>>> I'd like to use this same system to make a bib for the
FF165 after all the raveups Godzilla has given the driver
and then compare the FE127e BIB with that.
Loninappleton – I have both the 165k and 127e. This morning I listened to the 127e in the living room. The sound was excellent. Here is a pic of the finished speaker. Pine with dark walnut stain. They are small and fit nicely on either side of the fireplace. I’ve had no complaints from the wife. She called me to watch the boys play and I shut the system off and went out for some fun.
http://www.zillaspeak.com/fostex127eSSB.asp
Later this afternoon I went downstairs and listened to the 165k BIBs. Sound was also excellent. The performance comes alive with the BIBs. Jack Johnson sounded very much alive and in the room as did all the instruments. Then Regina Spektor was right there in my room. Amazing sound from the BIBs! You can hear all the spaces in between the instruments. Vocals are very real sounding. Maybe it was the tubes too… or the new room treatments absorbing all the echo in the room. Regardless, you want to listen forever. Wife called to take a ride somewhere. I told her just one minute but instead listened another 30 minutes before my butt would leave the listening position. Pine with red mahogany stain. Very nice look for a hack like me.
http://www.zillaspeak.com/bib-godzillabib.asp
127e BIBs may have the same -glue your butt to the chair magic- but in the slotted box they don’t sound anywhere near as good as the 165k BIBs.
G.Kennedy – your BIBs look fantastic! Amazingly, BIBs don’t take up a lot of floor space. They are tall, slim and elegant IMO. Great job!
FF165 after all the raveups Godzilla has given the driver
and then compare the FE127e BIB with that.
Loninappleton – I have both the 165k and 127e. This morning I listened to the 127e in the living room. The sound was excellent. Here is a pic of the finished speaker. Pine with dark walnut stain. They are small and fit nicely on either side of the fireplace. I’ve had no complaints from the wife. She called me to watch the boys play and I shut the system off and went out for some fun.
http://www.zillaspeak.com/fostex127eSSB.asp
Later this afternoon I went downstairs and listened to the 165k BIBs. Sound was also excellent. The performance comes alive with the BIBs. Jack Johnson sounded very much alive and in the room as did all the instruments. Then Regina Spektor was right there in my room. Amazing sound from the BIBs! You can hear all the spaces in between the instruments. Vocals are very real sounding. Maybe it was the tubes too… or the new room treatments absorbing all the echo in the room. Regardless, you want to listen forever. Wife called to take a ride somewhere. I told her just one minute but instead listened another 30 minutes before my butt would leave the listening position. Pine with red mahogany stain. Very nice look for a hack like me.
http://www.zillaspeak.com/bib-godzillabib.asp
127e BIBs may have the same -glue your butt to the chair magic- but in the slotted box they don’t sound anywhere near as good as the 165k BIBs.
G.Kennedy – your BIBs look fantastic! Amazingly, BIBs don’t take up a lot of floor space. They are tall, slim and elegant IMO. Great job!
Re. 127e slotted box...
I was worried when I simmed them in WinISD that they may sound a bit bloated but I must have gotten lucky. No bloat. They are pretty small and feather light made from pine. No one ever seems to notice them at all in the living room. I suppose they look rather bland. They do fill the room with sound and recreate piano pretty darn well (we have a piano in the room). They are very clear and image great but not as great as the bigger BIBs. These, the BIBs and the Straight Pipes are speaker cabinets I’ve kept and finished over the years. They don’t have major sonic flaws. Most all my ported cabinets end up gutted in storage because they sound hollow or bloated. I am going to build a similar slotted box - but much smaller - for a 3 inch TB for the den soon. I’m hoping for similar results!
I was worried when I simmed them in WinISD that they may sound a bit bloated but I must have gotten lucky. No bloat. They are pretty small and feather light made from pine. No one ever seems to notice them at all in the living room. I suppose they look rather bland. They do fill the room with sound and recreate piano pretty darn well (we have a piano in the room). They are very clear and image great but not as great as the bigger BIBs. These, the BIBs and the Straight Pipes are speaker cabinets I’ve kept and finished over the years. They don’t have major sonic flaws. Most all my ported cabinets end up gutted in storage because they sound hollow or bloated. I am going to build a similar slotted box - but much smaller - for a 3 inch TB for the den soon. I’m hoping for similar results!
copperhead said:
138"
Here is a quote from this thread regarding the 168 Sigma, not sure if it is Scottmoose or GM. I used these parameters to build mine.
"168EZ
All dimensions are internal. WxD ratio wants to be 1:1.4142 to preserve the flare around the base. Try not to deviate from this if possible. So internally 7.25in wide x 10.25in deep (always round up to the nearest sensible figure). If you're using 0.75in material, that will make for a box 8.75in wide x 12.5in deep.
The FE168ESigma can handle a slightly longer line than I suggested originally on the Zilla pages. I keep meaning to get the revision to Jeff. Increase the line length to 138in (70in tall cabinet externally) with a Zdriver of 29.25in from the internal sealed end."
Greets!
Out of curiosity I tried manipulating the simplified Margolis-Small max flat formula to see if I could find a simple formula to approximate a BIB 'close enough' and the few diverse ones I compared with this formula worked for me:
Vb = 20*Vas*Qts^1.25
(Vas can be either as liters or ft^3)
Note that this accounts 'close enough' IMO for the internal baffle, driver, bracing loss and when applied to T.C.'s or Scott's 'small' BIBs it's considerably bigger, with a relatively 'full' response more like all the ones I've posted. Since all I changed was the Qts exponent, you can decrease Vb, LF gain BW by increasing it.
Note too that the formula assumes a tuning of one ~octave below Fs, so for low Fs drivers where you want to tune it to ~Fs, then if you want to maintain the 'flavor' of the BIB's response you'll need to input half the driver's Vas and calc its path-length (L) based on Fs/4 in lieu of Fs/2. This way, the mouth area (Sm) remains constant and only the length, driver position changes.
Anyway, for those with the capability, please do some comparisons to a variety of existing sims and let me know if any appear to be unacceptable.
GM
Out of curiosity I tried manipulating the simplified Margolis-Small max flat formula to see if I could find a simple formula to approximate a BIB 'close enough' and the few diverse ones I compared with this formula worked for me:
Vb = 20*Vas*Qts^1.25
(Vas can be either as liters or ft^3)
Note that this accounts 'close enough' IMO for the internal baffle, driver, bracing loss and when applied to T.C.'s or Scott's 'small' BIBs it's considerably bigger, with a relatively 'full' response more like all the ones I've posted. Since all I changed was the Qts exponent, you can decrease Vb, LF gain BW by increasing it.
Note too that the formula assumes a tuning of one ~octave below Fs, so for low Fs drivers where you want to tune it to ~Fs, then if you want to maintain the 'flavor' of the BIB's response you'll need to input half the driver's Vas and calc its path-length (L) based on Fs/4 in lieu of Fs/2. This way, the mouth area (Sm) remains constant and only the length, driver position changes.
Anyway, for those with the capability, please do some comparisons to a variety of existing sims and let me know if any appear to be unacceptable.
GM
Nice one Greg -you've done it again. 
Thus far, in the comparisons I've made, this appears to work very well indeed. Vb usually comes out a little larger than I often use, which I know you prefer (& I confess you've convinced me to that way of thinking too) & response seems consistantly solid. Looks like you've cracked it, or at least one way to size the box for a target alignment. This is much better than what I was trying to work with.
Cheers
Scott
Thus far, in the comparisons I've made, this appears to work very well indeed. Vb usually comes out a little larger than I often use, which I know you prefer (& I confess you've convinced me to that way of thinking too) & response seems consistantly solid. Looks like you've cracked it, or at least one way to size the box for a target alignment. This is much better than what I was trying to work with.
Cheers
Scott
Hi GM -
with lower ceilings, a 206E BIB's exit could come within 5-6" - -- would that additional mass effect show on an impedance plot?
I'm lookin' for a good bass drum sound to get semblance of something like this little shell being whacked with a mallet
klipschorn have spatial disassociation and kinda muddy sound on drum - part is my flexy wall
how much drum sound can BIB do? Berlioz Requiem selection from 1971 with Ivan Kozlovsky has quite a nice drum and Kozlovsky the best on Sanctus!
lightly tapped drum - heads probably too loose
http://img215.imageshack.us/img215/2802/l261w2spne1.jpg
Freddy
with lower ceilings, a 206E BIB's exit could come within 5-6" - -- would that additional mass effect show on an impedance plot?
I'm lookin' for a good bass drum sound to get semblance of something like this little shell being whacked with a mallet
klipschorn have spatial disassociation and kinda muddy sound on drum - part is my flexy wall
how much drum sound can BIB do? Berlioz Requiem selection from 1971 with Ivan Kozlovsky has quite a nice drum and Kozlovsky the best on Sanctus!
lightly tapped drum - heads probably too loose
http://img215.imageshack.us/img215/2802/l261w2spne1.jpg
Freddy
Scottmoose said:Nice one Greg -you've done it again.
Greets!
Thanks, though all I did was spend ~15 min. finding a different exponent for a formula that took considerable R&D by others to develop and MJK's considerable efforts with a powerful computer program that gave me a visual aid to do it, so in the scheme of things my contribution was basically nil.
GM
freddi said:
Greets!
Probably, especially if corner loaded.
K-horns sound 'muddy' even loaded into a poured concrete basement corner. I assume it's due to insufficient material thickness and bracing.
I have no BIB experience per se, but the big 15" folded Voigt pipe floor loaders I built really impressed folks with their life-like drums, stand up and electric bass when combined with a 500 Hz Altec horn. Obviously, these instruments have a wide enough BW that it takes a really good wide BW, high volume system driven with the requisite power to do them justice, so I don't see a 206E BIB satisfying folks like you or me when it's time to 'get down n' boogie'.
GM
hey GM - got 511s and plenty of 15" and AJ-horn - how was/ should a pipe like that be done to get good impact?
wonder if Fulmer's lilttle pipe would play with 421-? - eyeballing, what would you estimate the first and second sections areas to be and the path (74?) length? - mot much internal volume, looks like ~ straight pipe- ~90sq.in.(?) Fulmer claimed the cut helped the sound.
Fulmer pipe
http://home.planet.nl/~ulfman/images/FulmerPlan.jpg
k-horn sound kinda like BP-box- not much mouth, low EBP woofer, sounds thuddy on harpsichord - I'm not sure if the material thickness is the main problem.
btw-got one ratty old Sentry IV loaded with two pym1298- no bass, good snap but no slam from around 60-up - efficiency somewhat higher than K-horn - could use TH subs - argggggh
Freddy
wonder if Fulmer's lilttle pipe would play with 421-? - eyeballing, what would you estimate the first and second sections areas to be and the path (74?) length? - mot much internal volume, looks like ~ straight pipe- ~90sq.in.(?) Fulmer claimed the cut helped the sound.
Fulmer pipe
http://home.planet.nl/~ulfman/images/FulmerPlan.jpg
k-horn sound kinda like BP-box- not much mouth, low EBP woofer, sounds thuddy on harpsichord - I'm not sure if the material thickness is the main problem.
btw-got one ratty old Sentry IV loaded with two pym1298- no bass, good snap but no slam from around 60-up - efficiency somewhat higher than K-horn - could use TH subs - argggggh
Freddy
Greets!
My best were reverse tapered (TQWT) with a large, straight ducted port and loaded with two drivers/channel to make up for the lack of proper horn loading. Corner loaded with Altecs, they had a similar sensitivity to a K-horn and put it to shame IMO.
Hmm, we had this conversation several years ago, though if I kept my notes I can't quickly find them, but I concluded it looked good for my ~NOS pair of 421-8Hs and one of the projects I want to do before I reach the point of not caring anymore. Instead of paying 'through the nose' for a pair of 808H horns like shown in the lead pic, I want to 'do a Bozak' and make pseudo multi-cells using a bunch of 'el cheapo' square frame paper cone tweeters.
I never studied the K-horn in detail since I learned early on that dual drivers with plenty of power trounced it overall without having to do all that woodworking, but a bass-horn really taxes its construction and the k-horn looks way too fragile for the app IMO. Anyway, I imagine all its design shortcomings are well known/understood by now, so no sense me speculating at this point.
I don't recall the Sentry IV, but the simple prosound horns of days gone by I'm familiar with typically needed to be at least two stacked/channel sitting on the ground to get below ~120 Hz with any 'slam' and four to complete the flare, so not a practical HIFI solution for most folks.
GM
My best were reverse tapered (TQWT) with a large, straight ducted port and loaded with two drivers/channel to make up for the lack of proper horn loading. Corner loaded with Altecs, they had a similar sensitivity to a K-horn and put it to shame IMO.
Hmm, we had this conversation several years ago, though if I kept my notes I can't quickly find them, but I concluded it looked good for my ~NOS pair of 421-8Hs and one of the projects I want to do before I reach the point of not caring anymore. Instead of paying 'through the nose' for a pair of 808H horns like shown in the lead pic, I want to 'do a Bozak' and make pseudo multi-cells using a bunch of 'el cheapo' square frame paper cone tweeters.
I never studied the K-horn in detail since I learned early on that dual drivers with plenty of power trounced it overall without having to do all that woodworking, but a bass-horn really taxes its construction and the k-horn looks way too fragile for the app IMO. Anyway, I imagine all its design shortcomings are well known/understood by now, so no sense me speculating at this point.
I don't recall the Sentry IV, but the simple prosound horns of days gone by I'm familiar with typically needed to be at least two stacked/channel sitting on the ground to get below ~120 Hz with any 'slam' and four to complete the flare, so not a practical HIFI solution for most folks.
GM
hi GM - bet that sure osunded a lot better than a k-horn - karlson coulld sound better i"n places"
1-15" might barely cut it - my K's clobber 1-15 and keep cone excursion down doing it - but theres a battle of artifacts, etc.
FWIW here's rough sims of 421-LF (only spec had loaded) in 1.82M striaght pipe vs two BVR about same bulk - figured Fulmer pipe area ~like 12" speaker and around 78-80(?)
its frustrating that only so much can be done for a given bulk :^)
15" B&C woofer (with higher xover) imo sound "thick" compared to lighter cone (low mass EM15, M151)
B&C 15" 3 boxes
http://img389.imageshack.us/img389/3106/15pzb403boxae7.jpg
pipe with 4212-LF vs 15pzb40
http://img239.imageshack.us/img239/3074/fulstra1uh3.jpg
Freddy
1-15" might barely cut it - my K's clobber 1-15 and keep cone excursion down doing it - but theres a battle of artifacts, etc.
FWIW here's rough sims of 421-LF (only spec had loaded) in 1.82M striaght pipe vs two BVR about same bulk - figured Fulmer pipe area ~like 12" speaker and around 78-80(?)
its frustrating that only so much can be done for a given bulk :^)
15" B&C woofer (with higher xover) imo sound "thick" compared to lighter cone (low mass EM15, M151)
B&C 15" 3 boxes
http://img389.imageshack.us/img389/3106/15pzb403boxae7.jpg
pipe with 4212-LF vs 15pzb40
http://img239.imageshack.us/img239/3074/fulstra1uh3.jpg
Freddy