http://www.zillaspeak.com/bib-howtobuild.asp
The BIB calculators on the link above are the most current ones I have.
The dimensions on the BIB site were originally what Scottmoose and GM calculated. As time when by and BIBs were built the math was further refined. This does not take away from the overall goodness of these original BIBs. I have not heard a single complaint that any of these designs is bad rather all of them are highly praised. BIBs are forgiving designs and minor differences in dimensions should not alter the sound much. The overall goodness of a BIB can be expressed as follows; Big open soundstage, Big bass (especially considering we are using full range drivers), high efficiency and dynamic.
Once someone has built their BIB it becomes a matter of tuning to taste by stuffing. Everyone’s room is different so I recommend tuning your BIB in the room it will be used in. I have moved my BIBs twice and decided to stuff differently each time. Since BIBs are tall speakers, to stuff I either stand on a chair and use a broomstick handle to carefully push the stuffing down to the bass of the BIB (I use Acoustastuff and recommend it. I do not recommend using fiberglass for health reasons). Or lay your BIB on the floor and stuff using the broomstick. My recommendation is to stuff lightly and loosely until you achieve the best balance of sound in your room. The goal is to eliminate the midrange frequencies emanating from the opening on top (or bottom if your BIB is inverted).
Measurements suggest BIBs are not the most refined speakers thru the midrange. Some who have compared BIBs to other designs say they can hear the raggedness thru the mids. Some say they hear no raggedness at all, only smooth midrange. There are tradeoffs with every speaker design. While some may sound smoother thru the mids they may not have the overall balance of a BIB. It is a personal choice. For me and many other BIBsters, BIBs are an excellent compromise with minimal flaws. They are an excellent way for audiophiles and music lovers to enjoy their music collection. They are also a great expression of what can be built with full range drivers.
Godzilla
PS. If the above BIB calculators are out of date please email me the latest versions at godzilla3@hotmail.com
The BIB calculators on the link above are the most current ones I have.
The dimensions on the BIB site were originally what Scottmoose and GM calculated. As time when by and BIBs were built the math was further refined. This does not take away from the overall goodness of these original BIBs. I have not heard a single complaint that any of these designs is bad rather all of them are highly praised. BIBs are forgiving designs and minor differences in dimensions should not alter the sound much. The overall goodness of a BIB can be expressed as follows; Big open soundstage, Big bass (especially considering we are using full range drivers), high efficiency and dynamic.
Once someone has built their BIB it becomes a matter of tuning to taste by stuffing. Everyone’s room is different so I recommend tuning your BIB in the room it will be used in. I have moved my BIBs twice and decided to stuff differently each time. Since BIBs are tall speakers, to stuff I either stand on a chair and use a broomstick handle to carefully push the stuffing down to the bass of the BIB (I use Acoustastuff and recommend it. I do not recommend using fiberglass for health reasons). Or lay your BIB on the floor and stuff using the broomstick. My recommendation is to stuff lightly and loosely until you achieve the best balance of sound in your room. The goal is to eliminate the midrange frequencies emanating from the opening on top (or bottom if your BIB is inverted).
Measurements suggest BIBs are not the most refined speakers thru the midrange. Some who have compared BIBs to other designs say they can hear the raggedness thru the mids. Some say they hear no raggedness at all, only smooth midrange. There are tradeoffs with every speaker design. While some may sound smoother thru the mids they may not have the overall balance of a BIB. It is a personal choice. For me and many other BIBsters, BIBs are an excellent compromise with minimal flaws. They are an excellent way for audiophiles and music lovers to enjoy their music collection. They are also a great expression of what can be built with full range drivers.
Godzilla
PS. If the above BIB calculators are out of date please email me the latest versions at godzilla3@hotmail.com
That's the calculation I'm using but I may have got something out of whack.
Sm is turning out at 39.37, about half what you have on the JX92 driver BIB page. All other measurements are pretty close to the online ones. I'm working on - Sm = Vb*1728/L (as I said, I don't know the driver example so using 1728 as a constant may be wrong).
Sm is turning out at 39.37, about half what you have on the JX92 driver BIB page. All other measurements are pretty close to the online ones. I'm working on - Sm = Vb*1728/L (as I said, I don't know the driver example so using 1728 as a constant may be wrong).
Greets!
FYI, yesterday in another thread it was pointed out to me that the calc for 'Sm' in my example listed on the BIB build page is incorrect and since my spreadsheet calc'd the right answer, in my haste assumed the example was correct also without bothering to look at it since AFAIK all I did was convert my spreadsheet to recognizable formulas.
Fortunately, Santiu wouldn't be so easily dismissed, so once I actually looked at it became depressingly obvious I'd screwed up since for the 'Sm' calc I posted the full height instead of the folded height to divide by to arrive at the right answer, so the correct formula is:
Sm = 2.10804*1728/48.088 = 75.751"^2
..........or if divided by the line length:
Sm = 2.10804*1728/(96.175/2) = 75.751"^2
The revised example for Godzilla to cut/paste into the BIB build site page:
L = 13464.54/2/70 = 96.175"
folded height = 96.175"/2 = 48.088"
Vb = 20*0.29*0.445^1.25 = 2.10804 ft^3
Sm = 2.10804*1728/48.088 = 75.751"^2
depth = SQRT((75.751*SQRT(2)) = 10.35"
width = 75.751/10.35 = 7.319"
zdriver = 96.175*0.217 = 20.87"
a-b-c = 10.35/2 = 5.175"
Sorry for any confusion this may have caused and/or too small (potentially bass shy) a BIB built, if any.
GM
PS: Note that mine and Scott's spreadsheets calc slightly different length, etc., dims due to each assuming a slightly different way of locating the internal baffle board, but regardless of which SS or BB location used, the cab's Vb is large enough that it will be completely inaudible.
FYI, yesterday in another thread it was pointed out to me that the calc for 'Sm' in my example listed on the BIB build page is incorrect and since my spreadsheet calc'd the right answer, in my haste assumed the example was correct also without bothering to look at it since AFAIK all I did was convert my spreadsheet to recognizable formulas.
Fortunately, Santiu wouldn't be so easily dismissed, so once I actually looked at it became depressingly obvious I'd screwed up since for the 'Sm' calc I posted the full height instead of the folded height to divide by to arrive at the right answer, so the correct formula is:
Sm = 2.10804*1728/48.088 = 75.751"^2
..........or if divided by the line length:
Sm = 2.10804*1728/(96.175/2) = 75.751"^2
The revised example for Godzilla to cut/paste into the BIB build site page:
L = 13464.54/2/70 = 96.175"
folded height = 96.175"/2 = 48.088"
Vb = 20*0.29*0.445^1.25 = 2.10804 ft^3
Sm = 2.10804*1728/48.088 = 75.751"^2
depth = SQRT((75.751*SQRT(2)) = 10.35"
width = 75.751/10.35 = 7.319"
zdriver = 96.175*0.217 = 20.87"
a-b-c = 10.35/2 = 5.175"
Sorry for any confusion this may have caused and/or too small (potentially bass shy) a BIB built, if any.
GM
PS: Note that mine and Scott's spreadsheets calc slightly different length, etc., dims due to each assuming a slightly different way of locating the internal baffle board, but regardless of which SS or BB location used, the cab's Vb is large enough that it will be completely inaudible.
Done. Thanks GM!
>>>The revised example for Godzilla to cut/paste into the BIB build site page:
L = 13464.54/2/70 = 96.175"
folded height = 96.175"/2 = 48.088"
Vb = 20*0.29*0.445^1.25 = 2.10804 ft^3
Sm = 2.10804*1728/48.088 = 75.751"^2
depth = SQRT((75.751*SQRT(2)) = 10.35"
width = 75.751/10.35 = 7.319"
zdriver = 96.175*0.217 = 20.87"
a-b-c = 10.35/2 = 5.175"
>>>The revised example for Godzilla to cut/paste into the BIB build site page:
L = 13464.54/2/70 = 96.175"
folded height = 96.175"/2 = 48.088"
Vb = 20*0.29*0.445^1.25 = 2.10804 ft^3
Sm = 2.10804*1728/48.088 = 75.751"^2
depth = SQRT((75.751*SQRT(2)) = 10.35"
width = 75.751/10.35 = 7.319"
zdriver = 96.175*0.217 = 20.87"
a-b-c = 10.35/2 = 5.175"
Aha! It was the full height/folded height which was throwing off my figures. Thanks for clearing that up, Greg. I thought it was looking super-model slim.
No, no intention to build as I doubt I could justify the room, especially with the toe in required on the Jordan drivers. However now I have the spreadsheet worked out, I can experiment a little.
No, no intention to build as I doubt I could justify the room, especially with the toe in required on the Jordan drivers. However now I have the spreadsheet worked out, I can experiment a little.
Well, with most 'FR' drivers using a slanted baffle to create toe-in ala the NHT 3.3 is the 'Hot Ticket': http://www.stereophile.com/loudspeakerreviews/1293nht/
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