>>> Hi, anyone simmed a Lowther DX2 in a BIB.
http://www.zillaspeak.com/bib-lowther.asp
No charts but I posted the dims with picturs of the drivers... the drivers look great to me!
Thanks GM. I just cut and pasted from your post while i had my web program open.
Truly,
Godzilla
http://www.zillaspeak.com/bib-lowther.asp
No charts but I posted the dims with picturs of the drivers... the drivers look great to me!
Thanks GM. I just cut and pasted from your post while i had my web program open.
Truly,
Godzilla
Hi GM, welcome back!
Considering your hint on post 1238 pag.124 , should be, the internal baffle, made of same lossy material (i.e. chipboard)?
Thanks.
Ciao.Fab.
Scottmoose said:
Considering your hint on post 1238 pag.124 , should be, the internal baffle, made of same lossy material (i.e. chipboard)?
Thanks.
Ciao.Fab.
The supraBaffle discussion has been split off to here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=86636
dave
http://www.diyaudio.com/forums/showthread.php?s=&threadid=86636
dave
Scottmoose said:
Hi Scott,
That's a fact I was considering too... but on the other hand I thought that a true rigid internal baffle would maybe caused some resonancies and as a consequence the use of more damping material.
Maybe as an option, GM post 1289 was talking about "Celotex", "relatively rigid, acoustic tile and like BobBrines uses"....
Goggle says about a kind of concrete composite, but I'm not sure about it.
We'll see what GM would suggest.
Ciao. Fab.
McFaBs said:
Greets!
Thanks! I can't keep up with you guys!
Yes, and no.
Let's drop back to 'square one' in that my default material choice is a very rigid one since it increases acoustic efficiency and pushes the cab's Fs up high enough to reduce the amount of damping required. But 99.9% of the cab alignments discussed on the various forums are limited to the LF/midbass/lower mids, so it's also more weight/cost effective than trying to damp the cab to below these passbands.
BIBs OTOH are relatively wide BW horns, ergo we ideally want rigid and well damped so that we can 'have our cake and eat it too' WRT acoustic gain and well damped HF. Factor in that it's folded and sitting on a relatively rigid surface and ideally up against relatively rigid walls and the cab can have lossy panels IF they are closely coupled enough not to vibrate against them, so if there's baseboards/carpet/whatever, then these must be accounted for to ensure a close fit.
WRT the internal baffle, it does double duty as a panel stiffener, so if it's a small cab, then you can use a semi-lossy material such as 19 mm MDF, but for wide spans you'll need to either double up to gain rigidity and damping or use something more rigid, such as 19 mm Baltic Birch. Remember, rigidity goes up at the cube of thickness, so it takes ~1.125 - 1.25" thick MDF to match the rigidity of 19 mm BB depending on what it's 'mix' is since it varies quite a bit from brand to brand, and even plant to plant within a brand in some cases.
Bottom line, when in doubt, better too rigid than not rigid enough IMO.
GM
Greg -in re the K-Slot idea you mentioned before, I'm going to give it a shot with my cabs. As (one of) the object of slicing the mouth at an angle is to increase it's size somewhat, I'm thinking the way forward is to leave the top open as usual and cut a slot in the rear baffle according to the dims your spreadsheet indicates. Am I on the right lines here? Or would you advise sealing the top off and replacing the whole lot with said Karlson vent? Karlson's are not something I've any practical experience in, though I've been reading the different articles you linked to over the last week or so and playing around with the Excel sheet, so you're advice would be appreciated.
Best
Scott
Best
Scott
Greets!
You would only seal the top off if you want to mass load it. While I understand the Karlson's basic design theory, I never could arrive at any decent ROT for choosing the right size/shape of the K-slot. Anyway, whether you use it or just slicing the top off at an angle, what you're basically doing is lowering the pipe's Q (peak gain), so it takes either a steep angle or large/long K-slot to make a real difference.
GM
You would only seal the top off if you want to mass load it. While I understand the Karlson's basic design theory, I never could arrive at any decent ROT for choosing the right size/shape of the K-slot. Anyway, whether you use it or just slicing the top off at an angle, what you're basically doing is lowering the pipe's Q (peak gain), so it takes either a steep angle or large/long K-slot to make a real difference.
GM
No action in this thread for a few days. I hope you
all are out building your BIBs now that the heat
has passed.
Anyone building the FE127e BIB? I'm curious about
moving my drivers to that for a BIB test. The
enclosure would be about as high as my tv on it's stand.
What I've found is that the downfiring port on my
GM MLTLs seems to put the back wave (or whatevs)
at good ear height. This may be just an impression.
Those boxes sit on a stand which are open at the
bottom w/no reflector panels unlike the Jordan
MLTL design.
But I digress.
How about some BIB updates?
all are out building your BIBs now that the heat
has passed.
Anyone building the FE127e BIB? I'm curious about
moving my drivers to that for a BIB test. The
enclosure would be about as high as my tv on it's stand.
What I've found is that the downfiring port on my
GM MLTLs seems to put the back wave (or whatevs)
at good ear height. This may be just an impression.
Those boxes sit on a stand which are open at the
bottom w/no reflector panels unlike the Jordan
MLTL design.
But I digress.
How about some BIB updates?
I just brought my pair of BIB's for the 166es-r inside from the shop and got ready to mount them when alas, no sufficiently long enough binding posts. So it looks like it may be brass bolts until I get the posts. If I am happy with them then I will throw some veneer or formica on them and redo my circular mounting baffle.
Andrew
okay,
BIB's hooked up yesterday thanks to the binding posts from a pair of Swans that I borrowed.
Quick take, very dynamic! Bass is not this speakers problem. I have them against the back wall and about 2 feet from side walls.
ceiling is wood and sloped, ~ 8 feet on one side and ~12 feet on the other.
I think someone (Scott?) referred to them as having a dipole bass sound? I don't know but the bass is different to even my Jerico horns which I describe as effortless and just being there.
The BIB's have a punchier more powerfull and natural bass, I can't describe it.
Well worth the minimal effort I think.
One of my bass reproductive test is Livingston Taylor- Grandma's Hand's.
I have it on two Chesky cd's.
There is a bass fundamental in there that is a bit down from the rest of the music which you sense more than hear. The BIB's reproduce it no problem.
If you have this song and cannot hear it look at the driver and see if it is moving
Tried them with a EL34 PP amp as well as my Charlize (Charlize wins by a mile).
Great stuff!
BIB's hooked up yesterday thanks to the binding posts from a pair of Swans that I borrowed.
Quick take, very dynamic! Bass is not this speakers problem. I have them against the back wall and about 2 feet from side walls.
ceiling is wood and sloped, ~ 8 feet on one side and ~12 feet on the other.
I think someone (Scott?) referred to them as having a dipole bass sound? I don't know but the bass is different to even my Jerico horns which I describe as effortless and just being there.
The BIB's have a punchier more powerfull and natural bass, I can't describe it.
Well worth the minimal effort I think.
One of my bass reproductive test is Livingston Taylor- Grandma's Hand's.
I have it on two Chesky cd's.
There is a bass fundamental in there that is a bit down from the rest of the music which you sense more than hear. The BIB's reproduce it no problem.
If you have this song and cannot hear it look at the driver and see if it is moving
Tried them with a EL34 PP amp as well as my Charlize (Charlize wins by a mile).
Great stuff!
Ive read most of this thread and I cant wait to build some on my own. I think I am going to go with the pioneer B20s. I wanna see just how low they can go. Its for my college "dorm".
Scott do you think you can go over my dimensions (Privately if needed) and see if I did it right? Just want to make sure. Its pretty simple, but as a college student I dont have the time to be making mistakes
Scott do you think you can go over my dimensions (Privately if needed) and see if I did it right? Just want to make sure. Its pretty simple, but as a college student I dont have the time to be making mistakes
Scott,
Yes, unusual bass but not unwelcomed.
For the amount of work involved I see no reason for anyone not to try them, just 6 pieces of wood like a normal box.
The only thing I may do just for my personal gratification is to make my baffle deeper and in so doing get the back of the driver out of the horn path.
Many thanks.
Yes, unusual bass but not unwelcomed.
For the amount of work involved I see no reason for anyone not to try them, just 6 pieces of wood like a normal box.
The only thing I may do just for my personal gratification is to make my baffle deeper and in so doing get the back of the driver out of the horn path.
Many thanks.