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

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Hello, I have just finished reading (and in the last 3/4 more or less just scrolling:) this monster thread. As I moved to my own apartment, I had to leave those big and ugly MLTL with Beta12CX and D210Ti designed by GM with MathCad worksheets in the cellar of my parents' house. I really loved the sound, but during the years, they have become also tiring to my ears (due to the crossover design and maybe room as well). In a 3,5 x 4,2 x2,4 m living room I must forget about my dream three way horn stack or large open baffles.

The BIB seems as the only "big box" design that I could fit into my living room that would be accepted by my wife:) Now I do not know, which driver/design should I choose.

The dimensions are limited to around 30x50 cm footprint and 180 cm height (+- something:)), I usually listen to rock/metal and classical orchestral music with some easier pieces time from time, more or less the same is true with my wife - with one exception - she plays the violin and therefore I would like to surprise her with as realistic (or say lively) violin / orchestra sound. To say, I am not able to listen at 120 dB peaks to have the dynamics of a large orchestra, the maximum is something around "louder TV" levels.

I do not know if a fullrange in a BIB is the best choice, but I think it is under those limiting conditions - or is there any better choice?

I think of using 6,5" or 8", I can buy at www.spectrumaudio.de (or maybe a better EU shop for fullrange units? Please suggest.) and I would not like to pay much more than 100-120 Eur per unit.

Thanks all in advance.

BTW: I have these D210Ti drivers left. Any suggestion what to do with them besides selling to someone else?:)
 
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Hello Peter,
good to know that - unfortunately, I live at the other end of CzR. But i sometimes travel through Brno, so I would definitely contact you and maybe we could arrange a small listening session for me. By the way, which horns did you build? As far as I could tell from your posts, you live in an apartment too.
 
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Hello Peter,
yes, three hours to Brno, three hours back - and then some at your place:) Sounds like a plan for a free day - and I do not have many of those:) Anyway, If I will have the chance, I will contact you in advance. Thanks for the offer, I am also very inerested in the Sonido drivers.


Best regards,
Jaroslav (that is the J in pelanj, I am sorry for introducing myself so late).
 
Hi,

I've visited a friend of mine, and we listened to some (house) music. He has a setup that would qualify as mid-fi: A Rotel amp (I don't remember the model), a pair of B&W DM 601 speakers, and a pair of DIY sealed subs. He was telling me that he would like to upgrade his hi-fi, because, at his current setup, house music did not sound particularly dynamic. He wants more bass, slam, punch in the chest... B&W's sounded loo lean...

So what could I recommend to him? Being a fullrange fan myself, I couldn't thing of anything much better and simpler than a BIB. But, which one? Due to a limited choice of drivers available locally, I thought of the following: How about removing the drivers from B&w smallish box and mounting them in a BIB? I tried to find some data about that kevlar midbass that B&W uses so that I could calculate BIB dimensions, but without success so far...If you think that these can be obtained, and the this BIB idea is doable and worth the effort, please tell !

The other option is to build a bib using some 8 or 10 inch midbass + a tweeter made by B&C speakers , since they are available locally...

Any advice highly appreciated....

Thanks,

Vix
 
Greets!

The odds of finding measured specs of any major manufacturer's consumer speaker drivers are slim at best, so either measuring them or use drivers with known reasonably accurate specs makes sense to me. Regardless, based on the dims and data here, I'm betting it has specs suitable for a BIB if it's tuned to around Fs, but you'll have to reverse engineer its cab alignment to find a Vas, Qts to input into the BIB calculator.

http://ultimateavmag.com/speakersystems/903BW/index2.html
http://ultimateavmag.com/speakersystems/903BW/index4.html

GM
 
Hi GM!

Reverse engineering of B&W's seems to be no easy task, so in the end it looks like some other speaker with known parameters will be a better choice.

On the other hand, I was looking more closely at some B&C midbass speaker parameters, and have been disappointed when i saw that 8-10 inch drivers have a relatively high Fs (99 and 60 Hz) + they'll need a good tweeter (waveguided).

Next I'll have a look at some JBL's, gotta check what models they have in a shop nearby, and see if any of them is suitable for the BiB..

Thanks a lot,

Vix
 
Greets!

You're welcome!

What about using one of the known 60 Hz (~40 Hz, better) drivers in a pair of 'sub' BIBs and roll in the B&Ws as required (either damp or plug its vent as required for best blend) or replace them with a HE two way monitor if they (probably) can't keep up?

GM
 
GM said:
Greets!

You're welcome!

What about using one of the known 60 Hz (~40 Hz, better) drivers in a pair of 'sub' BIBs and roll in the B&Ws as required (either damp or plug its vent as required for best blend) or replace them with a HE two way monitor if they (probably) can't keep up?

GM

I am not sure if that would work as nice as a single BIB could do. My friend has a pair of sealed subs, and no matter what crossover setting we tried, bass was never satisfactory. It went quite low enough, but sounded somehow "disjointed" and the midbass was lean, no matter what crossover settings we tried. (Lack of baffle step compensation might also play a role here, B&W were not so close to the wall).

On the other hand, if someone has already tried the approach you mentioned, and has successfully integrated the BIB-subwoofer with small monitors,we'll be happy to try it. :)
Most probably we will look for some locally available, bigger fullranger, or wideranger + a tweeter. There are some good car speakers that could be obtained locally,but, beside the fact that they don't publish T/S parameters, I guess that their Q and Vas are such that would require "enormous" BIB...

Thanks a lot,

Vix
 
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And how about a Beta 8 in a BIB? I would use either D210Ti on short horns or maybe an ST200 or a LeSon TLC-5. I would place the tweeter at the ear height - and the woofer can go below it and even on the top of it, if space permits.

I must admit I was caught by up-firing speakers for their nice ambience, but still consider other options with BIB among them.
 
I am going to build two H frame open baffle subwoofer bass modules for my 165k BIBs and was wondering if purposely limiting extension to around 150hz or 100hz is doable? I'd imagine this would result in smaller (thinner) BIBs, possibly even unfolded designs that neatly nestle into corners. Retaining the large and open soundstage of the BIB is an advantage. Supporting bass using larger drivers will probably also be an advantage assuming things can be blended together nicely. Currently, I am of the thinking of enhancing the bass in a similar fashion as enhancing the treble. Any thoughts?

Godzilla
 
I asked about the Omnes Audio BB 3.01 3" driver, and I missed your post, GM ...

GM said:


Greets!

Hmm, I noted this to do back on 12.28, but for whatever reason I forgot about it and don't see where anyone else did it, so at least for the record:

L = 70.866"
Sm = 16.332"^2
zdriver = 15.378"
a-b-c = 2.403"

Due to its size/high F3, best to floor load it IMO, though unfolded puts the driver too high for most folks and folded puts it too low, so I recommend moving it as close to the top as you can and add a supra baffle to space it out for the motor to just clear the internal baffle.

GM

Thanks!

I'm going to do these ... the thoughts I have now are that if I floor load it, the driver will be around 140 cm or 55 inches from the floor - I think this will be OK, as these drivers sound pretty good slightly off-axis. I'm doing a foam-board mockup first, wish me luck!

Edit: Actually, come to think of it, I might try a version that's floor loaded, and double-folds the last half of the line, so the driver will be at around ≈80cm off the floor, looking like this:

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