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

Missed that consideration! The simple radius shapes' area (both sides combined) is larger than the mouth's area. In the case of the right side, the area is slightly reduced. Does this add a mass loading effect?

In any case, opening up all sides with the split radius would beat the area.


Thanks!
 
A BIB for the CHR-70 from Mark Audio

Greetings to all BIB enthusiasts old and new.

I have not run the BIB calculator to compare the output from the calc of thr CHR-70 from Mark Audio with the BIBs I have for the FE127e. Has anyone done this?

I ask because I tend to be "all thumbs" with input for software. My BIBs were carefully measured for the Fostex and so I'm thinking of a drop in solution to see what the enthusiasm for Mark Audio and the CHR-70 is about. The fact Madisound now carries the line and I can order locally is also an influence.

If no replies I will post back after I do the data entry.
 
Well It turns out I did the CHR some time back but the current product shows some slightly different numbers. Line length difference is 5 in. and the volume of the CHR-70 box would be a bit smaller. An inch and half difference at A-B-C I could live with. Big test is if the CHR-70 gives that nice satisfying ring of chords played low register on piano.
 
Folding other than at .5 line length

Hi,

I've probably read the entire thread more than once, in total, but always in chunks over time, so maybe I missed the info. Is it workable to fold the line other than at the midpoint? For example, to raise the driver height in a short iBIB, could the fold be at .35 of line length? The internal baffle would become a sloping front (i.e., external) for the bottom of the cabinet.

Thanks,
bearberry
 
Like any horn, you ideally want the flare to be preserved or at least not contracting, so you can fold it up into a pretzel if you want if these guidelines are followed. The problem with short horns though is one of getting adequate boundary loading, so if too short to load the ceiling, then it needs a rigid, well damped wall or floor (non-floating) to load against and maybe even a restrictive mouth plug or reverse cone section added to it to mass load it a bit.

GM
 
Probably one of the easiest cabs to build that still provides some serious single driver sound.. Load them into or near room corners, get the stuffing or lack thereof right, just enjoy :)

I used to think an OB was easier to build, but you have to mess with x-overs and such, plus they are placement finicky... BIB is quick easy unfiltered sound, though not as refined as some more in depth designs from P10, Scott and others etc.. Still pretty decent sound for the effort involved in building a pair:cool:

If you're not gifted with fine woodworking skills heck these are the ticket.. Basically an open ended box with a divider inside, pretty simple... Even I pulled it off lol :)
 
Last edited:
Yes some good in room tweaking with baffles, stuffing and such, and they can sound really nice.. I have mine imaging just amazing this last while in my room... It's pretty awesome when it all comes together and each performer is right in front of you exactly where they should be, although invisible:cool:
 
BIBs do produce a very large image. It's amazing when the singer is dead center and the music is so wide and high all around.

Just spent $5 and a couple of hours on bodging together a pair of styrofoam BIBs. It looks like crap and theres a noticable styrofoam resonance in the upper bass but apart from that – its sumptious. The bass is astonishiningly musical. Everything just has a proper place with bass played correctly.

Im playing through my iMac + a Lepai T-amp with crap cabling and Im amazed. By golly.
 
Are my ideas for my planned BIB build crazy?

Hi all. Good to be back here! Good to see this thread is going strong as ever!
I haven't kept up with any developments so please excuse me if any of the
following has been covered! (I will attempt to read through the thread from about a year and a half ago!)

I have a pair of brand new pair fostex fe164 that I want to build BIBs for. There are a few ideas I have that I would like your comments on:

Firstly, and this is the big one, I was thinking of placing the driver at 0.416(smoother response) of line length, as proposed for floor firing BIB, BUT keeping them upright and lifting them off ground with legs(which will be about 10cm wide each and will extend up the cab, flush with baffle and past the driver to effectively widen the baffle- as wings or suprabaffles do)
This brings the driver to ear level, and brings the mouth closer to ceiling for better loading and bass reinforcement. I can't help thinking that this is a great idea! Am I crazy? Am I alone here?

Secondly, I was thinking of using deflex panels behind the drivers. They should do a great job of absorbing/dispersing the rear-firing waves and avoiding the reflected waves coming back out through the driver cone/surround. This in combination with the proposed stuffing.

Would like to hear your thoughts so I can eventually start building! Thanks
 
diagram of the above proposed BIB

A picture is worth a thousand words! Rocket BIB ?!
 

Attachments

  • diagram.jpg
    diagram.jpg
    62.6 KB · Views: 306