La Scala Woes

[Desert Noises]

I have a 1988 pair of La Scalas with two problems I'm trying to solve:boxy/stuffy bass and harsh midrange. Here's how they are configured:

 

Type A/4500 crossovers from Crites

CT120 Tweeters from Crites

Stock K-401 mid horn with the A-55-G drivers

Stock K-33-E woofers (also tried the Eminence Kappa 15C)

Room size is 16'x20' with high vaulted ceiling, floor carpeted, with La Scalas in corners along the 16' wall, toed in approx 20 deg.

SVS SB2000 sub crossed at 80 Hz near the right speaker

Amplification is from a fully restored/recapped Pioneer SX-1250

DAC for digital music is a Schiit Modi Uber

Turntable is Kenwood KD-750 with Audio-Technica VM540ML cartridge

 

My woes with the La Scalas are as follows: 1) The upper bass sounds boxy, nasal-y and stuffy. 2) The midrange at higher volume (~90 dB) is just plain harsh and unpleasant. I reduce the 100 Hz tone control a bit and that alleviates the boxy/stuffiness to a degree. Meanwhile, I connect my home-built Cornwalls (Clonewalls) with B2 crossovers, K-55 mid, K-77 tweet, and Kappa 15C, and they sound amazing with no fatigue, even at higher volumes. Plus I get bass! Classical music commands a lifelike presence. I used to love the La Scalas before my recently built Cornwalls. Now that I can compare between the two, I vastly prefer the sound of the Cornwall. Am I missing something, or has anyone else had the same experience? I've been considering dropping the mid down 3 dB and changing the capacitor to 6.8 uF. Is there anything else I can try short of doing anything drastic like cutting wood?

 

 

[avguytx]

It's an acquired taste to the LS and Belles and, apparently, the right signal chain combo.  Kind-of picky.  I've owned La Scalas and Klipschorns over the years and built a beautiful set of Belle inspired clones a few years back.  I had a pair of the Epic CF-3's prior but sold them once I was done with the Belle build, regrettably. I just never warmed up to their sound and worked out a deal where I now have CF-3 version 1's and I'm completely satisfied.  The Belle clones just didn't sound good upstairs in my music room and really had their limitations at our other house.  I'd also had a pair of '78 Cornwalls and KLF-30's at the same time as the first pair of CF-3's and the first two were sold off. 

 

It's all personal preference, what works in any given room, and the signal chain as a whole that let's you decide what sounds best to you.  At least in my humble opinion.  

[OO1]

2 hours ago, Desert Noises said:

I have a 1988 pair of La Scalas with two problems I'm trying to solve:boxy/stuffy bass and harsh midrange. Here's how they are configured:

 

Type A/4500 crossovers from Crites

CT120 Tweeters from Crites

Stock K-401 mid horn with the A-55-G drivers

Stock K-33-E woofers

. Is there anything else I can try short of doing anything drastic like cutting wood?

 

 

swap out the k55v, the K77  into the Lascala , and give your impressions--

[Marvel]

Bringing the mids down really helped both pair that I have owned. The 1" throat (actually more like 7/8") can be overdriven pretty easily, and sound harsh. However. I had my second pair out at a big party and they rocked.

 

~90 db is getting loud for me, but I've had there before and they were fine.

 

Do you have another amp you can try? I hate to use the word synergy, but some equipment just doesn't work together.

[Desert Noises]

18 minutes ago, 000 said:

swap out the k55v, the K77 and the B2 XO  into the Lascala , and give your impressions--

I didn’t think about swapping the B2 crossover to the La Scalas. Would the crossover points be wrong in this application? I have switched out all the drivers between the two. The A-55-G vs K-55-M in the LS sound very similar. The CT120 adds sparkle to the LS, which I like. For clarification, the drivers in the Cornwalls are K-55-M (what the La Scalas originally came with) and they sound amazing in the Cornwalls with the Crites cast aluminum C-600 horns (K-600 clones). Aside from the boxy/stuffy/nasal character coming from the bass horn, the LSs sound very good below ~80dB. When turned up they become a blaring mess and lose the soundstage and imaging. The Cornwalls have that live fullness of a concert when played loud. They are quite articulate and clear at 90dB, with tight rich bass. No boxy, nasal stuffy sounds. Any thoughts on the AL-3 crossover? My LSs originally had the AL, which I promptly (regrettably?) threw away.

[babadono]

one members solution:

I listened to stock La Scalas and KHorns for years(decades) until i found this forum and Tractrix horn replacements, I've never gone back.

[pcbiz]

I did this for my Heresys, Chorus IIs, and now my La Scalas. Knocks the boxy/stuffy/honking mid horn sound right out. It also improves the bass very politely.

 

[baron167]

FWIW, my 1990 stock La Scalas sound superb with their AL-3 crossovers. I also hear great things about running AA crossovers in La Scalas. Are you running flat from your Pioneer?

[OO1]

2 hours ago, Desert Noises said:

 I have switched out all the drivers between the two. The A-55-G vs K-55-M in the LS sound very similar.

you swapped out all the drivers ,and checked all the connections of the internal wiring ,   there's pretty much nothing else in the equation but the XO

[Desert Noises]

42 minutes ago, Marvel said:

Bringing the mids down really helped both pair that I have owned. The 1" throat (actually more like 7/8") can be overdriven pretty easily, and sound harsh. However. I had my second pair out at a big party and they rocked.

 

~90 db is getting loud for me, but I've had there before and they were fine.

 

Do you have another amp you can try? I hate to use the word synergy, but some equipment just doesn't work together.

I am leaning toward dropping the mids by 3dB. I’ve read that the K-55-M is a little hotter than other iterations, thus prompting Klipsch to make a number of crossover changes during its time. Speaking of that, I’m curious how the AL-3 would compare with the A/4500 I’m currently using. I do have another amp to try, which I had the LS hooked to a while back in a different space. It’s worth trying just to see.

[Marvel]

I've never heard one of the A/4500 crossovers. My first LS had ALs in them but I switched them out with another simple design from s member here. It has a swamping resistor to even out the impedance for SET amps.

[Desert Noises]

3 hours ago, avguytx said:

It's an acquired taste to the LS and Belles and, apparently, the right signal chain combo.  Kind-of picky.  I've owned La Scalas and Klipschorns over the years and built a beautiful set of Belle inspired clones a few years back.  I had a pair of the Epic CF-3's prior but sold them once I was done with the Belle build, regrettably. I just never warmed up to their sound and worked out a deal where I now have CF-3 version 1's and I'm completely satisfied.  The Belle clones just didn't sound good upstairs in my music room and really had their limitations at our other house.  I'd also had a pair of '78 Cornwalls and KLF-30's at the same time as the first pair of CF-3's and the first two were sold off. 

 

It's all personal preference, what works in any given room, and the signal chain as a whole that let's you decide what sounds best to you.  At least in my humble opinion.  

Sorry to hear about your Belles not working out. At least you had the experience of building them and putting them together. When I built my Cornwalls I couldn’t sleep because I couldn’t stop thinking about the project due to the excitement. I’m glad you are enjoying your CF-3s and are satisfied. I feel that way with my roll-my-own Cornwalls. They really scratch that itch just right. Funny that my La scalas were supposed to be my “endgame” speakers. Looks like the La Scalas are better suited to be my chill-out reasonable volume speakers and the Cornwalls are for when I want a good concert-level session.

[Dave A]

You will find that most La Scalas have sides that can really howl at volume and until you add mid braces all the other stuff is helpful but will not solve the problem. When I used to fix up La Scalas none would leave here without the sidewalls being fixed. Two little pieces of plywood and it is the cheapest and many times the single largest improvement I have personally seen.

 

[sootshe]

3 hours ago, 000 said:

you swapped out all the drivers ,and checked all the connections of the internal wiring ,   there's pretty much nothing else in the equation but the XO

 Apart from the "headache" mid horn. 

 

[sootshe]

4 hours ago, babadono said:

one members solution:

I listened to stock La Scalas and KHorns for years(decades) until i found this forum and Tractrix horn replacements, I've never gone back.

 

There's your answer right there. 

 

....and I'd be using an ALK crossover or if you can snag one of Deans.

[sootshe]

4 hours ago, babadono said:

one members solution:

I listened to stock La Scalas and KHorns for years(decades) until i found this forum and Tractrix horn replacements, I've never gone back.

 ...and there's your answer right there.

[Curious_George]

15 hours ago, Desert Noises said:

My woes with the La Scalas are as follows: 1) The upper bass sounds boxy, nasal-y and stuffy. 2) The midrange at higher volume (~90 dB) is just plain harsh and unpleasant. I reduce the 100 Hz tone control a bit and that alleviates the boxy/stuffiness to a degree”.

I have a sensitivity to mid-bass frequencies and found the side panel mod helps a lot. In addition, I converted the 6dB woofer crossover to 12dB to roll off the woofer a bit faster due to an anomaly around the 400Hz crossover frequency. This helped tighten up the bass too. To convert to 12dB, add an 80uF/100V bi-polar cap across the woofer terminals.

 

The K400 midrange horn can be quite “vocal” (pun intended). Replacing it will really open up the sound and have a more natural presentation even if you keep the K55.

[Desert Noises]

1 hour ago, Curious_George said:

I have a sensitivity to mid-bass frequencies and found the side panel mod helps a lot. In addition, I converted the 6dB woofer crossover to 12dB to roll off the woofer a bit faster due to an anomaly around the 400Hz crossover frequency. This helped tighten up the bass too. To convert to 12dB, add an 80uF/100V bi-polar cap across the woofer terminals.

 

The K400 midrange horn can be quite “vocal” (pun intended). Replacing it will really open up the sound and have a more natural presentation even if you keep the K55.

Interesting point. I think I'm going to try that 12dB roll off mod for the woofers. I know my Cornwalls (B2 crossover) and Heresys (E2 crossover) both have capacitors across their woofers. Possibly for the same purpose? Easy enough and reversible if needed. I'm also going to temporarily clamp some blocks to the sides of the bass bins to add support as a test to see if there's any resonances of the bass horn that are contributing to the sounds I'm hearing.

[Dave A]

9 hours ago, sootshe said:

 Apart from the "headache" mid horn. 

 

Apart from the howling side walls which is a far more egregious offender.

[Dave A]

4 minutes ago, Desert Noises said:

I'm also going to temporarily clamp some blocks to the sides of the bass bins to add support as a test to see if there's any resonances of the bass horn that are contributing to the sounds I'm hearing.

Quick easy test. I have had two sets that did not need side braces. One was a one piece LSI with fiberglass and AL trim. The other had plywood that measured .77" thick as compared to the normal .7" thick stuff. It was visually thicker which drew my attention and also sounded good without having the mod done.