La Scala squawker attenuation

[Unity_coupled]

My La Scalas begin to fatigue me after several minutes of listening to music and I think it's due to the midrange "squawker" is a little too loud (esp. since I use these in a near field space). Is there a quick way (a resistor in series with the driver perhaps?) to attenuate the squawker about 4 dB until I get updated networks?

[Guest " "]

It depends on which xover networks your LaScala has.

[4tay]

Edited

[Guest David H]

A 78 Lascala should have an AA crossover and K-55.

The mid is currently on tap 4, I believe you can attenuate 3 db by installing a 16 ohm resistor across the output to the mid driver, and dropping to tap #3.

Have you replaced the caps in your AA's yet? Sometimes older caps sound awful, and a refresh work wonders. Another worthy step is to replace the midhorns with wood Tractrix or dampen the K-400 lens.

I also like removing the bug screens and retainers from the K-55's... Personal preference.

Dave

[Marvel]

The mid is currently on tap 4, I believe you can attenuate 3 db by installing a 16 ohm resistor across the output to the mid driver, and dropping to tap #3.

Dave's answer above would be the simplest. Plus it's cheap. I dropped the mid in mine, even after I built new crossovers, and they sound way more balanced. I've attached a schematic of the AA.

Too bad you can't be at least ten or twelve feet back... That would help, too.

Bruce

[Guest David H]

Here is the modified schematic.

[Blvdre]

Drop the tap down from 4 to 3, and change the mid cap from 13uF to 6.2 or 6.8 to preserve the mid crossover point.

[Unity_coupled]

Thanks. I'm about to place an order for some sonicaps. Should I get Gen 1 or 2?

[Guest David H]

You will need Gen 1 Sonicaps. Gen2 are film and foil bypass caps I believe.

Dave

[Unity_coupled]

I don't see a 16 ohm resistor by mills but theres a 15 ohm one. Thatll work shouldnt it?

Just ordered sonicaps

[djk]

15R~20R should be OK.

[Unity_coupled]

Which terminal is tap 3 on the transformer?

[Guest David H]

Autoformer

[JohnA]

My La Scalas begin to fatigue me after several minutes of listening to music and I think it's due to the midrange "squawker" is a little too loud (esp. since I use these in a near field space). Is there a quick way (a resistor in series with the driver perhaps?) to attenuate the squawker about 4 dB until I get updated networks?

Before you get too carried away with crossover mods, remove the squawker horn and wrap it in warmed up original Dynamat or rope caulk from the hardware store to kill its edginess that comes from a ringing it has. Then, stuff the upper enclosure tightly with polyester fiberfil to reduce its ringing.

You'll want to do those things eventually and they may be enough.

If yours are 1978 models, the squawker driver, K-55-V, has the early, one-piece phase plug giving less output from 4k to 6k and frequently a 9k response "bounce". Search for P-trap to find a filter designed to cut out the 9k bounce. This may also be causing your faigue. If you can find solder terminal K-55-Vs, they do not have the bounce and are flatter above 4K.

http://cgi.ebay.com/Vintage-KLIPSCH-K-55-V-Squawker-K-700-Metal-Horn-/360265802265?cmd=ViewItem&pt=Vintage_Electronics_R2&hash=item53e183e219

[Unity_coupled]

Interesting suggestions. I'll try those.

I still have yet to experience these speakers with good capacitors too...

A bit of a side question- would padding the doghouse improve sound quality?

[Islander]

A bit of a side question- would padding the doghouse improve sound quality?

Not too likely. If you padded the inside, you'd change the volume behind the woofer and mess up the sound. If you padded the outside, you'd change the shape of the horn and mess up the sound.

When I first got my La Scalas, I found the mid-range to be kind of "shouty", so I added a couple of thicknesses of grille cloth to the front of the K400 horn (not the tweeter) and it made the sound more pleasant, although some purists on the forum scoffed at the idea.

I also applied Dynamat Xtreme to the squawker horns, but I'm not sure if that alone made much difference.

[Unity_coupled]

My capacitors should be delivered today. I had ordered both stock-value replacement caps plus the caps and resistors needed for the attenuation circuit.

I'll try just refreshing the network first and see how it sounds. If it's still too forward I'll add the other parts.

How do you remove the crossover from the box?

[Marvel]

There should be a couple of screws down into the cabinet.

Bruce

[billybobg]

Look for a couple of screw heads that don't appear to be holding anything else down.

[Olorin]

The Type ALs in my 83s had four screws holding each one down, and two each four were quite well hidden.