Terry Cain's BIB -why does it work and does anyone have those Fostex Craft Handbooks? - Page 111

Scottmoose · 12th August 2006, 11:30 AM

Something for you to try out guys. I shamelessly plundered it from Dan's Dark Star. Should be particularly useful for those running smaller drivers, and having problems with HF leakage through the horn (interesting that the larger drivers seem to have less of a problem with this).

Get hold of some of that thin cork that's used for lining purposes, or that you see on the front of cork-boards etc., and line the front of the inner baffle with the stuff (this needs to be the thin cork -not the heavy-duty stuff used for flooring tiles. I tried those a year back, and they killed the dynamics stone cold).

You can also line the inside of the rear baffle with it too to pretty good effect. What you should get is an instant, dramatic reduction in HF leakage, and also of what I suspect are reflections from inside the pipe back up through the driver cone. At the very least, line the front panel -you can always add some to the rear later, if necessary (top building tip: make sure that when you build your BIB, the base is screwed, not glued on, with a sealing strip to prevent leakage). I tried this last night on my 165 boxes and it was a huge step forward. Much cleaner than before -they remind me of the ESL988s I heard a while back, without the lack of grunt in the LF. You should be able to find some cork sheeting fairly easily, and for little cash (mine originally came out of an old semi-permenant building nearby, so I got it for free), so it's well worth experimenting.

Have fun
Scott

Ray Collins · 12th August 2006, 03:57 PM

Scott,
I think that you mean veneer the front and back faces of the internal baffle with thin cork? Does this eliminate the need for the pad behind the driver as well as the grill cloth around the back of the driver? Does it change the need for fill above the driver?

Ray

gychang · 12th August 2006, 05:34 PM

Quote:

Originally posted by Ray Collins
Scott,
I think that you mean veneer the front and back faces of the internal baffle with thin cork? Does this eliminate the need for the pad behind the driver as well as the grill cloth around the back of the driver? Does it change the need for fill above the driver?

Ray

Is there a picture of the thin cork and perhaps where I can get it on the web?

gychang

dmason · 12th August 2006, 06:49 PM

I got mine in rolls, at Wilson Art, I believe, so they should have some in O.C. Start there.

It was 1/8 X 30 as I recall. It also looks very good.

zek · 12th August 2006, 06:51 PM

How much thin cork must be - 3 mm, 5 mm or only 1 mm

Ray Collins · 12th August 2006, 09:57 PM

DMASON
Have you installed the cork on your BIB's? If so did you apply it to both faces of the baffle? What is your opinion on the results?

Ray

dmason · 12th August 2006, 11:36 PM

Ray

I have not. I have the basic Ray Collins Damping Technology applied, with the bit of stuffing and foam behind the driver, etc., and havent been in there for months. The cork comes from the open baffle diffraction issue, and there it works like a charm, particularly with the backwave, and looks the part too.

There doesnt seem to be much HF leakage with mine because of the foam I put onto the floor of the cabinet. I do like the idea of putting some on the front of the internal baffle though, but not enough to attempt it.

The more interesting thing is how much more real bass there is now with the BIB-168 hooked up to the Red Wine Signature 30 T amp of 30 watts, really grips the drivers and pushes LFR down quite abit. VERY fast, smooth, pretty flat to 30 I'd say, and pretty much perfect.

leonardc · 13th August 2006, 03:10 AM

do either of you have suprabaffles on your 168 sigma bib's ?

any pictures up anywhere?

I am about to order 4 drivers to build 2 pair of these, one for myself and one for a friend.

thanks

Leonard

Ray Collins · 13th August 2006, 04:10 AM

leonardc,
I didn't include the suprabaffles in my build.

I sent pictures of my 168's to Zilla for posting on the BIB site but they have not yet been posted. I had my attempts to post pictures here rejected due to excessive file size and I don't know how to comply. Perhaps Dan can post mine along with his?

Good luck with your build.....I assure you that you will not be disappointed.

Ray

leonardc · 13th August 2006, 07:12 AM

thanks for the reply Ray

re the pictures if you email them to me through the site I can put them up on the web and link to them and probably reduce the size and post them here as well

Leonard

12th August 2006, 06:49 PM	#1104
dmason diyAudio Member Join Date: May 2004 Location: Republik of Kalifonia	I got mine in rolls, at Wilson Art, I believe, so they should have some in O.C. Start there. It was 1/8 X 30 as I recall. It also looks very good. __________________ "Pilau Buggah, Big Islan Mo Betta!!"

12th August 2006, 11:36 PM	#1107
dmason diyAudio Member Join Date: May 2004 Location: Republik of Kalifonia	Ray I have not. I have the basic Ray Collins Damping Technology applied, with the bit of stuffing and foam behind the driver, etc., and havent been in there for months. The cork comes from the open baffle diffraction issue, and there it works like a charm, particularly with the backwave, and looks the part too. There doesnt seem to be much HF leakage with mine because of the foam I put onto the floor of the cabinet. I do like the idea of putting some on the front of the internal baffle though, but not enough to attempt it. The more interesting thing is how much more real bass there is now with the BIB-168 hooked up to the Red Wine Signature 30 T amp of 30 watts, really grips the drivers and pushes LFR down quite abit. VERY fast, smooth, pretty flat to 30 I'd say, and pretty much perfect. __________________ "Pilau Buggah, Big Islan Mo Betta!!"

13th August 2006, 03:10 AM	#1108
leonardc diyAudio Member Join Date: Nov 2005	dmason, ray do either of you have suprabaffles on your 168 sigma bib's ? any pictures up anywhere? I am about to order 4 drivers to build 2 pair of these, one for myself and one for a friend. thanks Leonard

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12th August 2006, 11:30 AM	#1101
Scottmoose diyAudio Member Join Date: Mar 2005 Location: UK	Something for you to try out guys. I shamelessly plundered it from Dan's Dark Star. Should be particularly useful for those running smaller drivers, and having problems with HF leakage through the horn (interesting that the larger drivers seem to have less of a problem with this). Get hold of some of that thin cork that's used for lining purposes, or that you see on the front of cork-boards etc., and line the front of the inner baffle with the stuff (this needs to be the thin cork -not the heavy-duty stuff used for flooring tiles. I tried those a year back, and they killed the dynamics stone cold). You can also line the inside of the rear baffle with it too to pretty good effect. What you should get is an instant, dramatic reduction in HF leakage, and also of what I suspect are reflections from inside the pipe back up through the driver cone. At the very least, line the front panel -you can always add some to the rear later, if necessary (top building tip: make sure that when you build your BIB, the base is screwed, not glued on, with a sealing strip to prevent leakage). I tried this last night on my 165 boxes and it was a huge step forward. Much cleaner than before -they remind me of the ESL988s I heard a while back, without the lack of grunt in the LF. You should be able to find some cork sheeting fairly easily, and for little cash (mine originally came out of an old semi-permenant building nearby, so I got it for free), so it's well worth experimenting. Have fun Scott

12th August 2006, 03:57 PM	#1102
Ray Collins diyAudio Member Join Date: Jan 2006 Location: Mobile, Al.	Scott, I think that you mean veneer the front and back faces of the internal baffle with thin cork? Does this eliminate the need for the pad behind the driver as well as the grill cloth around the back of the driver? Does it change the need for fill above the driver? Ray

12th August 2006, 06:51 PM	#1105
zek diyAudio Member Join Date: Aug 2003 Location: Belgrade, Serbia	How much thin cork must be - 3 mm, 5 mm or only 1 mm

12th August 2006, 09:57 PM	#1106
Ray Collins diyAudio Member Join Date: Jan 2006 Location: Mobile, Al.	DMASON Have you installed the cork on your BIB's? If so did you apply it to both faces of the baffle? What is your opinion on the results? Ray

13th August 2006, 04:10 AM	#1109
Ray Collins diyAudio Member Join Date: Jan 2006 Location: Mobile, Al.	leonardc, I didn't include the suprabaffles in my build. I sent pictures of my 168's to Zilla for posting on the BIB site but they have not yet been posted. I had my attempts to post pictures here rejected due to excessive file size and I don't know how to comply. Perhaps Dan can post mine along with his? Good luck with your build.....I assure you that you will not be disappointed. Ray

13th August 2006, 07:12 AM	#1110
leonardc diyAudio Member Join Date: Nov 2005	thanks for the reply Ray re the pictures if you email them to me through the site I can put them up on the web and link to them and probably reduce the size and post them here as well Leonard