Needle with Fostex 108 E

[Theon]

I'm looking for a slim design like the Needle but with around 90dB to accomodate my Class T Charlize amp. I thought the Fostex 108 might be a good choise (I've seen used in the Picolino).
Is it possible to adapt the Needle to the Fostex or will the Fostex simply not work in the QTWT design.

[Scottmoose]

The Fostex is basically a rather large tweeter in disguise & it has to be horn-loaded if you want any LF performance at all. We can QW load them down there, but distortion will rocket as their excursion is minimal to put it mildly, so you'll need a sub. If you have a sub, then a Metronome should do you: www.frugal-horn.com

If you're willing to go for a more complicated build, then the Frugal-horn is probably the best option, or even the old CT164 design which should also be good. Beyond that, you're looking at a dedicated multiway setup, with the 108 run widewand, with LF support, and possibly a supertweeter up top.

[chrisb]

Originally posted by Scottmoose
The Fostex is basically a rather large tweeter in disguise & it has to be horn-loaded if you want any LF performance at all. We can QW load them down there, but distortion will rocket as their excursion is minimal to put it mildly, so you'll need a sub. If you have a sub, then a Metronome should do you: www.frugal-horn.com

If you're willing to go for a more complicated build, then the Frugal-horn is probably the best option, or even the old CT164 design which should also be good. Beyond that, you're looking at a dedicated multiway setup, with the 108 run widewand, with LF support, and possibly a supertweeter up top.

Scott, the FE108E Sigma definitely works quite well in the Frugelhorn (although not as extending as deeply into LF area as the FE126E), with much smoother low control than a BIB. A supra-baffle is highly recommended on the FH with either driver.

[SCD]

Hello:
I had the pleasure of listening to a wonderful set of Frugal horns made that used the fe108 driver. The design was done by "Planet10" and the build was done by "Doorman".

I have been extremely impressed with this driver when listening at normal listen levels. As "Scottmoose" points out the driver does not have the umph to rattle your ribs. So look elsewhere if that is your objective.
During a listening session over the Christmas break last year Doorman brought his set of horns over to my place for a brew and bull session. We listened to his horns and his wonderful Bruce Rozinbult Grounded Grid Preamp. We hooked things up through my MiniA and sat and enjoyed the music. The things that impressed me were first and foremost the width and depth of the sound stage, followed by the clarity and crispness of the sound. We had my sub-woofer tuned to about 50 htz and set to a fairly low level to help pick up the bottom end.
All in all I would recommend this driver in the Frugal horn enclosure with and small sub to help out in the bottom end.

I have heard this driver in a few enclosures in the past as well. "Chrisby" made a set of Bushhorns or a variant a few years ago. These horns were a slim yet deep design. I am sure he will chime in and comment. I really liked the design and the workmanship of the enclosure.
Some folks say that it takes a long time to really break in and come to it's best.

I hope this helps

[chrisb]

"chime"

Scott, thanks for the opportunity to revisit this so quickly, as I realize in my prior post that I forgot to mention amp compatibility.

All of the Fostex based speakers we've played with during the past several years have been MLTL's modeled with MJK's spreadsheets; BLH's in the form of either Buschorn MkI or MkII, Dave's Frugelhorn, or Ron Clarke's A126; or the aperiodically damped Fonken; and finally, the other Dave's FE108 BIB's.

The Buschorns referred to by Scott were the MKII variant, and I've subsequently determined (by building a couple of pairs) that I actually prefer the smaller MkI. I can't tell you I've heard a direct comparison to any similar commercial product, but the MkI was a starting point for the form factor of the Frugelhorn, which certainly surpasses it (the MkI) sonically. Of course once you add the supra baffle and rear deflector, it can probably loose points on the WAF side of anyone's ledger.


During this period, I've had opportunity to hear numerous combinations of any of these speakers with a variety of SS and tube amps, ranging from my Denon HT receiver (don't ask!), at least 4 GainClones with different flavor of chips, the Mini-aleph; to SET, SEP and P/P tubed amps with 2A3, 300B, EL84 & EL34.

For me, the lower powered/ low damping factor SE amps (most notably the Bottlehead ParamourII and Dave's Decware Taboo) engaged in the most intimate and articulate dance with the full range drivers / horns of all of these combinations.

Don't get me wrong, for example, the Mini-aleph make for great 2.0 video amp (and small room heater) with the FE127/Mileva, but for goose-bump inspiring musical magic, it's hard to beat full-range/" triode cream" (thanks forever for that vision, Harvey R)

[hm]

I agree, scottmoose
"The Fostex is basically a rather large tweeter in disguise & it has to be horn-loaded if you want any LF performance at all. We can QW load them down there, but distortion will rocket as their excursion is minimal to put it mildly, so you'll need a sub."

the data shows ~0,26 mm Xmax,
thats enough for 0,2 watt, but for example a bass horn
would need at 70 Hz ~ 1mm and at ~150 Hz 0,6 mm
average for 1 Watt

http://www.fostexspeaker.de/fullrang...ma/fe108ez.pdf

an alternative with two 108 and membran cross seting would
realize 0,5 watt without distroition.
the small POSAUNE

[Theon]

Thanks. I figure the Fostex is not a good choise. Any suggestions for a full range driver with +/- 90 dB feeling at ease in a tube?

[Scottmoose]

If you want a simple pipe? Well, the FX120 is 89db for 1w. Not cheap, but a superb driver & decent excursion, that almost hits your goal. Off the top of my head, that's about the lot of the units I know, of that size. The Jordan is lovely of course, but less sensitive.

[Theon]

Originally posted by Scottmoose
If you want a simple pipe? Well, the FX120 is 89db for 1w. Not cheap, but a superb driver & decent excursion, that almost hits your goal. Off the top of my head, that's about the lot of the units I know, of that size. The Jordan is lovely of course, but less sensitive.

Yes, this driver has the specs i'm looking for. For sale for € 114 in Germany is not a cheap solution. Does somebody know the Seas 11F-LGWD. Seems to have the right spec but can't find any designs with them.

[Scottmoose]

From the parameters I've found, Fs is very high -about 112Hz, so to get any meaningful LF performance, they'll need a big hyperbolic horn with very slow flare.