All parameters are sensitive, and have different effects -you can't really pick one out as being more important than another. Line length sets the tuning frequency. Vb will determine the level of gain you get. Zdriver is there to supress the worst hamonic ripple.
Not technically a very correct or exact description, and it ignores the size of the terminus, the kind of effect on energy transfer placement et al will have, but it'll do, roughly.
Re the 126 boxes, the ideas on Zillaspeak are just that -ideas which will work fine as-is, and give people a starting point to tweak and play from there. If you went with a box between the two sizes, that'll work too. The kind of response you'll get will fall roughly between the two.
Not technically a very correct or exact description, and it ignores the size of the terminus, the kind of effect on energy transfer placement et al will have, but it'll do, roughly.
Re the 126 boxes, the ideas on Zillaspeak are just that -ideas which will work fine as-is, and give people a starting point to tweak and play from there. If you went with a box between the two sizes, that'll work too. The kind of response you'll get will fall roughly between the two.
Greg nails IT. As usual.
I love a good stream-of-consciousness.
Folks,
Stop analyzing all this stuff. Terry Cain said it straight to me, in person, threw it down thusly: "Dan, just build the fukcing thing." Build it and they will come. The 168 is CLEARLY the room-friendly, WAF, everything bullseye BIB, just,as TC says, f***ing build it. Stop all this navel-gazing.
Sorry, but look at ALL THE HAPPY MUSIC LOVERS with these things.
I love a good stream-of-consciousness.
Folks,
Stop analyzing all this stuff. Terry Cain said it straight to me, in person, threw it down thusly: "Dan, just build the fukcing thing." Build it and they will come. The 168 is CLEARLY the room-friendly, WAF, everything bullseye BIB, just,as TC says, f***ing build it. Stop all this navel-gazing.
Sorry, but look at ALL THE HAPPY MUSIC LOVERS with these things.
Yeah, but as a poor college student, before I go start cutting up nice sheets of plywood, I want to know that I'm not about to make a mistake
Would rather build it once and not have to worry.Scottmoose, I was going over your dimensions, and something doesn't seem right. An overall cabinet height of 70", with an external depth of 12.5" doesn't seem to give the driver enough room to be mounted 29.25" from the top, does it? I thought the 168EZ was almost 3.5" inches deep...I probably made a mistake somewhere though.
dmason, man, I truly respect your views and experiences. I can relate to your tastes and attitude, really, so I want NO contention ... But, on top of all the enjoyment of music, I also love analyzing things. I always have. I can't help it. I love it. You might not love it; that's fine with me, but please don't ask me to deny one of my joys, OK?
Anyway, all of the encouragement suggests that a pair of FE126E BIB's can be made from a single 4x8 sheet. This is really good for a person with really limited funds (me.) The line length will be a little less than the 97in 'idea' but it should still work well anyway. I can afford to do it with GOOD drivers instead of ...
-- Dave
Anyway, all of the encouragement suggests that a pair of FE126E BIB's can be made from a single 4x8 sheet. This is really good for a person with really limited funds (me.) The line length will be a little less than the 97in 'idea' but it should still work well anyway. I can afford to do it with GOOD drivers instead of ...
-- Dave
Glowbug said:
not scottmoose... but you will probably need to add a suprabaffle to space the driver from the internal baffle. if you look at some bib pics most have done this. also, it seems people suggest making the hole a bit wider toward the interior to give the driver a little more space to "breathe".
i just used a square but check out terry cain's original for some nice suprabaffles.
Dave Cigna said:
hi dave,
have you thought of adding a third fold and making these floor venting? doesn't add much to the depth and will keep the full line length to one sheet of ply. also, if you have tall ceilings the 97incher may not couple well with the ceiling. speaking from experience as my small(ish) fe108ez bib doesn't couple well with the 3m ceilings in my apt.
Just like I started over the last weekend...Dave Cigna said:
4'(== 122cm) high, instead of 125.6cm.. so what?
22mm MDF, an old quilt for stuffing, pva & PE glue, clamps, and Hit the road!
I've made a couple of pics, but as I've only done ONE so far, and haven't even finished finisching it, I'll upload them later.
Build those things, they rock!
Paul
Using the ideal 1:1.4142 WxD ratio, 9 times out of 10 an additional false baffle will be needed to give the driver clearance. Best way = get hold of some nice 1in or 1.25in hardwood, then grab a tame cabinet-maker (or a friend with a lathe), to turn them for you with a constantly decreasing radii, like a frisbee. Make them about 7in over the diameter of the driver. Shouldn't cost very much, & looks fantastic. Should improve wave-launch and help scatter reflections off the driver surround too.
Re Dan & Terry Cain's comments, I think some people are reading too much into them. What they are fundamentally saying is simply don't worry about whether or not these big pipes will sound good. Because they will. No problems there.
Re Dan & Terry Cain's comments, I think some people are reading too much into them. What they are fundamentally saying is simply don't worry about whether or not these big pipes will sound good. Because they will. No problems there.
Hey gianstairs,
If you're up for it you could always straighten them out like I did. They do the job very nicely! It does take up a bit more material though. And they make quite a statement....just seeing you have the drivers already.
A supra baffle makes a big improvement on mine...I think.
Cheers Stroop
If you're up for it you could always straighten them out like I did. They do the job very nicely! It does take up a bit more material though. And they make quite a statement....just seeing you have the drivers already.
A supra baffle makes a big improvement on mine...I think.
Cheers Stroop
giantstairs said:
I've done some back-of-an-envelope sketches and decided that it's not easy to put the driver in the right place along the line. On the other hand, it would be pretty easy to add a compression chamber.
My intuition suggests that part of the reason the BIB's work is that the upward facing mouth prevents much of the HF in the horn from interfering with the HF from the front of the driver. But, with a CC we might get away with turning the mouth forward. This is getting to look like an ordinary BLH, but with the twist that the length is (more) deliberately tuned to achieve 1/4 wave boost and the throat is partway down the line to avoid exciting the higher harmonics of the pipe. I'd be really surprised if I'm the first one to think of this, but WTH.How about turning the whole thing upside down and putting it on legs? It's small enough, and it might put the driver at a better height depending on how high off the floor you put it.
-- Dave
Attachments
Hi All,
I have recieved a pair of 168E Sigmas last week and I have bought a pile of birchply and mdf so I am ready to start building these BiBs.
It will be my first fullrange and my first horn so I am very eager to hear what it will do.
I have read most of this thread but I have a question left:
From what I understand the fact that So=0 is contrary to what you would expect from a good design eventhough the result is said to be a very good speaker. But has somebody (Scott?) tried simulations where So>0? and if so what difference did it make?
I have recieved a pair of 168E Sigmas last week and I have bought a pile of birchply and mdf so I am ready to start building these BiBs.
It will be my first fullrange and my first horn so I am very eager to hear what it will do.
I have read most of this thread but I have a question left:
From what I understand the fact that So=0 is contrary to what you would expect from a good design eventhough the result is said to be a very good speaker. But has somebody (Scott?) tried simulations where So>0? and if so what difference did it make?
There's nothing wrong with So=0. All it does is apply maximum pipe gain over the broadest possible passband of operation. Makes it a bit trickier to design well, but that's all. It got a bad reputation a couple of years ago becuase a few dodgy cabinets of were built, and for some reason, it was the feature blamed, whereas in fact, it was primarily the terminus / vent which were causing all the problems.
Why do we have binding posts and terminal cups?
Yeaha - its Wednesday and that means I'm not going to work today. Today I am spending some more time here, finding out all I need to know before I order materials for my BIB build.
I found the thread about using Cat5 cabling for hook up, which I can get from Maplins.
Then I thought, if you are using this for internal cabling why can't it be used for speaker cable? Is one run of single 14AWG copper really enough for speaker cable? I know that the industry is laughing at us with massively inflated prices for cables but this stuff looks pretty flimsy. Please correct me here, I need the reassurance.
Looking into getting binding posts / terminal cups and spade connectors in the same order as the drivers, but do I actually need them? If I am using the same cable from the amp to the outside of the speaker and then inside to the driver, what is the point in having a break in the signal wire (and another material like gold or even worse brass introduced).
Is it just for convenience sake that we (or the industry) uses terminals on the back of speakers or am I missing the point somewhere?
If I need to move the speakers for any reason I can just unplug from the amp right?
Saves precious money, and preserves signal..
Yeaha - its Wednesday and that means I'm not going to work today. Today I am spending some more time here, finding out all I need to know before I order materials for my BIB build.
I found the thread about using Cat5 cabling for hook up, which I can get from Maplins.
Then I thought, if you are using this for internal cabling why can't it be used for speaker cable? Is one run of single 14AWG copper really enough for speaker cable? I know that the industry is laughing at us with massively inflated prices for cables but this stuff looks pretty flimsy. Please correct me here, I need the reassurance.
Looking into getting binding posts / terminal cups and spade connectors in the same order as the drivers, but do I actually need them? If I am using the same cable from the amp to the outside of the speaker and then inside to the driver, what is the point in having a break in the signal wire (and another material like gold or even worse brass introduced).
Is it just for convenience sake that we (or the industry) uses terminals on the back of speakers or am I missing the point somewhere?
If I need to move the speakers for any reason I can just unplug from the amp right?
Saves precious money, and preserves signal..
Thanks for the fast response.
24AWG is like hair thickness! Wow. I guess everyone else says this too when they find out?
So do you use one single wire for + and one separate wire for - (for both speakers) and nothing else? No need for outer sleeving or anything.
If this is the case, I can afford to spend more elsewhere...
Cheers guys
24AWG is like hair thickness! Wow. I guess everyone else says this too when they find out?
So do you use one single wire for + and one separate wire for - (for both speakers) and nothing else? No need for outer sleeving or anything.
If this is the case, I can afford to spend more elsewhere...
Cheers guys
