[jrebman]

Folks,

I'm in kind of a rush and need to get this project going very quickly.  I'm hoping somebody here can give me the dimensions for one of the simple BR ported Fostex recommended designs for the FE-127.  I plan to use 3/4 BB ply, and I'd need to know the outside dimensions (or inside) the length and diameter of port (require front mounted for this situation), and the BSC circuit if needed.

Better yet would be if there were a pre-built PE box that could be used for this purpose that I could mount a driver and port in.  This is for my Dad's 80th birthday and will go in his shop so he can have some tunes to listen to while he works -- and the s.e.x. amp will supply the power.

Dad was an engine room officer on a Navy Destroyer so his hearing isn't great, but he can here well enough to appreciate this kind of system with his iPod or computer sound card as a source.

Thanks to anybody who can help.  Gotta sign off for the day, but I'll check back in tomorrow.

-- Jim

[chrisby]

well Jim, you can probably imagine my first recommendation, but due to the time constraint, a simpler box might be this variation on the Fostex recommended BR enclosure


this is nowhere as difficult a build as the "Prime", yet maintains many of its characteristics




e-mail Dave for PDF of the fully dimensioned drawings

FWIW, we've built a set of prototype flat-pak adapter baffles for FE127s in the very pretty curved /laminated MDF PE boxes (which took longer to get right than the above box  ) , but preferred the sound of several plywood boxes, from the millis to the "classic GR" above 

[planet10]

FWIW, we've built a set of prototype flat-pak adapter baffles for FE127s in the very pretty curved /laminated MDF PE boxes (which took longer to get right than the above box  ) , but preferred the sound of several plywood boxes, from the millis to the "classic GR" above

Here is a link to the PE box project http://www.diyaudio.com/forums/showthread.php?s=&threadid=148240

The mFonken started out as a simple BR -- we needed to know we could get away with such a small box... 3 iterations later we had a way better sounding box (same volume, same tuning)... i fell the highly resistive vent in the Fonkens and the other details give them an edge over simple BR.

Plans are here: http://www.planet10-hifi.com/fonken.html

The simplest box to build are the GR (Golden Ratio) Fonken, mFonken and Floorstander ...

We have built many, many variations of FE127 box, and the little extra bit of effort to build one of these is worthwhile IMHO

dave

[jrebman]

Thanks guys, but really, I want nothing more than a 6 sided box with a speaker and port cutout and that will mount flush on a wall (hence the front port).  Remember, this is my 80 year old dad -- decidedly not an audiophile -- and his sources will be mp3s from a Nano or the sound card in his Dell laptop.

I know that some of the basic fostex recommended enclosure fit this bill and I just want te dimensions and location of holes -- 6 pieces of wood each, ttwo holes, one port tube, stuffing and captive speaker lead hole.

It's also going in a garage.

Thanks,

Jim

[Blackmore]

pm sent about Madisound Fostex listing.

[planet10]

175 w x 295 h x 180 d internal.

port 50 d x 80 long

~10 litres tuned to 71 hz

dave

[opnly bafld]

http://www.fostexinternational.com/docs/speaker_comp/pdf/recom_enclose/127e_enclrev.pdf

Bottom right side of this page.

Lin

[jrebman]

Thhanks folks, I now have what I need.  Just need to get a sheet of ply and I can bang these out in a day or less and then another couple of days for finishing.

-- Jim

[planet10]

Bottom right side of this page.
Port length is 80.

Right you are, guess i didn't zoom in far enuff to compensate for my age onset near sightedness...

thanx for catching that.

dave

[jrebman]

Or far enough for my non-sightedness .

-- Jim

[JLM]

You could buy a Parts Express pre-built.  Just pick the next size up if they don't have the perfect size and provide fill for the difference.

[chrisby]

Jim,  you may have already made your decision on this project,  but a couple of guys have mentioned the pre-fab Parts Express boxes.  Provided they aren't damaged in shipping, they work fine.

The curved .75 cu ft box should be fine for your application - if you have no need to exchange the baffles, I'd strongly recommend gluing with a polyurethane adhesive once the dry fit of parts and damping has been confirmed.  The magnetic attachment of fabric grilles to mounting screws is a nifty trick which I've seen before, and finally adopted for all new builds. A 1/4 x 1/4" Neo magnet flush mounted under the veneer finish on the box and on the MDF grill frames give you a virtually invisible mounting (just be sure to pay attention to the polarities!)   

It took us a while to get around to working with a pair of these for a potential baffle kit for the FE127, but as noted in the following thread,  it was rather a lot of labor, and not a great return for the investment.   (in other words, a much simpler box could be scratch built in less time)



http://www.diyaudio.com/forums/showthread.php?s=&threadid=148240

[jrebman]

Chris,

Thanks as usual for the information.  I have been looking at the .385 cu ft. ready-built boxes from PE, which seem to come closer to the 10 liter volume, but each one is substantially more than a sheet of BB.

We also just got done a big clean-up revamp of our tool coop shop, added a dust collection system, got rid of several old and horribly innaccurate tools, including the table saw from hell, and got a donation of a real top quality cabinet makers table saw.  Don't even know what brand it is, but it's got a ni ce 3 hp 220 v motor and a really nice selection of blades -- forest Freud, etc.

So I'm really thinking that I'll save myself some money and buy the ply and build the boxes from scratch.

Whatever I do, I better do it soon .

-- Jim

[chrisby]

Jim, FWIW, the "Golden Ratio" box is not a difficult build at all, and the wide/shallow profile lends itself to wall / soffit  mounting that could well suit a workshop or garage.

It certainly delivers more extended LF response than the smaller members of the Fonken-klan, although suffers in terms of imaging and refined bass "articulation" compared to the "prime" .

In any case,  enjoy the new tools - a nicely sharpened 60T ATB carbide tipped blade will make smooth work on the BB ply.

cheers