Flush mounting tweeters on La Scala with new K-77-D?

[mr-b]

Hi

http://www.klipschcorner.com/special/LaScalaTimeline.aspx says:

"... April, 2006

The horn portion of the K-77-F tweeter was re-tooled to include a recessed flange
eliminating the need for the separate "Z" bracket and attachment rivets, the new
designation is the K-77-D. This also allowed the updating of pre-Z bracket La Scalas (prior
to May 2001) to flush tweeter status without motor board modification. "

So does this mean that I can use the K-77-D horn instead of having to route out my LS motorboard? I'm using BEC tweeters in case that makes any difference.

Also does anyone know if the K-77-D horns are available separately? I can't see any way of contacting Klipsch from their website - it just points you to the dealer locator (of which there are none in the UK of course ...).

[Guest " "]

"So does this mean that I can use the K-77-D horn instead of having to route out my LS motorboard"

 

I did not think to check for this when I had my k-77-d's removed 

[Coytee]

Hey Bruno,

I didn't take any pictures but when I was in Hope a long time ago, I happened to notice some of these tweeters laying around in the lab (at least I think they're the ones your referring to)

To me, they DID in fact look like a direct drop in replacement. The flange was on the back of the horn surface, instead of the front (don't know if that makes much sense)

By having the mounting flange on the backside, the effect was, it shoved the face of the driver (horn) flush with the face of the speaker. Looked very slick to me.

[Frzninvt]

You can get the "Z" brackets from Bob Crites as well but they still won't work without making the tweeter hole bigger. If your speakers came with the tweeter mounted behind the motorboard you will have to router or hog out the hole bigger to get the tweeter flush mounted.

Another way to go about it is to disassemble the tweeter flange from the magnet structure, and it may be possible to flush mount it that way without the "Z" brackets albiet more work and the hole might still have to be trimmed some.

Have fun!

[colterphoto1]

Hey Bruno,

I didn't take any pictures but when I was in Hope a long time ago, I happened to notice some of these tweeters laying around in the lab (at least I think they're the ones your referring to)

To me, they DID in fact look like a direct drop in replacement. The flange was on the back of the horn surface, instead of the front (don't know if that makes much sense)

By having the mounting flange on the backside, the effect was, it shoved the face of the driver (horn) flush with the face of the speaker. Looked very slick to me.

YES, they are a direct drop in replacment. The horn/flange is a cast piece now where the horn will stick through the existing hole so that the mouth is even with the FRONT of the motorboard, eliminating edge diffraction. So instead of using the Z brackets which require cabinet modification (requiring top hat grille removal in the case of a Khorn), you simply drill 4 new pilot holes for the new integral flange.

The casting is slightly small than the opening for easy retrofitting to upgrades. Therefore in some instances there will be a bit of gap around the horn mouth where the black cast flange can be seen. In a LS, the top horn section is not sealed, but in a CW or H you would not want any air leak around it. I believe that the flange will completely seal off any air leak, but there may be need for some gasketing material or sealant around that edge.

I'll check with Mark Kauffman today to see how much play is in the now horn with an older cabinet.

Michael

[mr-b]

Cool - sounds like it could save me having to mod the cabs (mine are '98s in case that makes any difference) although I do have the Z-brackets already.

Also any news on availability as a spare part?

I'll need to check with Bob too if that horn will fit the CT125s.

[Guest " "]

"I'll need to check with Bob too if that horn will fit the CT125s."

so you want to mount the CT125's behind the K-77-D?

sounds like you want to avoid cutting out the front boards to accept the z-brackets by instead using k-77-d's?  

thats probally a 40X more expensive way of doing this.

 

 

[mr-b]

Yep - it all depends on whether the cost of a pair of horns is relatively small compared to the cost of potentially getting the wood cutting wrong.

[Guest " "]

 

Someone with a hand router and a plunge bit can make the cut outs in 15 - 30 minutes.

You need a jig the width of the LaScala with the hole precut on it.  The jig gets clamped on using bar clamps on each end.   Using the plunge bit which rides on a bearing, tracing the hole on the jig makes a perfect cut.

You make the jig out a piece of scrap wood.  Make a frame the size of the hole you want, screw it on the jig using screws from behind, use the plung bit to transfer the hole to the jig on the side with out the screws. You need a pilot hole to let the router bit through.

 Plunge bits come in various sizes, 1/4 to 1/2 inch.

 

.

 

[mr-b]

Nice detail - tx!

I'll pass this on to my woodworker friend.

[colterphoto1]

Or you could just get the Klipsch factory replacement tweeter.

[mr-b]

Apparently the CT125 doesn't fit this new horn, so it looks like it's time for the sawdust to start flying!

[BEC]

With the CT-125, there is another way to flush mount without Z-brackets.  Since the driver screws on to the horn, you can just route the front to recess the horn flange and route out any area needed to clear the horn flare.  Then the horn can be installed from the front and the driver screwed on from the back. This method can be used even for speakers like the Cornwall or Heresy that need the the tweeter to be sealed. 

You can of course do this with a K-77, but you are likely to ruin a diaphragm when you take those apart.

Bob Crites

 

[Guest " "]

"" Since the driver screws on to the horn, you can just route the front to recess the horn flange and route out any area needed to clear the horn flare.  Then the horn can be installed from the front and the driver screwed on from the back.""

 

brilliant idea

 

 

 

 

[Islander]

Sounds logical, but can you actually hear a difference between tweeters that are mounted from the front or from the back?

Particularly when you're listening from an on-axis position, with the speakers facing directly at you?

[mr-b]

Tx Bob for that idea to minimise the routing - will def. give that a go.

[IndyKlipschFan]

In that golden old rule of PA Gear in my band, you wanted to look all the way down the throat of the tweeeter and if you could see all of the screen in the middle your "On Axis."

Of course you can still hear the tweeter just a little farther left or right "Off Axis" but it is was always better on than off.

So on to your house....

The idea behind the flush mount is to give you the real pathway of that horn as designed into the room and not surrounded at the end of it with plywood changing the pathway 3/4" back . This is a simple mod.. One that should give you great results..

[Islander]

Yes, the concept totally makes sense, but as in many things audio, logical doesn't always mean audible. Does anyone know if you can hear the difference between front-and rear-mounted tweeters and is one clearly better than the other?

[IndyKlipschFan]

So my answer is... If your dead on center to the horn.. probably not..

If you want your whole room to sound better.,.. Probably so.

Does this help? Do it, if you can.... and have the skills to do so..

[mas]

The biggest result is additional diffraction effects.

Each of the raised corners/edges act as a secondary transmission source, as if they are smaller speakers radiating signal off axis and unaligned in time.

The result is superposition of signals and the accompanying polar anomalies and comb filtring..

And we won't even mention the traditional rear mounting of the HF horn... ooops....