Heresy ll's

[BULLWINKLE]

Anyone know how to take the backs off of Heresy ll's? There are not any screws! :no: :scratch2: :scratch2: Just got an email from BEC over at Klipsch Forum. Backs are glued on. Have to go through the front, by removing one of the speakers.

[jaymanaa]

Just curious Bullwinle, but are you planning on modifying the backs (as in stiffening)? :scratch2: Jay

[BULLWINKLE]

No. One of them started to rattle when the low hz played. Quite frankly, I drilled and screwed 6 screws and solved the problem. But you raise an interesting question. I have read where some have replaced the backs with 3/4 ply or mdf. Have you any experience with this?

[jaymanaa]

No I haven't, but would like to get the skinny. Some speaker guys I've talked to say it really helps them out in the bass dept. Some go so far as to say the flimsy backs actually act as a passive radiator :sigh: The problem as I see it is, as you mentioned the backs are glued. I guess you would have to pull the woofer and horns to go in through the front :scratch2: Thats not a big deal, but I don't know the best way to brace it up. I don't really like the idea of sawing the backs out :no: Maybe one of the Klipsch guys here could give us some detailed instructions. My Heresy II's are just a little wimpy way down on the bottom. I've also wondered about X-over mods for these. Jay

[BULLWINKLE]

I just had an idea. You could marry a 3/4 mdf or ply to the existing back with liquid cement and properly placed screws. No need to switch the old back out. :yes:

[jaymanaa]

I don't know why that wouldn't work. I may fiddle with mine today if I get some time.

[BULLWINKLE]

Let me know how it goes.

[Groomlakearea51]

For my safe (WAF approved) hobby, I rebuild and refinish H-1's and H-2's (they are all over the house). Over the last few years, I've learned alot about how the H-1's and 2's were made (and learned real fast how to mess them up...)
The H-2 backs are 3/4" birch plywood, with a routed inset on the panels to match the back's dimensions. There were some exceptions apparently in the late 80's that I found (e.g. TH-SR's).
The H-2 backs were simply glued in place, and unfortunately, the only way to "unglue" them, as often as not, is to knock the cabinet apart....
One thing I have noticed on the H-2's is that by 2006, all of the glue often has dried out and the cabinet is no longer "airtight". On several H-2's I found that due to temperatures, humidity, etc. not only was the glue dry, the panels were ever so slightly warped.
Unlike the H-1 which uses staples on the internal braces (completely different arrangement than the H-2), the H-2's depend, unfortunately, entirely on the glue remaining intact.
So that being said,... If the glue is dried out to the point that things are getting "loose" or we get "rattles", then as likely as not, the glue on the braces, panels, and the driver board could be dry as well.
Taking them apart is not that difficult, just be careful and check the glue first. If the "beads" still have the consistency of a hard rubber, then you may not be able to do it without wrecking the cabinets. But..... If it's dry, "flaky" and peels off with your fingernail, then it will work.
Use a rubber mallet, lightly tapping the back panel all around by poking the head through the bass hole. Then carefully do the same working the front off. This could take a while! Then the sides and tops, and finally the brace pieces.
At this point, using a good quality straight edge, make sure the panels are not warped. If it is, furniture grade 3/4" birch is available, if sometimes pricy. For that you then ask the question is it worth it.... You can cut it side and top panels yourself (you need a good table saw that can accurately do miter/angle cuts and a very good minimum 100+ tooth blade), or get your local furniture/ cabinet maker to do it (great resource for wood and veneer! They commonly use 3/4" birch for kitchens, etc)
Cleaning up the old glue is problematic, but if it's dry, it's just very time consuming. Re-gluing a cabinet requires a very good carpenter's glue (I use Loctite Woodworx) and 12 quality wood clamps and a "form" that matches the external dimensions of the Heresy (2x4 works here...). Just re-gluing any one panel (or the back) requires at least 8 clamps (number of clamps is an opinion, but better safe than sorry).
Let dry for at least 48 - 72 hours, then lay the "sealing" bead on the inside joint.
Before reinstalling the drivers and crossover, now's a good time to go the BEC II route for the crossover. Bob also can take the crossover components off the plastic and mount them on a piece of wood, ala H-1, and it's a much more rugged arrangement.
Carefully clean the driver gasket areas, and replace them (very important!). Hope that helps.
I've got several old "disaster" quality H-1's (the "fall semester" project...) underway, new birch sides & top panels (and braces) cut, etc., but my stapler died (gotta have the stapler for the H-1's!!), otherwise I could send someone pictures. Next H-2 project is for "spring semester".
Good luck!!

[BULLWINKLE]

Welcome Groomlakearea51! Thanks for the info. Do you ever veneer the Heresies? I put some mahogany veneer on some old H1's and they look great. But, the veneer near the bottom edges tends to catch if they slide on the carpet. I must not have put on enough glue.

[Groomlakearea51]

I've done one veneer on H-1's (the first one was a disaster... second was much better). They are next on my H-1 list to re-do....

The trick on the edges is to use a very precise trim knife or veneer saw (Three Cherries brand) and the straight edge.

Another problem I first encountered was not using enough glue, as you might have found out.

Also, "veneered" speakers generally tend to stand up to moving them around if you put a riser on the bottom. Factory standard for H-1's was 1" with 3/4" birch as the material. I've used 3/4" x 3/4" pieces from scrap birch before also. On the bottoms, you might want to also use the stick on 2" round teflon "gliders" from home depot/ wall mart. First thing I did with my Klipschorns and LaScala's when I returned to the US was remove the metal factory glide buttons. They are about as useful as "buttons" on a football....., and will absolutely catch on carpet, tear up the really nice wood floor and get me in big trouble with the boss......

There are several ways to do veneer on Heresy's:

(1) cold glue veneer and use either a press board and all of your spare dive weights..., or a vacuum press (the cabinets must be dissassembled for this one...);

(2) "iron on" activated glue (actually a very good and modern method!); and;

(3) The "sticky back" method for the totally inept, but "gotta do it" folks....

On veneers, you've got "exotics" for up to $500 for enough to barely do a pair of Heresy's; all the way down to about $60 for a 4' x 8' sheet of standard walnut or oak.

Veneer is problematic for me in Florida.... From about May until October (the monsoon season...) the heat and humidity poses problems; .e.g, what should have only taken 24 hours to dry (wood filler/putty) on a pair of Klipschorns (chipped and peeling front raw birch (BR) bass bins...), took almost 72 hours! This poses problems because when veneer dries, it shrinks slightly. (Yes, I'm also working on a pair of K'horns, getting them ready to veneer with Brazilian Rosewood, but that's another story altogether...)

If you really want to work with with veneer, there is a site that I have found to be absolutely the best: joewoodworker.com.

I re-read just about everything on the site about once a month and learn something new every time.

Hope that helps!

[jaymanaa]

Welcome and thanks for the great info. Do you have any opinions on adding additional bracing to the back panels? Mine are HOO-SRB made 10/89. The glue joints "seem" to be OK. Just curious, Jay

[Groomlakearea51]

As long as there is no outer seam separation along the panels, then the glue is probably holding. As you noticed, the bracing is (or should be) just the four "front to rear" 3/4 x 3/4 birch pywood "sticks" (yours could also be plain wood, seen those a couple times) between the driver board and the rear panel.

What gives the cabinet it's side to side "not fall down" strength is the driver board and rear cover board. The way the cabinet is made (45 degree jointed) there is no method really to strengthen it like in the case of the H-1's.

You could, theoretically cut out a center section "driver board" with big holes in the middle, but.... that would probably alter the bass resonnance, although probably not where the average person could hear it. That would, from the side to side strength viewpoint, make it somewhat indestructible....

That being said..... the braces are, when you look at the geometry, not really for "strength". What they really do is keep the panels from separating. Knowing that, and knowing that an integral part of the strength comes from the panels staying "glued tight", you could get a staple gun. Use 1" crowned staples, and set the gun to recess them about 1/8", and shoot about four staples vertical and four staples horizontal.

If I were going to do that (and I may very well do so on the next H-2 project), I would make sure that I have the cabinet well clamped. If the glue is not as good as you think it is, the shock of the stapling could cause some separation.

The driver board is (or should be) real tight fit, so should the rear access panel. It becomes a cost vs benefit deal. How much time do you want to spend?, etc., etc. Hope that helps.