PDA

View Full Version : Cutting Baffle Board



majick47
10-30-2004, 10:13 AM
Re my L200b speakers I'm trying to "plan" the installation of 2405 tweeters. I did a search and saw a number of excellent speaker cabinets built from scratch but couldn't find any references to the installation of tweeters to pre existing cabinets. All the instructions refered to cutting the holes in the baffle board before it was installed in the speaker box. I'm looking for some advice as to the best tools to use. By the looks of the L200b baffle board there isn't a lot of room for a router between the LE85 and the cabinet frame. I'd be willing to farm this job out to a cabinet maker if necessary since my wood working skills and tools are limited, don't want to screw up the cabinets.

Zilch
10-30-2004, 10:27 AM
What's the requisite hole diameter? Is there a stardard hole saw that size? If not, there ARE adjustable ones, but they require some skill to use, thus are more a "cabinet guy" deal....

Alex Lancaster
10-30-2004, 10:32 AM
Buy a 3 1/8" holesaw, put masking tape where it is going to cut, to reduce splintering, use a 1/2" drill very carefully, and You will do fine, if it is going to be for the occasion buy some Taiwan or China el-cheapo┤s, I have a Milwaukee set that has been in use for 25 years, but they are more expensive.

Robh3606
10-30-2004, 10:56 AM
I bought a 3 1/8 hole bit for $20 and just used that. Worked like a champ. Just watch the torque when you cut. When it grabs WOW!

Rob:)

majick47
10-30-2004, 10:59 AM
Alex and Zilch thanks for the replies. I was thinking of useing the standard hole saw as an alternative to a router and the suggestion re the masking tape is going to be very helpful in making the cuts as clean as possible. I'm more then willing to pay extra for quality saw blades, Milwaukee etc. My brother is real handy at wood working and volunteered to help me. He remodeled his kitchen and the cabinets/woodwork rivaled the best any pro could do. From the pictures of 2405/077 tweeters installed in cabinets they appear to have a very small gap between the tweeter and the baffle board, would I be correct in assuming that the gasket at the base of the tweeter makes a tight seal against the baffle board?

majick47
10-30-2004, 11:07 AM
Robh3606 a picture is worth a thousand words. We will do a few practice cuts on some scrap mdf before we tackle the cabinets to get a good feel of the drill/blade.

johnaec
10-30-2004, 07:09 PM
Originally posted by majick47
...would I be correct in assuming that the gasket at the base of the tweeter makes a tight seal against the baffle board?Do you have the "o-ring" gaskets that came with some of the 2405 sets? (I've seen them new in the box both with and without the gasket...) It's a rubber ring about 3/32" diameter, and I'd suggest slightly beveling the back side of the hole you cut to ensure there's a little space for the ring to fill in to, or you could conceivably end up with the rubber ring preventing the driver from sitting flat. If you don't have these gaskets, you could probably find a suitable o-ring from an auto parts or hardware store.

John

Robh3606
10-30-2004, 07:18 PM
You can order the gaskets from JBL Pro part number is 51795

http://www.jblproservice.com/pdf/Discrete%20Sales%20Models/2405H.pdf

Rob:)

Alex Lancaster
10-30-2004, 07:45 PM
They are not orings, they are hollow, kind of spaggheti, and they will deform handily the first time, and of course You can use Silicone RTV, if You are not planning on changing them soon, like in ten years.

Zilch
10-30-2004, 07:56 PM
In the absolutely correct JBL Technical parlance, they are referred to as "noodles." :p

johnaec
10-30-2004, 09:06 PM
Originally posted by Alex Lancaster
They are not orings, they are hollow, kind of spaggheti, and they will deform handily the first time...You're right - I just did a squeeze test and they ARE hollow inside. 'Learn something new everyday... Forget my "o-ring" replacement suggestion.

John

andywin
10-31-2004, 04:38 AM
I've been thinking of adding 075 or 077 tweeters to my L200's. What additional crossovers do I need and how is the wiring configured?.

Earl K
10-31-2004, 06:39 AM
Hi Andy

There are already partial and entire threads devoted to that very topic .

To find those threads, you can use the "SEARCH" (http://audioheritage.csdco.com/vbulletin/search.php?s=) function ( 2nd button at the top ).

Try typing in L200. I just did and it returned a thread that is a more appropriate area for your question. It's called L200B = L300 (http://audioheritage.csdco.com/vbulletin/showthread.php?s=&threadid=3224&highlight=L200+conversion)
Read through the available info in that and other "searched" threads / if you still have questions ask them in the thread that you find most appropriate. That thread will now become "current" and "pop up" to the top level for peoples scruntiny and hopefully a response.


Now;
If your Web Browser doesn't load the "button bar" that includes the "search" function, then you should contact the sites' administrators or post your concerns (about this interactive deficiency) in the "FORUM ISSUES" (http://audioheritage.csdco.com/vbulletin/forumdisplay.php?s=&forumid=7) .

regards <. Earl K

andywin
10-31-2004, 01:59 PM
Earl

Thanks for the sound advice

Andy

B&KMan
10-31-2004, 05:31 PM
Originally posted by Robh3606
I bought a 3 1/8 hole bit for $20 and just used that. Worked like a champ. Just watch the torque when you cut. When it grabs WOW!
Rob:)

My experience in MDF and this type of swa id the thooth is jammed very fast by the fiber MDF and glue.,

After each 1/8 inch put out Saw and pass metal brush in thooth and put air pressure into groove. If you have a column press drill is the best..

In this the saw in not run with big vibration and build clean deep hole...

Best regards.

majick47
11-01-2004, 09:40 AM
B&KMan thanks for the tip re cleaning out the saw teeth and groove in the baffleboard. I don't have a column drill and agree that would be the best tool for the job. As it stands now I'm waiting for the two new JBL OEM diaphrams for the LE85 drivers. One of the 136a woofer cones was damaged in the past and a new cone was installed, hopefully it is OEM JBL. From the L200b tech sheet Mr. Widget posted they should both match and I will have the second original cone replaced or both if the first is not OEM JBL. Both the crossovers are going to have a checkup by the JBL Pro shop before they add 3106 crossovers for the 2405 tweeters. After reading numerous posts from senior board members I feel that this is the time to bring my L200b speakers up to spec with new OEM JBL parts while they are still available. The cost won't be cheap but the L200b speakers should sound as good as when they were new from the factory and even better with the added 2405 tweeter upgrade.

B&KMan
11-01-2004, 11:55 AM
Originally posted by majick47
re cleaning out the saw teeth and groove in the baffleboard

Welcome, :cool:

If you cut 1 inch MDF the in-and-out-and-clean motion is over 15 X
so Patience and PersÚverance
(french terme )

more dead more fast jam tooth. If you tried a couple of shot in this procedure you have ability to buid realy good hole...
P.S. put pinwood on bottom and clamp , because the end od cutting is bust the hole...

good luck
:cheers:

Finish by drum sand installed into a press drill is the best but any same procedure is OK Dremel in same tool but realy non comercial tool... :D
;)

majick47
11-01-2004, 10:34 PM
B&KMAN thanks for the additional advice. Talked with my brother and he agrees that securing a piece of wood to the baffleboard where the cut is to be made will help in controling "splintering". We will try to put pieces of wood on both sides of the MDF.