FE127e....build advice needed.

Definitely the .38. 2" port about 3.5" long. And I can't just let you go without letting you know that this is certainly not the best way to use these drivers, even if you're just wanting to drop them in a BR cab and forget about it. They'd rather have something more around .466 ft^3 and tuned a touch lower. In the .38 and tuned like I've suggested, your F3 will be about 65Hz. In the larger enclosure I've suggested and tuned around 65Hz, you'll get an F3 of about 60Hz. And this is not even mentioning the much more advanced (though often very easily built) cabinets that have been developed around here in the past couple of years. Just have a look around this forum and see what's been going on, and whatever the end result, make sure you're enjoying the sound above all else.

Kensai
 
Kensai - it should be no surprise that I agree with you in that a "simple" BR cabint is a total waste of this driver's potential - but having said that, the new Parts Express curved side panel enclosures are quite pretty indeed (even if they are MDF :hot: ), and impossible for the average diyer to duplicate for the money.

FWIW, one of the items on Dave's short list is an aftermarket baffle and slot port kit for these cabinets that will provide for Fonkenesque tuning.

The best sound I've heard from a design for the FE127E* that could be easily shoe-horned into this type of box would be approx 14litres or just over .5 ft^3 -

(* i.e. the slot ported Fonken)
 
If 0.25 and 0.38 are your choices, 0.38 is the better choice for BR. .25 will work if you go sealed and use a sub for the bottom end. I really like this driver in a sealed enclosure.

There are other ported enclosure types that will squeeze some more performance from this inexpensive driver, but it can also sound very good in a BR.

Let us know how you make out.
 
As Chris mentioned we have some of these cabinets with the intention of making flat-pak baffle/driver kits (and maybe completely assembled).

The 1/2 ft^3 (14 litre) cabinet will get the most out of the FE127. I have managed to shoe-horn the 127 into a box as small as 4.5 litre, so it should be possible to make the 7 and 10.5 litre (1/4 & 3/8 ft^3) boxes work. A simple bass reflex isn't going to be best, it will need to be somewhat aperiodic. This is best done with a long high aspect ratio port but can be faked with a regular tubular port with added resistance (ie foam plug).

A comment on these cabinets... they are made from MDF, but except for the sides the panels are quite small. The larger top and bottom are braced by a holey brace running vertically parallel to the baffle. The sides which are not only curved which really helps they are made of a plywood that consistes of 6 layers of 1/8" MDF. This leaves only the baffle which is 1" MDF. With only 4 bolts securing the front, there are some potential worries about how tightly the baffle can be coupled to the rest of the box -- especially once you cut holes in it. Plywood will be stiffer and stronger, but we are considering additional fasteners.

The RoboBaffles (to get the proces of these boxes down where they are, they are built with a lot of help from robots) will be made from plywood, with driver braces and rebated for the installed driver. So far we are planning 1/ a convertible CSS FR125SR for the 7 litre box (a port that gives the recommended tuning & a foam plug to turn it aperiodic (where i think it works better), 2/ a roboFonken for the 14 litre and 3/ FE167 for the 28 litre box.

dave
 
The 127e is a very nice driver in a proper box. It can also sound bad in the wrong box. Its the driver people say sounds like an AM radio speaker when done wrong and the driver no one can believe is making all that natural sounding music when done right. The PE box is pretty and will look amazing. If i were to use it i would replace the front baffle with plywood or a piece of pine. Personally, i feel the 127e likes a plywood or natural wood box because it enhances its sound.

Regardless, I would use the larger .38 box from PE with a 2 inch by 3 inch long tube. PE can cut one for you if you ask i think. This will tune the box around 70hz and provide a mild hump in bass repsonse so the sound is a little fuller overall. Shorten the port to 2.75 inches for a little more bloat and the illusion of even more bass. Stuff to taste with some Acoustastuff and you are done. Enjoy, it will sound great with the Sonic Impact amp too... great cheap sound!

Godzilla
 
Godzilla said:
The PE box is pretty and will look amazing. If i were to use it i would replace the front baffle with plywood or a piece of pine.

They sure are good looking boxes. The baffle that comes with the box is rabbeted. While there is merit in replacing the baffle, it may be hard to get a good seal with your own baffle without a gasket of sorts.
 
gmilitano said:


They sure are good looking boxes. The baffle that comes with the box is rabbeted. While there is merit in replacing the baffle, it may be hard to get a good seal with your own baffle without a gasket of sorts.


Gio - why would a properly made (i.e. rabbeted) DIY baffle provide any less of a seal than the factory MDF piece (which from the samples I've seen also lacks gasketing) ?

Use 2 layers of 12mm BB and some 1/8" closed cell weatherstrip tape and I'd venture a guess at equal seal to the stock. IMHO, the real issue is the use of only 4 bolts in the corners - although it does allow for the very neat he magnetic capture of the grille cover.

If you wanted to get really anal about it, and were certain that you weren't gonna be swapping drivers or otherwise needing access to the inside of the enclosure, then just permanently glue it with moisture cured polyurethane.
 
chrisb said:

Gio - why would a properly made (i.e. rabbeted) DIY baffle provide any less of a seal than the factory MDF piece (which from the samples I've seen also lacks gasketing) ?

Hi Chris,

Of course a rabbeted DIY baffle would seal just as good! I was looking at this from the perspective that a lot of people that buy ready made enclosures may not have the know how to construct a rabbeted baffle (like myself).

The nice thing about these boxes is that one can easily try different drivers by just changing the baffle. I'm looking forward to the aftermarket baffle and slot port kits that you and Dave come up with.

Cheers,
Gio
 
type said:
Thanks for all your replies. I should mention that they won't be played at very high volume levels.

So, to confuse you, I can also throw my design in.

www.yildiz.edu.tr/~ilkorur/ILKORUR/FE127E.html

Strong points, you get more and detailed bass as compared to bass reflex designs. The sound is relaxed and far away from being boxy, so you can think of a better midrange response as compared to small enclosures. Good staging can also be mentioned but it has not much to do with the enclosure really.

Lacking hitting dynamics on the other hand if you play loud. It is not easy to build since there are some angled-cuts.

Finally you end up with a balanced sound for 127E with a nice tonality.

/Onur
 
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