Terry Cain's BIB -why does it work and does anyone have those Fostex Craft Handbooks?

The terminal CSA Scott mentions is identical to that of my own. Works a treat; no point in reinventing the wheel, I think. Makes for a stable footprint as well.

Listening to Gershwin #1/F+ there is nothing missing in the lower lines at all. Very, verrrrrrrrry smooth presentation. Good luck wit yo SigmaBIB.
 
Thank you for your reply and advise.

I suspected the height would be a bit much for the room I have. If I could only find a replacement driver for the 168 Sigma (one working, one not) I suspect this one would be close to perfect. The old 168 is a very nice driver. How does the new compare to it?

Peter
 
Peter

I am not familiar with the earlier Sigmae, but the total rethink version works very well; I have played around with almost all the Fostex line, and I strongly believe the FE168Sig to be the best overall compromise; I think nothing can touch the 108 for mids and highs, but you need some stout juice to do it justice, so micro powering is out. The Sigmae lack the whiz, which I believe to be good. The 168 has what I think is a perfect Fs/Q for the BIB overall, none too chunky, good 94db, which is quite honest, and with DEQ, it absolutely does not need a supertweeter. Perhaps in a larger room one would be good, having tried it both ways with and without the VIsaton TL16. The extra sparkle is simply just ...more, in my home at least. I would head straight for the FE168Sigma, and the FE166esr are no longer available. Build with good material as several are doing currently, follow the findings thus far, and prepare for a complete disconnect between what your brain understands to be the case, and what it is you are hearing.

Someone was asking about OB, bit off topic, BUT, I thought I would add that the $Money Zone with OB dipole sonic is 50-1500Hz, above which frequencies become forward, and directional. Whatever is happening with the ceiling loading with the BIB's is sounding almost exactly like extremely well done dipole, with bass/critical mids propagating along the ceiling, into the room. It simply sounds like good dipole bass when corner loaded. This, to me, after screwing around with all the DarkStar stuff, represented a Bonus that I could not convey in mere words, I was completely shocked. So, to summarize, my conclusion thus far is that the Fostex FE168sig may well be the best spec'd for this app, best sounding for the $ driver, option you could have for building your own BIB, and the BIB is about the choicest load for a wideband driver yet, and comes complete with magic pseudo dipolar bass.
 
Thank you for your reply, I will simply have to try the new 168, sounds like the match to the BIB is perfect.

Another thought. In building boxes, I always have trouble with the joints. If anyone with a CNC machine cut all pieces and pre-drilled holes with good precision (like the IKEA bookcase I just put together), a BIB would be easy to ship and could be put together in 30 min. I would be very interested in bying a set like that.

Thanks / Peter
 
A CNC BIB milled up with good joints for glue, in Maple 13X 3/4 would be the ultimate DIY flat pack. Put felt on the back of the driver, mount driver and play BIB. Only 6 pieces to the lot. T'would be outstanding because anything metal in there destroys the TONE, of these babies.

Anyone out there?
 
Re: flatpacks.

This reminds me of the projects that are being
done at the Full Range Driver forum. I drool over this
stuff. :)

Elsewhere, Madisound has offered a B16 flatpack
for some time. That one didn't even have any
joints in it.

How does the Net figure in to making local setups
for CNC much easier than shipping a load of wood
across country? How are the calculations sent and
shared to local pickup/manufacture (purchase) points?


I'll introduce a new phrase here called The Amateur
Professional. I've seen these types locally. The
Amateur Professional will do a job for you and expect to
pay for his machine on the first sale. Some project
will be developed only to come up against an
outrageous quotation in time and machine 'cost' for
the end user in what would be one-off projects.

Stop by your local Woodcrafters(c) store. Those places
usually have a tack board with a bunch of business
cards from the local Amateur Professionals. Get a quote
from any one of them and you will see what I mean.

I hope this will be the starting point in a discussion of how
the combination of remote designs for production could
be implemented with local manufacture.
 
It should be possible to DIY it without resorting to hefty machines or even routers, if you use a good ply of course. Simply mark up the edges, score with a knife, and, er, get the old chisel out. 'ere be an Ariel that was made in just that way. Doesn't look too shabby huh? http://www.iol.ie/~waltonaudio/ariel1.html

Of course, it takes a bit of time, and over long runs, it's easier to make a mistake... The flat pack approach has much to commend it! Brilliant kit idea that.
 
dmason said:
A CNC BIB milled up with good joints for glue, in Maple 13X 3/4 would be the ultimate DIY flat pack. Put felt on the back of the driver, mount driver and play BIB. Only 6 pieces to the lot. T'would be outstanding because anything metal in there destroys the TONE, of these babies.

Anyone out there?

Hi

Here is the good joint for glue, Max Bills "Ulmer Hocker".

best, LC
 
... and look at that perfect bracing for the mouth area, and the beautiful feet ... it's all there.

I opt for two design options, square and golden ratio. Wood will be marple, treated with that special danish soap only, for perfectly smooth surface and most natural colour.

Production starting monday, preorders accepted only via PM please. :D :D :D

best, LC
 
As a previous post said, I'm planning to use stick wood
(72 x 6 x 3.75) and clamps to put one together to see
how it sounds. Dry clamping can be used to get the
notion of what the sound is like.


I'm hoping that the how-to pix start to come in here
and some actual hearing tests will be posted.


About those hearing tests: in another forum I made the
modest proposal that before actually doing a listening test,
the writer go to an audiologist and have his specs posted
in a sig file. For those of you new readers who think I am
a troll, I'm not. I've been reading the hobby and single driver
design for a number of years. The variable of audio
_acuity_ never seems to be part of the speaker or design
application. The whole subject came up a part of a
different discussion on music.
 
frugal-phile™
Joined 2001
Paid Member
Scottmoose said:
One thing about the FR125 that I've gathered is that its Fs is a bit of a mystery. Dave, what's the definitive on the CSS?

Seems to have more to do with the drive level than the actual Fs (ie Fs is not a constant but a function of voltage drive). Using the low V output from my computer i have an average Fs of 81.7 across 70 drivers (all new out of the box)

dave
 
I built a BIB FE126E. Based on the suggested specs on zillaspeak.com. Took me about a day or so to put together. Internal dimensions are 48x11x6 inches. One 8'x4' of birch plywood for both speakers. I had the store cut it for me for the most part.

Sounds really great! The depth of the low end is truly surprising. Smooth and well balanced too - no boomy odd low notes but a nice continous roll off. It is hard to reconcile the size of the sound with the size of the driver.

Note that it takes some judcious use of acousta-stuf to get the midrange and highs in line. The mouth of the pipe puts out quite a bit of the upper frequencies along with all that wonderful bass. Without stuffing the highs were bright and mid-range bloated.(piano notes in the lower mid-rangeswere the worst sounding). Also the sounstage was not as broad or 3D as I would have liked no doubt for the same reason.
This is what I was finally happy with - loose stuffing above the driver on the closed end as well as some behind the driver. A strip of egg-shell foam at the base(the fold). And some more loose stuffing near the mouth.
Thanks a lot to you guys who have done all the research on this and put together the specs for all those drivers.

UV
 
Here is a picture -
 

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BIB dip around 100 - 150 HZ

Just been reading about cavity resonance and bass traps thanks to Cortez. States that a reflective cavity can be used to fill in a dip. Is the idea suitable for building into the narrow end of this BIB enclosure to help with the dip? Shouldn't complicate things too much as far as building goes.
jamikl
 
Possibly. I don't know enough about it -any thoughts?

Dave -thanks for that. Best not to push them with too much power then, right. A Zen version might be good. I'm going to build the latest since I passed on my SoZ -love those JFET / VFETs.

Uvellani -very nice. I'm really glad you like them! The smaller ones will have more of an issue with HF leakage as they don't interact with the room quite as well, which is likely why you needed the stuffing near the mouth. I'll remember that -I'm writing a rough 'how-to' guide at the moment. You have entered into the spirit of the thing with your well-judged tweaks to optimise for your own room and conditions / taste, and I shall refer to them, if I may? What finish are you going to apply by the way? I'd give them a good sanding, then a few coats of clear hard floor varnish. Brings the edges out beautifully. I love the appearence of plywood. Very art deco! Can Jeff use the pic on the site? It'll be the first I believe!

Best regards
Scott
 
Scott, feel free to use my notes and pictures.(I have attached a couple more construction pics).

I dadn't thought of using floor varnnish for a finish. I was thinking of the usual stain and polish finish. Maybe I will give your suggestion a try and leave it with the natural color.

Thanks
UV