Fostex FE108E Sigma - Your thoughts?

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Hi everybody,

I came across this driver recently and it has caught my attention
http://www.madisound.com/pdf/fostexdrivers/fe108ez.pdf

I plan on using this in a car audio application as a midrange (200Hz-6.3KHz) only. I have been searching long and hard for a reasonably affordable midrange unit that will play linearly from 200Hz to 6.3KHz at 30 degrees off axis for quite a while and so far i have finally, on paper at least, found something that just might work. The only worry for me is the low powerhandling of 24W music power(although its offset somewhat by the highish sensitivity and the fact that it will be bandpassed so i expect powerhandling will increase from its full range spec), and of course, its sound quality. Its a little pricey also, but if it does what i want it to do, i'll be more than willing to pay(about 90USD)

I was hoping i could get some opinions about how it sounds and how well i can expect it to work at the frequency range and off axis characteristics i'm considering. I will have a few(2-4) parametric bands of equalisation to work on the response dips at about 500Hz and 1KHz and any other in-car response anomalies.

Also, if anyone has any other drivers to recommend which fit the bill, feel free to suggest!

P.S Just thought i'd add: Up till i managed to find this driver, i was planning on using the SEAS Lotus(car audio version of SEAS Excel) 4 inch driver as a midrange. I am already using the SEAS Lotus 7 incher as a midbass/midrange unit in a 2 way setup and properly set up, i absolutely love it. The drawback of the 4 inch SEAS, however, is the fact that i cant hope to cross it any higher tha 3KHz because of its breakup. I am quite a stereo imaging addict, and am looking for a driver which will play the entire vocal range + harmonics, hence my search for a speaker which will play such a wide range. Off axis capability is a must as well since its car audio and the best i can do in terms of mounting is 30 degrees off and no less.

Best regards
 
I think you would be very please with the fostex 108e sigma, I have owned my for a good little while now and have tried them in a couple of different cabinets have been quite impressed with this little driver. I have never heard the SEAS Lotus series so I can not make any comparisons there.
I don't have any measuring equipment so I cann't comment on the off axis response at 6kHz. I do however listen to mine from all location in my house and find the sound quite pleasing no matter where I am. If you do get them I would at least try running them open on the top end, you may find that you need a little more sparkle, but it cann't hurt to try. It just seems a shame to cut off the top end of this driver, which is so good, in my opinion.
Joe
 
All the Fostex drivers that I have tried have a beautiful mid-range and rising response toward the high end which allows them to actually sound better off axis than on axis if no compensation filters are used. I've not used the FE108EZ but it has found it's way into Ed Schilling's Horn (http://www.thehornshoppe.com). I've used the FE103E, FE127E, FE167E and FE207E and been very pleased with all of them.
 
misc info

Ask over at http://fullrangedriver.com/tiki-view_forum.php?forumId=1 and I'm sure you'll get more information. These guys are meant to be run full-range, maybe with the bottom lopped off, maybe with a tweeter crossed in with a capacitor. The goal is to avoid a crossover between the amp and your nice speaker. You get a very immidiate sound this way. I'm working on some 168esigma cabs right now, and I'm pretty excited. The word is that these Fostex full-range speakers need a few hundred hours of break-in. At first they sound screachy but then smooth out. My 168s are in a box facing each other, wired out of phase, playing the radio at about 2 watts for a week now. Even in their cardboard box, I can tell that they've warmed up, gotten louder, smoothed out. I built a pair of RS1197 (fostex 103 knock-offs) Tlines running full-range that are very listenable, although they don't rock. Good luck! /jd
 
frugal-phile™
Joined 2001
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My buddy Chris has FE108e Sigmas (in a Buschorn II). He is using it full range. In the horn it is a bit bass shy but elsewhere it is sublime... should worl well. I'd make sure i braced the magnet in a car setup.

I wouldn't worry about the power handling spec (people worry about those numbers WAY too much)

dave
 
Hey thanks for the replies guys!

It seems this driver is definitely worth giving a try. How exciting! :D

Does it really make a difference to play the driver full range from 200Hz onwards? The main issue i have is directivity, because i will be mounting the driver 30 degrees off axis(any more on-axis is pretty much impossible in a car environment) which is why i plan on switching to a tweeter after 6KHz. I suppose its worth a shot since all it takes to try is is an adjustment on the electronic crossover but i'm not sure how well i'll hold up.

If there are any more opinions, feel free to contribute! Maybe you guys could also suggest a great small sized tweeter to take care of the highs from 6KHz onwards. Only requirement is that its small enough to install easily and performs reasonably well from 30 degrees off axis. At this point i am using a Morel MT-2 car tweeter and i must admit i do like it, but as we all know in audio, we can never be satisfied!

I like the look of the fostex super-tweeter range but they seem largish and dont perform very well off axis
 
Does it really make a difference to play the driver full range from 200Hz onwards?

It's difficult for us lovers of quality full-range drivers to accept chopping off such a great speaker so early. I don't see the harm in bringing in your tweeter later than 6k. Think of it more as a helper tweeter rather than your sole source of HF. The 108 has excellent off-axis characteristics. IMHO, I don't think you'll miss anything.
 
hehe thanks. I promise i will at least try playing the speaker full range before thinking of adding a tweeter into the mix. I seriously have doubts looking at the off axis response above 7KHz but if you guys think it'll work, i'll definitely give it a go at least.

On another note: has anyone heaard of the FE108E Sigma II speaker? I saw a website for it on the fostex japan site i think, and i noticed that the rising response is more pronounced on this model which makes it even better off axis(one would think, at least). It also has a much bigger magnet, although i am unsure how this will help, if it does at all.

I dont suppose anyone here knows how much it costs or how i could get my hands on a pair of those? If it's about 120USD or less a driver i might be willing to give them a try although i am exceeding my budget a little already(so what else is new???)

Oh yes, forgot to mention, the reason for me going for a 200Hz crossover point is because the fostex will probably be mounted in a custom kickpanel fibreglass enclosure , and since i drive a right hand drive car, space will be very very limited. I have at most about 1-2 litres of sealed space available. I plugged the driver's T/S specs in WinISD and in that kind of enclosure, rolloff will start to begin at 300Hz(-3db at about 250Hz). I do plan to compensate for the rolloff with an EQ but any lower than 200Hz doesnt seem feasible given these limitations. I could mount the driver in the dash but the pathlength differences will result in very poor imaging which defeats the purpose of my using a splendid full range driver like this in the first place :xeye:

Now if i could fit a nice, low tuned TL enclosure somehow....:clown: then we'd really be talking!
 
The one and only
Joined 2001
Paid Member
I understand that Madisound has a single pair in anticipation
of a batch of several hundred. Silver wire, magnet diameter
bigger than the speaker, and some other tweaks. I believe
it will cost more than you want to pay....

Meanwhile, you may find that the FE108ES is adequate on the
top end by itself. Bit of a peak around 15 K, and while it doesn't
have a dip at 500 itself, it does have one at 1KHz, but it's only
a few dB. I'm not sure I would even bother with it.

I think it will work well down to below 200, but you'll probably
want to put in a shelving network to take the upper mid and
high frequencies down a few dB. :cool:
 
Thanks Mr Pass!

I've got another final(hopefully) question. From the opinions i gather so far, it seems the Fostex is a very good driver, but how does it stand(in the 200+Hz region onwards) when stacked up against other, more expensive superdrivers like the revelators or the SEAS excels, or anything else in that bracket? I know i do have a limited budget, but i am hoping to build up a speaker system which will hopefully have very few equals, regardless of price. If the performance is not top notch(i'm hoping it is though), i would welcome alternative suggestions, regardless of cost, which i will hopefully be able to save up for in the long term. Of course if it costs more than about 250USD per driver, then i probably will never be able to afford it, period, but i thought i'd ask anyway.

I've already checked out other full range drivers like the jordans(off axis response too poor) and manger(too expensive), among others, but i might have left something out. I'm hoping for something about 4" or so of course

As long as the performance of the speaker justifies its price, i'll consider it.

Also, i just read that very long thread about the disadvantages of full range drivers. It was very interesting, and i'm wondering if the IM distortion will come into play if the speaker plays from 200 to as high as 8-9KHz. I saw a formula there that can calculate the answer to this question(it was a function of the xmax, wavelength of the highest frequency, and some other variables which escape me at this point in time) but have no idea how to calculate. Anyway its a little OT but i thought i'd bring it up

Best regards
 
The one and only
Joined 2001
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I personally have quite a bit of affection for full-range sensitive
drivers, particularly the Lowthers, Fostex. I like Jordans quite
well but they and the Mangers would not qualify as particularly
sensitive.

I haven't played with the Revelators, but as compared to the
Seas, Vifa, Polydax, and other products, they are decidedly
different. It's a taste issue, but I am also influenced by the
aesthetic concept and the efficiency, which allows me to make
the most of my little bitty amplifiers.

Again personally, my favorites are the Lowther DX55's followed
by the Fostex FE166E and 206E, and I get the best out of them
driven by current source amplifiers and shunting networks.
Others have found single-ended tubes to be an appropriate
source. See the paper on www.firstwatt.com
 
Nelson Pass said:


Again personally, my favorites are the Lowther DX55's followed
by the Fostex FE166E and 206E, and I get the best out of them
driven by current source amplifiers and shunting networks.
Others have found single-ended tubes to be an appropriate
source. See the paper on www.firstwatt.com

Are you saying that you prefer the FE166e and 206e to the 108e sigma? I have thought about switching to one of the larger "FE" drivers and sell my fostex 108e sigmas, but I was always afraid I would lose something in steping up in size, and down in quality. I'm listening to my 108e sigmas right now in a sealed box augmented by a pair of subs. My thought was that the larger driver would give me a lower crossover as well as greater dynamics/effeciency. Of course dynamics don't mean much if you're giving up tonal quality/detail.
Any thoughts?
Joe
 
The one and only
Joined 2001
Paid Member
I think it's partly a matter of how you load them, how loud
you want to play them, etc.

I just got a pair of Ed's FE108E's in "The Horn"s from The
Horn Shoppe, and I'll play with them some more this week
and get back to you.

Meanwhile, these drivers are cheap enough that I don't see
any reason to be selling them. :cool:
 
I'll be interested in hearing your opinions.... as far as loading is concerned, I've got my 108s in ceramic sealed enclosures sitting on top of a stereo pair of subwoofers. I would probably do the same for the whatever other driver I get... that is put them in a large sealed ceramic container.
As far as selling the drivers to pay for new ones.... you're probably right. I've always sold my speakers to pay for my new projects.... I'm a bit of a tightwad. But maybe I could splurge for once.
Joe
 
The one and only
Joined 2001
Paid Member
navin said:
how do the 108s compared with say the FX120 or JX92 or other such drivers in their size? I was looking at fullrange for a HT/AV system. one driver per channel in a 10liter box should do it. I like the power handling of the JX92 and the response of the FX120.

The Jordans need the power handling, as they are less efficient,
as I recall. I have some J92S units and I think they're great,
but I don't know what the sonic difference is between them
and the JX92.
 
Nelson Pass said:


The Jordans need the power handling, as they are less efficient,
as I recall. I have some J92S units and I think they're great,
but I don't know what the sonic difference is between them
and the JX92.

I had a pair of JX92S in small BR boxes to demo for a couple of weeks. I think they would make exceptional HT speakers coupled with a nice sub. Crossed at 80Hz power handling would not be a problem and I thought the high end on the Jordan was quite good.
 
well i have 2 applications.
1. 2 channel stereo using a EL84 PPP power amp in a small 150 sq. ft. room.
2. 2 channel stereo for office conference room driven by a small 40W stereo amp.
2. 5 channel HT/AV using a Maratnz SR7000 (I already got a sub and sub amp) for a 450 sq. ft. room.

I was looking at the FX120 for the 1st and 2nd application and the JX92 for the 3rd.

from what i know the JX92 is about 88db and can absorb about 50W (if XOed at 100Hz). I figured this would make it better match (than the FX120) for the SR7000. The Fostex 5" drivers are 89-91db but cant absorb more than 20W rms. Also the JX92's LF response is a bit better than either of the 5" Fosex fullranges.

My guess is:
JX92 max SPL (XOed at 100Hz): 88db+17dbW = 105db
FX120 and F120 max SPL (XOed at 100Hz): 89db+10dbW = 99db
FE127 max SPL (XOed at 100HZ): 91+12dbW = 103db.

anyone know how the other 5" fostex drivers compare. Fostex makes such a large variety of fullrange drivers that I am really confused.

The ones I am looking at are the FE127, FF125K, F120A and FX120. The reason I narrowed down to the FX120 was that I felt the FF125K was better suited for a horn as it's low end rolls off awful fast and would need the support of a horn. of the 3 (FX120, F120, FE127) the 127s off axis response was the worst. even it's on axis response had a peak around 8k.the FX120 had 2mm Xmax v/s 1.5mm for teh F120. I am just not sure if my line of reasoning is right. I dont need a magnetically sheilded driver for my applications.

given the hassles one has to undergo importing into india i need to have my homework done before i import anything.
 
navin said:
well i have 2 applications.
1. 2 channel stereo using a EL84 PPP power amp in a small 150 sq. ft. room.
2. 2 channel stereo for office conference room driven by a small 40W stereo amp.
2. 5 channel HT/AV using a Maratnz SR7000 (I already got a sub and sub amp) for a 450 sq. ft. room.

I was looking at the FX120 for the 1st and 2nd application and the JX92 for the 3rd.

from what i know the JX92 is about 88db and can absorb about 50W (if XOed at 100Hz). I figured this would make it better match (than the FX120) for the SR7000. The Fostex 5" drivers are 89-91db but cant absorb more than 20W rms. Also the JX92's LF response is a bit better than either of the 5" Fosex fullranges.

My guess is:
JX92 max SPL (XOed at 100Hz): 88db+17dbW = 105db
FX120 and F120 max SPL (XOed at 100Hz): 89db+10dbW = 99db
FE127 max SPL (XOed at 100HZ): 91+12dbW = 103db.

anyone know how the other 5" fostex drivers compare. Fostex makes such a large variety of fullrange drivers that I am really confused.

The ones I am looking at are the FE127, FF125K, F120A and FX120. The reason I narrowed down to the FX120 was that I felt the FF125K was better suited for a horn as it's low end rolls off awful fast and would need the support of a horn. of the 3 (FX120, F120, FE127) the 127s off axis response was the worst. even it's on axis response had a peak around 8k.the FX120 had 2mm Xmax v/s 1.5mm for teh F120. I am just not sure if my line of reasoning is right. I dont need a magnetically sheilded driver for my applications.

given the hassles one has to undergo importing into india i need to have my homework done before i import anything.

Navin,

I think the Jordan would be the best for your application, having heard it in a MLTL a month ago and owning fostex 166E back horns myself.
IMO, the fostex are a bit of an acquired taste (some people will love them, others won't) while the jordan will appeal to a wider audience and can have impressive bass and smoother frequency response in the right design.

Just my 0.03c :)
 
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