Full-range question to Fostex experts

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Hi-

I am building a budget speaker system, but decided to take a different approach to keeping costs down. Instead of buying inexpensive tweeter/mid/bass combo, I think it would make more sense for me to buy one good or very good Fostex full range driver (per channel of course). This way, at a later date and when funds allow, I can add other components of similar quality and end up with possibly better combination. These other components would augment the full range on the bottom, and probably on top (via supertweeter...). But I defiantly need help deciding which drivers to go with. So far I am looking at three serious contenders:

FX200 - $150. Almost flat from 40 to 20k, 92 dB sens. Only 1 mm Xmax; impedance very linear

FE208ESIGMA - $175 Not very flat but 97 dB sens (needs subtractive eq)! impedance not too flat (needs compensation?) Xmax 1.25 mm very cool looking driver!!!!

F200A - $400 Expensive... Alnico... Xmax 2 mm. Freq resp flat. Impedance not flat. Did I mention $400? Will probably output twice the volume as the FX200.

This will end up in a sealed box, but until the final config is reached it may be ported...

Please help. Thanks!!!
 
Not a Fostex expert _grin_

amo said:
FX200 - $150.
F200A - $400

If you're going with a BR, or ported design I would go with one of the above. I've never heard either one of them, but they seem to be well thought of. Kloss at AA says that the F200A is one of the best 8" drivers around for use in a cabinet - I've seen other posters say that the FX200 makes a really nice BR speaker

then later stick a tweeter on top.

The FE208EZ Sigma's specs are better for Horn loading, and not well suited to BR. However, if you built Martin King's MLTL at

http://www.quarter-wave.com you might want to use the FE208EZ Sigma = It was originally designed for the old Sigma so I would think it would work well in that enclosure.

I haven't heard that one either but there have been a number of good posts about it - it is tempting because the cabinet is so simple - I've thought about it more than once myself - and may in fact build it at some point

regards

Ken L
 
The 3 best sounding speakers I've ever heard were (not in order)

A fostex fe164e in a ML TQWT (more info on www.quarter-wave.com)

A Loth-X full range in a TL(?) Its the Loth-X Ambience

and my Philips AD2800M full rangers in dipole (I'll post pics soon).

Some say horns and full rangers are the best match, but I've never heard a good one, and this doesen't mean I've never heard expensive commercial horns.

So by choosing to go on the full rangers path, your on the right way.

In the choices you mentioned, the one that I like the most is the F200A, probably because of the the AlNiCo :) Only if it wasn't for it's low efficiency.....
And seems preety suitable for a TL.
 
Please don't overlook the FE206E. A much better, overall choice than the 208EZ, the sigma does not have enough high frequency extension to run on it's own in my and many others opinions. True the 206 does not have the beefy, technically advanced construction of the 208sigma but it's sound is, nontheless, incredible. Plus you'll save money on the drivers and by not having to buy a supertweeter, which you can decide if you need later. I have not found the need to boost the high end of this driver.

I second the ML TL option, take a look at mr.King's site (I just built a pair of ML TL cabs with FE206e based loosely on his design and am very impressed, blows my 2.5 ways out of the water). These are fairly easy to construct when compared to BL horns.

For some die hard Fostex full range fans to help you along go to http://melhuish.org/audio/index.htm for information and Look to GM for guidence, he is usually the first to respond with excellent, detailed help anyway. (thank you GM).
guidance.

Be aware that most of the full range Fostex drivers have a very limited xMax and low Q making them unsuitable for simple BR design, most require a back horn to boost bass without losing effeciency, or compensation networks which lower effeciency considerably to achieve good tonal balance, the FX200 is an exception. Also be prepared for a large enclosure. Thorsten is a big fan of the FX200, and has sparked a huge interest in me, I will be building cabs for these soon.

There are many choices out there so take your time researching them all before you comit to one. Good luck.

Bart G.
 
BTW this is a pic of one of my ML TL cabs featuring the FE206E. constucted of Baltic Birch ply with MDF outer layer and still showing it's nakedness, paint to come in spring. Behind it(not visible) sits the compensation network in it's own box. Standing next to it is one of my old 2.5 way HT speakers, nothing hot to begin with but definitely uncomparable in sound quality to the Fostex.
 

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Hi amo

I'd like to put a plug in for the FX200. I've had them in a ML TL, on open baffles, and they're now in 39 liter sealed boxes actively crossed at 100Hz to a pair of large (~15 ft^3) ML TL subs. This is a full range driver that's very easy to recommend and seems to work in just about anything. Response is pretty much like you see it in their plot, with some peaking around 4.5kHz and good HF extension out to at least 15Khz (probably more, but I can't hear much above 12K soooo...

In a large ML TL, I was getting pretty usable extension down to 30Hz but if I had to do it again, I'd probably shrink the box and tune it a little higher - I had lots of cone excursion when I was really pushing the low notes loudly and it was making me a little nervous. It probably says something about Fostex build quality, 'cause they were waaaay beyond the rated 1mm xmax:)

After spending some time with them in their sealed boxes, I've decided to leave them there. When you relieve them of bass duties, they are really performing at their best IMO. Very smooth and refined with an enormous soundstage and really remarkable imaging. I probably sound like a Fostex salesman, but they really did something amazing with these pups. Very nice driver.

Allan

PS - I don't know if they'll output twice the volume of the F200A, but they'll leave twice the volume in your wallet:)
 
nice thread. hope it clears my confusions.

one option i am looking at is a 1.5 way using say a FE107E with a 4" woofer (recomendations anyone). this works well for AV as one can use the FE107E for rar and have small boxes.
FE107 specs:
http://www.fostex.com/support/pdf/fostex/fe_av_series/fe107e_data_sheet.pdf

the second option is to use a lerger driver for teh front channels like the FE207E fullrange
specs:
http://www.fostex.com/support/pdf/fostex/fe_av_series/fe207e_data_sheet.pdf

from what i see there are 3 types of fostex fullranges
FE, FE-AV and Sigma. the FE-AV seems to be a sheilded version of the FE.
 
Thank you all for your comments!

If my budged would allow it, I would definitely go with the F200A, but since it does not, I think the FX200 is the next best thing for me. If we compare the price to performance ratios for these two I believe they are fair contenders.

What I really like to hear is that the FX200 works well in a sealed box, as well as others, as my application will include a sealed design. I will take the good advice of not running lows to this driver as well. Eventually I hope to make this into a little 3 way system, perhaps with an Eaton 11" for lows, and some type of supertweeter. I think a very exciting aspect of working with a full range driver will be the ability to use first order slopes. This system will be intended for PASS diy hardware - the BOSOZ and the upcoming XO. I also hope to build a balanced DAC, however I doubt I will attempt to tackle the amps, as I will need at least 6 monoblocks... Thank you again.
 
Fostex Fe167E drivers

I've recently built a pair of ML TL speakers using the Fostex FE167E drivers. My first diy project. I've been a music lover all my life, had MANY different systems. These speakers are very good, out of all proportion to their cost (around $400 Canadian) The design is from Bob Brines. Check them out!
 
Does any one know what material is used for the surrounds on FX200 and F200A? Based on all the photographs I could find, it is hard to tell. Sometimes it looks like foam... Also, does anyone have any idea as to what some other TS params for these two drivers are? Bl product, etc... Thanks!
 
Don't know about the surrounds, but you can calculate the others:

Cms = Vas/(Sd^2*rho*c^2)

where:

Vas needs to be in m^3, so multiply liters by 0.001
Sd needs to be in m^2, so multiply cm^2 by 0.0001

rho = density of air in kg/m^3, or ~1.21 at a typical room temperature

c = speed of sound in meters, or ~344.42 at typical room temperature

then:

Mms = 1/[(2*pi*Fs)^2*Cms]

BL = [(2*Pi*Fs*Re*Mms)/Qes]^0.5

GM
 
Surround Material

amo,

The surround is indeed foam, but it's not your basic self-destructuing type. :D I don't have the information directly from Fostex, but i was told by someone I believe to be closer to Fostex than I am, that it's a special poly-space-age something that won't degrade. It does appear to be very dense and different looking than other foam surrounds I've seen.

As for the other parameters, GM is right you can calculate them. I did that once or twice and decided it was easier to just let Unibox do it...I know, I'm lazy...you'll have the added advantage of though of being able to model the driver in Unibox when you're done. Unibox requires Excel.

Allan
 
Illusus said:
BTW this is a pic of one of my ML TL cabs featuring the FE206E. constucted of Baltic Birch ply with MDF outer layer and still showing it's nakedness, paint to come in spring. Behind it(not visible) sits the compensation network in it's own box. Standing next to it is one of my old 2.5 way HT speakers, nothing hot to begin with but definitely uncomparable in sound quality to the Fostex.


Hi to all,
After building a GC (inspired from this forum) and really liking the results and because I'm a believer in the "less is more" aproach I have been looking at the full range speakers and I liked the FE206E driver. What do you think of the following article?

http://www.oldhifi.com/fostex.html

They say they liked the BR the best. I have never heard any of them so I really don't know much.

Ireally prefer if I can do less wood work (not my thing), so BR would be my choice. Any advice would be strongly apreciated.

Thanks a lot!

/Greg
 
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