LaScala K-77 square magnet tweeters dead on arrival

[codewritinfool]

On 4/12/2017 at 2:03 PM, Innocent_George said:

0 Ohms

On a Fluke 7-300, "OL" is not zero ohms.  It means "overload" which means >400 ohms.  Touching the leads together would show you what zero ohms looks like.  The tweeters are then  likely open circuit, which is the opposite of zero ohms.

 

 

[wvu80]

5 hours ago, BEC said:

 

And now the mold that made the plastic cups has been lost!!

Wow, that's incredible!  With thousands and thousands of those things out there, did someone just show up to work one day and it was just gone?   

 

There has got to be a story there.

+++

 

Bob, I was interested in your signature quote, "a dime's worth of difference."  You put it in quotes and actually I found it very profound and indeed, a very good quote!  I've seen that phrase from Mr. HDBR bulilder but he never defined it as you did.  Does that definition come from you, or from someone in the Klipsch world?  Just curious. 

[babadono]

3 hours ago, codewritinfool said:

On a Flue 7-300, "OL" is not zero ohms.  It means "overload" which means >400 ohms.  Touching the leads together would show you what zero ohms looks like.  The tweeters are then  likely open circuit, which is the opposite of zero ohms.

 

 

What he said

[babadono]

1 hour ago, wvu80 said:

, "a dime's worth of difference." 

I always thought that was from the man himself, PWK. As in it won't "a dime's worth of difference".

[DizRotus]

PWK used that exact phrase, "not a dime's worth of difference," when I asked him why the horns were attached to the rear of the motorboards.  The time was the mid-70s.  I understood him to be saying, not that surface mounting would not be an improvement, but that the improvement was not justified by the expense.

 

Irrespective of what some here believe, as all excellent engineers do, PWK designed to commercially reasonable goals, not to perfection.  

[wvu80]

18 minutes ago, DizRotus said:

PWK used that exact phrase, "not a dime's worth of difference," when I asked him why the horns were attached to the rear of the motorboards.  The time was the mid-70s.  I understood him to be saying, not that surface mounting would not be an improvement, but that the improvement was not justified by the expense.

 

Irrespective of what some here believe, as al excellent engineers do, PWK designed to commercially reasonable goals, not to perfection.  

Thanks, that all makes sense.

 

I have some made some changes to my speakers which are improvements in a technical sense, like additional cabinet bracing and it falls perfectly into that category of "doesn't make a dime worth of difference."  It was a time consuming task and I guarantee I could not tell a braced cab from one that was unbraced.

 

The Legend continues.

[DizRotus]

Exactly Dave!  There is room for DIY modifications to make improvements that are not commercially viable.  That's not to say that all DIY changes are genuine "improvements" or "upgrades."

[HDBRbuilder]

RE: "Doesn't make a dimes worth of difference" from PWK...yes, he had to design with production costs in mind.  I firmly believe that his MAIN genius was in being able to do things with less...such as in the drivers used in his speakers.  Way too much has been said about "this driver is not nearly as good as that driver, woofer, etc" without taking into consideration production costs which have to be kept low in order to make things affordable to consumers and keep the company in business.

 

For the original so-called "Heritage" line he used only ONE 15" woofer or one 12" woofer, in all the PRODUCTION models (this is not including the earliest of Heresys)...the SAME mid-range driver in EVERYTHING and the same tweeter in EVERYTHING.  THis allowed him to save in material costs because of the VOLUME these items were purchased in...especially so for SHIPPING COSTS to the factory...swinging a deal for "the more you buy the less the per unit cost per item type."

 

PLUS he designed to USE these items in the designs he came up with.  Pretty intelligent thinking, if you ask me!

 

As for mounting to the INSIDE of the motorboard using wood screws, keep in mind that his largest sales were the Heresy models, and OF THOSE HERESYS, the largest in sales BY FAR were the decorator version....WITHOUT a grille cloth on it. Grille cloth was an additional cost.  So for aesthetics purposes and for ease of assembly, and lower labor cost during final assembly (meaning FASTER!), they were mounted to the inside of the cabinet on pre-drilled pilot holes.

 

The same goes for everything else he was making.  In final assembly you took the heresy cabinet...laid it face down with its top edge sticking over the edge of the carpeted rolling table top in final assembly.  Take your non-screw-gun hand and reach under that edge and FEEL for alignment of the horn lens to the hole in the front of the motorboard, and as you do the final tightening of the horn lens from the backside your non-screw gun hand fingers are ensuring centering left and right and up and down of the horn lens face in alignment with the hole.  The same went for the mid horn lens and the woofer.

 

Make sense?

[DizRotus]

Yes.  Thanks for that perspective.

[HDBRbuilder]

4 hours ago, wvu80 said:

Thanks, that all makes sense.

 

I have some made some changes to my speakers which are improvements in a technical sense, like additional cabinet bracing and it falls perfectly into that category of "doesn't make a dime worth of difference."  It was a time consuming task and I guarantee I could not tell a braced cab from one that was unbraced.

 

The Legend continues.

interior bracing of the cabinet COULD make a difference, but quite often does NOT do so.  It depends on the cabinet build of the particular model of speaker, AND EVEN MORESO on the MATERIALS USED in that cabinet build of a particular model.  For example...a Cornwall decorator cabinet MADE using  FIR  plywood.  First of all, that Cornwall was made a very long time ago if it is made out of FIR plywood, and the nature of fir wood is to absorb air moisture more rapidly to meet ambient air moisture levels...so since the cabinet is PORTED, then air moisture has the ability to get inside the cabinet and change the sonic signature as the UNFINISHED inside panels absorb the moisture.

 

ADDITIONALLY, the fir plywood used in that era, is also lighter in weight and less dense than the Birch plywood used later...and also has FEWER PLYS for the same thickness as the birch plywood has....so between the denser WOOD of the Birch combined with MORE layers of bonding (glue) AND more directional criss-crossing of the wood fiber in alternating layers of the plys....it isn't exactly rocket science to understand a fir decorator Cormwall cabinet would MOST LIKELY be a better candidate for interior reinforcement with NOTICIEABLE  results, than a Decorator Cornwall made of Birch plywood.

 

Add to that that the decorator cabinet BUILD, in and of itself, is actually already a stiffer cabinet (WHERE the panels MEET each other in the build) than the mitered ones of the same era due to the overlapping butt joinery used...they also survive corner drop tests better...believe it or not!  Mitered ones tend to start coming apart at the miter joints on the affected corner way more often than the decorator ones do on the affected corner in drop testing (even though the miters are reinforced from the inside with glue blocks at the joints!).  This is because the glue blocks inside the mitered cabinets, reinforcing the miter joints, do NOT extend completely from the cabinet front edge to the rear cabinet edge, so in corner drop tests the only thing really holding the corner together at the front and rear of the mitered cabinet is the glue bond in the miter joints.

 

It is what it is! 

[BEC]

15 hours ago, wvu80 said:

Wow, that's incredible!  With thousands and thousands of those things out there, did someone just show up to work one day and it was just gone?   

 

There has got to be a story there.

+++

 

Bob, I was interested in your signature quote, "a dime's worth of difference."  You put it in quotes and actually I found it very profound and indeed, a very good quote!  I've seen that phrase from Mr. HDBR bulilder but he never defined it as you did.  Does that definition come from you, or from someone in the Klipsch world?  Just curious. 

Just goes to prove once again that you should never leave a mold anywhere except a place under your personal control.  To the person who had the mold made, it is a 10 to 20 thousand dollar investment.  To a place that uses the mold to make your parts, it is just a heavy chunk of metal in the way until the next time someone puts in an order to use it to make some parts again.  The first mold I ever had made, I left at the foundry that made my parts.  The second time I wanted some parts made from that mold, found out the foundry went bankrupt and my mold was just in a pile of "company assets" that got sold for scrap to pay off creditors.  The next mold I had made stays in a wooden box with handles in my warehouse.  We call it the Ark of the Covenant.  Just yesterday, we got it out and hauled it to Grace Manufacturing to have 1000 horns made.  When I pick up those horns, next week, I will have them put the mold back in my "Ark" and it will go immediately back into my warehouse until needed again. I will not leave it with the place that is going to use it (like most people do).