Scottmoose said:
Greets!
Double blind questioning eh?
Agreed, up to point, as on several occasions I've noted that down low the room will dominate, but higher up where the driver dominates, increasing aspect ratios will affect cone modulation, though selective damping can overcome this. While any audible effects are likely to be subtle at best until extreme aspect ratios are used, any attention to details that reduces the stuffing density is worthwhile IMO since it will also affect pipe output.
GM
I like the idea of a "two way" in the BIB, optimizing the thang; I cut the whizzers off a pair of Hemp 8 and it made them a better driver, then stuck a 1" socket in each pole piece and they became better again, and they reach up pretty high as well...sound better. I always thought the hemp cone sounded so delicious that ANY whizzer was a blight on the proceedings. Now I know.
I think the SEAS 6.5 and 7 inch coaxials would be fantastic for a powerBIB, with a powerful amp, not SET, Madisound has prebuilt XO for them with upgrade options on doodads.
Who has opinions on a good tweeter for a wideband +; some ideas I had were:
HiVi planar ribbon tweeter (very sweet and smooth, 94db perfect)
Fountek/Aurum Cantus ribbon tweeter
BMS compression driver + 18Sound Oblate Horn (personal favorite, and would be good to get GM's thoughts on using small spheroid aluminum horn mounting and use)
Fostex T90A supertweeter horn ( also very nice)
Both the 168EZ and Hemp reach well high enough that a simple cap and attenuator would do the trick nicely.
I think the SEAS 6.5 and 7 inch coaxials would be fantastic for a powerBIB, with a powerful amp, not SET, Madisound has prebuilt XO for them with upgrade options on doodads.
Who has opinions on a good tweeter for a wideband +; some ideas I had were:
HiVi planar ribbon tweeter (very sweet and smooth, 94db perfect)
Fountek/Aurum Cantus ribbon tweeter
BMS compression driver + 18Sound Oblate Horn (personal favorite, and would be good to get GM's thoughts on using small spheroid aluminum horn mounting and use)
Fostex T90A supertweeter horn ( also very nice)
Both the 168EZ and Hemp reach well high enough that a simple cap and attenuator would do the trick nicely.
GM said:
Thanks as ever Greg. More to ponder over. Agreed with the stuffing BTW -increasingly I'm viewing it purely as a patch for mediocre design if anything much over 0.25lbs ft^3 is needed to tame the harmonics.
Not really double blind questioning
(sorry about that -my duff way of putting things) as I was asking different things -in Martin's case about modelling different WxD dimensions in MathCad, and how a steeper or shallower flare angle down to a given CSA for Sl might affect the harmonic structure (for example, Sl=100in^2, and the possible difference between 10in x 10in WxD, and 5in x 20in WxD). He didn't think it'd be significant as the CSA down the line doesn't change (assuming no folds of course) between the two of them. Any thoughts you could add on that one? Cheers
Scott
http://www.madisound.com/MD04.html
http://www.madisound.com/cgi-bin/index.cgi?cart_id=3113121.21533&pid=1961
I’d imagine these would work well in a BIB.
From Madisound’s website: “The H1333 and H1353 will have a leaner bass sound, perhaps blending a little better with a subwoofer in a purely audio system.”
Or perhaps the BIB cabinet design could bump up that bass nicely and eliminate the need for a sub?
These drivers look very cool and could be a good solution for SS fans wanting to hear the BIB benefits of more bass, enhanced imaging, ease of presentation, increased soundstage, etc…
Godzilla
http://www.madisound.com/cgi-bin/index.cgi?cart_id=3113121.21533&pid=1961
I’d imagine these would work well in a BIB.
From Madisound’s website: “The H1333 and H1353 will have a leaner bass sound, perhaps blending a little better with a subwoofer in a purely audio system.”
Or perhaps the BIB cabinet design could bump up that bass nicely and eliminate the need for a sub?
These drivers look very cool and could be a good solution for SS fans wanting to hear the BIB benefits of more bass, enhanced imaging, ease of presentation, increased soundstage, etc…
Godzilla
Oh they'll work. They'll thunder. Those little boxes Madisound suggest? I ask you! What are they on? Those guys have spent too much time eating broccoli and drinking Perrier if you ask me.
If anyone want's some numbers run just ask. You know those MaxxHorn things? (you can see what I'm driving at can't you
) Well, kiss them goodbye. Especially as these are far, far finer drivers than those in that thing. How low we go depends entirely on how tall a cabinet you can take.
If anyone want's some numbers run just ask. You know those MaxxHorn things? (you can see what I'm driving at can't you
) Well, kiss them goodbye. Especially as these are far, far finer drivers than those in that thing. How low we go depends entirely on how tall a cabinet you can take.
Oh, heck with it -it's Christmas!
Here's a 'short' version with 150in of line length, zdriver of 32.5in and 75in^2 Sl. Target F10 of 23Hz, before room gain.
Ha! And that's the 200 pages! It's important. Our little tribute to Terry Cain. He certainly didn't invent them, but without him, not as many of us would have heard of this alignment. Me included.
Here's a 'short' version with 150in of line length, zdriver of 32.5in and 75in^2 Sl. Target F10 of 23Hz, before room gain.
Ha! And that's the 200 pages! It's important. Our little tribute to Terry Cain. He certainly didn't invent them, but without him, not as many of us would have heard of this alignment. Me included.
Attachments
Bump the bass up abit?? 
.....Jus' abit methinks. Think: flat to 25Hz. Imagine the SEAS coaxials in a BIB with a BIG T amp.
Paul, I saw those today; I smell kevlar. I want them round and li' dat. Cut the whizz and add the treble. The Alnico one, nix the whizz. Mmmmmm. Things are getting interesting.
.....Jus' abit methinks. Think: flat to 25Hz. Imagine the SEAS coaxials in a BIB with a BIG T amp.Paul, I saw those today; I smell kevlar.
I want them round and li' dat. Cut the whizz and add the treble. The Alnico one, nix the whizz. Mmmmmm. Things are getting interesting.
Guys-
Might as well take the opportunity now to wish you and your families a very happy Christmas, and New Year.
And as it's the season for having fun -you know I said 'short' version' above? You didn't think I'd leave it there did you? The long one. Full 1/2 wave tuned TQWT for Seas Coax with 26Hz Fs. Triple fold, floor-venting BIB -it needs the triple fold, I promise.
Line Length = 260.5in.
Zdriver = 28.25in
Sl = 85in^2
Flat to 20Hz in 1/2 space. F10 ~12Hz before room-gain. If anyone is insane enough to build this (and it's certainly not impossible by any stretch of the imagination) be aware you'll need a suprabaffle to space the driver out from the first sloping internal baffle. I'll let you sort out the internal layout as I'm lousy at drawing. Hope Terry would approve. I think he'd have a grin on his face at least.
MaxxHorn -thank you, and goodnight.
Have fun
Scott
Might as well take the opportunity now to wish you and your families a very happy Christmas, and New Year.
And as it's the season for having fun -you know I said 'short' version' above? You didn't think I'd leave it there did you?
The long one. Full 1/2 wave tuned TQWT for Seas Coax with 26Hz Fs. Triple fold, floor-venting BIB -it needs the triple fold, I promise. Line Length = 260.5in.
Zdriver = 28.25in
Sl = 85in^2
Flat to 20Hz in 1/2 space. F10 ~12Hz before room-gain. If anyone is insane enough to build this (and it's certainly not impossible by any stretch of the imagination) be aware you'll need a suprabaffle to space the driver out from the first sloping internal baffle. I'll let you sort out the internal layout as I'm lousy at drawing. Hope Terry would approve. I think he'd have a grin on his face at least.
MaxxHorn -thank you, and goodnight.
Have fun
Scott
Attachments
Thanks Scott! I want to add the Seas logo to the BIB page so folks can see these designs. I will try to juggle things around on the BIB site over the next week or two. I know there are nits to pick… I also want to add the ‘fine tuned’ BIBs you’ve designed along with the original dims that are already there.
Also, maybe it’s not audible but the three fold BIB seems to minimize frequency aberrations somewhat. Maybe someone can draw up a three fold BIB so I can add it to the site?
Maybe a BIB with no folds (and a brace/leg treatment), folded and folded again BIB may be nice to put on the site too.
Peace,
Godzilla
Also, maybe it’s not audible but the three fold BIB seems to minimize frequency aberrations somewhat. Maybe someone can draw up a three fold BIB so I can add it to the site?
Maybe a BIB with no folds (and a brace/leg treatment), folded and folded again BIB may be nice to put on the site too.
Peace,
Godzilla
Scottmoose said:
How's this for starters? Not to scale... definitely low on the WAF... I'm guestimating it would be about 80" high and about 18" deep, maybe 12" wide.
An externally hosted image should be here but it was not working when we last tested it.
'Displacement has merits with horns and their variations. Bigger Is Better and Longer Is Stronger.'
Something Terry Cain said to me when I built my first pair of FE166E BIB test boxes and spent an hour trying to push my jaw back into place.
Accidentally deleted post when editing. Quad fold is theoretically possible. Target 19Hz. Absolute limit for the insane. Nurse! Thought Experiment. Almost certainly won't work in real life. But a bit of fun.
Line length = 356.5in
Zdriver = 38.75in
SL = 85in^2.
Note: these aren't actually very wide boxes. To get the 85in^2 terminus I assumed 8.5in wide x 10in deep mouth. Not the ideal flare rate, but for these particular sims it's not important as they are assumed to be unfolded.
Of course, as you'll see from the graphs, you loose gain in the LF from the longer lines in favour of extension. Not automatically a bad thing, as we've got room lift to add to this little lot.
Greg -tell us this doesn't work and get us back on the planet after our quick indulgence in madness. It's the silly season after all.
Something Terry Cain said to me when I built my first pair of FE166E BIB test boxes and spent an hour trying to push my jaw back into place.
Accidentally deleted post when editing. Quad fold is theoretically possible. Target 19Hz. Absolute limit for the insane. Nurse! Thought Experiment. Almost certainly won't work in real life. But a bit of fun.
Line length = 356.5in
Zdriver = 38.75in
SL = 85in^2.
Note: these aren't actually very wide boxes. To get the 85in^2 terminus I assumed 8.5in wide x 10in deep mouth. Not the ideal flare rate, but for these particular sims it's not important as they are assumed to be unfolded.
Of course, as you'll see from the graphs, you loose gain in the LF from the longer lines in favour of extension. Not automatically a bad thing, as we've got room lift to add to this little lot.
Greg -tell us this doesn't work and get us back on the planet after our quick indulgence in madness.
It's the silly season after all.Attachments
For the three fold... make the the first two bends like a conventional BIB upside down then the 3rd going to the side/s at an angle. Rather than the rear, should still get the benefit of the cieling?! Driver will be 28" off the floor (which would be sealed end) I can't draw it on the puter, sorry. The front would be kind of trapezoidal instead of rectangular!
I'm getting a set of fe108ez's for christmas from my wife. yay! and also the wood for a pair of straight pipes, with BIB dims. Bigger will be hopefully better! 27mm solid birch! yeah!
Stroop
I'm getting a set of fe108ez's for christmas from my wife. yay! and also the wood for a pair of straight pipes, with BIB dims. Bigger will be hopefully better! 27mm solid birch! yeah!
Stroop