best enclosure for fostex fe103

[jesserparker]

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

[gatedriver]

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

[planet10]

We call those FE103A... they look like this?



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.



dave

[Cal Weldon]

Hey, I recognize those

Cal

[planet10]

Originally posted by Cal Weldon
Hey, I recognize those

You should -- they are yours

dave

[Timn8ter]

What about one of the "Swan" enclosures? I heard one using a 103 and it was pretty darn good.

[planet10]

Originally posted by Timn8ter
What about one of the "Swan" enclosures?

i have a much more elegant version of that box percolating in my head

dave

[s_zimble]

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.

[Scottmoose]

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.

[planet10]

Originally posted by s_zimble
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