is it possible to get low extension from 103e??

[aural_junkie]

Is it possible to achieve low bass extension from a fostex 103e and forgetting about overall max spl across the range
??
Cheers

[Scottmoose]

Yes if you're not bothered about the quality / distortion / linear response / spls. No if you are bothered about these.

[GM]

Oops! Beat me to it!

GM

[Scottmoose]

Sorry Greg... I'll try not to make a habit of it!

[blumenco]

I "quested" for 103e bass for years because I like the midrange of that driver so much. BIB was nice, not flat enough though. OB with woofer, blasting Hendrix sounded nice but for everything else fughettaboutit! Reflex? Stick to the 107e. the 103e though is really a "red headed step child" of the Fostex line in most western countries. Japan? People eat em up.

My quest ended for the most part when I found pleasing response out of the Nagaoka "103e Cobra" build that I did. I made them mirror imaged and faced the port backwards. A few other tweaks to the design that significantly helped the sound otherwise, but basically the Nagaoka design.

Sorry I do not remember the specific number of the design, nor did I take any pictures other than the top boxes before I gave them to my girlfriend. (funny enough, I still consider them to be the best Fostex based speakers I ever made in prettymuch all respects. Especially SQ from parts cost. As an important note, I liked the sound FAR more than the 206ES-R build that i did (and those are some nice speakers...). The stock 103e, properly treated is more agile and balanced sonically with good dispersion and works better for real people in real rooms, IMO. The number of the design is lookupable though, and is in the Nagaoka manuals.

Properly placed in a room, the cobra had stunning low end response, I thought. Very pleasing. not super duper deep (I never measured them), but definitely "impossible" from the credit most folks give the little drivers.

Perfect? from an absolutist's perspective, of course not. Typical "issues" found in all horn bass. It seemed though that the room coupling via rear mouth exit simply did nice things. Also the length of the horn seemed to just simply work well. counterintuitively a keeper, IMO.

Also the upper volume limit of this design is stunning. Perhaps good compression and proper resonance behavior of the horn (making up for what the driver does not do too well, and staying out of the picture when the driver is yeehawing keeps the driver from doing too much work? I dunno.

The little box on top, I hand sanded a short "front horn" to deal with the slightest bit of funnyness (almost a slight compressive sound) on top of the 103. It seemed to work pretty well.

Also, the driver was "back mounted" inside the top box. VERY important for the sound.

It was a difficult build, especially to do it "right" meaning with unstressed wood (accurate cuts and proper gluing technique) the whole way, coating the inside with oil, shellac or something, coating the outside with the same oil, and using only a tiny scrap of damping at the point where the neck meets the body.

I later planned on doing a "two story" horn shape with a similar expansion (did not sound like much needed to change horn dimension wise from the nagaoka specs, but it is a big speaker)

It would have a spiral on the top story, and then looking like a mayan temple, drop a story at one fold and go only back and forth a few times before the rear exit.

funny looking, compact nice sound though.

In ways, it is a cheap driver inside of a stunning cabinet. the parts cost weighed heavily towards the difficulty of cabinet work, and the not so cheap woods I used in the construction. This was the only design for the 103e I ever built that actually managed to make the little things sound "high class" to an extent. There are other promising horn designs out there, like Swan variations. Also, the BIB could have be done well (better than I did). Also, out here in Japan, I have heard some solidly performing, (and creatively constructed) bass reflex for the little things also.

-Clark

[Andrewbee]

IIRC, the Cobra with the FE103e is the D-115. There is also another version of the Cobra which again IIRC is slightly larger in volume which uses the FE-103e or better, the FE-127. Whichever, there are two versions one slightly larger.

I have the Cobra for the 103e on my to do list and also will be turning the mouth to the rear as well although for completeness you could always make the head removable and rotate it.

I built a pair of 101a Swans with FE-108 E sigmas and find them excellent but do prefer the tone of the 103e.

Andrew

[blumenco]

Originally posted by Andrewbee

I have the Cobra for the 103e on my to do list and also will be turning the mouth to the rear as well although for completeness you could always make the head removable and rotate it.

do prefer the tone of the 103e.

Andrew

Thats what I did: make the neck removable. and screw from the bottom. I altered the horn dimentions somewhat to do this, and let it be a little long. It was nice. next time would shorten horn length by half of what I added and see the effects. For me, the whole thing was the pleasing nature of the sound out of this cabinet. It is a sexy, relaxed yet relatively high speed sound and the imaging was to die for.

hardly perfect, and the cabinet building involved for such a cheap driver was a little dismaying, but eventually it was worth it.

127e, that would be interesting...but still, I prefer the tone of the 103e. Out here, I have had a chance to play around with the old 103. It is a nice driver and all, but I DEFINITELY prefer the new 103e. And further than that, they changed the design a little bit recently and added a tad more glue around the center cap (at least this is the case with new production 83e and 107e: assuming 103e too. tames some of the HF response.

Good luck on your cobra project!

[Andrewbee]

Thats what I did: make the neck removable

I did this also with my Swan's so I could change the head / neck assy with a different sized head. I used screws in the side of the collar where the neck joins the body.

127e, that would be interesting...but still, I prefer the tone of the 103e

I have not heard the 127e and to be honest I am so happy/biased with the 103e that I don't know if I would prefer the 127. Having said that I do have a pair of 127's to be ordered with some other drivers to try them.
I did have a pair of orgininal 103's but sold them a while back. I am also getting another pair of 103e's, one from the pair I have has some sort of brown "stain" (perhaps adhesive) migrating from the surround into the cone and the cone has separated from the surround, the other driver is fine.

The only other driver I have that sounds in the "class" of the 103e is the original FE208 Sigma and those I will not part with. I do prefer the 103e though, it just sound "right".

"edit" I will take a look and see the correct model numbers (D-115 / D-11?) for the speakers over the weekend. With your new locale perhaps you will be able to get more info about them.

Good luck on your cobra project!

Thanks!

[aural_junkie]

wow, excellent response peeps. Cheers

Certainly food for thought!!

Thanks very much.

Gravity-Junkie

[Andrewbee]

D-108S is for 103 / 103e and has a side exiting mouth.

D-115 is for 103 / 108 Sigma / FF125K and is the larger of the two and has
a front exiting mouth.

Andrew