Invidiosulus Posted February 4, 2010 Share Posted February 4, 2010 I think that the stiffness to thickness relationship is one of a cubed nature when dealing with a flat plane. So a 33% increase in thickness would result in 235% stiffness? Then again I don't really know what I'm talking about, where are those engineer types? -Josh Quote Link to comment Share on other sites More sharing options...
kg4guy Posted February 4, 2010 Author Share Posted February 4, 2010 Greg I think if you use 1" you don't need braces that is why the La scala II's went to 1" Ply bass bins.Again I think. I have to agree completely. I'm in the middle of a 1" La Scala rebuild and the difference between a stock 3/4" and 1" is remarkably different. Yes, it's only 1/4", but that is 33 percent more. I have a stock pair and the 1" side by side and when hit with a knuckle the comparison is dramatic. Even the bass bin is more solid. Keep in mind, these are stock cabinets with 1/4" mdf laminated. Look at all of the threads on rope caulk. Most have been disputed due to the fact that the horn wasn't solid against the motor board. The La Scala cabinet is exactly the same. It's just an extension of the bass horn. There are two ways to remedy the resonance. Brace the sides, or add damping to the sides. Klipsch has already made the modifications, and opted with the 1" mdf. Killer thread KG4. Your work bench is a piece of art. Try to work outside if it is nice and especially when I am using silicon or poly as the fumes are bad also I like to use my router outside as it makes alot of dust in my garage and my cat hangs out in there . Quote Link to comment Share on other sites More sharing options...
greg928gts Posted February 5, 2010 Share Posted February 5, 2010 Greg you have braced a few pair of 3/4 inch La scalas is there a big difference as I am sure you have A B tested them? You know, I never did AB test them. I can tell you that the Rosewood split LS's I did sounded incredible in my little listening room at my shop, but I don't know how much of that had to do with the braces. I actually got the best sound with the bass bins turned around backwards into the corners. Greg Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 5, 2010 Share Posted February 5, 2010 the mouth braces should be standard on any La Scala. I have a picture of Mr. Paul with a braced La Scala in the background. The outer walls of mine get to vibrating quite a lot when they get loud. The corner reflectors will extend the upper frequency response of the bass horn until it looks something like a Peavey FH-1. I can't recall anyone here curving a bass bin with the reflectors installed. Klipsch did not do it because it is not necessary with a K-400/K-55. They would help build a nice 2-way system. A La Scala's response has a dip at 500 Hz and starts falling pretty fast above 650 Hz. I agree with you, John. I had a pair of LaScalas for my commercial sound system in the 70's and 80's. Even without a sub, I had not problems getting paid to play music at parties, while everyone in the biz was using BOSE 801's (that was an easy contest to win). I currently own 6 FH-1 bins with and without the split top end (I call them cheap-Scalas). What I"m wondering is WHY, (if someone is going to all the trouble of making sawdust to get a pretty cabinet), don't they built THAT cab instead of a LaScala, which it isn't anyhow, unless it's Klipsch made (Trademark Violations). The FH-1 is clearly a superior construction of a slightly improved design. I had a pair of FH-1s with old K-33 woofers in them. Yes they still had the same approx. 160 Hz peak in the response as a LaScala, but when I tamed those FH-1's with a broad dip in the Behringer 2496 Xover to compensate for the peak, my friend and were amazed to find that those FH-1's got down to 30 Hz. in the small room they were in at the time. I had a 2-way top end wiht the EV DH-1/960 horn combe. That was an amazing sound for a 2-way.There are no vibration issues with the FH-1 and they go to 1 Khz, although it's pretty ragged after 600 Hz. Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted February 5, 2010 Share Posted February 5, 2010 Going from 3/4 to 1 ply wood should lower the resonant frequency. Example would be a bell. The bigger it is, the lower the natural freq. and tone. Now stiffness, that would be greater. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 5, 2010 Share Posted February 5, 2010 I'm leaning towards doing both the 1" and the braces. I think the 1" is only going to really make a difference on the sides, I doubt it would be any advantage on the rest. But I would also do the top and bottom of the bass bin so the front edge thickness is the same. I'm building split LS's. Greg Since you have mastered the craft of creating new improved products, riding on to of Klipsch designs, why don't you try building an FH-1 cabinet, or get a hold of Gary Gillum (former chief engineer at Klipsch, retired) and see if he will let you have plans for his son's 555 bass bin (LaScala on steroids that outperforms both?). Quote Link to comment Share on other sites More sharing options...
Invidiosulus Posted February 5, 2010 Share Posted February 5, 2010 D'oh, I wasn't thinking when I said that about resonance. anyways, It seems to me that it should be pretty easy to take the room eq wizard software or similar and use that to test resonance in a cabinet. instead of using a microphone, use a piezo guitar pickup, the kind that comes with a reuseable putty for mounting. Just mount the pickup at some consistant places on braced and non braced cabs and you should be able to see the difference in the response plots right? these pickups are usually pretty cheap. alternately one could get an accelerometer and some datalogging equipment, I've got some datalogging stuff down at marvel's house from my hotrodding days, just need to finf some accelerometers with a 0,5v output and that should work. Quote Link to comment Share on other sites More sharing options...
kg4guy Posted February 5, 2010 Author Share Posted February 5, 2010 Has anyone done a side by side comparison with braces and without to hear the difference to the human ear ?: Quote Link to comment Share on other sites More sharing options...
greg928gts Posted February 5, 2010 Share Posted February 5, 2010 I'm leaning towards doing both the 1" and the braces. I think the 1" is only going to really make a difference on the sides, I doubt it would be any advantage on the rest. But I would also do the top and bottom of the bass bin so the front edge thickness is the same. I'm building split LS's. Greg Since you have mastered the craft of creating new improved products, riding on to of Klipsch designs, why don't you try building an FH-1 cabinet, or get a hold of Gary Gillum (former chief engineer at Klipsch, retired) and see if he will let you have plans for his son's 555 bass bin (LaScala on steroids that outperforms both?). If someone asks me to build FH-1's, I will. Not too much extra time these days, just built my 100th mid horn! Greg Quote Link to comment Share on other sites More sharing options...
Pete H Posted February 5, 2010 Share Posted February 5, 2010 I'm leaning towards doing both the 1" and the braces. I think the 1" is only going to really make a difference on the sides, I doubt it would be any advantage on the rest. But I would also do the top and bottom of the bass bin so the front edge thickness is the same. I'm building split LS's. Greg Since you have mastered the craft of creating new improved products, riding on to of Klipsch designs, why don't you try building an FH-1 cabinet, or get a hold of Gary Gillum (former chief engineer at Klipsch, retired) and see if he will let you have plans for his son's 555 bass bin (LaScala on steroids that outperforms both?). If someone asks me to build FH-1's, I will. Not too much extra time these days, just built my 100th mid horn! Greg What's a 555 bass bin?Congrats Greg on number 100![Y] Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 5, 2010 Share Posted February 5, 2010 If someone asks me to build FH-1's, I will. Not too much extra time these days, just built my 100th mid horn! wow, congrats on the mid horn. Just know that FH-1's are 30" wide so they may not be as efficient in terms of material usage as a La Scala, but that should be minor. Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 5, 2010 Share Posted February 5, 2010 What's a 555 bass bin? Congrats Greg on number 100! http://www.hps4000.com/pages/speak_index_.html Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted February 5, 2010 Share Posted February 5, 2010 try this 555.pdf 555.pdf 555.pdf Quote Link to comment Share on other sites More sharing options...
jwc Posted February 5, 2010 Share Posted February 5, 2010 I've always admired the 555...would love to hear one. Greg your midhorn/tweet combo on that bass bin would make for a great speaker. jc Quote Link to comment Share on other sites More sharing options...
greg928gts Posted February 6, 2010 Share Posted February 6, 2010 I've always admired the 555...would love to hear one. Greg your midhorn/tweet combo on that bass bin would make for a great speaker. jc I agree. Quote Link to comment Share on other sites More sharing options...
kg4guy Posted February 6, 2010 Author Share Posted February 6, 2010 Well I will not be assembling the other cabinet or putting braces in for about a month or so as I went in Wed. and had 3 hernias repaired one umbilical and two inguinal not as bad as I thought it would be but still not fun. Quote Link to comment Share on other sites More sharing options...
Carbon_66 Posted February 6, 2010 Share Posted February 6, 2010 Well I will not be assembling the other cabinet or putting braces in for about a month or so as I went in Wed. and had 3 hernias repaired one umbilical and two inguinal not as bad as I thought it would be but still not fun. That's what happens when you play with 100+lb speakers. [] All kidding aside, good luck on a speedy recovery. You'll be back in no time. The rain is almost done. Enjoy some of our California sunshine, sit back, turn it up, and relax...... Greg Quote Link to comment Share on other sites More sharing options...
kg4guy Posted February 6, 2010 Author Share Posted February 6, 2010 Well I will not be assembling the other cabinet or putting braces in for about a month or so as I went in Wed. and had 3 hernias repaired one umbilical and two inguinal not as bad as I thought it would be but still not fun. That's what happens when you play with 100+lb speakers. All kidding aside, good luck on a speedy recovery. You'll be back in no time. The rain is almost done. Enjoy some of our California sunshine, sit back, turn it up, and relax...... Greg Yes 100 +lbs. but I just can't see myself becoming a Bose guy![] Quote Link to comment Share on other sites More sharing options...
Invidiosulus Posted February 6, 2010 Share Posted February 6, 2010 Sounds like it's time for an electronics project. Maybe you should build a tube amp or one of those newfangled chip amp kits. Hope the recovery goes well and quick. -Josh Quote Link to comment Share on other sites More sharing options...
ZombieWoof Posted February 6, 2010 Share Posted February 6, 2010 Greg Said ==>******************* @ 100 +lbs. but I just can't see myself becoming a Bose guy!**************** Us Klipsch Men love the heavy duty stuff ! ;p Mike Quote Link to comment Share on other sites More sharing options...
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