Updated LaScalas and KG 4

[Urizen]

Thanks to the good folks at B&K Sound (Bob and Michael Crites), I transformed my La Scalas and KG 4 this weekend. For the La Scalas, new Type A/4500 Hz crossovers and Crites CT-125 tweeters. For the KG 4, new titanium diaphragms. Thanks for the speedy service, Messrs. Crites!

Having refurbished the crossovers on my KG 4 some months ago, and
hearing an improvement, I still found the K-74 horns a bit ragged
sounding and muffled compared to other tweeters I've heard, although
they still sounded pretty good, and much better on tubes than sand.



Replacing the diaphragm on the K-74 tweeter horn is super easy. The
only tools needed are a Phillips head screwdriver, a pair of pliers,
and a multi-meter (to check for Ohms and continuity). Eight screws
attach each horn to the cabinets and three small nuts hold each driver
to the horns. The old phenolic diaphragms had ferro-fluid surrounding
the voice coils, so there was no cleaning of the gap needed.



Bob told me on the phone that the old phenolic measured -3 dB at 18kHz,
and the new titanium are -1dB at 23kHz. Comparing one to the other, the
titanium definitely extends higher, has more air and is dramatically
smoother. The old tweeter sounded "hollow" and slightly distorted,
comparing them side by side. Sibilance has been all but eliminated. The
difference is not subtle.

The La Scalas were a little more difficult due to the awkwardness of working
inside their tops. Four screws hold each AL crossover in place. As
you can see in the pic below, the AL crossover has a bunch of extra
components that are said to make it the poorest sounding crossover ever
used in this model. The new Type A-4500 Hz Crites crossover is so much
simpler, and I've always found the simpler, the better, when it comes
to an audio signal path. The Crites boards come with Velcro tabs to
attach them inside the cabinets.

It's much easier to remove the tweeter with the speaker's
baffle face-down on the floor. It's difficult to get leverage on the
screws which hold the tweeter to the baffle when it's upright. The only
damage is one slightly skinned knuckle. It's tight in there. The CT-125
is a drop-in replacement for the K-77 with no modification of the
cabinet needed.

I listened to them for about 30 minutes, comparing the difference
between the modded and stock cabs. What's immediately audible is a
"toning down" of the squawker, higher extension and smoothness of the
tweeter, and tightening up of the bass. The first speaker took 30 minutes, compared to 10 minutes on the second. With both finished, I just spent a few hours listening.
Amazing, killer dynamics. Startling at times. The speakers have
slam, which they didn't have before, and that's with just 5 WPC SEP
behind them.

I've finally, with the help of the Crites boys, heard La Scalas disappear. Thanks Bob & Michael!

[jbsl]

what year are your La Scalas?

[SilverSport]

beauty...I may have to try new diphragms...nice set up and welcome...

Bill

[Urizen]

1988.

Thanks for the welcome, Silversport.

[Normo]

Nice job, I see from your pictures that the La scalas are against the wall. Is this the best position for the speakers. I just got a pair, and am trying to figure out where they might sound best. Thanks for the post. Norm

[Marvel]

Nice job, I see from your pictures that the La scalas are against the wall. Is this the best position for the speakers. I just got a pair, and am trying to figure out where they might sound best. Thanks for the post. Norm

I think about every room is going to be different. I had mine against the long wall in my living room, but I couldn't get far enough back from them. I have since rotated 90 degrees and have them on each side of the opening leading into the room. Pulled in from the sides a bit. Now the imaging is way better, and in MY room, the bass is better too.

They would benefit from corner, corner/wall placement, but you just need to experiment. I have mine toed in a little bit, but not aimed directly at the center of the couch. The converging point would be behind me a bit. This gives me a slightly wider sweet spot.

Bruce

[Urizen]

Thanks, Normo.

I tried them further from the back wall, but they were overwhelming. They load this room best where I've shoehorned them in. It's a nearfield setup, for sure.

Ken