best enclosure for fostex fe103

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i've recently come into possesion of some fostex fe103 (the older version with the alnico magnet), and was wondering what experiences/recommendations anyone out there has for an enclosure.

as i tend to use rather low-powered amplifiers, and also play things rather loudly, i'm hoping to maintain as much efficiency as possible with this design. thanks.


jesse
 
Hello Jesse,

i have a pair of FE103 Sigma (ferrite magnet) in BK101 backloaded horn cabinets made from solid pine wood.
They sound pretty good, astonishing bass when corner loaded.

However, the max. SPL is not very big!
If you want to play loud, you're going to be dissappointed by these little drivers.
I would not rate them as high efficiency drivers...

i used to use them in a *front loaded* 300 Hz midrange horn. This was in the early days of my horn experiments, i think my second horn. this horn is what hooked me on horns. But this is a three-way system and tweeter integration is difficult.

Regards
Timo
 
frugal-phile™
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We call those FE103A... they look like this?

An externally hosted image should be here but it was not working when we last tested it.


These are really an excellent driver. Especially when tweaked up.

I've used pairs in BD-Pipes and singles in a number of enclosures. The best has the Buschorn Mk II. There is reason to suspect that they might work even better in the Fostex recommended horn. I haven't generated T/S parameters, but impedance curves of a fairly large sample set match a similarily large set of Radio Shack 40-1197s to a pretty good degree (ie Fs ranging from 85-105. This means that you are fairly safe popping them into almost any RS 40-1197/Fostex FE103 box.

calWeldon-10F3.jpg


dave
 
Hi Dave,
I was just going over some old posts trying to decide what to do with a couple pairs of drivers I got while in Tokyo. I picked up a pair of FE103E and these funny little 6cm (F700) fostex full range kits that came with a Japanese DIY speaker mag called "Gallen" (I think...no English Im afraid). I built them and they look very nice. Not sure of the sound yet.

Anyway, I saw that you had some ideas for a rear loaded horn (swan variation), or other creative ideas for the 103's. Have you developed anything? I was going to do a slightly modified version of the fostex recommended RLH thinking that they would probably have the best design. I would like to try to avoid any circuitry and therefore challenge myself to make single driver enclosures.

Thanks for your thoughts.

Stuart.
 
Here's an idea I've been wanting to try for a while: mirror the factory design, so you end up with a double horn a la Terry Cain's BEN. I seem to remember Terry mentioning that it's possible to do with the factory 166 design, providing you keep the compression chamber the same volume as the original, or slightly larger. As the drivers are so cheap, and we have proper distribution in the UK at last through Wilmslow audio, I'm running out of reasons not to give it a go, now my Zigmas are complete and playing in the attic office.

My only concern is that the layout would mean that the first passages of the two lines would be directly behind the driver: would this cause problems for the compression chamber anyone, and any ideas about a solution? I don't think I'm the first to try this out; I ran across this (attached) picture a while ago, but I can't remember where -apologies if it's someone here! I'll ask over in the full-range driver section too.

Gentlemen, sharpen your wit!
Cheers
Scott.
 

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frugal-phile™
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s_zimble said:
I saw that you had some ideas for a rear loaded horn (swan variation), or other creative ideas for the 103's.

The mouth end is sketched out, the horn flare is designed. We got stuck at using Marshall Leach's throat moth to optimixe the compression chamber & throat size. Gave us weird results. I have to revist that design soon but have much on my plate.

dave
 
Hi all,
One correction on my previous post....the baby Fostex's I built are labled as "P700" not F700.

Interisting ideas from Scott, but I think you are right (in my non-technical way of thinking) that there will be some physical price to pay bu splitting the compression chamber.....also a practical space issue. Those things in the picture are BIG. My idea is based on the fact that these little drivers are best in modest spaces, therefore I was trying to minimize the size of the cabinets, but still use a RL horn idea. I suppose that my hesitation with the original Fostex enclosure design is that I have read some luke warm reviews of it on some posts. Not sure why these people don't like it. Again I am an amature with the technical details (learning as I go) as I am not an engineer....more of an artist type with a strong interest in the techie stuff.

I have sptted some interesting items to research like the Buschhorn MK11, or some interesting TL designs but because I have not actually listened to any of these, I am swimming with my eyes closed, so to speak.

Thanks for your thoughts.

Stuart
 
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