Terry Cain's BIB -why does it work and does anyone have those Fostex Craft Handbooks? - Page 61 - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 9th May 2006, 01:09 AM   #601
jacojnr is offline jacojnr  New Zealand
diyAudio Member
 
Join Date: Apr 2006
Location: wellington
hi scott
thanks for your input in another thread re voigt pipe tweaks -- they all work -- really improved on what was before.
now my ff165ks have arrived from madisound, i am onto the BIB, having cut the panels and so on. glueing up next. plan to adopt yr stuffing suggestions -- will lining with felt the rear wall, the internal baffle and front baffle be the way to go as well?
as for the speakers, i guess i will have to get them going and listen to them before eyeing up more tweaks -- but what do you think of phase plugs for the 165ks? planet 10s' perhaps? and what others done in terms of reducing ringing on the speakers -- shall i try that or just put them in and let them sing?
my equipment to be used with the BIBS are decware's se84cs, the decware pre-amp and an old but trusted CAL Aria 3 cd player. Any thoughts if i need to put some resistors in the speaker wire path?
cheers
peter

cheers
peter
  Reply With Quote
Old 9th May 2006, 01:29 AM   #602
BTW is offline BTW
diyAudio Member
 
Join Date: Nov 2002
Location: Singapore
Default Multi-Purpose BIB

Wow, what a thread...thanks guys.. I'm still trying to digest the first part. I have a question, as I have quite a few fullrangers from 6" to 8" , Fs from 80 to 40 Hz. Can I make a BIB cabinet that'll allow me to swap in and out different drivers, of course I intend to make a small removable speaker mounting front baffle. Can let say a huge BIB cabinet be a good for all the different drivers or is the BIB spk specific ie individual cabinets for each type of fullrangers ?
  Reply With Quote
Old 9th May 2006, 08:59 AM   #603
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
Looking good Jeff! (Let me re-phrase that... )

Peter, the Planet10 phase plug idea with the 165 could be very interesting indeed. I haven't myself yet, simply because I'm not sure it's possible to do it on the FF series drivers. Dave, any thoughts? If it is, this would be a killer tweak, and elevate the performance even further up the ladder. The 165 is much underrated -it really is the best-kept secret of the Fostex range. Doesn't go up as high, but goes lower, and has a smoother midrange. Lovely.

Resistors? Good question. With your Decware, I'd say probably not, but don't hold me to that. Try with a thin cable first -a pair of 24AWG twisted conductors extracted from a run of Cat5 should do, or some magnet wire of the same cross section or thinner. I'd stuff the point above the driver, thick layer on the bottom, and line the front of the internal baffle initially. If it needs more, line the rear of the internal baffle, and the top few inches around the mouth. But you don't want to go too far: it've very room-dependent.

BTW: good question. The BIB is very heavily room-dependant, so performance is not as predictable as many other types. We optimise the cabinets as far as possible for specific drivers, though there is considerable lattitude for experiment, and they are fairly forgiving to driver-rolling, providing the differences in Fs, Sd and Vas are not extreme. Something like a 120in line length, Zdriver of 24in and a 175in^2 terminus area might be your best generic solution.
__________________
Community sites www.frugal-horn.com http://frugal-phile.com/
  Reply With Quote
Old 9th May 2006, 11:34 AM   #604
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
The Acuhorn 125 we suspected of being an inverted BIB is actually a rearward-firing horn. Just found this picture of it.

Looks like there are currently no commerical BIB's on the market after all. I'm guessing big CC, short horn, a la the Replikon.

By the way, is it me, or is that plywood? Nice finish, but perhaps not quite the vaunted proceedures they claim...
Attached Images
File Type: jpg nero-3.jpg (27.2 KB, 931 views)
__________________
Community sites www.frugal-horn.com http://frugal-phile.com/
  Reply With Quote
Old 9th May 2006, 02:36 PM   #605
bluegti is offline bluegti  United States
diyAudio Member
 
Join Date: Nov 2004
Location: Northern Virginia
Default BIB for FE127E

I've drew up some plans for a FE127E. I have pair of drivers and though it might be interesting to compare the BIB to the reference project's design.

I added some extra height to the cabinet and a chamber that can be filled with sand or something. With a fairly short line length of 97", the driver would only be around 30 inches off the ground. That's a little low. I chose 42 inches as an arbitrary height (measured my ear to the flow while sitting in a chair).

What to you think? This is my first attempt at drawing up plans. Do the dimensions make sense?
Attached Images
File Type: gif bibfe127e.gif (41.2 KB, 912 views)
  Reply With Quote
Old 9th May 2006, 03:48 PM   #606
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
Looks fair enough to me, although 'So' is not the distance of the driver-centre from the sealed end. So is the area of the sealed end itself (in the case of the BIB, So=0, nominally at least). Jeff hasn't had time to change the annotation on the BIB pages yet. Zdriver is a better moniker.

The sand-filled lower chamber looks a good idea. Nice solid base for the rest of the enclosure, and both elevates the driver to listening heigh, and moves the terminus nearer the ceiling.
__________________
Community sites www.frugal-horn.com http://frugal-phile.com/
  Reply With Quote
Old 9th May 2006, 04:59 PM   #607
diyAudio Member
 
Join Date: Jan 2006
Location: Mobile, Al.
My 168E Sigma's were just delivered a few minutes ago and as a first time Foxtex buyer I have three questions.

Do they require a rebate when mounting them? The flange is thick with an arched bevel that would cause the inner edge of the flange to protrude above the surface of the baffle with a rebate equal to th flange thidkness. Are they designed for simple surface mounting?

Also included is a foam gasket that appears to be packing material; however, it has the mounting holes cut in it and is a good fit behind the flange. Is this to be used for an air tight seal instead of foam tape I purchased from Madisound?

Four short, black sheet metal or wood screws with washers were included in the Fostex box. Since there are eight mounting holes in the flange I am puzzled. I purchased eight bolts and T-nuts from Madisound to mount each driver. Is this over kill? Either way I am covered.

I cut the birch plywood last Saturday and intend to route the mounting holes tonight now that I have the speakers. The diameter of the drivers was given by Fostex as 190mm or 7.5". That is not an accurate conversion. 190/24.5 = 7.755". I will measure and cut based on my measurements and whether or not I need a rebate.

Your patience in helping me through this project is greatly appreciated.

Ray
  Reply With Quote
Old 9th May 2006, 05:29 PM   #608
dmason is offline dmason  United States
diyAudio Member
 
Join Date: May 2004
Location: Republik of Kalifonia
Ray,

The short answer is, you are good to go! I am excited for you, all the parts ready to move ahead.

The foam gasket is a nice touch and works well as a seal. I would use it. If you are intending to use countersunk T-nuts and threaded inserts, this is the way to go. Especially as you will likely be in there from time to time.

Don't worry about rebates, I have never seen any of the Sigmae flush mounted, and they look quite nice on the surface. You are all ready. We look forward to your progress reports!
__________________
"Pilau Buggah, Big Islan Mo Betta!!"
  Reply With Quote
Old 9th May 2006, 05:35 PM   #609
diyAudio Member
 
Join Date: Jan 2006
Location: Mobile, Al.
Thanks dmason......off we go!!!
  Reply With Quote
Old 9th May 2006, 06:13 PM   #610
diyAudio Member
 
Godzilla's Avatar
 
Join Date: Nov 2005
Location: New York
http://www.zillaspeak.com/zillaspeakfostex24L168.asp

Enjoy Ray!

You can see how i mounted my older style 168S right on the front baffle. I also doubled up behind to sink the screws and add strength.

Also, it seems you should have gotten more screws than 4 per side.

Peace,
Godzilla
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 02:07 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2