Thanks, even by my tolerance for large cabs this is a biggun'. Once built it would be almost as big as my ~20 ft^3ers and 20" taller, so will need a helper for some of the assembly and a hand truck/strong back to move around due to its weight and why I'm not 'holding my breath' waiting for a review. Hope springs eternal though. 
Fe208Ez calcs
Doing some calcs for a FE208EZ Sigma BIB. When I check against what is on zillaspeak for a 206 I seem to be quite a bit out on the cross section size (I know the 206 is not quite the same as the 208 but not that far off). So could some kind guru verify my calcs.
Using the following to calculate (all in metric - cm)
1) L = speed of sound (340m/s)/2/Fs Note - this varies a bit depending where you look
2) H = L/2
3) Vb = 20*Vas*(Qts^1.25)
4) Sl = Vb*1000/H
5) D = (Sl*(2^.5))^.5
6) W = Sl/D
7) Zd - L*0.217
For the FE208EZ Sigma
Vas = 60L
Qts = 0.18
Fs = 42
I get:
L = 404.7
H = 202.3 cm
Vb = 140.7 cu/cm
Sl = 695.5 sq/cm
D = 31.4 cm
W = 22.1 cm
Zd = 87.8 cm
The Sl I get is 111.3 sq" whereas the 206 (Qts 0.18, Vas 54l, Fs 39) on zilla is 133 sq" (if I recall - can't get through now!)
Yes, I have no will power, yes the NZ$ is an all time high against the US$, yes I ordered a pair of FE208EZ/T90A today.
Thanks,
Chris
Doing some calcs for a FE208EZ Sigma BIB. When I check against what is on zillaspeak for a 206 I seem to be quite a bit out on the cross section size (I know the 206 is not quite the same as the 208 but not that far off). So could some kind guru verify my calcs.
Using the following to calculate (all in metric - cm)
1) L = speed of sound (340m/s)/2/Fs Note - this varies a bit depending where you look
2) H = L/2
3) Vb = 20*Vas*(Qts^1.25)
4) Sl = Vb*1000/H
5) D = (Sl*(2^.5))^.5
6) W = Sl/D
7) Zd - L*0.217
For the FE208EZ Sigma
Vas = 60L
Qts = 0.18
Fs = 42
I get:
L = 404.7
H = 202.3 cm
Vb = 140.7 cu/cm
Sl = 695.5 sq/cm
D = 31.4 cm
W = 22.1 cm
Zd = 87.8 cm
The Sl I get is 111.3 sq" whereas the 206 (Qts 0.18, Vas 54l, Fs 39) on zilla is 133 sq" (if I recall - can't get through now!)
Yes, I have no will power, yes the NZ$ is an all time high against the US$, yes I ordered a pair of FE208EZ/T90A today.
Thanks,
Chris
The reason Vb is substantially different is that I didn't use the aforementioned formula for to calculate it. The greater volume from the Vb=20*Vas*(Qt^1.25) alignment will give considerably better performance, particularly in terms of driver excursion, so it's the one to go for if you can, but for many of the zillaspeak boxes I deliberately decided to restrict the footprint as not everyone can fit such huge pipes into their living room. In which case, they really should have an extension built, or move house.
Scottmoose said:The reason Vb is substantially different is that I didn't use the aforementioned formula for to calculate it. The greater volume from the Vb=20*Vas*(Qt^1.25) alignment will give considerably better performance, particularly in terms of driver excursion, so it's the one to go for if you can, but for many of the zillaspeak boxes I deliberately decided to restrict the footprint as not everyone can fit such huge pipes into their living room. In which case, they really should have an extension built, or move house.
Thanks Scott. But I am confused, are you saying the Vb=20*Vas*(Qts^1.25) will give greater volume than the zillaspeak figures? I am getting smaller Sl than the zillaspeak figures (Vb not shown) wich would mean I must be calculating lower Vb???
Not all the time. Just most of it because I restricted a lot of my boxes.
Anyway, using the now-standardised pipe-horn volume formula Greg established
for the FE208ESigma (I want to know how these sound... ) I make it a total line length 161.5in, for a ~80.75in tall cabinet, Zdriver of 35in, Sl=106.4953in^2. 8.647in x 12.315in (internal WxD, not in.c the sloping baffle) A+B+C= 6.1575; all dimensions rounded up to the nearest logical figure. If you fancy building the bigger cabinet of course, there's no reason why not.
Anyway, using the now-standardised pipe-horn volume formula Greg established
for the FE208ESigma (I want to know how these sound... ) I make it a total line length 161.5in, for a ~80.75in tall cabinet, Zdriver of 35in, Sl=106.4953in^2. 8.647in x 12.315in (internal WxD, not in.c the sloping baffle) A+B+C= 6.1575; all dimensions rounded up to the nearest logical figure. If you fancy building the bigger cabinet of course, there's no reason why not.
Many thanks Scott. Pretty much matches my calcs - difference probably a result of metric/imperial conversion!
You may rest assured I will report back on how they sound. May be a while tho, Madisound are out of the T90A (coming in 2 weeks) and I will be taking my time over this build. Probably be the last pair I build for a while (yeah right!) so I want to savour the whole process
You may rest assured I will report back on how they sound. May be a while tho, Madisound are out of the T90A (coming in 2 weeks) and I will be taking my time over this build. Probably be the last pair I build for a while (yeah right!) so I want to savour the whole process
Wouldn't surprise me. I grew up with Metric, was taught it, not taught Imperial. And yet I much prefer using it. Works for me anyway, but to each their own!
What are you building your new pipes out of Chris? Birch ply? If so, then this might be of interest to you. In fact, it'll probably be of interest to just about everyone on the thread. A few words of wisdom on finshing the stuff from Terry Cain (otherwise known as the God of cabinetry )
"On birch I like a lighter look than tung oil. The air will darken birch nicely after a year or so regardless. Tung oil is very durable and fine for darker woods like gunstocks etc., but birch goes blotchy a bit.
A better goo is polyurethane (oil based, Sherwin Williams or any oil based varnish gloss) mixed 60% poly - 40% mineral spirits (maybe stiffer weather permitting) and applied like a tung oil. Brush on and wipe off about 3 - 8 coats (24 hrs between coats min) sanding with 320 grit on a padded block. Then use a nice beeswax diluted into min. spirits (shave the beeswax with a chisel a few days ahead) add lilac or juniper oil -maybe some cheap perfume. Apply wax with #0000 steel wool and buff with cotton. And you have a faux French polish that will wear better than shellac. Has a stronger film against abrasion and moisture than tung. Smells good too. Basically this is Simon Watts and Jason La Trobe Bateman's finish, cabinetmakers to the Rothchilds, drawers and furniture etc. Some of the better Italian finishers inspect the cotton seed fields the varnish is squished from, Varnish-o-philes. TC"
Can you guess how my 167 boxes will be finished?
What are you building your new pipes out of Chris? Birch ply? If so, then this might be of interest to you. In fact, it'll probably be of interest to just about everyone on the thread. A few words of wisdom on finshing the stuff from Terry Cain (otherwise known as the God of cabinetry
)"On birch I like a lighter look than tung oil. The air will darken birch nicely after a year or so regardless. Tung oil is very durable and fine for darker woods like gunstocks etc., but birch goes blotchy a bit.
A better goo is polyurethane (oil based, Sherwin Williams or any oil based varnish gloss) mixed 60% poly - 40% mineral spirits (maybe stiffer weather permitting) and applied like a tung oil. Brush on and wipe off about 3 - 8 coats (24 hrs between coats min) sanding with 320 grit on a padded block. Then use a nice beeswax diluted into min. spirits (shave the beeswax with a chisel a few days ahead) add lilac or juniper oil -maybe some cheap perfume. Apply wax with #0000 steel wool and buff with cotton. And you have a faux French polish that will wear better than shellac. Has a stronger film against abrasion and moisture than tung. Smells good too. Basically this is Simon Watts and Jason La Trobe Bateman's finish, cabinetmakers to the Rothchilds, drawers and furniture etc. Some of the better Italian finishers inspect the cotton seed fields the varnish is squished from, Varnish-o-philes. TC"
Can you guess how my 167 boxes will be finished?
I will use what is availabe locally which is marine ply (11 or 14 ply I think) nearly void free. This is comes in a few finishes being a variety of exotic (i.e. grown in Pacific locations like PNG) timbers. My 168BIBs have a slightly redish tinge which is quite attractive. I used straight Polyurethane which is good from a distance! I intend taking a bit more trouble over the finish this time so this info is very useful, thanks.
I went the easy route and painted mine black satin
Always nice to get tips from the masters, thanks for posting that TC wisdom on finishing Scott... I never knew TC ,but many times I'm amazed at the sound from such a simple cabinet and I'm very greatful for his kindness to pass it on for others to enjoy.. I've had so many hours of absolute delight listening to my BIB's and will probabley always stick with the design no matter what driver I go for.
Yesterday I had a awesome evening listening and I was thinking that the BIB's do have a sort of compression chamber.. Maybe some of you math guru's could look into it. I was thinking the driver fires sound down into the sealed end which is quite narrow and then has to go back past the driver to exit up the line etc. Would'nt that be somewhat of a compression considering the speed of sound etc? Dave
Always nice to get tips from the masters, thanks for posting that TC wisdom on finishing Scott... I never knew TC ,but many times I'm amazed at the sound from such a simple cabinet and I'm very greatful for his kindness to pass it on for others to enjoy.. I've had so many hours of absolute delight listening to my BIB's and will probabley always stick with the design no matter what driver I go for.
Yesterday I had a awesome evening listening and I was thinking that the BIB's do have a sort of compression chamber.. Maybe some of you math guru's could look into it. I was thinking the driver fires sound down into the sealed end which is quite narrow and then has to go back past the driver to exit up the line etc. Would'nt that be somewhat of a compression considering the speed of sound etc? Dave
FYI: Lowther DX2/Fostex FE207E bipole BIB
http://fullrangedriver.com/forum/viewtopic.php?pid=15480#p15480
http://fullrangedriver.com/forum/viewtopic.php?pid=15480#p15480
I think the bipole, floor-loaded BIB represents the very best of this type of alignment, and the very best thinking on the matter.
I cannot imagine a more fun sounding speaker.
I have a pair of the third run of the TT FR8, and these in the above, I think would be absolutely killer! They at Misco really seem to be getting their act together with the hempcone 8, and very soon we can expect a whizzerless wideband 8 with a purported reach to ~9KHz, which is the apple of my eye, as my ears arent too interested in much above that...... now With Foobar 1/2 octave EQ, the level of control, so easy, so economical, it could be completely tailored to a "tee" very exciting stuff. The whizzerless cone, for example, can have the high end EQ'd, and this alone should satisfy many ears over 30, IMHO.
And a Happy 4th of July to all of the American DIY'rs. And a toast to all the Hanoverians, who allowed this experiment to happen, in the first place.
I cannot imagine a more fun sounding speaker.
I have a pair of the third run of the TT FR8, and these in the above, I think would be absolutely killer! They at Misco really seem to be getting their act together with the hempcone 8, and very soon we can expect a whizzerless wideband 8 with a purported reach to ~9KHz, which is the apple of my eye, as my ears arent too interested in much above that...... now With Foobar 1/2 octave EQ, the level of control, so easy, so economical, it could be completely tailored to a "tee" very exciting stuff. The whizzerless cone, for example, can have the high end EQ'd, and this alone should satisfy many ears over 30, IMHO.
And a Happy 4th of July to all of the American DIY'rs. And a toast to all the Hanoverians, who allowed this experiment to happen, in the first place.
Indeed. Happy 4th to all in the States. Enjoy! 
I wouldn't have chosen to pay duty on our tea either....
Greg, Dan, I like the sound of this. My only slight concern is that pipe-horns benefit from nearby boundary conditions to flatten the ripple, and going bipole reduces your options a bit, unless a couple of side-walls are available. I bet the balance would tip in favour of the bipole though. If those TT drivers are as good as you say Dan, things are looking good for driver-choice.
In a sense Dave you're right -they're end-loaded horns. Most BLHs don't have a compression-chamber per-se, unless they're designed with reference to compression horns -it's just a filter-chamber. Pipe horns have considerable compression effects at the sealed end of the line (particularly significant with them being an So=0 design), with no filter other than some damping, and the 180 degree bend, which kills a lot of the unwanted HF.
I wouldn't have chosen to pay duty on our tea either.... Greg, Dan, I like the sound of this. My only slight concern is that pipe-horns benefit from nearby boundary conditions to flatten the ripple, and going bipole reduces your options a bit, unless a couple of side-walls are available. I bet the balance would tip in favour of the bipole though. If those TT drivers are as good as you say Dan, things are looking good for driver-choice.
In a sense Dave you're right -they're end-loaded horns. Most BLHs don't have a compression-chamber per-se, unless they're designed with reference to compression horns -it's just a filter-chamber. Pipe horns have considerable compression effects at the sealed end of the line (particularly significant with them being an So=0 design), with no filter other than some damping, and the 180 degree bend, which kills a lot of the unwanted HF.
My sense is that in an appropriate room, something like a bipole Hemp 8 BIB, would be such a BABIB, (Bad *** BIB) that you wouldnt be caring too much about the technical considerations.
I think this type of thing would sound SO powerful, so high calorie, so alive, and so much ******* FUN!! that none of that would matter after the first chestnut, with a pint. The hemp 8 seem quite particular about amplification. They really sound their best with those tiny little "flea" amps.
I really wish I had a bigger place now...
I think this type of thing would sound SO powerful, so high calorie, so alive, and so much ******* FUN!! that none of that would matter after the first chestnut, with a pint. The hemp 8 seem quite particular about amplification. They really sound their best with those tiny little "flea" amps.
I really wish I had a bigger place now...
Scottmoose said:Indeed. Happy 4th to all in the States. Enjoy!
Greg, Dan, I like the sound of this. My only slight concern is that pipe-horns benefit from nearby boundary conditions to flatten the ripple, and going bipole reduces your options a bit, unless a couple of side-walls are available. I bet the balance would tip in favour of the bipole though.
Happy 4th to ya'll too! Oh, I did! A neighbor hickory smoked/BBQ'd a bunch of chickens n' ribs n' baked beans, so combined with homemade cornbread and Vidalia onion coleslaw and plenty of your beverage of choice, we sat back all fat n' happy and watched all the fireworks going off around us.
Understood, but with the extra gain, more stuffing can be used to smooth its response without losing the acoustic BSC, though of course the extreme bottom end suffers if there's not enough room gain, so a 'rumble' filter may be required on some music.
Hi everybody!
Interesting field HDD, USB dac, D or Set amps.....and BIB...
Just a question; Considering not to use a PC as a main source but instead a TTable, would be passive pre with pre-phono and D-amp or Set a reasonable match for BIB?
Any suggestion for a passive pre for starting?
Hi Scott,
If I remember well You had a Monacor BIB in the past.... do you recon a minimum power needs for those drivers? Flea watt amps will works?
Thanks. Ciao. Fab.
P.S. some more pictures
Raw baffles....
Semi raw...
and nearly finished...
Interesting field HDD, USB dac, D or Set amps.....and BIB...
Just a question; Considering not to use a PC as a main source but instead a TTable, would be passive pre with pre-phono and D-amp or Set a reasonable match for BIB?
Any suggestion for a passive pre for starting?
Hi Scott,
If I remember well You had a Monacor BIB in the past.... do you recon a minimum power needs for those drivers? Flea watt amps will works?
Thanks. Ciao. Fab.
P.S. some more pictures
Raw baffles....
An externally hosted image should be here but it was not working when we last tested it.
Semi raw...
An externally hosted image should be here but it was not working when we last tested it.
and nearly finished...
An externally hosted image should be here but it was not working when we last tested it.
