Going to build a BIB - please help with driver selection - Fostex FE138ES-R ?

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okayfine

Member
Joined 2007
Madisound has the Fostex FE138ES-R on sale right now for $289.

Would this be a suitable choice for a BIB ? It is right at the upper limit of my budget for a driver.

As far as the actual build goes, my plywod supplier has a 7-ply cherry plywood. The veneer cores are american birch. Some voids but very few. Is this no good? Should I got with 11 ply baltic birch and put a veneer on it?

How about if I build it with 6/4 solid mahagony with dovetail joints? Would it have weird resonances if made of solid wood?

Thanks in advance for your replies.
 
Scottmoose

Scottmoose

Member
Joined 2005
wodendesign.com
It will work fine. Pretty much any driver can be used -it's just a question of cabinet size.

Void free. Voids are bad. That's one of the reasons BB is prefered. Some solid woods are fine, if the material has been seasoned etc correctly, you know what you're doing, and it's not going to be subjected to major temperature / humidity variations.
 
C

chrisb

Member
Joined 2002
okayfine said:


As far as the actual build goes, my plywod supplier has a 7-ply cherry plywood. The veneer cores are american birch. Some voids but very few. Is this no good? Should I got with 11 ply baltic birch and put a veneer on it?
Click to expand...

11 ply would make that 5/8" (15mm), which might be a bit thin for a BIB - 3/4" (18mm) would be a better bet, but as BB is sold in many jurisdictions in 5x5ft sheets (1524mm), you might need to get creative with your joinery (biscuits, lap joints, etc).

If you plan on a nice finish veneer, you could certain hide it with a wood on wood 2 ply veneer.

When it comes to loudspeaker cabinets, IMHO it's the high ply count that give BB or similar plywoods ( Appleply, etc) their major advantage over MDF/chipboard or even low ply count plywoods, and a driver of this caliber certainly deserves the extra effort.



How about if I build it with 6/4 solid mahagony with dovetail joints? Would it have weird resonances if made of solid wood?

Thanks in advance for your replies.
Click to expand...

As Scott said, providing you have a good handle on working with solid woods, there's no overwhelming reason why not - although 6/4 could be a bit overkill in terms of thickness.
 
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serenechaos

Member
Joined 2004
Do you just not like the designs supplied w/ the 138 driver?
Or already tried them?

(I've just never heard a bib impressed, pretty disappointing compared to the swans & nessies i've heard, but ymmv...)

i ask because i've tried a few cabs for the 138, plan to try the resonate pipe next (in spruce), just haven't heard but one other person who built it (a very experienced builder, who did like it).

or maybe try one of these:
http://www.geocities.com/sg_suzuki/MCAP-CR.html
http://www.geocities.com/sg_suzuki/Feastrex_Project.html

r
 
O

okayfine

Member
Joined 2007
Re: Re: Going to build a BIB - please help with driver selection - Fostex FE138ES-R ?

chrisb said:


11 ply would make that 5/8" (15mm), which might be a bit thin for a BIB - 3/4" (18mm) would be a better bet, but as BB is sold in many jurisdictions in 5x5ft sheets (1524mm), you might need to get creative with your joinery (biscuits, lap joints, etc).

If you plan on a nice finish veneer, you could certain hide it with a wood on wood 2 ply veneer.

When it comes to loudspeaker cabinets, IMHO it's the high ply count that give BB or similar plywoods ( Appleply, etc) their major advantage over MDF/chipboard or even low ply count plywoods, and a driver of this caliber certainly deserves the extra effort.



As Scott said, providing you have a good handle on working with solid woods, there's no overwhelming reason why not - although 6/4 could be a bit overkill in terms of thickness.
Click to expand...

Correction - the BB i have must be 13 ply then. It is 18 or 19mm. It is 5x5 sheets, but I do have access to 4x8 sheets.

My main concern using solid wood is the seasonal expansion/contractions. For small bookshelf or even regular floor standing applications, the wood movement is not terrible, but for a long BIB, it might lead to splitting.

Has anyone built or listened to a BIB using Jordan JX92S drivers? (I did do a search).

Thanks.
 
M

mp9

Member
Joined 2006
serenechaos said:
(I've just never heard a bib impressed, pretty disappointing compared to the swans & nessies i've heard, but ymmv...)

i ask because i've tried a few cabs for the 138, plan to try the resonate pipe next (in spruce), just haven't heard but one other person who built it (a very experienced builder, who did like it).

or maybe try one of these:
http://www.geocities.com/sg_suzuki/MCAP-CR.html
http://www.geocities.com/sg_suzuki/Feastrex_Project.html

r
Click to expand...
hi robert, been wondering what you've been up to. so a Multiple-Chamber Aligned in Parallel Cavity Resonator (MCAP-CR), don't know where you found it but looks interesting. keep us posted on the build (you may as well get on with it, (lol)). it's different and jack k. already did the nessie and didn't seem as enamored with them as he was with the exotic's unfiltered in a simple sealed box. he said something wrt the exotic/sealed enclosure having more bass output than a 138es-r/nessie. any idea how the mcap-cr concept is being accepted by other builders and by those who've been able to hear them?
 
S

serenechaos

Member
Joined 2004
hi mp9,
i saw the MCAP-CR in the feastrex thread; thought it looked interesting.
i talked to Kloss about different cabs for the 138; he said he liked the nessies. he also used a lcy for the top.
wasn't the exotic in a three-way?
(doesn't any "full-range" seem to end up being a three-way if you actually want to go the full range).

what i've been up to...
haven't done anything else w/ the 138s, they're still in the bvrs, collecting dust, waiting for the spruce to dry some more, & me to get enough time to mess w/ them.
did finish a pair of tapped horns, but still need to finish the middle three of the five-way front-loaded horns i'm building.
& finish a 76 > 304TL transmitter tube amp.
& build some lowther field-coil conversions.
then build field-coil compression drivers for the flhs...
then build a smaller four-way flh second system.
then the wood should be dry enough to build a nessie.
yeah, enough to stay busy... :)
 
M

mp9

Member
Joined 2006
wow that's very impressive.

jack had the exotics in a "bookshelf" stand mounted box when i asked how the two compared, although i think i remember him planning to do a multi-way design.

lack of and waiting for bass to develop over time as the drivers break in wrt a 138es-r/BLH build was one thing i think i was able to make out from japanese web site google translation, haven't found a follow-up.

*138 BLH design for anyone interested: http://makizouphoto.hp.infoseek.co.jp/furukawa7.html
 
M

MDOFCR

Member
Joined 2009
geocities.com/sg_suzuki
mp9 said:

hi robert, been wondering what you've been up to. so a Multiple-Chamber Aligned in Parallel Cavity Resonator (MCAP-CR), don't know where you found it but looks interesting. keep us posted on the build (you may as well get on with it, (lol)). it's different and jack k. already did the nessie and didn't seem as enamored with them as he was with the exotic's unfiltered in a simple sealed box. he said something wrt the exotic/sealed enclosure having more bass output than a 138es-r/nessie. any idea how the mcap-cr concept is being accepted by other builders and by those who've been able to hear them?
Click to expand...


Hi,

You will find detailed documents with equations of MCAP-CR in my pages. It is your decision if you believe my model of physics that represents multiple degree of freedom cavity resonators.

I will talk with Feastrex if there is any possibility for non Japanese residents to hear MCAP-CR. Hearing is believing a lot more than equations...

FE138ES-R will be a good example for MCAP-CR. I guess my TR130c will fit FE138ES-R. You need two of 3' x 6' x 18mm panels for TR130c cabinet.

Please email me, if you want to more about MCAP-CR.

Regards,

Shigeruhttp://www.geocities.com/sg_suzuki/index.html
 
S

serenechaos

Member
Joined 2004
Shigeru,

Thank you for responding with information, and that you feel TR130c cabinet would be appropriate for FE138ES-R.

Do you have a feel as to what type of room these cabinets prefer? Or appropriate placement?
e.g. 138s are currently in BVRs, I hadn't played them in weeks, thought I'd try them in a different, very live room.
They sounded very different...
 
M

MDOFCR

Member
Joined 2009
geocities.com/sg_suzuki
serenechaos said:
Shigeru,

Thank you for responding with information, and that you feel TR130c cabinet would be appropriate for FE138ES-R.

Do you have a feel as to what type of room these cabinets prefer? Or appropriate placement?
e.g. 138s are currently in BVRs, I hadn't played them in weeks, thought I'd try them in a different, very live room.
They sounded very different...
Click to expand...


Room's character is different problem. I have very small listening room in Tokyo. I suppose you have nice spacious rooms. My TR130c cabinet with Feastrex Nf5Ex regenerates 32Hz at equivalent level as 50 to 100Hz. It seemed a little bit too powerful for my small room, but better for spacious room. You may choose my TR130b type cabinet if your room is too live. TR130b with Feastrex Nf5Ex is well balanced.
I think that FE138ES-R has strong character in higher frequency range. It made some people hate the driver itself; however, boosting lower frequency than 40Hz will make good match with higher frequency character.

I guess these cabinets with FE138ES-R will match the room with carpet rather than wood deck floor, since their lower frequency energy is so strong.

Sincerely,

Good night!
 
S

serenechaos

Member
Joined 2004
MDOFCR said:


Room's character is different problem. I have very small listening room in Tokyo. I suppose you have nice spacious rooms. My TR130c cabinet with Feastrex Nf5Ex regenerates 32Hz at equivalent level as 50 to 100Hz. It seemed a little bit too powerful for my small room, but better for spacious room. You may choose my TR130b type cabinet if your room is too live. TR130b with Feastrex Nf5Ex is well balanced.
I think that FE138ES-R has strong character in higher frequency range. It made some people hate the driver itself; however, boosting lower frequency than 40Hz will make good match with higher frequency character.

I guess these cabinets with FE138ES-R will match the room with carpet rather than wood deck floor, since their lower frequency energy is so strong.

Sincerely,

Good night!
Click to expand...

Shigeru,
I want to use FE138ES-R in a fairly dead, (carpeted, bookshelves, plants) 12' x 14' room, as simple, second system to five-way horn system.

The FE138ES-R are in BVR now. They sound like a blanket is wraped around them.
I tried them in a very live room yesterday- 11' x 13' sunroom, glass on two sides, concrete two walls, hard tile floor.
Still sound muffled, "felted;" my wife calls it, but not as bad.
May be the cabinet, may be the driver; don't know.
The room greatly changed the bass response though, big bump (~60Hz I'd guess, didn't measure), as would be expected.
This was w/ Zen amp & cat 5e cables.
So much for background.

Yes, I did find High freq range to be a problem, it is now rolled off w/ coil & a ribbon tweeter used.
Highs are nice now.
No, I don't want to use this speaker in a live room, I want to use them in the 12' x 14' room mentioned above.
What is F3 with TR130b or TR130c cabinet in what size room (for general idea)?

Thank you,
r
 
M

MDOFCR

Member
Joined 2009
geocities.com/sg_suzuki
serenechaos said:


Shigeru,
I want to use FE138ES-R in a fairly dead, (carpeted, bookshelves, plants) 12' x 14' room, as simple, second system to five-way horn system.

The FE138ES-R are in BVR now. They sound like a blanket is wraped around them.
I tried them in a very live room yesterday- 11' x 13' sunroom, glass on two sides, concrete two walls, hard tile floor.
Still sound muffled, "felted;" my wife calls it, but not as bad.
May be the cabinet, may be the driver; don't know.
The room greatly changed the bass response though, big bump (~60Hz I'd guess, didn't measure), as would be expected.
This was w/ Zen amp & cat 5e cables.
So much for background.

Yes, I did find High freq range to be a problem, it is now rolled off w/ coil & a ribbon tweeter used.
Highs are nice now.
No, I don't want to use this speaker in a live room, I want to use them in the 12' x 14' room mentioned above.
What is F3 with TR130b or TR130c cabinet in what size room (for general idea)?

Thank you,
r
Click to expand...


Hello serenechaos,

You want your FE138ES-R as a part of 5 way horn system? Do you want to use it as mid-range horn driver?

Could you tell me what BVR is? Just to let me know where I find BVR. It seems necessary to give you my suggestion.

I would say, FE138ES-R seems to be good for your fairly dead room. You might try speaker matrix system, if you feel too dead. Rear speakers generate additional pseud reflection sound. Someone else will be better for speaker matrix connection.
Type of speaker enclosure may not be good parameter to solve your problem.

Regards,
 
M

MDOFCR

Member
Joined 2009
geocities.com/sg_suzuki
Hello I saw your enclosure. It is interesting.
Your problem sounds like higher frequency problem (muffled). Did you use coil to the fullrange driver? If some network is used, I suggest you remove network first: I am sure FE138ES-R sounds really dead with networks.
Do I understand your problem correctly? I am very new here and not used to this forum. Please let me know.

Regards,

Shigeru
 
Scottmoose

Scottmoose

Member
Joined 2005
wodendesign.com
I suspect you probably do understand it correctly mate. AFAIK, no network -I certainly didn't design one for it at any rate. BVRs rarely need them, unless a very low Q driver is used, or a notch / shelving filter is needed to solve some response issues higher up.

No -they may be over-damped (I design for minimal damping), but my gut feeling is that the 138 just doesn't like this kind of cabinet. I didn't especially wish to design a box for it, but I was asked, so I did. Came out reasonably enough in theoretical terms, but that only goes so far, & not owning a pair of the drivers (which themselves appear to have dropped somewhat in people's estimations since their launch) I can't do any testing, even if I felt so inclined. TBH, I'm gradually moving away from the Fostex drivers generally -they're good, but they don't quite do what I want / need.
 
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