LaScala With AL Network Upgrade Question

[tidmack]

Hi all,

Here's the scoop: I had a pair of LaScalas some years ago that seemed harsh to my ears. They had AL networks. At the same time, I had a pair of mid 70s LaScalas with AA networks that sounded absolutely beautiful to me. I put AA networks in the pair with AL's and it didn't really help. This was several years ago, but I thought I remembered reading that the K55-M in later LaScalas (with AL's) wasn't really "made" for AA networks, which is why I didn't get the same sound as my mid '70s pair. Am I remembering correctly?

Fast forward about three years. . .I now have another pair of LaScalas with AL networks. What can I do to help them sound smoother? Is a steep-slope network the way to go? Would a ALK jr. do, or is a full-out steep-slope what I need? Thanks in advance, I always appreciate the help.

Jeff

[Coytee]

I've had some of Al's ES slopes. I've come to feel that the steeper "skirts" (as he calls them) [*-)] are better. I had two of them in my Khorns (sold Khorns) and I have three of them in my LaScalas.

http://alkeng.com/

[Guest " "]

it sounds like your preference is AA networks, alinco k-55 mids and alinco k-77 tweets.

I'm assuming you have k-55-m's, and k-77-m's along with the AL xovers.

[tidmack]

Right on, speakerfritz. With preferring AA's and alnico drivers, will a steeper slope network help my current AL equipped speakers? Or, is my preference not able to be had with the K-55M and K77M? I thought a long time ago John Albright said it didn't matter which version of the 55 or 77 you had, it was all in the network. But when I put the AA network in place with my "M" drivers, I didn't think the speakers sounded anything like my alnico driven '70s models with AA networks.

Jeff

[BEC]

The main difference between the K-55V and K-55M (assuming both are working right) is that the K-55M is a bit smoother above about 4khz than the K-55V. Here we are talking about the K-55V with push-pin terminals. The relatively rare K-55V with solder terminals which was made in the early 80s only has the two piece phase plug like the K-55M and is also as smooth as the K-55M

In general, the main difference between the alnico K-77 and the ceramic K-77M is that the K-77M has more output at the higher frequencies. A lot of alnico K-77s quit by 12 khz and most K-77Ms go up to around 16 khz.

Bob Crites

[Marvel]

Jeff,

When I got my LS, they had the AL crossovers in them. They didn't sound very good. I built my own, from a design by John Albright (a forum member). If you do a search and find a reference to a DHA or DHA2 network, that is what I built. These are first order crossovers ( 6db slope ). They were not too expensive to build, and work well for MY listening environment. That is, mostly a lower volume, and I use SET amps (most of the time). Many have felt that the ALK extreme slope networks require a lot of volume to sound their best. Plus, they cost a lot, even if you build your own.

Bob can help out with the Klipsch equivalent( A or AA), new woofers, tweeters, etc.

Just don't forget it is the music that matters.

Bruce

[tidmack]

I appreciate the input so far. After reading the posts, I don't think I'm typing what I mean. I like the sound of the mid '70s LaScalas with AA networks and alnico drivers. From my experience, simply adding AA networks to a pair of LaScalas with AL networks doesn't equal the sound I got with AA networks and alnico drivers. Is that because it's not supposed to sound the same or because of something else with my system (older, unrebuilt networks, etc.)?

I have a pair of AA's laying around. I'd pay to have them rebuilt if I knew that when I installed them in my AL equipped speakers, they'd sound the way my AA equipped speakers sounded.

Bob Crites made me think of something when he posted earlier: do the AA networks raise the mid and tweeter levels to accomodate the lower frequency on the V's vs. the M's? At the same time, do AL networks attenuate the mid and tweeter to accomodate the higher frequency of the M's? Is it possible that by adding an AA network to a AL equipped speaker that you're "double boosting" the K55 and K77 M's? Does that make any sense? []

Jeff

[BEC]

In the Lascala networks, Type AA, AL, AL-2 and AL-3 we can say that for all, the tweeter and woofer are essentially run wide open doing all they are capable of doing, volume wise. The squawker is attenuated to match those drivers using the autotransformer. The AA, crossover attenuates the squawker by 6 db using the T2A autotransformer and the AL also attenuates the squawker by 6 db using the T-3A autotransformer. Then the AL-2 came along with a new autotransformer, the T4A. That autotransformer attenuates the squawker 4 db. The AL-3 also used that same attenuation.

Bob Crites

[tidmack]

Thanks for the clarification, Bob. It seems like the AA and AL networks should sound fairly similar. LaScalas with AL networks seem much more harsh to me. Is it all in my head that there seems to be such a distinct difference in sound to my ears?

Jeff

[BEC]

Jeff,

Perhaps when both were new, they might have sounded somewhat similar. Chances of finding an original AL or AA that is on factory spec still would be slim to none. So, who knows how two old crossovers might compare.

Bob

[tidmack]

Thanks Bob, that's where I was going. Have a great weekend.

Jeff