1st BIB

ronnchy · 19th February 2007, 08:33 PM

Slapped together my first set of BIB's based on specs found on this forum. WOW they sound amazing! I'm hooked!
A few questions though.
1) (sorry if this sounds stupid) but if baltic birch is the best material to use and if baltic only comes in 60"x60" sheets.... then what do you do if your panels need to be bigger? (the design for my fostex FE168EZ called for 64") Do I simply add the additional 4" piece and seal all the air gaps between pieces?

2) Do I have to caulk the joint where the internal partition meets the wall? (I'm thinking no, since the air will take the path of least resistance, which is out the top anyways)

Thanks everyone who offered ideas and advice. You're a very friendly bunch.

this is a great hobby!

Ron
Bottlehead Paramours (2A3 SET)
Bottlehead Extended Foreplay
Fostex FE168EZ in BIB

Scottmoose · 19th February 2007, 10:56 PM

Good question. Not a problem in the UK, because on the rare occasions we can ever get birch ply, it usually comes in 4ftx8ft sheets like most other materials. Goodness knows why.

I'm really glad you like them as I suspect it was the dims muggins here came up with that you used. What are they built with at the moment? From your remarks, I'm guessing the current boxes are a test pair, and you're looking to do a 'finished' one? If that's the case, it might be worth going for a solid wood with a good stiffness to weight ratio. Not cheap, but probably worth it in the long run. BTW: if you want a little more extension, you can increase the height of the cabinets to 70in, Zdriver of 30in if you want -the 168 has enough excursion to be OK in this load.

Kensai · 20th February 2007, 12:30 PM

You made FE168 BiBs? I think we'd like pics, even if they are test mules ;-p

Kensai

ronnchy · 20th February 2007, 01:13 PM

hey thanks for the advice Scottmoose! I'll mock one up using mdf to see if I like them. If they sound as good as I hope they will, I will consider making them out of solid cherry. (I have access to a full woodshop)
Would the internal partition still be 6" up and 6" in from the base?
And how much carpet underlay should I install? The full length of the internal partition on both sides?
What about stuffing the enclosure? With what and how much?

thanks for all your help. I'll post pics of the finished unit once I'm done.

Ron

Scottmoose · 20th February 2007, 03:23 PM

Hi Ron. Yeah, the CSA of the line is as before, so the baffle end-position will stay as it is at present, 6in equidistant from all walls & floor.

Solid cherry. Nice.

Don't forget to turn a couple of suprabaffles while you're at it on your lathe. Make them about 7in over the diameter of the driver with a constantly decreasing radii.

I'd line the front of the sloping internal baffle with stiff acoustic fiberglass, down to just below the driver, one side wall (front part of the line) to the same level, and the internal base with the same. GM's favoured approach. I tried it out & it worked considerably better than the stuffing.

ronnchy · 20th February 2007, 04:06 PM

"Make them about 7in over the diameter of the driver with a constantly decreasing radii."

Can't wait to get to the lumber mill.... I'm thinking cherry enclosure with a hard maple base and matching suprabaffle.
Thanks once again for all the helpful info. I'm off to make sawdust....

Ron

bibster · 20th February 2007, 05:27 PM

Go Ronnchi, GO!! Love the smell of sawdust in the morning!!

Wish I had access to a lathe... I have a wheel for my (attempt to make a) hurdy gurdy (kind a like thinggy) be made...
And I'd make some supra's whilst there, ofcourse

Paul

Scottmoose · 20th February 2007, 08:24 PM

For reference; one of Terry Cain's prototype BIBs with the original non 'E' FE168Sigma. I believe these were supposed to go into production but had to be abandoned when Fostex discontinued the driver.

Martin Prothero · 21st February 2007, 05:42 PM

ronnchy - Sounds like you are about to build a beautiful set of speakers. I am also in the middle of building some using the 168EZ. I've chosen to burn-in the drivers for a few weeks before listening to them, which is so frustrating as I am dying to hear what they sound like.
Just ordered some bowl blanks from a woodturners supplies, to make the suprabaffles. I have gone with burr elm

I will post some images when everything gets up and running and I would love to see some pics of yours too. Keep us informed...

All the best

M

Scottmoose · 21st February 2007, 07:28 PM

Another man of taste and decency.

19th February 2007, 08:33 PM	#1
ronnchy diyAudio Member Join Date: Feb 2007 Location: Toronto, Ontario	1st BIB Slapped together my first set of BIB's based on specs found on this forum. WOW they sound amazing! I'm hooked! A few questions though. 1) (sorry if this sounds stupid) but if baltic birch is the best material to use and if baltic only comes in 60"x60" sheets.... then what do you do if your panels need to be bigger? (the design for my fostex FE168EZ called for 64") Do I simply add the additional 4" piece and seal all the air gaps between pieces? 2) Do I have to caulk the joint where the internal partition meets the wall? (I'm thinking no, since the air will take the path of least resistance, which is out the top anyways) Thanks everyone who offered ideas and advice. You're a very friendly bunch. this is a great hobby! Ron Bottlehead Paramours (2A3 SET) Bottlehead Extended Foreplay Fostex FE168EZ in BIB

20th February 2007, 01:13 PM	#4
ronnchy diyAudio Member Join Date: Feb 2007 Location: Toronto, Ontario	they just keep sounding better & better hey thanks for the advice Scottmoose! I'll mock one up using mdf to see if I like them. If they sound as good as I hope they will, I will consider making them out of solid cherry. (I have access to a full woodshop) Would the internal partition still be 6" up and 6" in from the base? And how much carpet underlay should I install? The full length of the internal partition on both sides? What about stuffing the enclosure? With what and how much? thanks for all your help. I'll post pics of the finished unit once I'm done. Ron

20th February 2007, 05:27 PM	#7
bibster diyAudio Member Join Date: Aug 2004 Location: Lasbordes, 11400	Go Ronnchi, GO!! Love the smell of sawdust in the morning!! Wish I had access to a lathe... I have a wheel for my (attempt to make a) hurdy gurdy (kind a like thinggy) be made... And I'd make some supra's whilst there, ofcourse Paul __________________ Demagogue: One who preaches a doctrine he knows to be untrue to men he knows to be idiots. H.L. Mencken

21st February 2007, 05:42 PM	#9
Martin Prothero diyAudio Member Join Date: Jan 2007 Location: Devon, UK	ronnchy - Sounds like you are about to build a beautiful set of speakers. I am also in the middle of building some using the 168EZ. I've chosen to burn-in the drivers for a few weeks before listening to them, which is so frustrating as I am dying to hear what they sound like. Just ordered some bowl blanks from a woodturners supplies, to make the suprabaffles. I have gone with burr elm I will post some images when everything gets up and running and I would love to see some pics of yours too. Keep us informed... All the best M __________________ Keep a green bough in your heart, the singing bird will come.

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19th February 2007, 10:56 PM	#2
Scottmoose diyAudio Member Join Date: Mar 2005 Location: UK	Good question. Not a problem in the UK, because on the rare occasions we can ever get birch ply, it usually comes in 4ftx8ft sheets like most other materials. Goodness knows why. I'm really glad you like them as I suspect it was the dims muggins here came up with that you used. What are they built with at the moment? From your remarks, I'm guessing the current boxes are a test pair, and you're looking to do a 'finished' one? If that's the case, it might be worth going for a solid wood with a good stiffness to weight ratio. Not cheap, but probably worth it in the long run. BTW: if you want a little more extension, you can increase the height of the cabinets to 70in, Zdriver of 30in if you want -the 168 has enough excursion to be OK in this load.

20th February 2007, 12:30 PM	#3
Kensai diyAudio Member Join Date: Jan 2004 Location: St. Louis	You made FE168 BiBs? I think we'd like pics, even if they are test mules ;-p Kensai

20th February 2007, 03:23 PM	#5
Scottmoose diyAudio Member Join Date: Mar 2005 Location: UK	Hi Ron. Yeah, the CSA of the line is as before, so the baffle end-position will stay as it is at present, 6in equidistant from all walls & floor. Solid cherry. Nice. Don't forget to turn a couple of suprabaffles while you're at it on your lathe. Make them about 7in over the diameter of the driver with a constantly decreasing radii. I'd line the front of the sloping internal baffle with stiff acoustic fiberglass, down to just below the driver, one side wall (front part of the line) to the same level, and the internal base with the same. GM's favoured approach. I tried it out & it worked considerably better than the stuffing.

20th February 2007, 04:06 PM	#6
ronnchy diyAudio Member Join Date: Feb 2007 Location: Toronto, Ontario	"Make them about 7in over the diameter of the driver with a constantly decreasing radii." Can't wait to get to the lumber mill.... I'm thinking cherry enclosure with a hard maple base and matching suprabaffle. Thanks once again for all the helpful info. I'm off to make sawdust.... Ron

21st February 2007, 07:28 PM	#10
Scottmoose diyAudio Member Join Date: Mar 2005 Location: UK	Another man of taste and decency.

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