Janszen Model 1 (New ESL & Woofer Arrangement)

[bolserst]

Originally Posted by DavidJanszen

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?

Yes, I have been building my own ESL panels. Most have been hybrids crossing at 250Hz - 350Hz. But, even with "perfect" measured integration somehow my ears/brain still sense a discontinuity at times. More so in some rooms than in others, which led me to believe it has to do with the differing radiation pattern between the two sources; cylindrical for ESL, point for woofer.

After getting to hear several full range ESLs two years ago I was struck by the absolute seamlessness of the sound. There were the short comings of lean midbass and low efficiency however. But, I was bit by the ESL bug again, and have been working toward the goal of extending the low end of an ESL panel by a couple of octaves to cross over in the 70Hz-90Hz range. With the size of the wavelengths here in the range of room dimensions, my thought is that the differing radiations patterns won't be as audible. By resisting the temptation to go full range, I hope to keep the efficiency up near typical hybrid levels.

[Calvin]

Hi,

the solution to seamless integration of dynamic bass and tall thin ESL panels has been posted in this forum since long
Same distribution pattern and symmetrical crossover response.
Just two bass drivers on top and below a panel don´t create the same cylindrical pattern as the panel´s, especially not if crossed over too high.

jauu
Calvin

[MJ Dijkstra]

Originally Posted by Calvin

Hi,

the solution to seamless integration of dynamic bass and tall thin ESL panels has been posted in this forum since long
Same distribution pattern and symmetrical crossover response.
Just two bass drivers on top and below a panel don´t create the same cylindrical pattern as the panel´s, especially not if crossed over too high.

jauu
Calvin

Hi
Whether these are THE or the only solutions I don't know. In fact I doubt. Remember, as we sit in a chair we do not listen to a radiationpattern. You could ofcourse say that there might be some leveldifference between ESL and woofer upon different listeningpositions though I have to see some measurements which prove this to be relevant in a normal living room.
Also the radiation pattern of the ESL itself usually is not constant but depends on frequency as well.

In my experience some woofer designs can sound quite coloured which makes them not the best match with an esl. So poor integration if you like.
For example the old sequel2 model of ML in which the panel resonances could be easily felt by putting your hand on the enclosure.

[Calvin]

Hi,

I should have been more specific. the distribution character should be same or at least very similar minimum +- 1octave around the crossover frequency.
With the Sequel not only distribution character changed the amplitude response of panel and bass crossed over very asymmetric. On the panels side something >24dB/oct on the bass side just some 6dB/oct. This should be audible under any condition. To drive the panel down into its resonance just added to the problem.

jauu
Calvin

[DavidJanszen]

Originally Posted by Calvin

Hi,

the solution to seamless integration of dynamic bass and tall thin ESL panels has been posted in this forum since long
Same distribution pattern and symmetrical crossover response.
Just two bass drivers on top and below a panel don´t create the same cylindrical pattern as the panel´s, especially not if crossed over too high.

jauu
Calvin

I think there should be a forum rule that people should actually read a post, and then think for at least two seconds before they respond, because posting here would then feel less of a waste of time.

To spell it out as clearly as I can for you, I did not write that this created "the same cylindrical pattern". That is impossible anyway for any transducer or system of transducers, I indicated that it is an improvement over a single woofer near the floor. I wrote, ". . . better match the cylindrical shape of the ESL's sound front . . . ". Please think twice in the future before implying that someone is an idiot. While you're at it, you might want to try not hanging your own self with unsupportable statements while rebutting imaginary points.

[Calvin]

Hi,

the demand for same or at least similar distribution character has been researched and can be found in literature. Sharp breaks in distribution character have been found to be audible (see for example the threads about wave guides). Same is said for differing steepness of flanks in the crossover region. This is not specific to ESL hybrids or line sources, but applies generally.

@David: for "match" the dictionary tells me "conformance, identicalness, concurrence, et al". As a non native english speaker this sounds equal or very similar to "same" to me. Sorry for my imperfect english knowledge. So, to avoid future misunderstandings I suggest we both conclude in german from now on. My responses will be perfectly correct. I hope Your german is too!! And don´t be afraid, I won´t call You idiot like You did!
Besides, post #12 and #14 answered to post #11 and #13, both not of Yours.
#14 has obviously neither been read nor understood by You. So why don´t you simply stick to Your own postulates to read and understand and especially the one about implying that others might be idiots! There´s no reason to get impertinant and I will certainly report Your insult to the mods. it would be nice too if Your posts would become on topic again.

jauu
Calvin

[DavidJanszen]

Sorry, Calvin. I do not speak German at all. Did not realize that you are not a native English speaker. I was reacting to the now apparent fact that, as a result of your loose translation, you concluded that I was making an idiotic claim. I would have been an idiot to think a match is even possible, never mind to claim this characteristic exists in our designs. I was not calling you an idiot. I was saying that you implied that I am an idiot.

I claim only a better match, among other things, for our dual woofer arrangement. At any rate, modifiers like "better" make all the difference, and should not be skipped over when reading. When you respond to something different than what was actually written, it tends to obscure what was actually written.

As to your post #14, I can not see how my lack of response means I did not understand it. I understood it, being clearly written, but do not see how it relates to your initial criticism of what you incorrectly thought that I wrote.

FWIW, compromises in M-L designs, most apparent in the smaller and less expensive ones, indicate that they were designed for non-audiophiles, not that this has anything to do with the thread topic, namely our dual woofer arrangement. Now, if we are insisting on discussing M-L, let's try to find something to say about the CLX, or the new Summit with its dual woofer arrangement that goes from bipole to dipole below around 160 Hz . . . at least that would be partially on topic.

[Calvin]

Hi,

this is no ML-Thread of course, but I chose the Sequel as an example, because its design is well known to many people and it is a prime example of how to design a hybrid so that seamless integration of bass and panel must fail. A 2 driver bass system one atop and one below the panel is afaik certainly a step in the direction to control distribution character in the bass region too. As Capaciti already mentioned problems of interference should be kept in mind when the distance of the drivers falls into the range of the wavelengths involved with the working range of the driver. Adding one octave to the crossover frequency (as ´safety´ reserve) the wavelengths could already be smaller than the driver´s distance (170Hz for example: -->340Hz -->1m wavelength) and interference effects can occur.

jauu
Calvin

[bolserst]

Originally Posted by 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

I had the same thought about the woofers being too far apart to sum properly. Obviously they won't sum properly from floor to ceiling, but I wondered how well they would sum at a typical listening postion of 10 ft away with your ears no lower or higher than the bottom and top edges of the ESL. Assuming I did my summation calculations properly, things look to work out quite will for a 225hz crossover. Not perfect, but I could be convinced this works out better acoustically than just a lone woofer on the floor. I did a summation straight up at 90 degrees as a check to make sure I got a null at 1/2 wavelength of the distance between the drivers( I estimated 5 ft).

Now the shaking of the cabinet due to the upper woofer mass being so far from the base of the cabinet...that could be an issue. Any shaking of the cabinet would shake the ESL panels as well. Not a good thing. Perhaps the cabinets are extremely heavy in comparison to the 8" woofer cone to make this not a big problem. I could not find a specification for the weight of the cabinets. Perhaps David can provide that information.

I did find this recent brief review of the Model One where the reviewer made this comment; and this with a listening distance of only 5 ft, if I read the article correctly, where the summation would not be quite as good as at 10 ft.

“As for the bottom-end, the Model One features different top and bottom woofers so as to eradicate woofer coloration. To my ears, the woofers' integration with the main electrostatic elements was such that the transition was undetectable and the large floorstander behaved like one big panel.”

The review starts about 2/3 the way down the page.
Coverage 5: Aaudio Imports (Tidal speakers), Lotus Group USA, Lowther America, Janszen Loudspeaker, Soundsmith - Event Reports - Dagogo

Oh! be sure to see the new smaller model zA that JansZen is coming out with pictured at the bottom of the review text. Hmmmmmm...perhaps this is where they got the idea to use top and bottom woofers on the Model One.

[bolserst]

Originally Posted by Calvin

Hi,

the solution to seamless integration of dynamic bass and tall thin ESL panels has been posted in this forum since long
Same distribution pattern and symmetrical crossover response.
Just two bass drivers on top and below a panel don´t create the same cylindrical pattern as the panel´s, especially not if crossed over too high.

jauu
Calvin

Hello Calvin,

I understand the need for symmetrical crossover response and similar distribution pattern.
Other than building a line source with a stack of 6 to 8 woofers set up in a column (separated from the ESL) I don't know a way to match the cylindrical pattern of the ESL. I am trying to avoid this approach for a variety of reasons.

You say that solutions to the integration problem have been posted in the forum for a long time. I haven't been able to locate them with the search tool. Could you point me to this information? Thanks.