Newbie needs advice. Fostex 208/cabs/SEX amp.

[adejacko]

I've recently acquired a pair of Fostex 208 Sigma drivers (just because they were a bargain on ebay), and when it arrives (has been waiting in Uk customs for 8 days), a Bottlehead SEX amp kit. I chose this for headphones, and because it's an easy build. And then decided to build a speaker, so I got things back to front. In hindsight, and because now I feel more confident and ambitious, I would have chose the Stereomour and smaller drivers.

I don't have a large listening room (15ft x 13ft), and these are my first projects, ever, but my brother knows a bit, so he'll help.

These are some possibilities;
Build the Fostex 208 recommended cabinets -the Nagoaka design with the steps. I've written to Wilmslow Audio asking if they'll do a kit in birch. This is the maximum sized enclosure I could have.
+
Build the SEX amp, with a possibility of buying another
in the future to use as monoblocks (I presume this can be done.?).

or

Sell the SEX amp as kit or assembled, and buy a Stereomour instead.
+
Sell the Fostex drivers, buy smaller ones, and build different speakers. (more choices of cabs for smaller drivers) suitable with Stereomour or 2 SEX monoblocks as lower SPL.



For thoughts or any advice on these matters I would be extremely grateful.

[rjbond3rd]

I'm not sure if the driver is the older, discontinued FE208-Sigma (whizzer) or the "bumpy cone" FE208E-Sigma (which needs a supertweeter at ~10k). Both are excellent as 8-inchers go. But not interchangeable so each must be mated to the proper cab.

The S.E.X. is sonically the best I've had among many, and it's my main amp. If you have the latest revision, then it's even better. Mated to either of the 208's in that sized room, I doubt you need more watts. I listen in a bigger room with -less- efficient speakers and I'm not changing it because I'm in love with the sound, which far outstrips its utilitarian appearance.

Regarding the Stereomour, yes it's worth it if you're running a vastly more resolving, vastly more dynamic multi-way horn system driven to concert-level peaks. But for the Fostex, the S.E.X. is a dream match for most musical genres.

In terms of trading down to smaller Fostex, a 3" will sound sweeter and image effortlessly compared to an 8", but the 8" will have more impact and weight. So pick your poison Chances are this isn't your last build.

[adejacko]

Thanks for the advice. It's the new driver, without the whizzer. The S.E.X. amp is the new version. So I'll stick with option 1, build the 208 cab and SEX amp. Have you considered getting a second SEX amp as 2 monoblocks.

I've decided to get the FT17H tweeter. Unless I win the lotto, I won't be getting the T900A or the T500A, but perhaps the T90A is it's so much better. Anyway, the Ft17H has a higher SPL, matching the 209 Sigma.

As far as size is concerned, the 208 enclosure isn't that big compared the other horn cabs. I'd like the Dallas II or III, but they are beyond my building limits. One day.

Cheers.
Ade.

[jrenkin]

I made a BIB with these drivers. Large, but easy to build and sounds superb.

[adejacko]

My brother recommended a BIB, but with 8'' drivers, I think it would be too big. What dimensions? I didn't like the new 208 enclosure at first, but it's grown on me. If. I can get the flat pack in birch I'll be happy.

[lousymusician]

The Fostex-recommended cabinets aren't all that well regarded around here. Never heard one myself, can't really comment.

Another approach would be to put the Sigmas into simple, small sealed boxes, and use separate powered woofers to fill in the bass. The cost vs. a second S.E.X. might be a wash, especially if you DIY the woofers.

Doc Bottlehead endorses that approach:

great speakers for S.E.X.

I have done this with FE166E's, and thought it worked well. These days I have those same drivers in open baffles, biamped with dual 15" woofers and DSP crossover.

Mount the Sigmas on open baffles, add tweeters and woofers, and you're on the road towards Basszillas:

Black Dahlia Acoustics - Loudspeaker Kit Plans

I heard Variac's 'zillas at the first Burning Amp, and that would be a speaker worth emulating.

Bill

[adejacko]

I've searched all the forums and websites for 208 sigma enclosures. I like the Cain & Cain's and Blumenstein's speakers among others. For DIY, I like the internal design of the Dallas III the most (lovely curves). There just aren't a huge number of designs for the 8'' driver. I know that the Fostex recommended enclosures often have a poor reputation, but from what info I can find online, the new Sigma design is a big improvement on the old one. It's a few inches taller, but I can live with that.

For a first build, the flat pack makes life easier, and has clinched it for me.

[dondiba]

hi
i builded a bib with the FE208E-Sigma and the sound is rather good, very tall but small foot print enclosure
dondiba