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

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#622
I see alot of people using pine for their speakers, has anyone tried poplar? It is denser than pine and more stable. Pretty easy to find, at your local hardware/lumber and since its pre-cut into boards you might find you won't have much cutting to do. Slightly more expensive than the pine, but I don't think its a big difference. Just a thought.
 
#624
Re: Re: Help calculate BIB

Scottmoose said:



You've lost me: what are you asking?
Click to expand...


I am asking haw to calculate L - line lenght, Sm - terminus area and So - lenght from sealed end top to driver center, for some drivers I can find here (Visaton, or Gradient).

Hereis data for Gradient W160AL8 driver:
Fs = 44.5 Hz
Qms = 2.30
Qes = 0.63
Qts = 0.49
Sd = 127 cm2
Vas = 22 l
Eff. = 87.9 dB

please make a BIB sim for this driver
 
#625
choose of wood cabinet

MuaDibb said:
I see alot of people using pine for their speakers, has anyone tried poplar? It is denser than pine and more stable. Pretty easy to find, at your local hardware/lumber and since its pre-cut into boards you might find you won't have much cutting to do. Slightly more expensive than the pine, but I don't think its a big difference. Just a thought.
Click to expand...

i'm looking for suggestions for what wood to use for my bib, as i'm having a hard time finding birch ply. the big shop near me has beech ply and plenty of other types of wood, including pine. i'm looking for something that sounds good and is stable, cost is not too much of an issue as this is a relatively small build. no mahogany of course and there is always the option of mdf.

thanks!
 
#627
Re: choose of wood cabinet

Greets!

Any of the hardwoods with low moisture retention properties is suitable, such as white oak, white ash, black ash, green ash, and hard maple. Then for those with machining capability or more patience than me: Lignum Vitae, Kingwood, Cocobolo, Tulipwood, Pau Ferro, Honduras Rosewood, Goncalo Alves, Bubinga, Wenge, and Purpleheart.

I love the look of Pine, but until it's been weathered for several decades is it ideally suited for speaker cabs unless well damped like Bob Brines does his MDF cabs and any knots epoxied to ensure they can't rattle/squeak/leak.

GM
 
#628
Audio Nirvana 6.5

Audio Nirvana Standard 6.5BIB

Line length 133in.
Zdriver 26.75in
Terminus area 118.125in^2
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Hi Scott,

here are messured TSPs from Audio Nirvana 6.5 Standard. Just wondering if the ANs 6.5 BIB would need to be modified for these ... as I might go for this driver.

fs 56Hz
Re 7,1
Rms 1,14
Qms 2,94
Qes 0,27
Qts 0,25
Cms 0,85
Mms 9,49 g
BxL 9,33
Vas 19,7
Le 0,07
Sd 129 qcm

Zilla, did you get my email with the How to Pics? ... got yours mail with the pic (nice one!).

best, martin
 
#629
This is the last one i got from you LC... Is this the latest one? I want to put to bed the confusion of building BiBs soon and would like to clear up any inconsistancy.

Thanks.

Godzilla
 

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#630
Re: Re: choose of wood cabinet

dmason said:
Use the best ply you can.
Click to expand...

i'm not really sure which plys are good, i've only heard of people using birch.

GM said:
Greets!

Any of the hardwoods with low moisture retention properties is suitable, such as white oak, white ash, black ash, green ash, and hard maple. Then for those with machining capability or more patience than me: Lignum Vitae, Kingwood, Cocobolo, Tulipwood, Pau Ferro, Honduras Rosewood, Goncalo Alves, Bubinga, Wenge, and Purpleheart.

I love the look of Pine, but until it's been weathered for several decades is it ideally suited for speaker cabs unless well damped like Bob Brines does his MDF cabs and any knots epoxied to ensure they can't rattle/squeak/leak.

GM
Click to expand...

thanks, gm. i don't know much about wood and less about woodworking, so i guess you are referring to solid wood. i will inquire about the prices of some aged oak or ash and i will go this route if it's not too much more than ply. i've also seen some nice solid beech (again, i know) that looks quite old and solid. i have a friend that uses it as a base for large iron sculptures, but i'm not sure how it would "sound".
 
#632
Hi Martin

Hell's teeth, that's getting on for Lowther levels of difference between T/S parameters. That said, I'd still leave it as is, or use the same line length and driver position, with the terminus area from the Super. The extra length won't be a problem, and the extra volume won't hurt. Personally I'd still buy a Fostex unit, but that's just me. I know them and trust them. Insofar as you can trust any big company. Or little one, come to think of it.
 
#633
Scottmoose said:
Hi Martin

Hell's teeth, that's getting on for Lowther levels of difference between T/S parameters. That said, I'd still leave it as is, or use the same line length and driver position, with the terminus area from the Super. The extra length won't be a problem, and the extra volume won't hurt. Personally I'd still buy a Fostex unit, but that's just me. I know them and trust them. Insofar as you can trust any big company. Or little one, come to think of it.
Click to expand...

Thanks Scott!

I see what you mean regarding 'Majors', 's why I rather keep my old Mercedes than get some 'el cheapo' newone...

But for the AN 6.5, I have a personal recommendation from someone I trust alot when it comes to FR drivers, he owns several Fostex and about each and every Modell of the good old Corals. He was actually pretty enthusiastic about the AN 6.5 in Horns, might be his personal taste... as always, there's only one way to find out!

best, martin
 
#635
I love the look of Pine, but until it's been weathered for several decades is it ideally suited for speaker cabs unless well damped like Bob Brines does his MDF cabs and any knots epoxied to ensure they can't rattle/squeak/leak.
Click to expand...
😕

Im confused by this statements language. Could you please clear up what was meant. Pine is good until it gets weathered, or that weathered pine is good, or that unweathered Pine is fine, so long as extensive measures are taken? Thank you.
 
#638
Hi

On the topic of enclosure materials, has anyone here tried HDF (medite)? We have pinus radiata marine plywood here, eg no voids 7pcs. compressed for 18mm. It just sucks that it can only be bought by bulk.


Scott and GM,

BTW, I have these old Coral drivers on OB right now, but I'd like to try em on BiB's too. They are 8" coax types - very deep curvilinear cone with annular rings and diffraction horn bullet tweeter rigidly placed in front. Tweeter's magnet very near cone's felt dustcap. Frequency response was 'published' as 30-25kHz. The Fs is quite high though. I only have some of the T/S parameters.

Re: 7.8 Ohms
Fo: 30-45Hz
Fs: 100Hz
Qms: 4.33
Qes: 1.15
Qts: 0.91
Qo: 0.45 (40Hz)

Sensitivity is ~94dB. 15W.

I don't have the Vas. But maybe based on the recommended BR Enclosure Vb from the old catalog, a guesstimate could be arrived at?

BR Plan: http://pic4.picturetrail.com/VOL706/2663514/5316039/93893985.jpg

It has a cloth type reverse roll edge surround much like the Beta series. Sorry, no idea on Xmax too etc. It has pretty stiff surround material almost like thin leather, but it sounds great on OB (needs sub set ~50Hz though for 'heavier' material). Magnet is pretty large, ~4.5" starting from basket legs.

I know it lacks data, hopefully though I can get a ballpark idea on the dims. Thanks!🙂 You guys rock *we salute you*.😉
 
#639
Godzilla said:
Last weekend me and my boys were pushing knots out of the pine at Home Depot. We were lucky to find a few good straight pieces. In the end it will all work out fine... as long as nothing cracks!
Click to expand...

The edge glued panels they have in lengths
out to 6 ft look nice and can be found with few
if any knots.


I'm playing with these for a bib build.


I've not seen any panel sizes 6 ' x 16" though
width seems to be limited to 12" shelf depth.
 
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