I have recently bought two Fostex FE103 Sigma for a pair of single driver loudspeakers.
I have found several possibilities in the net about using it in horns, TQWP, etc.
Did anybody of you made a PETITE (bass reflex) and can report about the results ?
I must admit that I am a bit hesitating making a more complex box when a simpler one is also working.
Since no one takes the bait, I feel obliged to respond.
The only impressions I have read on "le petit" were very positive.
Personally, I would choose (as I mailed you) the "Zigmahornet", a very slim, 150 cm tall pipe for the Fostex FE103s, which is supposedly very good. Drawings at: http://audionova.nu/docs/KVARTSVAG.HTM
Have you tried to ask the (very good) full range driver forum?
Petite is gorgeous
a few years ago I had extended opportunity to listen to that speaker as a buddy owned one.
It is usable as fullrange speaker, although my buddy added a subwoofer and a tweeter soon.
It is very musical, rhythmically incredible coherent, very dynamic, a joy to listen to.
If you are after high detail resolution and complete lack of coloration, maybe the Fostex FE103 Sigma is not the best choice, no matter in which enclosure.
If you are into music listnening and focusing on music instead on hifi, it is a simple way to get to heaven. Particularly with single-ended triode amps.
I found quite a lot of information by one person (Martin King) who is attempting to write some software to predict the behaviour of 'transmission-line' boxes.
http://www.t-linespeakers.org/projec...QWT/index.html has quite a bit of detail on the designing and building of a 'Fostex FE164 Mass Loaded Tapered Quarter Wave Tube'.
Interesting reading... there is also a section on why he didn't build a 'petite' - including what his software predicted for the results.
Sorry, folks, to answer so late.
Thanks for the hints and links.
I am very busy at the moment, that is why I did not simply build the cabinets yet and listen...
One thing puzzles me:
A "normal" calculation for a bass reflex enclosure for the FE103Sigma would result in a much smaller box than the orginal two versions of the Petite. How were they calculated ?
I remember having read an article in the German mag KLANG&TON about the FE103S, that it will only have bass in a backloaded horn.
But I know that I will not get thundering bass.
I want to get a loudspeaker with the natural- and easyness I remember from the "old mono tube age" and what I still miss even in many good designs.
I think I could modify the Petite construction plans by making them less rectangelous, which is one of the main problems Martin King was highlighting (but I must admit, I was just browsing through, I have to read the article more carefully). This will reduce standing waves.
The two plans suggested at http://audionova.nu/docs/KVARTSVAG.HTM are really interesting though. I am not sure about the damping, and I cannnot understand the writing (in norwegian :confused: ).
Even more intersting could be a open non damped enclosure like the RONDO by Auditorium23 www.auditorium23.de (no parallel sides, resonances are accepted and used somehow). But I do not have any idea how to calculate a loudspeaker like this.
Concerning the Zigmahornet, this is a quote from a reply (by Pär) I got in the "high efficiency speaker asylum", with the translation of the text on this design:
A popular model with Fostex FE103Z. The box is from Le Audiophiles latest design. Incredibly good sound from a small 4" speaker.Dampened lightly with a 1" mat behind the driver. Cabinet built from 1/2".
I haven't heard them myself but know lots of people here i sweden who would swear by their mother that this is the only speaker you would ever need (though I know a few of them kicks in a sub below 50Hz). Go for it: I suppose there is about $15 in material to loose :-) There was a huge rave it a swedish asylum about theese (du lax lasse) where eweryone trying them jouned the choir of praise...
All the best,
btw the writing is in swedish (on audionova) i can translate it if you want
Oh, sorry, no insult intended, I really should know the difference between swedish and norwegian - we are all europeans at the end of the day, citizens of the world actually.
After a closer look at the "Zigmahornet" (Sigma-horn ? although it has nothing to do with a horn...) I think that it is a petite-like bassreflex construction, in a different, acoustically not uncritical form (The drawing is not very legible). This enclosure will probably have a kind of strong lenghth resonance, like a tube actually, and I tend to think that the slope at the top will not cancel this out totally. It will be very instabil, because it is so narrow and high, so it will need a broad base or foot construction.
I am tempted nevertheless. I think I am going to build more than one pair of enclosures just to try.
Can you Dirk (are you not in Belgium ?) or hifi/micke please translate the chapters of the Zigmahornet and the following TQWT for me/us ?
I am not sure about the damping and construction.
I would like to use this little beasts, the FE103Sigma, without any crossover/equalizer, as you can imagine, because I want to get rid of all the side effects, which, although I am used to that, still bother me a lot. Driving a single speaker withput passive components in the way could give the same amount of control as I can get in an all active systems. I will even accept a slight imbalance in the frequency response curve for that.
I was never really happy with crossovers, it was always like "fighting for peace" for me...
Let me state some of the - in my opinion - most interesting different possibilities for a single FE103Sigma here (all measures in mm B*H*D):
1.1 Orginal Fostex Suggestion for the FE103 (134*270*171 with a 50d/m*45 port)
Comment: Too small for significant bass probably.
1.2 Orginal Petite I ( L'audiophile Nr. 31 )
Comment: Not to be overlooked. The speaker is very directional anyway, so the relativly broad box will not create interferences, but the case can be constructed very strong with bracings, etc. so that the cabinet colorations will be less than with a standmounter. The necessary stands are a disadvantage nevertheless.
1.3 Orginal Petite II ( L'audiophile Nr. 41 ) (mailto:IKSchiffer@aol.com )
(210*840*250 with a 70d/m*140 port)
Comment: That is the Petite we are referring to, am I right ?
Very tempting, but cabinet colorations can be higher, which can be reduced by clever construction. My version 1.
1.4 Zigmahornet at audionova
Comment: see above
1.1 TQWT at audionova
Comment: Looks very resonable. My version 2.
1.2 Solo at www.diyaudio.8m.com and other places (looks like a BD-Design originally ?)
Comment: This is a mixture between a bassreflex and a TQWT construction,as far as I can understand that, and is slightly more difficult to build. A passive equalizer is needed/suggested.
Cheap Trick 164
This is a hyperbolic backloaded horn designed by Bernd Timmermanns for the FE103sigma. It was published some years ago in the German speaker building magazine Klang&Ton #5/96.
Comment: It is a pain to build probably and will need a two stage passive equalizer, which cancels all the advantages of beeing coupled to the amp directly, but will offer significant more bass probably.
I have more drawings of exponential horns somewhere, I just do not find them at the moment.
To be continued...
The Cheap Trick 164 by Stefan Klose can be found <a href="http://melhuish.org/audio/diy32.htm">here</a>
Show plans for both oriiiginal and modified versions.
An add on to your list (buschor mk2):
Btw, I also like to read the zigmahorn translation (its simplicity is quite appealing).
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