M.H Posted December 16, 2001 Share Posted December 16, 2001 Hello.. I have a question for the LaScala owners again. Since i own a pair for myself i am verry happy with the sound. But there is 1 big thing that bothers me. This is kind a hard to discribe,but i will give it a try. Most times i hear in the mid-low section a echo resound. Specially with drum/deep voices and guitar. It looks like there is something vibrating inside the speaker. Like the speaker cant handle that part of the sound verry well. I know this aint the case,but it just sound like that. In the beginning i thought it whas in the recording him self. That perhaps the microphone coudnt handle the sound corectly. But i hear it in so many cd's,and a friend of my has also a full horned system (Kustom) and there it sound perfect. Another friend who also own a pair of LaScala has the same problem so the problem cant be my speakers. I hope u know what kind of sound i mean. But it's verry anoying,becuase the rest of the music sound's verry life like. And suddenly u hear that "echo resound" and *PLOP*...u are back in the real world,gone is that magic feeling u had. Again,i hear it only when there is some "puch" in the sound.. Like i said,when u hear a gitar ore a deep voice ore drum.. Can someone pls tell me what causes this problem? And what can i do to eliminate it? I really hope u understand what i mean and give me some good advise, Greetings M.H Quote Link to comment Share on other sites More sharing options...
soundog Posted December 16, 2001 Share Posted December 16, 2001 I think your talking about horn resonance or "ringing" which is a higher pitched phenomenon than you describe. There are a number of posts regarding damping of horns. Do you have the older metal horns or the plastic horns? Of course something else in the cabinet or the room may be resonating (or the room itself may be causing it). See if you can feel anything vibrating or if you find that the "echo" stops when you hold something (like the horn) or when you lean on the cabinet. Are the drivers screwed in tight? In short, your first task is to identify the problem - good luck. You'll get a lot of ideas and help from people on this site ------------------ Soundog's HT Systems Quote Link to comment Share on other sites More sharing options...
M.H Posted December 16, 2001 Author Share Posted December 16, 2001 quote: Originally posted by soundog: I think your talking about horn resonance or "ringing" which is a higher pitched phenomenon than you describe. There are a number of posts regarding damping of horns. Do you have the older metal horns or the plastic horns? Of course something else in the cabinet or the room may be resonating (or the room itself may be causing it). See if you can feel anything vibrating or if you find that the "echo" stops when you hold something (like the horn) or when you lean on the cabinet. Are the drivers screwed in tight? In short, your first task is to identify the problem - good luck. You'll get a lot of ideas and help from people on this site Well..it aint really a "ringing" sound. It is really in the lower section. It has a bit of a muddy "wood" sound..ppfff..so hard to discribe. I have the plastic horn (is this better ore worse?)and the sound is really coming from the speaker. The sound doesnt sound like something is vibrating BECUASE of the music (like when u play really loud and things start to vibrate)it has a more "the sound cant get out of the speaker" feeling..and because of that the cabinet is vibrating.. Sorry for my poor desciption,but i hope some lasala owners know what kinda sound i mean This message has been edited by M.H on 12-18-2001 at 03:43 PM Quote Link to comment Share on other sites More sharing options...
soundog Posted December 16, 2001 Share Posted December 16, 2001 The plastic horns are less in need of damping ... I was thinking midrange squawker ...the problem might be the woofer. In which case you'll have to turn it upside down and take out 16 screws so you can lift off the base panel and see if the woofer is loose, torn, etc. If its higher than bass, the problem might be in the mid driver - torn diaphram, possibly. Do both LaScalas manifest the same problem? If so it might also be something earlier in the chain. Is your equiptment isolated from vibrations? ------------------ Soundog's HT Systems This message has been edited by soundog on 12-16-2001 at 03:52 PM Quote Link to comment Share on other sites More sharing options...
RossVTaylor Posted December 16, 2001 Share Posted December 16, 2001 M.H., I think Soundog's on the right track in having you turn the speaker over and open the bottom panel. I might add, though, that your "pffft" (nice description, by the way!) sound might be from a loose or warped panel. If the speakers sat on a damp surface, they may warp or delaminate and may not seal well. While you're down there anyway, check the flatness of the panel and the weatherstrip gasket/seal. Ross ------------------ My System's Stuff Quote Link to comment Share on other sites More sharing options...
JohnA Posted December 16, 2001 Share Posted December 16, 2001 There could also be something in the chamber between the woofer cone and the slot that opens into the bass horn. Sometimes I will hear a chestyness or extra bassiness to male vocals (listen to either od Seal's CDs). That is a resonance in the bass horn. You can feel the sides vibrating at that same frequency. Other than that, I get no unusual sounds from my La Scalas. John Quote Link to comment Share on other sites More sharing options...
J M O N Posted December 17, 2001 Share Posted December 17, 2001 Without actually hearing the speakers, it sounds to me that John may describing what the problem is. If your friend's La Scalas have the same problem, then there is a good chance that nothing is wrong with the speakers and you are just hearing cabinet resonances which are prevalent with La Scalas. The resonances should only happen during low notes and at somewhat loud volumes. You won't likely notice the resonances at lower volumes. Bracing the cabinet can help reduce these resonances. Quote Link to comment Share on other sites More sharing options...
M.H Posted December 18, 2001 Author Share Posted December 18, 2001 quote: . I might add, though, that your "pffft" (nice description, by the way!) sound might be from a loose or warped panel Hahaha..sorry..but with "ppfff" i didnt mean that as the sound i hear from the speakers.. I mean that as a expresion..something like "Pfew".. But i expected that his would be a typical LaScala problem. I guess i whas wrong...hmmmmm Well..then i have to test some things first.. Do i hear it from both speakers?? If it is "yes" then i cant imagine that there is a problem with the speaker. It would be verry weird if both speakers would have the same problem. I havent heard it by my friend..i only told him my problem and he recognised it.. So i shall listen to his set with the right cd's and hear for my self if he has the same problem. If so i think it is a typical LaScala problem. The funny thing is that his speakers are verry verry old..and mine are the new type (2 years old). And still we have the same problems (i think) .. I want to re-wire my speakers in a couple day's so i will see for my self if the woofer is ok. quote: The resonances should only happen during low notes and at somewhat loud volumes. well..u are right about that..at low volumes i dont hear that sound. But like i said before..i really expected that other LaScala owners recognised this problem imiditaly.. To be honest i am a bit suprised that this is not the case. Well..thx for the reply's anyway. I still hope someboddy can give me a helping hand Quote Link to comment Share on other sites More sharing options...
jnorv Posted December 28, 2001 Share Posted December 28, 2001 It could be cabinet resonance. I fixed mine by putting a 70 pound bag of sand on top and the cutting some trapezoidal wedges ( think of a square, about 11 inches on a side, and then cut a line from one corner at a 30 degree angle) that I fitted between the woofer housing and the side wall. I made mine from 1/2 particle board. If the angle is just right they will stay in without glue. Jim Norvell Quote Link to comment Share on other sites More sharing options...
M.H Posted December 30, 2001 Author Share Posted December 30, 2001 quote: Originally posted by jnorv: It could be cabinet resonance. I fixed mine by putting a 70 pound bag of sand on top and the cutting some trapezoidal wedges ( think of a square, about 11 inches on a side, and then cut a line from one corner at a 30 degree angle) that I fitted between the woofer housing and the side wall. I made mine from 1/2 particle board. If the angle is just right they will stay in without glue. Jim Norvell Hello..thx for youre help Do u recognise the problem i describe? Nice of u to explain what i could try,but it's a bit hard for me to follow it. For example,did u put a bag on the top of youre peaker? ore on top of youre midhorn? And what do u mean with"trapezoidal wedges "? Can u pls explain it to me with some simpler words? Ore perhaps with a phote? ore drawning? I really hope u can because if this will fix my problem it will make me very happy Thank u for the help so far. Greetings M.H 1 Quote Link to comment Share on other sites More sharing options...
Lone Palm Posted January 1, 2002 Share Posted January 1, 2002 I have noticed an abrasive ringing sound in my SCALAS. I do sound recording for a local folk group. On my Mackie 16 channel mixer there are sensativity settings for the mikes. If the setting is too high the mikes produce this ringing sound. Many engineers in their quest for the loudest recording may get careless and overlook this. Klipcsh speakers are probably more accurate than the monitors the studios use and this ringing is not heard in the mix. When I first heard it I freaked,but I chenged to a CD that I knew was cleanly recorded. Guess whet, The ringing was gone. Quote Link to comment Share on other sites More sharing options...
M.H Posted January 1, 2002 Author Share Posted January 1, 2002 Funny.. U describe exactly my first thoughts about that problem. I thought also that the record causes this problem. But a good friend of me also owns a pair of full horn peakers and they are eaven more accurate then the Lacala. And when i listen on his peakers the sound is perfect. But youre right about that clean-record point. I noticed also that cleanly record's doesnt show this problem that often. I hear it most thime with "life" ore "acoustic" music. And specially when there is a lot of "punch" in the music like drum/acoustic guitar. Thats why i still dont know what causes this problem. The speakers? (but why does 1 cd sounds perfect and the other has this problem) ore is it the recording (but why does it sound perfect on my friends speakers who are even more sensitive then mine). So i'm still trugling with this problem. I still hope tat Jnorv can explain to me in simple words how i can fix the vibration. By the way..best wishes and happy new year Greetings M.H 1 Quote Link to comment Share on other sites More sharing options...
jnorv Posted January 1, 2002 Share Posted January 1, 2002 To dampen the metal, mid range horn, I used a product called Q-Pads, that I got at my local automobile parts store. They are used to deaden vibration in metal panels. They have a self adhesive backing. Worked quite well. I put the bag of sand on top of the wooden cabinet to dampen the top panel vibration. Now for the wedges that I cut to dampen the side panel vibrations. Take a square piece of cardboard, 11 inches on a side. From one corner measure over 6 3/8 inch. Now draw a line from that point to the furthermost corner on the opposite side. Cut along that line. You should have a piece that is 11 inches on two adjacent sides and one side that is 4 5/8 inches. It is the same shape as the bottom of the cabinet between the side wall and the woofer housing. If you cut 4 of these pieces from 1/2 to 5/8 particle board, they will fit in between the side wall and the woofer housing. Once wedged into place, they kill the side wall vibration. One way to tell if you are having base cabinet resonance problems is to lay your speakers on their sides and put the bag of sand on the now top side. You can feel the panel vibrations disappear. Hope this helps. Jim Quote Link to comment Share on other sites More sharing options...
M.H Posted January 1, 2002 Author Share Posted January 1, 2002 Thank u for explaining it again jnorv. The trick u told me for the midhorn is worth a try. But how about that test for the base cabinet? What if i do the "sandbag" test and suddenly the vibrations disappear? So i know that the base cabinet causes the problem? I can't let the speaker lay down permanent on his side ofcourse. Are there also tricks to fix the vibrations in the base cabinet? M.H 1 Quote Link to comment Share on other sites More sharing options...
jnorv Posted January 1, 2002 Share Posted January 1, 2002 The Trapezoidal wedges fix the side panel resonance. See attached picture. Quote Link to comment Share on other sites More sharing options...
M.H Posted January 1, 2002 Author Share Posted January 1, 2002 quote: Originally posted by jnorv: The Trapezoidal wedges fix the side panel resonance. See attached picture. Cool Thx for the picture.. This is a good helping hand. Are there no bad points about this trick? And can u show me alo a pic of the trick with the midhorn? (i do understand the story u told better now). Thx for the help p.s. How did u atached those wedges?..is glueing enough? ore do i have to screw it..i hope not because of the damage M.H This message has been edited by M.H on 01-01-2002 at 05:59 PM 1 Quote Link to comment Share on other sites More sharing options...
jnorv Posted January 1, 2002 Share Posted January 1, 2002 I havent noticed any acoustic problems with the installation, yet. I may taper the back exposed edges, but I doubt that I will notice the difference. I have not glue or screwed them in place. If the angle is cut just right, the friction and the angle seem to hold them in place. I have only had one of them get spit out the front so far. Like you, I dont want to ruin the original box. The stuff I used for the mid range horn comes in one foot square sheets and is about .070 inch thich. go to http://www.dynamat.com/ for a discription of it. Different brand but similar.I tried taking a picture but it is like looking down a black hole in the back of the La Scala. Jim Quote Link to comment Share on other sites More sharing options...
M.H Posted January 2, 2002 Author Share Posted January 2, 2002 Glad to hear i dont have to screw ore glue. So it al depends on right measure. I have looked at the site u gave to me. This product is new to me,it looks intresting. Pitty the picture didnt succeed,but u explained it well the last time so i dont think it will be a problem anymore. Thx again for helping and i really hope it will work. Greetings M.H 1 Quote Link to comment Share on other sites More sharing options...
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