in Elektuur) deals with these vibrations by putting the woofer encloser on three pvc tubes filled with sand. The back pvc-tube worked as a diffusor for the esl at the same time.
The whole thing looked quite ugly in my opinion, but it is claimed to be effective.
Not something to commercialize I think, but that me be food for thought for Davidjanszen

[bolserst]

Originally Posted by DavidJanszen

The tilt on the ESL module in the original, fully powered version was to distribute the diffraction interference frequencies so that none dominates. In fact, there is very little diffraction interference in this design to begin with, and the small improvement was far outweighed by audience aversion.

I had tried a similar diffraction distributing baffle technique last year with good results...tilting the baffle instead of the panel.
However, even with the wings made of plexiglass so as to be less obtrusive, the whole affair was still a bit offsetting to most people.
Personally I thought it looked rather...purposeful, and modern.
I can't seem to find any pics I took of it, but here is a graphical representation.

[DavidJanszen]

Originally Posted by bolserst

I had tried a similar diffraction distributing baffle technique last year with good results...tilting the baffle instead of the panel.
However, even with the wings made of plexiglass so as to be less obtrusive, the whole affair was still a bit offsetting to most people.
Personally I thought it looked rather...purposeful, and modern.
I can't seem to find any pics I took of it, but here is a graphical representation.

Looks cool to me. I was urged by an industrial designer to make our panels parallelograms, only after it was too late. It would not have made the best use of the panel area, anyway, but I suppose it might have elicited less resistance.

The first question from every single man who saw the original Model One was, "Why are the ESL's tilted?", often with an undertone of, "What kind of ** is this?". A majority of women seemed to like it visually, though, and didn't seem to care much about the purpose.

You build your own ESL's? Other type panels?