La Scala Upgrade

[tragusa3]

Of all the reading I've done on JubScalas, I've yet to see anyone talk cost? Assume you have a pair of LaScala, what does it take in cash to make the transformation?

[Islander]

The K510 horns with drivers cost about $1500 a pair, while the big K402 horns are around $2000, also with drivers. The Electro-Voice Dx38 processor is about $1500 new/$700 used in the US. It's the processor Roy used in developing the Jubilee and the JubScala, so it's the simplest way to go, and it is a high-quality pro sound unit.

Then you need a pair of amplifiers, since the speakers are bi-amped (in the true sense). Having each amplifier cover only a portion of the musical frequency range results in lower distortion. Folks often think you can use a lower-powered amp for the tweeters, but not in this case. The crossover point is around 475Hz, meaning that the bass amp covers the lowest 5 octaves of the audible range, while the treble amp covers the upper 5 octaves, so the power requirements for both are about the same.

Accordingly, it works out simplest for level matching, as well as best-sounding, if you have a pair of matching stereo power amps, or I guess you could go with four monoblocks.

The Dx38 processor has the usual 2 channels for inputs, but 4 channels for outputs, so that's where the signal gets split into high and low. It also does the custom EQ and delay. It allows you to delay the treble as needed to correct for the different lengths of the bass and treble horns, so the speakers are time-aligned. It's a subtle difference, but it's worth having.

You'll also need four speaker cables, and whatever type of interconnects you need to hook up to the Dx. It has XLR (balanced) inputs and outputs, no RCA.

I lucked out and found, all within a month or so, a pair of near-new K510s from a fellow forum member who really likes regularly upgrading his system, a used Dx38 from a guitar shop in California, and a used second power amp that matched the one I was already using, from a forum member who was switching to tubes from solid state. When I saw the parts were all available, I realized it was a golden opportunity and jumped on it.

After I added up everything, including shipping, taxes and import duties, the total came to near $4000. If you're buying new components, the prices will naturally be quite a bit higher.

The ideal alternative, or first choice if you can afford it, is a pair of Jubilee speakers, with either the small K510 tweeters or the more preferred and size-matched K402 tweeters. They come without crossovers, so you still need the Dx38. The speakers are special order and cost around $7000 a pair. They come in the usual stage black, but can be had with wood trim on the front for an extra charge.

To reduce the cost, some folks have gone with a pair of Crown XTi power amps, which have built-in digital sound processing (DSP), so the Dx38 is not needed. Results have been mixed. The high sensitivity of the speakers makes any extraneous noise produced by the electronics quite noticeable, and some users have found they're hearing more hiss than they like from the XTi amps. Some others are very happy with them.

I've been listening to the JubScalas for about thirty months now, and they always put a smile on my face when I listen to them. Everyone who hears them is highly impressed with the clarity and life-like dynamics, as well as the remarkably low distortion at all volume levels, from fairly soft to run-out-of-the room loud.

Compared with any readily available speakers that can match their sound quality, the JubScalas and Jubilees are real bargains, so you can feel like a smart shopper as well as a high-end listener when you're enjoying them.

[BEC]

A little OT here I guess, but does anyone have a raw FR curve of the Lascala Bass bin?

Bob Crites

[tragusa3]

Pat, thanks so much for the in depth response! I learned a lot on that one. Main thing I learned is that to avoid spending another 4k, I need to NOT HEAR a pair of JubScalas! LOL Truely, I feel my LaScalas are blissful and don't want to ruin that illusion. Maybe one day, but no time soon.

[Islander]

Truely, I feel my LaScalas are blissful and don't want to ruin that illusion. Maybe one day, but no time soon.

For now, some fresh caps and a pair of CT125s would make a noticeable improvement and not break the bank. Those were the first upgrades/updates I did to my La Scalas and I was happy with the results. I did the caps first, listened for a day or two and could hear the improvement, then put in the new tweeters and heard more improvement in the sound.

The CT125s are a little bit bulkier than K-77s, so on my speakers they touched the tops of the cabinets, requiring a 1/4" clearance groove to be chiselled in the underside of the tops. It's on the inside and the panels are 3/4" thick, so no problem.

I ordered the CT125s and Sonicaps from BEC and he was very good to deal with.

[drbtt]

I installed Crites CT125 tweeters and ALK universals. I have listened to
them for the past couple weeks and have to admit I'm a little
disappointed. The speakers sound a little flat and bland . They have lost their live presence, which first attracted me to these speakers. Perhaps the
frequency response is flatter but I can't say I enjoy the sound as much as when they were stock. I recently changed the tap setting on the autotransformer but still feel they are lacking. The only change which has been favourable was changing my push/pull tube amp to a triode tube amp. I do wonder if member's recomendations were more relevant to SS equipment? I was going to purchase Fastracs but now with the results I've seen to this point I doubt I will.

Does anyone have any thoughts?

[Coytee]

Does anyone have any thoughts?

Perhaps there is a technical reason for this result...I don't know about that stuff. Where are you located?

I'm here to tell you, (IMHO of course) the first/best thing you can do for your LaScalas is set the mid/tweet aside and convert them to a JubeScala. If you are anywhere near me (Knoxville, TN) I can set a stock LaScala outside (with Al's ESN networks) next to a biamped, signal aligned JubeScala with the larger K402 horn (I don't have the smaller K510).

If you can hear them side by side and tell me the 3-way LaScala sounds better, then I'll buy dinner. If you agree that the 2-way JubeScala sounds better, then I'll still buy dinner! [Y]

[Johnny's Jill]

I can set a stock LaScala outside (with Al's ESN networks) next to a biamped, signal aligned JubeScala with the larger K402 horn (I don't have the smaller K510).

If you can hear them side by side and tell me the 3-way LaScala sounds better, then I'll buy dinner. If you agree that the 2-way JubeScala sounds better, then

I am sure there is a big difference in that setup. However by simply installing a better crossover you have not addressed the problem. In most every post ALK reccomends installing the Trachorns first and foremost then going with a crossover upgrade. Even then the driver is now a consideration.

IMO a pair of upgraded horns and an ALK Universal is a huge improvement.

"drbtt" Quote: "Does anyone have any thoughts." The Universal crossover has adjustable taps for the midrange, try adjusting the tap to your liking.

Craig.

[Coytee]

IMO a pair of upgraded horns and an ALK Universal is a huge improvement.

Looks like we're actually in total agreement. My proposal to him would also give him a fully aligned signal and a situation where he'd be biamping. He could mix/match as he wanted with solid state on bottom and tubes on top or any other configuration.

The BIGGEST improvement in my opinion is dropping the 3-way configuration and going to a 2-way.

I still marvel at how impactful that single change was.

[bliss53]

Let me throw out an obvious possible solution which I discovered by making some stupid hook up mistakes. Are the any of the connections out phase (positive and negative switched, or a stray wire fray that it touching something it should not). This can cause the flat sound you described. It can also be interesting to switch just the mid drivers phase while leaving the rest of the drivers properly phased.

[Marvel]

My 2A3 amp was a huge improvement for my LS, but I listen at an approx. 85-90db level. I put CT125 tweeters in my LS and find them far nicer sounding than the K77s. I did pull the midrange down on my crossover, which helped the balance quite a bit.

I'm using a DHA2 crossover (lower order) which sounds fine at the lower volumes. The ES crossovers are better for those who crank the volume a bit more.

Bruce

[Chris A]

Let's take this one at a time...

1. I listen to everything from classical to rock at low to medium levels. I use a 50wpc tube amp.

The K77 is notorious for being a bit harsh, especially in its usual crossover region. The CT125 would like need a bit of a boost to compensate for the fact that you are listening at medium to low levels (due to Fletcher-Munson effects). I'd try pushing the gain on the high end a bit more when using the Crites tweeters.

2. The room is approximately 24'Lx11'Wx7'H and is carpeted.

The La Scala and the other Heritage midrange horns all have an issue related to the midrange horn--and that issue is that the vertical dimension of the horn's mouth is too short to control its polar response down to the lower crossover frequency (400 Hz). What this results in is ceiling/floor bounce, and your room has a low ceiling-10' is much better but still a little low. I'd try putting a diffuser on the ceiling half-way between your speakers and your listening position, or alternatively placing absorbing foam strips on the upper and lower lips of the midrange horn's mouth to suppress some of that ceiling/floor bounce.

3. I don't care about the <50 Hz absence but I do wish the highs were more distinct and airy, as Bob has said, the cymbals don't sound right.

This could be the tweeter harshness/distortion, midrange loss of polar control (the "ceiling bounce" that I referred to) resulting in a timbre shift in midrange, and/or your amplifier's characteristics (try using a SS amp and listening - this may make all the difference in the world for sparkle and airiness).

I would very much appreciate any guidance you might give me.

Sorry I didn't read this thread earlier, but I would have recommended bi-amping (like Coytee) but at a much lower price point using P.Audio drivers/horns and a DCX-2496 active crossover (~$270 new), using whatever amps that you have to drive the woofers and your tube amp on the hf horns/drivers. This would have resulted in much improved performance, IMHO. You could have upgraded gradually to better equipment as your pocketbook allowed.

Sorry about that...

Chris[:#]

[Chris A]

and a DCX-2496 active crossover

Well, maybe not the Behringer active crossover, but I'd recommend a used EV crossover--like a Dx38 or a DC-One.

Chris

P.S. -- There are actually quite a few digital crossovers on the market and a few that are not digital (Rane, etc.) that are now represented well on the used marketplace, too. The EV Dx38 is what Roy Delgado , et al., use at Klipsch to test their developmental speakers. Any of these will probably work quite well for La Scala upgrades, and I believe will fairly dramatically increase the fidelity of your listening experience.

Here is a thread on active crossovers/bi-amping that might answer some questions.

[winli]

If there's a bright center to the universe, ugg boots for saleyou're on the planet that it's farthest from it. Hesperia CA.

[Coytee]

If there was a bright center to the universe, it would be a black hole sucking in all the spammers of the world.

Alas... I just proved that the universe does not have a bright center. []

[JohnA]

The Type AL crossover is your biggest problem. Replace it, with anything.