Fonken - Fostex FE127e - planet10 - build

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hello everybody,

i have just finished a Fonken - Fostex FE127e;
it is the "regular version" of it, (im also building the golden ration version).

my impression:

well let me start by this

my system
a)pc
b)gamma 1 usb dac
c)ta2020 heavy modded (still a ta2020 nothing more, nothing less)

what do i like and what i'm a used to
i like an open sound, detailed, musical. i rather loose low end and airy high end for good midrange. Well not really off course but speakers are always a trade off. and i rather have a bit less extension in bass then muddy bass. same with highs: i rather have no highs then contraint and compressed high sound. i'm a singer (not professional) but i get a headache with stress on the highs, and if the low's are not clear they tend the mess up the rest of the sound too, even if the rest of the sound is not produced by the woofer.
so i really like a good sound, but a good sound over the whole spectrum is just not that easy and cheap to get right. so i'm used to do some confessions.

what i think is my ideal system: an active open baffle with large woofer (+15 inch) a big midrange, and a high end tweeter: ribbon, esl, or something else.

the last 3 speakers i build were fullrangers. they are cheap, easy and deliver a lot of sound for the money.
a) a pair of BR coral flat 8's
b) a bob brines fe167e
c) fonken fe127e

how do i listen
i listen near field: that means in the middle i have my pc screen and at each side i have a speaker, so i'm very close the the speakers. i estimate 1 meter away.

HOW DO THEY SOUND ?
well in between building the fonken i played the the fostex drivers in an cupboard open baffle, and i must say, it was astonishing what they ware capable of. in windows XP i was able to EQ very heavy and getting a lot of bass out of them: well i pumped up everything expect the highs and the speakers was quite perfect. but in linux my cpu wasn't powerfull enough to do a good job and i left out the EQ, still the open baffle was good.

then i finished the speakers, and i played left with the fonken and right with open baffle. i compared what i heared.
a)the fonken sounded a bit boxy; but not that much compared to other boxed things i have heard, i hate the boxy sound, but it is only a little bit, so that was okee
b)the fonken lost a bit on the highs, a banjo for example was less loud and "airy", but the fonken offcourse gave a much more flat response then the open baffle and the sound got less thin off course. i must say that i prefered the fonken over the non-eq open baffle.
c)dissapearing: well the open baffle might dissapear a bit better, but it's like a very close call. the fonken does this trick very well too.
d)impulse and low: off course the fonken is the king in this region, the open baffle shorts out the low's or the impact on the low. nothing new here.
e)detail: the fonken looses detail on the highs, but midrange and low the fonken wins from the open baffle, (what was expected) still the fonken delivers much more detail in the mid and low, and looses only a bit on the high.


after all: i'm quite happy with the fonken, there is a lot of detail, the response is quite flat and for me there is just enough low (i would not be bad if there was a tad more).

it is a good speaker, that does a lot of things okee, it is not a super speaker, but hé for 120 euro wood and drivers, you cannot expect the best. but to be honest: people coming by are pretty amazed by the sound, maybe i'm just to spoiled...

if you have any questions: shoot, i'll try to answer them, but describing sound isn't my most gifted talent. i'll try to upload some pictures, if i can get my pc-camera connection up and running.

greetz

oh yes: thanks to planet10, he awsered all my silly questions with great enthousiasm and lucidity
 
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i still need to angle the sides,
and don't pay attention to the beer can's, it is my cantenna for my dvbt :)
 

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The enclosure will "disappear" even more with the sides beveled, and if you want to hear deeper into the low level detail and even further increase dimensionality of soundstage, you should consider trying EnABL on the cones.

If the drivers have less than 100hrs of break-in time, much of the congestion/compression that you hear in the upper octaves will dissipate, and the bass extension will improve more than a little bit.

With all due respect to the Tripath amp (I've heard a couple on these drivers), you might want to treat yourself to trying these on a small tube amp - they're small enough boxes to be easily transportable if you have a friend with such a rig. I've built more than a few pairs of these, and powered them with everything from 2-3W ( 2A3 DHT, EL84 SET) to 25ish W EL34 P/P triode - for bang for buck an EL84 P/P like an old Dyna SCA35 would be a sweet zone.



but then, Dave has probably made similar suggestions


I'll be very interested in your impressions of the GR vs "Prime" version of this design.
 
hi guys,

thanks for the comments,

i guess they will indeed disappear more with the sides beveled, but that's a tricky job. cause the multiplex seems to splinter very fast.
so i'm a bit stuck:
a)i can use a circulair saw, but i must use a 48t blade i suppose, and even then i need to cut in two times, cause it's on 45 degrees, and needs to be 7cm deep: that's a lot for a circulair saw.
b)i can do it by hand, but then i need a new saw, one with very fine and straight teeths. and off couse trying to saw in a straight line. (i could use an alumium rod to keep straight).

i have broke in the cones, long time ago, i let them run for hours and hours with all kinds of sound: 40hz; sweep tones, pink and white noise... i had them in the open baffles for more then 2 months. so that should be done.

i know that my ta2020 isn't the best kid on the block, it's a high end ta2020 but still a ta2020; i'm looking to build a tk2050: something like amp4 from 41hz. i could go with tube amp, i sold one, an push pull el84 (which wasn't working, i cleaned the chasis and the transfo's). i don't know about buying a tube amp. it could sound great, but a good tube amp still cost quite a bit of money. maybe i can go OTL if i need only 1 watt.

i also have a few headphone amps AMB design, it's the ck2III, i could use it as amp but it has not much power offcourse. theoreticly it could output 6 watt, but by no means is the psu capable of delivering so much current and also heat is a problem. anyway i'll give it a try, cause that's a high end class A (if not driven to hard) design.

the GR version, is gonna take some time, i'm a slow builder, but a steady one

btw: i'm gonna get the screws out, and put wood in it, then bevel all sides (5mm), sand the speakers and put a vernish on it, (otherwise i'm gonna hurt myself a lot: splinters)
 
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hi guys,

thanks for the comments,

i guess they will indeed disappear more with the sides beveled, but that's a tricky job. cause the multiplex seems to splinter very fast.
so i'm a bit stuck:
a)i can use a circulair saw, but i must use a 48t blade i suppose, and even then i need to cut in two times, cause it's on 45 degrees, and needs to be 7cm deep: that's a lot for a circulair saw.
b)i can do it by hand, but then i need a new saw, one with very fine and straight teeths. and off couse trying to saw in a straight line. (i could use an alumium rod to keep straight).

i have broke in the cones, long time ago, i let them run for hours and hours with all kinds of sound: 40hz; sweep tones, pink and white noise... i had them in the open baffles for more then 2 months. so that should be done.

i know that my ta2020 isn't the best kid on the block, it's a high end ta2020 but still a ta2020; i'm looking to build a tk2050: something like amp4 from 41hz. i could go with tube amp, i sold one, an push pull el84 (which wasn't working, i cleaned the chasis and the transfo's). i don't know about buying a tube amp. it could sound great, but a good tube amp still cost quite a bit of money. maybe i can go OTL if i need only 1 watt.

i also have a few headphone amps AMB design, it's the ck2III, i could use it as amp but it has not much power offcourse. theoreticly it could output 6 watt, but by no means is the psu capable of delivering so much current and also heat is a problem. anyway i'll give it a try, cause that's a high end class A (if not driven to hard) design.

the GR version, is gonna take some time, i'm a slow builder, but a steady one

btw: i'm gonna get the screws out, and put wood in it, then bevel all sides (5mm), sand the speakers and put a vernish on it, (otherwise i'm gonna hurt myself a lot: splinters)


If you have access to a table saw, it will make things a lot easier - although unless it's a large commercial machine you'll likely still need to make several slow passes for each edge. Actually, this is a case where a lower tooth count rip blade can speed things up, but will increase the chipping. I'm generally using a 60 or 72T carbide tipped ATB blade.

Set the blade to tilt away from the rip fence, and to reduce splinters clamp a sacrificial block of scrap at the trailing end of the box.

It's not clear from the photos what material you used on the port spacers, but keep your feed rate slow and steady to reduce burning on the plywood panels and splitting on the trailing edge of the spacers. Even then, you'll likely need some filling and sanding prior to finishing.

Regarding DIY tube amps, I guess it depends on budget and what you'd consider "expensive" but there are several very decent kits available that could produce enough power for these speakers. The first that comes to mind is probably the Decware Zenkit. I've heard a couple of the factory made version of this, and let's not get into the "how much power must [/] I have?" debate - but it was enough for my taste.

Zen Triode SET kit amplifier model ZKIT1

no doubt this is an area where you could receive as much helpful advice as with speaker building - just enjoy the journey
 
i have no acces to a tablesaw. good lord you use a 60-70t saw, that's impressive, no wonder the chips are flying around my head.
i have a circular saw, but buying a 72t is not exactly cheap. mmhh, that's not good. i'm gonna look around how to fix this.

i was planing on attaching a piece of wood on both sides so that the chipping reduces. still thanks for the heads up.

the spacers are also from multiplex, but 9mm. there is still a lot of work to the speakers. but they are growing on me, sometimes i jump up and realize they offer a lot off bass, just not used to it anymore i guess. (well i'm in for a suprise, cause my next build is an open baffle with a 15" and a fe87)

well i'm tight on the budget, and a 300 dollar amp like zenkit is not for me. i have sold my amp for 75 euro, i can buy a working one for 100 euro: that is a lafayette push pull el84, tube rectified; and i would put it in triode mode, giving me 4 watt, what is more than enough. and the output trannies are even bigger than the psu trannie of the zenkit, so that is a no brainer. (yep i'm very tight on the budget :) )

wel the FR is not flat, that's right; me and a friend of mine are building a troels gravesen design, that should be quite flat, i will compare when that build is done (it is a very small two way peerless).

i'll start looking for some decent tools. damn, that's always the expensive part of this hobby, you need more equipment then the stuff you put together. i guess it's the burden of feeling the need to DIY
 
hello people,

some update,

i have been living with the fonken for a while and the FR is indeed not flat enough. For me there is much to much midrange. treble and bass stays behind. in the open baffle the FR must be more awful but the midrange wasn't shouting as this. i haven't done the mods to the driver, given extra weight to the driver might make it less shouty. i don't know, i feel the need for a filter to tame the mid section down. anyone ever tried to design one ?
i have already looked at tony gee solo 103: the proto-fonken and he uses a correction filter too. i can follow his thoughts on this.
 
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Hi Then_dude,

Concerning the shouty midrange on the FE-127e:
Try to toe-in the speakers so that they cross *BEFORE* 1 meter before your ears.
The drivers won't point (and shout) at you as you will be listening off-axis.
You have to experiment a little with the toe-in and listening distance and you
will find a sweet spot that is quite perfect.

I'm using the above setup with a mFonken and listen to them near-field without any correction network.

I eNABL'd the FE-127e drivers as described by Bud Purvine and Planet-10 in some posts
here on diyaudio and for me it made a large difference.
The shoutyness was reduced and brought out the remarkable holographic soundstage these drivers have. My FE-127e's needed at least 200 hours of run-in before being listenable.

They did so well in the mFonken that i'm currently building the slightly larger Fonken.

Kind regards,

Yves
 
For the angle cut it might be worth it to go to a planing mill or cabinet shop that makes kitchen stuff and the like to get that saw tooth problem solved. Plus they may have larger blade setups (12 in vs 10 inch I think but don't quote me) and higher torque motors.

For this hobby, a one time use might be preferred at a local wood shop.

And don't forget that sacrificial piece to avoid major chipouts.
 
For the angle cut it might be worth it to go to a planing mill or cabinet shop that makes kitchen stuff and the like to get that saw tooth problem solved. Plus they may have larger blade setups (12 in vs 10 inch I think but don't quote me) and higher torque motors.

For this hobby, a one time use might be preferred at a local wood shop.

And don't forget that sacrificial piece to avoid major chipouts.


yup, clamped down to big-a$$ sliding table saw with 12" blade and 15hp main blade motor makes relatively simple work of this, but as Lon notes, don't forget the sacrificial board at the tail end of cut


whatever you do, don't cut with the scrap pinched against the rip fence
 
A 15" woofer per side really brings out the bass. I love my H-frames and believe everyone should build a pair just to hear what they can do. Just sit your Fonken's on top of the H-frames and the sound will really fill out and you keep all the benefits of the Fonken. I used the Alpha 15 in the H-frames but also built another set of open baffle speakers using inexpensive Jamo woofers (a PE buyout) that had specs suitable for open baffle (if i remember correctly the qts was .85 and the fs 27hz). As a suggestion, use a separate amp for the wooofers to match with the output of whatever speaker you will partner them with. Of course there are different ways to achieve great sound. Go for the 15" woofers... however you incorporate them they should prove satisfying.
 
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