hightone Posted January 28, 2003 Share Posted January 28, 2003 A quick question about the tweeter(k77)in my cornwall. I recently have had the diaphragms replaced (5 months ago) and the went out again. the have not been played very loud at all. I pulled them apart to see if the leads were still attached and they are. Then I put one in on of my hereseys and it did not work. the question is what is causeing them to not work. should I try puting the tweeters from my hereseys into the cornwalls. Is it possible there is a problem in the crossover? I dont know I have to take A deep breath I am sure you all can help. thanks Quote Link to comment Share on other sites More sharing options...
lynnm Posted January 28, 2003 Share Posted January 28, 2003 What are using for an amplifier for your Cornwalls? I suspect that your amp is clipping and sending relatively long burst of high energy high frequency pulses to the tweeters. For information on clipping see: http://www.audiovideo101.com/dictionary/clipping.asp When you run out of power, the amplifier does not just shut off. It begins to distort, called amplifier clipping (fig. 12). At full power we have a beautiful "sine wave", when you misuse the controls, the beautiful sine wave becomes a 'square wave'. This produces harmonics, or signals that were not part of the original music signal. These harmonics, at a very high frequency will ultimately ruin your tweeter. This is labeled as 'abuse' and not usually covered under manufacturers limited warranties. Warning! Power amp clipping: When a power amplifier is pushed to or above its rated power output the distortion level increases rapidly to astronomical levels (from <.08% to 1.5% or more), And the electrical wave form it produces changes radically. This is called clipping. This phenomenon has the potential to instantly damage or destroy a speaker and crossover network, as well as the amplifier itself! Most power amps have protection circuitry that will shut the amplifier down before it can damage itself, in addition to warning lights to show that the amp is being driven too hard. Unfortunately fuses or protection circuitry for the speaker tend to degrade the sound and are often ineffective as well. it is usually amplifier clipping and not excessive clean power that damages speakers. A 25 watt amplifier driven to clipping can destroy a speaker rated at 200 watts! When the amplifier warning LEDs light up it is time to turn down! Remember to turn down at the pre-amp output stage not at the power amp. Amplifiers can also eat tweeters through the too exuberant use of the tone controls. It is not uncommon to see tone control circuits that introduce as much as 12 db. boost to the treble. This represents a huge increase in high frequency output as compared to flat frequency response and can destroy tweeters if the amp is playing moderately loudly. Quote Link to comment Share on other sites More sharing options...
cranked Posted January 28, 2003 Share Posted January 28, 2003 I doubt klipping is whats causing your problem. I had a similar situation with my speakers and I found the cause was much different than i had originally thought. See, If you spend a lot of time with your equipment it becomes part of you. If you make a major life decision it may affect your equipment.If you think about it this makes perfect sense. Quote Link to comment Share on other sites More sharing options...
hightone Posted January 28, 2003 Author Share Posted January 28, 2003 I am useing an anthem mac 5 series 2 amp 200 watts per channel. The hereses are also hooked up to this amp so far without any problems. Great plains auido installed the diaphagms. Could a bad installation cause them to work for awhile and than fail ? Quote Link to comment Share on other sites More sharing options...
hightone Posted January 28, 2003 Author Share Posted January 28, 2003 YES!!! The major life decision. If I only knew. Quote Link to comment Share on other sites More sharing options...
cranked Posted January 28, 2003 Share Posted January 28, 2003 So this will show you the power of your relationship to your equipment and how it is affected by your everyday life. Its a Klipsch thing. Quote Link to comment Share on other sites More sharing options...
hightone Posted January 28, 2003 Author Share Posted January 28, 2003 Yes. My sanity went with the tweeters. The only way to restore my sanity is to replace the tweeters.Or better yet part out the cornwalls and get some k-horns. HELP IN TWEETERVILLE !!!! Quote Link to comment Share on other sites More sharing options...
dbflash Posted January 29, 2003 Share Posted January 29, 2003 OK what's blowing them? I bought a pair without listening to them and both tweeters were blown. My thought was someone was using an amp that was clipping and blew the tweeters. I sent them to Simply Speakers and they replaced both diaphrams. I should get them back this week. I will be hooking them up to a SET amp (3.5W). I would think that if your amp is the cause of the blown tweeters, then changing to a pair of Khorns will not help. The tweeters are acting as fuses. Danny Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted January 29, 2003 Share Posted January 29, 2003 Hightone, Your amp is likely the culprit here. You are simply overdriving the tweeters. Klipsch recommends using amplification with NO MORE THAN 105 watts per channel with its Heritage series speakers...you are using a 200 watt per channel amp...think about it! On transients, you are pushing way more power to those tweeters than they are designed to handle...and if there is any distortion involved, you are making things even MORE difficult for them! Quote Link to comment Share on other sites More sharing options...
hightone Posted January 29, 2003 Author Share Posted January 29, 2003 Its like I said They have not been played loud at all. I live in a condo the neighbors would call the cops I know they did the one time I did play them loud. Any way the hereseys are hooked up to the same amp and the tweeters in them are fine. Is there any other reason the amp would blow the tweeters in only the cornwalls while being played at moderate levels? Could it be something else ? At any rate it looks like new diaphragms again. Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted January 29, 2003 Share Posted January 29, 2003 Hightone...here is the deal. It depends on when your Cornwalls were made whether there was any tweeter protection built into the crossover network...same for your Heresys. Having the serial numbers will determine the year of manufacture. If the Cornwalls have NO tweeter protection built into the crossover networks, then you don't have to play them LOUD with 200 watts per channel to blow the tweeters...all you hae to do is play them with too much AVAILABLE POWER able to get to the tweeter during complex musical passages...that is ENOUGH to blow the diaphragms in itself...all it takes is the right amount of distortion from the amp and the amp's having enough available power to blow them...it IS NOT dependent upon how loud the volume control is set. Your amp puts out 200 watts PER CHANNEL...which is still TWICE the recommended RMS power output for Heritage series speakers...when certain frequencies go to speakers...the actual wattage going into them can FAR EXCEED that 200 watts per channel rating even at lower listening volumes...thereby blowing the tweeter diaphragms...if there is no tweeter protective circuitry in the speakers. The K-77 will blow its diaphragm at sustained input of 12 volts(8 watts)...and a transient surge of 15 volts will kill its diaphragm immediately...remember that the tweeter gets only about 1% of the total power input in your Cornwalls...but if the transients are pushing JUST 200 watts at times(and with a 200 wpc amp those transients can go MUCH higher in wattage than JUST 200...even at lower volume settings!)...that 1% is over 20 watts...more than enough to blow em! Of course, it MAY BE SOMETHING ELSE, too...but in order to be sure, you need to find out dates of speaker manufacture to determine if your Cornwalls were made before the tweeter protection was added...and either way you look at it...your amplifier is still pushing more power than the speakers NEED!...at ANY VOLUME! One thing to watch out for is power surges...as seen when changing switches with the volume still turned up...ie., going from CD player to turntable or tuner, etc...always turn the volume DOWN completely when doing these changes...and wait a few seconds after turning the volume down before switching anything...in order to discharge the capacitors some. Quote Link to comment Share on other sites More sharing options...
cranked Posted January 29, 2003 Share Posted January 29, 2003 Arent these speakers rated at 100 watts continuous 1000 watts peak. If that is the case it seems unlikely someone listening in an apartment is sending to much power into there speakers. I have about 1/3 that amount of power and the spl levels will get my neighbors knocked out of bed. It seems unlikely someone in an apartment could be putting that much power into speakers rated at 1000 watts peak to blow them. I have chorus II and at the same efficiency I would think that anything near the earthshaking volume levels that I attain would have you arrested in an apartment in a heartbeat.I Admit I have nothing to base my thoughts on other than If these speakers will blow that easily mine should have been buried long ago due to clipping issues as opposed to clean spikes of power on some passages. Quote Link to comment Share on other sites More sharing options...
hightone Posted January 29, 2003 Author Share Posted January 29, 2003 OK That I did not know. I will hook the amp up to a marantz sr 7200 rated at 105 watts per chanell. I was thinking of tradeing in that amp anyway for something with tubes for music.I used that that amp when I had these other speakers.The sound was better through the amp for music than the marantz so I used it I knew it was over kill just not tweeter kill. The cornwalls were built 1975 type b crossover the hereseys 1982 type e2 crossover no protection in the cornwall I dont know about the hereseys. thanks for the info. Quote Link to comment Share on other sites More sharing options...
BigBusa Posted January 29, 2003 Share Posted January 29, 2003 if you installed a known good heresy tweeter and it too did not work then it sounds like a problem BEFORE the tweeter. Quote Link to comment Share on other sites More sharing options...
JohnA Posted January 29, 2003 Share Posted January 29, 2003 The 1975 AlNiCo tweeter has a rating of 2 watts continuous, 20 watts music and 40 watts instantaneous paek. The Cornwall crossover would almost double that. You need to replace the tweeters with known good ones to test the crossover. Quote Link to comment Share on other sites More sharing options...
BEC Posted January 29, 2003 Share Posted January 29, 2003 Builder, Don't you mean that 1% is 2 watts. The cornwalls are rated 105 watts continuous 1000 watts peak. BigBusa, I think he said he tried one of the bad ones in a heresy to verify it was bad. Bob Quote Link to comment Share on other sites More sharing options...
michael hurd Posted January 29, 2003 Share Posted January 29, 2003 I dunno where you get the ratings. RMS is .707 of peak power, or peak is 1.414 of rms. Quote Link to comment Share on other sites More sharing options...
hightone Posted January 29, 2003 Author Share Posted January 29, 2003 Ok I took the tweeter out of one heresey and put in the cornwall and it works fine through the marantz (just to be safe) should I leave it in I prefer listining to the cornwalls. I use the hereseys for surrounds. Quote Link to comment Share on other sites More sharing options...
ricktate Posted January 30, 2003 Share Posted January 30, 2003 if the heresy one works in cornwall now,,,then something was wrong with others ones before,,,i dont think you did it,,,maybe rebuilt wrong,maybe damaged in shipping,,,ups..you know what they do with little boxes well better you not know....keep the heresy ones in cornwall for awhile....bet they work fine...rick Quote Link to comment Share on other sites More sharing options...
BEC Posted January 30, 2003 Share Posted January 30, 2003 Michael Hurd, The ratings I listed are on this site (Kilpsch) from the specs for the cornwall. Bob Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.