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

[Ian444]

any thoughts on question 1/3?

cj,

Hardware - you didn't mention the screws to hold the drivers in.

Re stuffing -
http://www.diyaudio.com/forums/showpost.php?p=1106793&postcount=2171
http://www.diyaudio.com/forums/showpost.php?p=1278294&postcount=3445
http://www.diyaudio.com/forums/showpost.php?p=1278087&postcount=3442
http://www.zillaspeak.com/bib-howtobuild.asp
http://www.diyaudio.com/forums/showpost.php?p=1663760&postcount=4360
http://www.diyaudio.com/forums/showpost.php?p=1659926&postcount=4346
http://www.diyaudio.com/forums/showpost.php?p=1839263&postcount=4492

Ian.

 

[croat47]

In using the sheets: if you wanted to build a 1.5 or MTM BIB, would you just double the VAS for the drivers if driven in parallel? This doubles the volume of the box but keeps the expansion and length the same based on Fs and Qts, correct?

 

[Scottmoose]

Right. Impedance etc. also change but that doesn't affect Vp or Fp.

 

[croat47]

Great. Thought is along the lines of Jim Griffin's offset MLTL that he derived from AudioKinesis' DreamMaker conept. For a small driver like the B3S or RS125, could you do a bipolar iBIB with the front driver at ear height (0.41*L) and the rear at a lower position (0.21*L). The drivers would have to be on the "depth"/long sides and offset towards one side. But, would allow moving the speaker off the wall yet avoid need for BSC.

Thoughts? Build it and see? Or is the spacing too large for this idea. 0.21 and 0.41 heights would be 13" apart for the B3S version.

 

[GM]

Ideally you want them <1/4 WL apart through the XO BW, but this means a near bipolar layout for all but the lowest point/highest order XOs, so 1 WL/XO point is the accepted limit: ~13560/4/13 = ~261 Hz upper limit and the lower the better.

GM

 

[Trooper46]

any thoughts on an iBIBk for the FE87E? Using the BIB calculator i got prety small box. approx 7"x9"x24". the zdriver was about 10". could be a nifty little desktop speaker if pushed up against a wall.

 

[GM]

Don't see why not, awhile back a local was using small 126?/127? floor loaded BIBs in his office and once backed up against the wall on the ends of a large 'V' corner desktop they came 'alive' within their design limitations.

GM

 

[giantstairs]

or how about a floorstander at 48" (no fold) spaced up a few inches off the floor, against a wall? i put together a double folded, floor loaded fe108ez and wish it were taller. getting some serious bass though.

 

[Trooper46]

i just thought it would be kinda cool to have a desktop sized bib. i got some peerless csx 8 inchers that i could use to make a "sub" and have myself a pretty unique 2.1 system. i just dont know if my marantz 2216 or gainclone will play nice with a fostex. they both play nice with vintage 70s AAL speakers.

 

[CLS]

You forget BIB is "Bigger Is Better". How can a normal desktop space accommodate that properly?

Maybe the pipe(s) can form a large frame and wrap around the desk, or folded to form a thick wall then put in front of the desk. However those are not desk 'top'.

 

[GM]

or how about a floorstander at 48" (no fold) spaced up a few inches off the floor, against a wall?

Works for me! Let a sub handle the bottom 2, 3 octaves.

GM

 

[Trooper46]

You forget BIB is "Bigger Is Better". How can a normal desktop space accommodate that properly?

my desk is roughly 3x8ft. plus the little foot print of the FE87E bib would allow me to place them almost anywhere on my desk. maybe ill just have to drive over to madisound and pick up a pair just to mess around with. i have an idea of making the boxes out of pine ply or osb and wrapping them in fabric then coating them with epoxy or something. they did this on the original gem guitars and they look absolutly amazing.

 

[giantstairs]

not sure how much difference it will make but you could try a downward firing version with zdriver approx 20" up and adjust the bass by spacing it from the wall. either way just go for it, looks like a quick, low cost project with lots of upside. the finish sounds interesting -- any links to pictures?

 

[Trooper46]

i have heard rumors that the floral pattern fabric matched the drapes in steve vais house.

 

[GM]

i have heard rumors that the floral pattern fabric matched the drapes in steve vais house.

This business of not being able to see some attachments without researching them is getting old quick! http://gtrkev.tripod.com/guitars/JEM-BODY.JPG

Regardless, yes, a lot of the speakers I did for others was during the '70s decoupage 'craze', so all manner of materials coverings/coating was tried and yes, if epoxy is used, then a viable way to stiffen up a cab, audibly improving the then existing 'junk' speakers that were made of low density particleboard (PB) held together with cheap, thin, vinyl coverings.

GM

 

[sedge1]

RE Ripple...

If ripple is caused by the roof reflecting back into the horn has anyone tried fitting a corner wedge to combat this ?

What effect would that have ? Just curious, if you've got a set of these then you probably don't suffer from WAF anyway.

I'm just finishing up a new pair.

Sedge.

 

[Pit Hinder]

sedge - wavelengths. Good idea, but the wavelengths involved won´t even notice that size of deflector.
Having the perfect room would mean having a perfect bank account...

 

[loninappleton]

Has anyone made a side mounted BIB lately? I was wondering what the difference would be having the speaker on the long side. Drawings for this were around ages ago along with iBIBk and others.

 

[GM]

Less potentially audible 'ripple' from baffle step losses due to a shorter path-length from the driver to walls and a good argument for a high aspect ratio BIB IMO.

GM

 

[Pit Hinder]

So - a sidefiring BIB as close to ceiling height as feasible? You can´t camouflage BIBs as PC screamcubes anyway, so who not take all you can get.