A resonant pipe has a pattern of dips at harmonic intervals. The offsett driver position compensates for one dip. When using two drivers, I think it's advantageous to put them at different positions, to cancel out different dips and maximizing the benefits. But the volume and taper also play a role in reducing the basic ripple of a pipe and I am not sure that an extra driver would make that much difference in this case. But I have to look into that.
What is the consensus solution of how to handle when i a driver is too deep, and interferes with the internal baffle?
How much is it "ok" to space out the driver from the front baffle?
How much is it "ok" to space out the driver from the front baffle?
I just used the MDF for the cabinet to make a baffle. 2,2mm thick MDF + 2,2mm baffle.
I think the general rule of speaker building applies here, too: As long as you don't go totally overboard, there won't be much difference.
I am planing to build a corner mounted bib upp against the ceiling. My initial idea was to have a complete BIB, only that it's in triangular shape and mounts in the corner like this:
Due to the altered proportion, the possible driver depth is reduced Hence my question earilier.
Although i would like them to be pointing a bit downward and then the taper of the horn have to be changed with uncertain results.
The other option would be to would be to unfold them. The image above the height is the same as for the BIB excelfile of 855cm. and if i make them straight i assume i would do them the "line lenght"?
Then they would be 1710cm tall and look like this, given the same Sm (Terminus area) and length, Although the volume would be different due to the shape here as well..
Does this unfolded variant have anything similar with the BIB or will they sound completely different than what a normal bib would?
The reason i post in this thread is due to the modeling being as the initial post say.. pretty shitty!
The unfolded one would of course be very simple to build and test! but if i put it up it stays there permanently, so would like to get some input before.
Edit: The driver is a 4FE32 with a FS of 100, which makes such an arrangement possible due to the fairly high tuning frequency.
Due to the altered proportion, the possible driver depth is reduced Hence my question earilier.
Although i would like them to be pointing a bit downward and then the taper of the horn have to be changed with uncertain results.
The other option would be to would be to unfold them. The image above the height is the same as for the BIB excelfile of 855cm. and if i make them straight i assume i would do them the "line lenght"?
Then they would be 1710cm tall and look like this, given the same Sm (Terminus area) and length, Although the volume would be different due to the shape here as well..
Does this unfolded variant have anything similar with the BIB or will they sound completely different than what a normal bib would?
The reason i post in this thread is due to the modeling being as the initial post say.. pretty shitty!
The unfolded one would of course be very simple to build and test! but if i put it up it stays there permanently, so would like to get some input before.
Edit: The driver is a 4FE32 with a FS of 100, which makes such an arrangement possible due to the fairly high tuning frequency.
Folding or unfolding doesn't alter the sound that much, I'd wager. I even played with folding a BIB sideways to make a cabinet that you can put things on. https://www.diyaudio.com/community/...esult-could-be-a-cupoard-like-speaker.407371/
but I put that thought on halt for the moment :-D
but I put that thought on halt for the moment :-D
elleman, very elegant. As long as the suprabaffle does not load the back of the driver in a tunnel you shoukd be fine.
You could also use a trick i first saw when we built Lowther Acousta, add a little pocket in the internal divide rot slide the magnet into.
sB is easier, has other advantages, and can be used as part of the cosmetics.
dave
You could also use a trick i first saw when we built Lowther Acousta, add a little pocket in the internal divide rot slide the magnet into.
sB is easier, has other advantages, and can be used as part of the cosmetics.
dave
Starting at age 10, all my early corner horn experiments were like this except went to the floor, i.e. just a plywood baffle attached/sealed to the wall, spending most of my time finding where the little 'FR' driver, vent/terminus sounded best overall, though had to learn room acoustics to find that they theoretically should be at an odd harmonic and later that a downward shift dials it in a bit better, but not till Martin King 'did the math' using the wave equations did I get the theoretically correct offsets.
A pity his WS's are permanently MIA and can't recall if I tried a corner variant in Hornresp, but assume you can and there's AKABAK and maybe LA TL.
Yeah the BIB calculator is set with the driver default at a Z=0.217 of line length from the beginning of the horn, clearified in blue below, But in the BIB case this is also the distance from the vent? So ideally this distances should be different, or did i misunderstand what you mean with Vent offset?
In the corner case these will of course be different, Zv for vent and Zd for driver:
In the corner case these will of course be different, Zv for vent and Zd for driver:
Both driver and vent offsets are ideally measured from the inside top, so 1-0.848 = ~0.152 from vent centerline to inside bottom, though of course ignoring typical panel thickness won't impact its performance, ergo if ceiling loaded either need to lengthen the horn or rethink length Vs driver offset.
But what is the vented offset in the BIB, and how is it measured? I don't really understand what to measure here.
As-is / as-standard there isn't one: the horn / pipe terminus is at the end, without any offset. You can, but it's tricky & potentially (potentially -there are always exceptions) counter-productive for most top-venting types, with the main interest being as he noted with those where the terminus is close to the floor. If yours is floor venting, then he's given the offsets above -simply substitute the relevant decimals for the default 0.217*L used as the driver offset for the standard version of this pipe-horn.
Is this calculator alright?
One or two fold.
https://web.archive.org/web/20230603001107/http://www.mh-audio.nl/ChooseBIB.html
One or two fold.
https://web.archive.org/web/20230603001107/http://www.mh-audio.nl/ChooseBIB.html
Although i am not sure about the Corrected height and the Corrected Z-drivel actually doing any good. It seems to me that the "compenstaion" get's it further from the from the desired line length as well as using 0,2 instead of 0,217 of the newly calculated Driver postion. This is the same as in the Excel though. I have searched the thread and it doesn't seem to be too many comments about why the correction makes these simplifications.
Oh I like that very much!
I make a hornresp model when I design a BIB, and I tend to stick to the basic guidelines for volume and driver position. I will increase and decrease volume a bit and will try out 1x0.21xL, 2x0.21xL etc driver positions. In my experience, in my listening space, in nearfield the measured response matches my hornresp model. Further away, the room dominates. It seems to sound best if my model in hornresp performs well (linear, no big suckouts etc), so that's what I focus on.
My advice: the design recipe for a BIB is precise enough to get you close to a fine-tunes pipe horn. If you want to improve on that, start with making it model well in hornresp. Fine-tuning it to your listening environment is the last to do and will work best with an already balanced design.
I make a hornresp model when I design a BIB, and I tend to stick to the basic guidelines for volume and driver position. I will increase and decrease volume a bit and will try out 1x0.21xL, 2x0.21xL etc driver positions. In my experience, in my listening space, in nearfield the measured response matches my hornresp model. Further away, the room dominates. It seems to sound best if my model in hornresp performs well (linear, no big suckouts etc), so that's what I focus on.
My advice: the design recipe for a BIB is precise enough to get you close to a fine-tunes pipe horn. If you want to improve on that, start with making it model well in hornresp. Fine-tuning it to your listening environment is the last to do and will work best with an already balanced design.
Yeah the "issue" with this corner version is that it is a conical and not a parabolic horn, meaning that the volume will be almost half of a normal bib at the same length and Sm.
Due to limitation of a 295mm X 1800mm shelf as the only board, the prototype is something like this in Hornresp:
Due to limitation of a 295mm X 1800mm shelf as the only board, the prototype is something like this in Hornresp:
Second prototype up 😊
First BIBs dedicated for kitchen?
Yes, they are made to replace the hideous sound from the Google Display. Since it's used almost every day it needed an upgrade!
6000th post in the thread! 🥳
GM and Scottmoose you are living legends 👍
First BIBs dedicated for kitchen?
Yes, they are made to replace the hideous sound from the Google Display. Since it's used almost every day it needed an upgrade!
6000th post in the thread! 🥳
GM and Scottmoose you are living legends 👍