Very cool looking driver.Don't like the super swan box though.
Dave won't be the only one just ichin' to get his hands on a pair of 138ES-R's.
Jeff
certainly a cool looking driver...i dont like the +10dB rise and wiggles above from 1,5k up to 5k and the others.....i suppose you COULD contour it out with a low Q RCL tank but its kinda going against the whole FR philosophy isnt it?
surely some of the older and high sensitivity fostex are better drivers especially for those SET tube fans....................
persoanlly, as much as FR is the 'holy grail' of audio, id still prefer a well designed 2 way, but thats my opinion, many will differ
Hi All,
I haven't heard any updates on these drivers so I thought I'd put in my 2 cents. I have a pair of the Fostex FE138ES-R drivers crossed over to two AE Dipole 15 drivers per channel and mounted on a 20 X 48 inch OB. They have a LR4 active crossover and have active EQ. (The active EQ is required!)
At first I was very disappointed with these drivers. Fingernails on a chalkboard were less harsh than these drivers! After about 50 hours they were a bit more mellow, but still not great. I was even considering throwing these drivers in the trash. But, instead, I ordered a pair of Tang Band W8-1808 drivers to compare to the Fostex drivers. By the time the Tang Band drivers arrived, the FE138ES-R drivers mellowed out. (Or, at least I found a good EQ setting for the Fostex drivers.) Although the Fostex drivers were still a bit bright at this point, the difference between the Tang Band and the Fostex was like the difference between night and day. (And the Tang Band sounded quite good out of the box; they are indeed a good sounding speaker.)
After about 100 hours, the FE138ES-R continues to mellow out. This is now, by far, the mellowest Fostex driver that I've heard. And, combined with the Dipole 15, this is the best speaker system that I've ever heard. That's probably not saying much. But, it does mean that I've stopped looking for the perfect speaker system -- this one will do just fine!
Sincerely,
Rich
I haven't heard any updates on these drivers so I thought I'd put in my 2 cents. I have a pair of the Fostex FE138ES-R drivers crossed over to two AE Dipole 15 drivers per channel and mounted on a 20 X 48 inch OB. They have a LR4 active crossover and have active EQ. (The active EQ is required!)
At first I was very disappointed with these drivers. Fingernails on a chalkboard were less harsh than these drivers! After about 50 hours they were a bit more mellow, but still not great. I was even considering throwing these drivers in the trash. But, instead, I ordered a pair of Tang Band W8-1808 drivers to compare to the Fostex drivers. By the time the Tang Band drivers arrived, the FE138ES-R drivers mellowed out. (Or, at least I found a good EQ setting for the Fostex drivers.) Although the Fostex drivers were still a bit bright at this point, the difference between the Tang Band and the Fostex was like the difference between night and day. (And the Tang Band sounded quite good out of the box; they are indeed a good sounding speaker.)
After about 100 hours, the FE138ES-R continues to mellow out. This is now, by far, the mellowest Fostex driver that I've heard. And, combined with the Dipole 15, this is the best speaker system that I've ever heard. That's probably not saying much. But, it does mean that I've stopped looking for the perfect speaker system -- this one will do just fine!
Sincerely,
Rich
So you prefer the Fostex? I wonder if these are amounst the ones where 100s & 100s of hours are needed to tame them?
dave
Yep. I prefer the Fostex...and by a huge margin. But, only when active EQ is used. Without active EQ, the Fostex would need a tweeter. For Example, I'm currently using 14.5 dB of boost at 16 KHz.
I hope not! I haven't counted the hours, but I'm guessing that it's between 100 and 200 hours. Right now they sound perfect. I'd hate for them to mellow out much more!
-Rich
I get the idea you're not listening to the driver's rising HF as it is sans some type of filter network knocking it down. In addition to bringing up the 16k HF, is the active EQ also bringing down the 10db rise above @ 3.2K - 4.8K and again @ 10k?
I'm guessing you're listening way off-axis as well, as the 138 is only a dB or two down @ 16k, even @ 30 degrees off axis, and less than 10dB @ 60degrees?
And maybe trying to bring the lows up to meet the two resonate peaks mp9 mentioned?
And eq ing room modes, etc?
What are you using for an amp?
Throwing power at it did seem to help mine.
http://www.madisound.com/catalog/PDF/FE138ES-R-1.pdf
And maybe trying to bring the lows up to meet the two resonate peaks mp9 mentioned?
And eq ing room modes, etc?
What are you using for an amp?
Throwing power at it did seem to help mine.
http://www.madisound.com/catalog/PDF/FE138ES-R-1.pdf
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Well, I'm using a Behringer DEQ2496 to EQ my speakers. I'm using the auto EQ feature of the Behringer DEQ with a Behringer microphone. I don't have any other sound analysis equipment. A Behringer A500 amp drives the Fostex drivers. My speakers are crossed slightly in front of the listener; pretty close to on axis.
According to the Behringer DEQ, the Fostex is fairly flat from crossover (238 Hz) to 4 KHz (the flatest midrange of my three Fostex drivers), with the exception of a 5 dB boost at 315 Hz. (This 5 dB boost is probably a room mode because it occurs with almost all speakers.) After 4 KHz it takes a gradual but slightly wavy boost increasing up to 14.5 dB at 16 KHz and back down to a 7 dB boost at 20 KHz.
BTW, my listing room is very dead. Perhaps that could account for the differences we're experiencing?
Sincerely,
Rich
maybe a tweeter is a good solution?
works for me; get +/- ~1dB using a nice ribbon, get real nice highs.
and no digital processing, opamps, etc, can keep everything analog.
i'm baffled on how you need 14.5 dB of boost on something w/ a 10db rise on the top end?
other than it's boosting a dip in the highs to fill in between the resonate peaks?
what about the mids being 10db down, are they bosted also? (~150Hz - 3kHz)
maybe this is a room mode thing?
and/or an ob thing/artifact (i don't know much about ob implementation, don't like the sound, delayed reflection, comb filtering).
or the other drivers are crossed high enough to be adding enough through the mid-range?
the mids are what were dull, and "uninteresting" sounding on my 138s.
this really has me scratching my head; why yours sound so much different than mine.
other than i too felt like throwing the things away a few times, except they cost so much (i bought them when they first came out, expecting way too much)...
Yep. I'd agree. A tweeter is a good solution if you don't want to use active EQ. But, I like using active EQ anyway to get rid of room nodes. Besides, the Dipole 15 drivers require heavy EQ, too.
The mids are the smoothest of all of my drivers except for a boost at 315 Hz which occurs in most of my drivers so it's probably a room or OB mode.
I doubt it. None of my other drivers need this much high frequency EQ
It might be related to the OB. Of all of my drivers, this has a much better high frequency output (when EQ'd) from the back of the baffle. In other words, the high frequency output is nearly the same from the front of the baffle as it is from the back of the baffle. I've tried crossing over anywhere from 100hz to 5KHz; I'm currently using 238 Hz. That's where they seem to sound best. I haven't noticed a problem with comb filtering; it can usually be actively filtered out.
My 138s have a great midrange!
Well, these are the best drivers I've heard so far. But, I'd be hesitant to recommend them to someone else since we're having such a different response. With a tweeter, do you like the sound of these drivers?
Sincerely,
Rich
FE138ES-R the Big Question
Hello friends, long time lurker, infrequent poster. Let me ask the forum, why hasn't anyone attempted to remove the dust cap on these things? I'll admit it's a thing of beauty and it would take a really nice phase plug to equal the looks of it. Isn't the metal cap probably the culprit, adding more variable to each driver?
I bought a pair of 4" 138 sigmas about 8 years ago and the first thing I did was upgrade to wood plugs, adding an even faster dynamic to the sound. I am currently using my 5" 138s' in a crossover configuration 'til they're well broken in and am considering building a BMVR for them. My hand trembles at the thought of putting an exacto to these puppies but it is my future intention. Any thoughts on the best way to remove them? Maybe heat them with a soldering iron to soften the glue? It seems to be the same kind of adhesive the 4"ers had, that hard black stuff.
Thanks for any consideration!
Hello friends, long time lurker, infrequent poster. Let me ask the forum, why hasn't anyone attempted to remove the dust cap on these things? I'll admit it's a thing of beauty and it would take a really nice phase plug to equal the looks of it. Isn't the metal cap probably the culprit, adding more variable to each driver?
I bought a pair of 4" 138 sigmas about 8 years ago and the first thing I did was upgrade to wood plugs, adding an even faster dynamic to the sound. I am currently using my 5" 138s' in a crossover configuration 'til they're well broken in and am considering building a BMVR for them. My hand trembles at the thought of putting an exacto to these puppies but it is my future intention. Any thoughts on the best way to remove them? Maybe heat them with a soldering iron to soften the glue? It seems to be the same kind of adhesive the 4"ers had, that hard black stuff.
Thanks for any consideration!
I think you mean 108 sigmas?
Of the several models of the new FF-WK series that I've heard employing a "dust cap" similar to that on the 138 ESR, I'd assess them as a significant improvement over their immediate predecessors, and certainly not attribute the dual elliptical profile metal dome with any deleterious effects.
It's unlikely that it's removal on the 138s would mitigate the driver's issues, ut if you are determined to do so, be very careful with a soldering iron - unintended consequences and all that.
I'd simply consider the 138ESR a "bridge too far" when used full-range - we did find them tolerably acceptable when used as a mid woofer, crossed over in the approx 100Hz range, IIRC
In Frugel-Horn Mk3 they were very good as a bass driver, they could likely be XOed higher, that was just the XO that was handy at the time.
dave