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Well I think I've cleared up most of the problems I've been experiencing with my K55's & now have no need to go to a larger format driver............ Last night I popped in an Ayre Acoustics V3 power amp & the difference is astounding. .............Who would have thought that the old K55 could produce such clarity & subtlety........and it's not as if I was using inferior equipment before......an Audio Research D240.......must be a better match with the Ayre........Still going to go ahead with the Dual Phase Plug drivers for another improvement.

What sort of horn would you run with these?

No lack of bottom end there then!!![]

My thoughts exactly John.............for the time being I'm going to try the dual phase plug K55.......& I've started saving up for the Altec driver & some appropriate horns to match......In my opinion you can't beat the sound of the original Altec drivers, their quality is second to none. []

Rudy, Yes, that's my take as well.........but that still leaves a gap between 2K & 2.9K???............Sometimes the more I read forum inputs the more confused I get............and just because someone uses a LS bass bin to 2 K doesn't mean it sounds right. []............your DBB set up should be awesome with the new bottom end............what was your low frequency limit running the DBB's on the bottom?

Sorry, but I can't figure out what you're doing here........you're using the W bin as the mid range?..................so the bottom end is handled by something up to 125Hz?.........from 125Hz to 2K is the LS W Bin?.............then there's something else to 2.93K?.................then there must be something else to 10.9K?.................& then something else from 10.9K up?....................sorry but I can't get my head around this.[*-)]

Going to try some of the dual phase plug K55's....they are supposed to be the goods. Probably take a couple of weeks to get here, but I will post thoughts after listening. []

Shawn.....very interesting reading.....hard to believe you gave up all those Altecs........those Peaveys must really fire along! Thanks, John

Shawn.......good to hear comments from someone who has used the large format Atec drivers.....the 288's go to about 15K & the 390's top out at about 6 or 7K, so yes, you need to run them 3 way, which is not really a problem as I already have the tweeters. Interested in your comments on the Peaveys.....did you find they had the same quality of sound as the Altec combinations? ............I know Altec did use the 902's at 500, but their recommendation is to use the loading cap......with all these options it certainly gets very confusing...........I'm sooo close to the sound that I'm after but I can't live with the resonances at certain frequencies of the K55........have been talking to Bob about the 2 piece phase plug design in the K55, which he says is a lot smoother.....if that cures the problem then it will make things a whole lot easier......Cheers, John []

If it matters or helps to know... it seems that for the 2-way "JubeScala" the crossover used for the LaScala bass bin and the K402 horn is at 420 hz (LR/24) on the bass bin and 470 hz (LR/24) on the K402/K69. I don't know why each section uses a different frequency. I speculate it has something to do with electrical crossover verses acoustic crossover? I don't know if this helps you at all but I figure since this is what Klipsch is doing there is probably some logic in it. Side note, I just looked up the JubeScala when being used with the K510/K69. It too is crossed at the same values as above. Thanks Coytee & others,.........I tend to agree....there must be a valid reason that Klipsch uses this crossover point & I think the 902 used down that low is a stop gap measure at best..........You can use the 902 at 500Hz providing you use a loading cap, but some say that this affects the sound.............With all I've been through with these speakers I don't want to go for a part remedy, at least trying the 902's gave me an idea of what to expect........Looks like the larger format is the way to go & I really like the look of the GPA 390 series......Thanks again, John []

Shawn....I was going to use my ALK Trachorn.....and yes I was thinking the 600's also. I did notice a gap in the response when I connected the 902's directly to the Universals.

Thanks Rudy.....is anyone able to interpret this for me?....is it meaningful data?

Thoughts? Anyone heard one of these? http://www.greatplainsaudio.com/downloads/390series.pdf

Yes, they do sound great. I've just hooked a pair up & running them through the standard universal (at very low volume). They sound much more detailed & refined. If 500 is the limit of the bass bin then I may have to use loading caps as well as the ES crossover to fully protect the drivers. Hopefully someone will have the data on these cabs....I can't believe that after 40 odd years no one hasn't figured out the upper limit of this horn.

I'm going to change the set up in my La Scala's & run them with an Altec 902 as the mid driver with one of Al's ES crossovers. Not sure yet whether I'll run 2 way or 3 way, but will experiment with both options. Does anyone have any conclusive data for the upper frequency limit of the La Scala bass bin to enable me to select the best crossover point? Many thanks, John

Here's the link to my build of the ported bass reflex cab that sits underneath the W Bin. http://forums.klipsch.com/forums/t/123298.aspx?PageIndex=1

Well, I didn't need to run them loud to produce the nasties that came from these......they made cymbals sound like trash cans...there was never any shimmer or quality to cymbals.....on almost any recording, they had an unpleasant sizzle that produced the most unlife like quality I've ever heard......and I'm comparing these to CT125's, Altec 902's, JBL slots (2405?).

No, it was the Eminence APT200 horn mounted to the CT125......you need to use a screw on adaptor as well. If you need some I'm sure Bob C will get them for you.....Cheers, John []

"I simply plugged in different tweeters into the top of a Khorn and listened to the results. I then put what I heard into words and presented it to my customers just as though they were a friend, interested in what I've done. It's an artistic and subjective approach. I'm simply taking those products and plugging them into a specific system and analyzing what I hear, just like any casual audiophile would like to do." Quote Greg 928 GTS. The problem arises though when what you perceive as good is perceived in a different manner by someone else. I recently purchesed a set of Beyma tweeters (CP 21's) from you which you described as "not as good as the CP25's but still very good". In my opinion they were complete rubbish & I sold them straight away....the Crites 125's fitted with Baby cheeks flares blew them out of the water. [8-)]

Beautiful work........[]

Thats good to know......I wasn't sure what port tuning I had & was looking to get a little lower.....If I'm at 35 Hz now thats fine. Seems like this would be the case, as in the absence of any testing equipment I know I can hear 35 Hz quite clearly from a test disc I have & 30 Hz I can just barely hear. On my Altec 19's I can hear 30 quite clearly & can just hear 25 Hz................Great job on the LS........looking forward to seeing the finished product with the grilles.

Dave......any suggestions as to how to port the original design for the bass reflex cab with the 2 round ports to 40HZ? At the moment I am running 2 x 4 inch diameter x 7 inches long as per my avatar. The box is 10 inches high x 221/2 inches deep x 221/2 inches wide........Or are they already 40HZ? Nice work......good idea with the E Brace. Thanks, John

Yes, I agree Bruce, the horn changes the character of the CT125 completely. I would be interested in your impressions of the CT125 with the baby cheeks horn fitted to it.....I found it to be a lot better. John

Rudy, Glad to hear these are working out for you.....it's a bold move to replace the K Horns!! [Y]

Just wanted to post some follow up impressions since making the thicker wall mods. My previous report was....well, a little underwhelming. I've now had a chance to listen to a great deal of different material over a prolonged period & I have to say that this mod is right up there with all of the other accepted mods to the LS. Those who have done these they will understand when I say that this offers a degree of improvement equal to, if not more than, these other mods. The ALK uni's & Trachorn take the LS to another level, the Crites woofers & tweeters offer a significant improvement & the removal of the resonances in the bass bin lets all of these things perform to their best. I already had the bass bin braces from day one on these cabinets, but let me tell you that this does not get rid of the resonances. The thicker side walls & rear has brought the performance of these speakers to a whole new level....and it hasn't just improved the bottom end....the whole frequency range is now cleaner, clearer & a heap more solid. I've heard some pretty top end systems, but I believe this is just about as good as it gets (I'm talking about speakers you can actually fit in your room...LOL). I would urge anyone doing a rebuild on a pair of LS to make this the first thing you do....you won't regret it.....you haven't really heard a pair of La Scalas until you've heard them like this!!! So, after nearly 12 months I'm finally finished. I'd like to thank everyone who helped with this project. To Bob Crites for his wonderful cast woofers & tweeters, to Al K for his Trachorns & unis & to Greg Roberts for his cabinet inspirations....and to everyone on this forum who posted with ideas & suggestions that gave me some great ideas & made these speakers come to life. [] John