Hi All,
After making my introductions... here's my first attempt at advice-seeking...
I have a pair of Fostex FE108 Sigma's in the cupboard, unused, and would like to build a good, possibly temporary, small enclosure for them. Ultimately I would prefer experimenting with the Frugal Horn and/or MJK's OB design, but at this time I only have space for a bookshelf type enclosure. Something like the "Fonken" or "Solo" would be perfect.
They would be placed on existing heavy furniture at ear-height. The room is small, 28m2 or so, the distance to the listener no more than 3,5 meters. The distance from the back wall would be 40 cm or so, they would be 1,5 - 2,0 meters from the side walls.
Due to the temporary nature (depending on the outcome) of the project, as well as the simple nature of the music they will play (light jazz, vocal, acoustic guitar for example) I don't mind compromises with bass; it's imaging I'm really after.
The speakers would be driven by either an ECL82 PP amp of approximately 8 watts or a KT88 SE of 10 watts or so. The (unfinished but playing) CD player is featured in my "introduction" post.
The reason I could not find any examples could well be related to my limited search prowess or the fact that it simply can not be done... Either way, I'd appreciate a nudge in the right direction or post, or some advice...
Ron
After making my introductions... here's my first attempt at advice-seeking...
I have a pair of Fostex FE108 Sigma's in the cupboard, unused, and would like to build a good, possibly temporary, small enclosure for them. Ultimately I would prefer experimenting with the Frugal Horn and/or MJK's OB design, but at this time I only have space for a bookshelf type enclosure. Something like the "Fonken" or "Solo" would be perfect.
They would be placed on existing heavy furniture at ear-height. The room is small, 28m2 or so, the distance to the listener no more than 3,5 meters. The distance from the back wall would be 40 cm or so, they would be 1,5 - 2,0 meters from the side walls.
Due to the temporary nature (depending on the outcome) of the project, as well as the simple nature of the music they will play (light jazz, vocal, acoustic guitar for example) I don't mind compromises with bass; it's imaging I'm really after.
The speakers would be driven by either an ECL82 PP amp of approximately 8 watts or a KT88 SE of 10 watts or so. The (unfinished but playing) CD player is featured in my "introduction" post.
The reason I could not find any examples could well be related to my limited search prowess or the fact that it simply can not be done... Either way, I'd appreciate a nudge in the right direction or post, or some advice...
Ron
I don't know about bookshelf cabinets for the 108eSig, but if you can spare just a little bit of floor space, then try a Metronome. I love my 108eSig Mets!
You will find a few threads about Mets, incl the one I did "My Metronome Experience." (I was new to the forum & didn't know that it was SOP to add onto existing threads on the same topic.)
Cheers, Jim
You will find a few threads about Mets, incl the one I did "My Metronome Experience." (I was new to the forum & didn't know that it was SOP to add onto existing threads on the same topic.)
Cheers, Jim
Hi Ronmeister, your situation is very similar to mine (small Fostex FR in two small cabs plus a sub, on stands, from 2 to 8 watts).
For maximum imaging, don't you have to be able to pull them way into the room? That's what I've found (that, plus a very narrow baffle). It works great, if stands can be worked in. (I haven't heard the Metronome yet.)
Also, just to confirm, you have the older discontinued FE108-Sigma, rather than the newer, current FE108E-Sigma?
For maximum imaging, don't you have to be able to pull them way into the room? That's what I've found (that, plus a very narrow baffle). It works great, if stands can be worked in. (I haven't heard the Metronome yet.)
Also, just to confirm, you have the older discontinued FE108-Sigma, rather than the newer, current FE108E-Sigma?
another "don't know about bookshelf cabinets , but if you can spare just a little bit of floor space" that may be a waste of your time...
what may be seen as a small floor standing speaker;
or seen as a very small cabinet, glued to a stand,
is Nagaoka's Swan.
Some say they're ugly, I really like 'em, they're my wife's favorite. Very detailed w/ 108s, great imaging when you get them in the room right.
Usually don't even use a sub with them.
what may be seen as a small floor standing speaker;
or seen as a very small cabinet, glued to a stand,
is Nagaoka's Swan.
Some say they're ugly, I really like 'em, they're my wife's favorite. Very detailed w/ 108s, great imaging when you get them in the room right.
Usually don't even use a sub with them.
rjbond3rd said:
Very true, you do need room to create an image. Unfortunately I do not have much space to play with. It's a small room, with limited options. If I'd move them more forward they'd be head-phones... kidding... It is what makes this challenging, the limited space, the size and placement of the cabinet etc. Ultimately we might decide it's impossible...
As for the type, it's the E-sigma, late 2007. My apologies...
Have a happy and healthy new year of course!
Ron
And now in MJK: The best I could do is a box barely big enough to hold the driver: internal dims are 5.25" x 5.25" x 2.5", the port is a diminutive 0.375" x 0.75" located 5 inches from the top, and 4 ohms series resistance was required.
I'm not suggesting any of this is a good way to go -- it seems insane, in fact. But it's what I could churn out with my limited experience. Maybe a guru will be kind enough to weigh in on this.
I'm not suggesting any of this is a good way to go -- it seems insane, in fact. But it's what I could churn out with my limited experience. Maybe a guru will be kind enough to weigh in on this.
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I don't have MJK anymore; let it lapse, now can't renew itrjbond3rd said:
oh well... Anyway, I built a tiny box like that, which I modeled in AJ a couple weeks ago for a FE138.
A suprising amount of bass for something so small, but it sounded like, well, box colored--
It took about ten minutes for my wife to ask when I was going to put the swans back...
I'm thinking they might make nice bird houses...
Hope you have better luck than I did...
It's not a great idea to run these units in a regular box-speaker. However, if you really can't do anything else, I'd try this mini MLTL.
Internal length 18in, CSA 33in^2, Zdriver 7.5in, Zvent 17in, vent 2in diameter x 1.75in long. Line cabinet with 1in acoustic fiberglass or stuff the entire box 0.5lbs ft^3.
Internal length 18in, CSA 33in^2, Zdriver 7.5in, Zvent 17in, vent 2in diameter x 1.75in long. Line cabinet with 1in acoustic fiberglass or stuff the entire box 0.5lbs ft^3.
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Scott how did you do that?! I labored for hours just to get my sad little box with a pinhole for a vent. It would have made a better camera, actually.
Ronmeister, help has arrived. I hope you didn't build to the dims I provided -- ha ha ha!
OT but Mssr. Robert SereneChaos, what you do have your 138's in at the moment? I keep wondering if they can be tamed with materials, e.g. piece of felt?
Ronmeister, help has arrived. I hope you didn't build to the dims I provided -- ha ha ha!
OT but Mssr. Robert SereneChaos, what you do have your 138's in at the moment? I keep wondering if they can be tamed with materials, e.g. piece of felt?
Here you go... variation on the mFonken, using the data measured for my FE108eS. F3 on the order of 110Hz, it is going past xMax at about 87 dB below 250 hz.
http://p10hifi.net/FAL/downloads/Fonken108-0v7-map-311208.pdf
dave
http://p10hifi.net/FAL/downloads/Fonken108-0v7-map-311208.pdf
dave
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Thanks for trying as well as the suggestions. The Swans look interesting, but unfortunately too large. I'm looking for something smaller and bookshelf, if I can utilize them as bird-houses once I have the space for Horns/Swans/OB... all the better...
I did try a few simulations of my own, not that it's my strength either, and found 5 liter to do fairly well. Tuned to 80 or so Hz with an anomaly around 500Hz. I realize I'm risking actually sounding like I know what I'm talking about - I don't - but it was one of the reasons I considered posting the question: The knowledge the question may not equate to insanity.
The simulation brought me to Tony Gee's "Solo 103"; built for the Fostex FE103. It is around 4.9 Liter, with a baffle width of 16 cm and a height of 27 cm. This would be the approximate size I'm looking for as it will leave some room for maneuvering the loudspeaker in position. Here's his website:
www.humblehomemadehifi.com/Solo103.html
The question is, of course, is it suitable for the FE108ESigma? Has anyone actually built an enclosure such as the Solo 103 (or the Fonken designs) utilizing a 108? Can we go even smaller...?
Ron
I did try a few simulations of my own, not that it's my strength either, and found 5 liter to do fairly well. Tuned to 80 or so Hz with an anomaly around 500Hz. I realize I'm risking actually sounding like I know what I'm talking about - I don't - but it was one of the reasons I considered posting the question: The knowledge the question may not equate to insanity.
The simulation brought me to Tony Gee's "Solo 103"; built for the Fostex FE103. It is around 4.9 Liter, with a baffle width of 16 cm and a height of 27 cm. This would be the approximate size I'm looking for as it will leave some room for maneuvering the loudspeaker in position. Here's his website:
www.humblehomemadehifi.com/Solo103.html
The question is, of course, is it suitable for the FE108ESigma? Has anyone actually built an enclosure such as the Solo 103 (or the Fonken designs) utilizing a 108? Can we go even smaller...?
Ron
planet10 said:
Thanks Dave!
Both you an Scottmoose are very helpful; I believe I'll build both suggestions after I get home in February (working at sea - patience is a virtue). My 11 weeks 'leave' should suffice for these little 'ns. But then, of course, there are the granite creations...
More suggestions are of course always welcome. I could have my own private 'sound off' early '09...
Ron
rjbond3rd said:
138s are last in line of things to do...
One's still in the "bird house," one's out to fit to the drawing dave posted a couple days ago.
I've got the week off, & building all kinds of stuff though.
Did the "bird houses," almost finished a pair of tapped horns that that will do 25Hz-100Hz +/- 3dB at 100.5dB for subs, am in the middle of a pair of mid bass FLHs that will do 65 - 450 @ 108 dB to match compression drivers for a five-way I'm building...
The wood's mostly cut for the 138, just need to do the inner braces & glue it together, & finish it.
Listen to that one while the spruce I got dries out to build Nessies.
Then decide what I like the 138s in, or maybe even build another swan...
That's the plan(s)...
even further OT; when are we all supposed to be getting together for another listening party?
I've got those austin cabinets up here if you want to hear them.
Been using them in the shop with the THs & a UREI 650w studio amp...
I got hammered elsewhere for my general disdain for small drivers, but....
If you must use a low to nonexistent Xmax driver, a sealed box with a Q ~1 is not a bad idea. This gives you some degree of protection from over excursion and a built in BSC. Of course, you are going to have to cross to a woofer somewhere in the 200-300Hz range. Using a real cross over is not a bad idea either.
Bob
If you must use a low to nonexistent Xmax driver, a sealed box with a Q ~1 is not a bad idea. This gives you some degree of protection from over excursion and a built in BSC. Of course, you are going to have to cross to a woofer somewhere in the 200-300Hz range. Using a real cross over is not a bad idea either.
Bob
Bob Brines said:
Hi Bob,
No worries, I don't hammer, I prefer glue and the occasional screw...
I'll definitely make an attempt at Dave and Scottmoose's suggestions. However...
One of the thoughts I played with was to put the Fe108 in a 1,5 Liter sealed enclosure, supported by another unit I have in the cupboard (yes - it's a sizeable cupboard), the Peerless 830874. I've asked help from a fellow enthusiast in creating a 3rd order crossover at... you guessed it... 300Hz. With 14 Liters for the 830874 (with a 15cm long 5cm diameter port) and 1,5 Liters or so for the FE108 you still have a fairly small loudspeaker. Not "full range" in the exact sense of the words, but close.
I did stray from this idea because my DIY roots drew me back to full range, single driver etc. The other reservation I had was the cross-over point. I'm not entirely sure at which point it is best to cross units. In other words, which frequency range is more critical than others? I remember reading somewhere that 200Hz to 300Hz is a critical range.
On the other hand - when you do move up and away from this frequency it quickly approaches regular 2-way designs at which stage it's fruitless utilizing a unit such as the Fostex.
I could be wrong about the cross-over point and would welcome any suggestions or feedback from individuals who attempted to mate a full range unit with a woofer.... and yes... in a small enclosure. The space limitations still stand.
Ron
Ronmeister said:
exactly why would it be "fruitless"? - many of the small diameter Fostex drivers, and particularly the FE108E Sigma, are excellent from the upper midbass on up - and most "regular 2-way designs" XO are at least several octaves above the 200 -300 region - many right in the middle of the mid-range (gee, could that be one of the reasons they're hard not to hear?) ,
Of the frequent DIY contributors herein, Mr Dlugos and the Planet10 clan have some experience doing exactly that - i.e. with several models of Fostex "FR" drivers and various woofer arrangements.
There is no "magic" XO frequency or combination of slopes - so Bob makes a very good suggestion for a "real" XO, which I assume to mean as flexible as possible (such as with his PC based front end, Behringer, et al).
and Ron, Bob - this is New Years (second 4 day week-end in a row in my case) , if ever a there was a time for a DIYer to get hammered (provided all the power tools are locked out) this would be it.
cheers, y'all
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