erdric Posted August 24, 2001 Share Posted August 24, 2001 I was watching Super Speedway tonight and I noticed that my right KG-4 sounded a bit out of balance with the left speaker. At first I thought that it was because the DVD has a lot going on in the right channel but I wanted to make sure. Out came Avia and the sound meter. When I ran the tones I noticed that the right speaker was, in fact, 1 dB higher. I switched the L+R speakers and re-tested. Now the left speaker was higher by 1 dB. So I ask myself 'Does one dB matter? The other thing is that the speaker that's reading higher sounds different in timbre than the other. The pitch seems higher. The thing that worries me is that the last time I calibrated I didn't measure/hear a difference. Sure, the two speakers weren't EXACTLY the same measurement but they were close. Now there is a clear difference. I don't know if something's wrong but I suspect that there is. I don't know an awful lot about the guts of a speaker so I don't know how to diagnose the offending part. If it's a driver will it continue it's downward spiral and become obvious? Any other ideas on what it might be? If there's a problem I'd like to try to fix it before any more damage occurs. I just got the #@%$*! matching center for the Kg-4's and now there's a problem with the mains? Piss me off! Help!!! PS I suppose that the speaker that's reading lower could be the problem but at the moment I'm working on the assumption that it's the higher sounding one. ------------------ Primary System: Main KG-4 Center KV-3 Rear RS-3 Yamaha HTR-5250 Sony DVP-S560D Panasonic PV-9664 Sony DBS system Studio: Main KG-3 Sony STR-AV920 Pioneer PD-4351 Quote Link to comment Share on other sites More sharing options...
oogins Posted August 25, 2001 Share Posted August 25, 2001 Well I learned in science class two years ago that an increase in 3 dB is twice as loud. ie. 93 dB is twice as loud as 90 dB. So a one dB increase is actually quite a bit. However, it's summer time and my brain is not working to full capacity, so I might be wrong. ------------------ -Paul AMD T-Bird 900 Asus A7V Micron 256 MB PC-133 IBM 30 GB 7200 rpm ATA 100 Pioneer DVD-105 Slot-Load (16X/40X) 3Dfx Voodoo5 5500 AGP Sound Blaster Live! X-Gamer 5.1 (soon to be Hercules Fortissimo II) NEC MultiSync M700 17" (soon to be LG Flatron 915FT Plus 19") Razor Boomslang 2000 w/Everglide Giganta These speakers are for my computer, not a HT Receiver: Kenwood VR-409 (soon to be Denon AVR-2802) Speakers: Klipsch Quintets (5 sats. adding Quintet center or Klipsch KSC-C1) Sub: Sony SA-W305 mini-sub (soon to be HSU Research VTF-2 or Klipsch RSW-10) Quote Link to comment Share on other sites More sharing options...
Jim Cornell Posted August 25, 2001 Share Posted August 25, 2001 Check the positive and negative, make sure their hooked up properly, also check all 4 woofers, see if there all working, last but least, check the passive radiator for cracks, if so patch them!!! Been there done that Jim Quote Link to comment Share on other sites More sharing options...
erdric Posted August 25, 2001 Author Share Posted August 25, 2001 Well, I checked the connections and they're fine. I checked to see if sound is coming out of each woofer, tweeter, and radiator and there is. BTW, no cracks in any of them. Any other thoughts? ------------------ Primary System: Main KG-4 Center KV-3 Rear RS-3 Yamaha HTR-5250 Sony DVP-S560D Panasonic PV-9664 Sony DBS system Studio: Main KG-3 Sony STR-AV920 Pioneer PD-4351 Quote Link to comment Share on other sites More sharing options...
dougdrake2 Posted August 25, 2001 Share Posted August 25, 2001 I'm probably confusing these two items, but I think I remember reading on this forum that a change of 10db is generally perceived to be twice as loud, and that it takes twice as much amp power to have an increase of 3db (meaning it would take roughly 8 times the power to double the perceived volume). DD Quote Link to comment Share on other sites More sharing options...
Marvel Posted August 25, 2001 Share Posted August 25, 2001 A 1db increase is usually the smallest amount the ear can detect. A 3db increase is a doubling in volume but requires a ten times increase in power. So if you are cranking at 10 watts, to make it twice as loud would require 100 watts. The next step would be 200 watts. Some of this is also freq. dependent. Lower freq. require more than treble. That's why a large amp is sometimes required just for the headroom on the bass endeven though it won't seem louder. Quote Link to comment Share on other sites More sharing options...
erdric Posted August 25, 2001 Author Share Posted August 25, 2001 I understand what you guys are saying about wattage-volume relationships but I'm not sure if it gets to the core of the problem. I'm not changing volume setting during calibration and both main channels have the same wattage. The problem is that one sounds "louder". Perhaps louder is not the right term. Maybe "higher pitched" would be better, I don't know. I've verified that it's not the amp and that the problem is following the speaker. I set the main volume to output a reading of 85 dB on the sound meter. I get 85 dB from all the speakers but this one. From the suspect speaker I'm getting a solid 86 dB. It doesn't matter if it's connected to the L or R channel it's still reading higher. I verified that my bass management as well as all of my connections are set up properly. The speaker is not playing twice as loud, just a bit louder. On most of the movies I've tested with I can't even tell that there's a difference in sound. I only hear it during SS and when I'm calibrating. I know that you might say 'if you can't tell during movies then what's the problem?' and I somewhat agree. My concern is that there is a more serious problem that's going to cause more significant problems in the near future. I guess what I'm asking is: Does this sound like a bad driver, woofer, crossover, etc? Is there a way to check on a more scientific level? Finally, is there a parts list somewhere on the website in case I need to replace something? Thanks again. ------------------ Primary System: Main KG-4 Center KV-3 Rear RS-3 Yamaha HTR-5250 Sony DVP-S560D Panasonic PV-9664 Sony DBS system Studio: Main KG-3 Sony STR-AV920 Pioneer PD-4351 Quote Link to comment Share on other sites More sharing options...
dougdrake2 Posted August 25, 2001 Share Posted August 25, 2001 quote: Originally posted by erdric: I understand what you guys are saying about wattage-volume relationships but I'm not sure if it gets to the core of the problem. Well, of course it has nothing to do with the problem - we're doing our math by going off on tangents. DD Quote Link to comment Share on other sites More sharing options...
boa12 Posted August 25, 2001 Share Posted August 25, 2001 quote: Originally posted by erdric: PS I suppose that the speaker that's reading lower could be the problem but at the moment I'm working on the assumption that it's the higher sounding one. er, i'd definitely set my sights on the lower sounding 1. what could be wrong w/ a louder speaker as long as it sounds ok? send/take that lower soundin 1 in & have it checked. or for the do it yoreself, stick that ear up to each driver. sound ok? open it up & rearrange the filling & check the internal wiring. that do anything? ------------------ Klipsch KLF 30 (front), KLF C7, Cornwall I (rear) Velodyne HGS-18 sub woofer Monsterbass 400 sub interconnect/Monster MCX-2 biwire & Z1 cable Marantz SR-8000 receiver Sony DVP-C650D 5-disk cd/dvd player Sony Trinitron 27" stereo tv Toshiba hi-fi stereo vcr Technics dual cassette deck Scientific Atlanta Explorer 2100 digital cable box Monster HTS1000 PowerCenter Boa's Listenin Lounge: Klipsch RF-3, RC-3 Monster MCX-1 Biwire Sony STR-DE935 a/v receiver Kenwood KR-9600 AM/FM stereo receiver (vintage 1975) Russound AB-2 receiver switch to RF-3 Teac PD-D1200 5-disk cd changer Technics SL-1950 turntable/AT LS500 cartridge rock on! Quote Link to comment Share on other sites More sharing options...
erdric Posted August 26, 2001 Author Share Posted August 26, 2001 Okay Boa, I'll check out the lower sounding one. I've never opened up a speaker before but I'll give it a shot. I can't see myself bringing it to the shop without checking it out myself first. Besides, It'll be a good learning experience. Thanks. ------------------ Primary System: Main KG-4 Center KV-3 Rear RS-3 Yamaha HTR-5250 Sony DVP-S560D Panasonic PV-9664 Sony DBS system Studio: Main KG-3 Sony STR-AV920 Pioneer PD-4351 Quote Link to comment Share on other sites More sharing options...
Jim Cornell Posted August 27, 2001 Share Posted August 27, 2001 OK Do you have one thats 4ohm, and the other 6 ohm? Are the woofers black or white? Are they all the same color? If so, you have a worn driver, or a crossover problem!! Regards Jim Quote Link to comment Share on other sites More sharing options...
erdric Posted August 28, 2001 Author Share Posted August 28, 2001 The KG-4's are the 1985 models. They are 4 ohm speakers with all original white woofers. I'm probably going to open them up in the next couple of days and look for anything obvious. If nothing looks wrong then I guess I'll need to take them in. Anyone in Mass know of a good repair shop to take older Klipsch to? I've been very lucky in that I've never had to have anything repaired. I'm not sure where to take the speakers to if it comes to that. ------------------ Primary System: Main KG-4 Center KV-3 Rear RS-3 Yamaha HTR-5250 Sony DVP-S560D Panasonic PV-9664 Sony DBS system Studio: Main KG-3 Sony STR-AV920 Pioneer PD-4351 Quote Link to comment Share on other sites More sharing options...
Jim Cornell Posted August 28, 2001 Share Posted August 28, 2001 OK, sounds good, good luck on the repair shop, i think your ganna need one!! Regards Jim Quote Link to comment Share on other sites More sharing options...
Ray Garrison Posted August 29, 2001 Share Posted August 29, 2001 uh, Marvel... Conventional wisdom holds that 1dB is the minimal sound level change necessary to be reliably and repeatably detectable. 3dB sounds noticeably louder, and requires twice the power (see below). 10dB is said to sound "twice as loud", whatever that means, and requires 10 times the power (see below). The decibel (dB) is a logarithmic unit used to describe a ratio. The ratio may be power, or voltage or intensity or several other things. To get a taste for logarithmic units, first let's look at some numbers: For instance, suppose we have two loudspeakers, the first playing a sound with power P1, and another playing a louder version of the same sound with power P2, but everything else (how far away, frequency) kept the same. The difference in decibels between the two is given by 10 log (P2/P1) dB ........ where the log is to base 10. If the second produces twice as much power than the first, the difference in dB is 10 log (P2/P1) = 10 log 2 = 3 dB. If the second had 10 times the power of the first, the difference in dB would be 10 log (P2/P1)= 10 log 10 = 10 dB. If the second had a million times the power of the first, the difference in dB would be 10 log (P2/P1) = 10 log 1000000 = 60 dB. Sound is usually measured with microphones and they respond (approximately) proportionally to the sound pressure, p. Now the power in a sound wave, all else equal, goes as the square of the pressure. The log of the square of x is just 2 log x, so this introduces a factor of 2 when we convert to decibels for pressures. The difference in sound pressure level between two sounds with p1 and p2 is defined as: 20 log (p2/p1) dB ........ where the log is to base 10. When the decibel is used to give the sound level for a single sound rather than a ratio, then a reference level must be chosen. For sound intensity, the reference level (for air) is usually chosen as 20 micropascals, or 20 mPa. (This is very low: it is 2 ten millionths of an atmosphere. Nevertheless, this is about the limit of sensitivity of the human ear, in its most sensitive range of frequency. Usually this sensitivity is only found in rather young people who have not been exposed to loud music or other loud noises.) So if you read of a sound intensity level of 86 dB, it means that 20 log (p2/p1) = 86 dB where p2 is the sound pressure of the reference level, and p2 that of the sound in question. Divide both sides by 20: log (p2/p1) = 4.3 dB 4 is the log of 10 thousand, 0.3 is the log of 2, so this sound has a sound pressure 20 thousand times greater than that of the reference level. 86 dB is a loud but not dangerous level of sound, if it is not maintained for very long. What does 0 dB mean? This level occurs when the measured intensity is equal to the reference level. i.e., it is the sound level corresponding to 20 mPa. In this case we have sound level = 20 log (p.measured/p.reference) = 20 log 1 = 0 dB So 0 dB does not mean no sound, it means a sound level where the sound pressure is equal to that of the reference level. This is a small pressure, but not zero. It is also possible to have negative sound levels: - 20 dB would mean a sound with pressure 10 times smaller than the reference pressure. Not all sound pressures are equally loud. This is because the human ear does not respond equally to all frequencies: we are much more sensitive to sounds in the frequency range about 1 kHz to 4 kHz than to very low or high frequency sounds. For this reason, sound meters are usually fitted with a filter whose response to frequency is a bit like that of the human ear. (More about these filters below.) If the "A weighting filter" is used, the sound pressure level is given in units of dB(A). Sound pressure level on the dB(A) scale is easy to measure and is therefore widely used. It is still different from loudness, however, because the filter does not respond in quite the same way as the ear. To determine the loudness of a sound, one needs to consult some (idealised) curves representing the frequency response of the human ear. The unit of loudness is the sone, which is defined so that it equals sound pressure level at a frequency of 1 kHz, and is assigned values at oher frequencies by the response curves. Why do we use decibels? The ear is capable of hearing a very large range of sounds: the ratio of the sound pressure that causes permanent damage from short exposure to the limit that (undamaged) ears can hear is more than a million. To deal with such a range, logarithmic units are useful: the log of a million is 6, so this ratio represents a difference of 120 dB. Psychologists also say that our sense of hearing is roughly logarithmic. In other words, they think that you have to increase the sound intensity by the same factor to have the same increase in loudness. Whether you agree or not is up to you, because this is a rather subjective question. ------------------ Music is art Audio is engineering Quote Link to comment Share on other sites More sharing options...
fini Posted August 30, 2001 Share Posted August 30, 2001 Uh, yeah, that's what I was going to say, but Ray beat me to it. Thanks, Ray. fini Quote Link to comment Share on other sites More sharing options...
dougdrake2 Posted August 30, 2001 Share Posted August 30, 2001 Not only does Ray do well on the techno-speak, il parle francais aussi? Tres bien!!! DD2 Quote Link to comment Share on other sites More sharing options...
Craig6519 Posted August 31, 2001 Share Posted August 31, 2001 edric, I hope I'm not missing the obvious here but you said your right speakers was 1db higher when you measured it and when you switched the L/R your left speak was now 1db higher. Sounds to me like your speakers are fine, something's wrong in your reciever or wires. Good Luck Craig ------------------ Klipsch KLF30 Mains Klipsch KLF-C7 Center Klipsch KSP-S6 Surrounds Klipsch KSB 1.1 Front Effects Dual SVS 20-39CS Sub's Samaon S700 Sub Amp Yamaha DSP-A1 Yamaha MDX-793 Mini disc Yamaha TX-492 Tuner Sony CDP-C701ES 5 disc Player Panasonic A110 DVD Hitachi MX6080EM Muli-system HI-FI VCR Hitachi 29" T.V. Denon DP-37F Turntable Quote Link to comment Share on other sites More sharing options...
erdric Posted August 31, 2001 Author Share Posted August 31, 2001 Hi Craig. What I did was measure the left and then right speaker. The left read 85 dB and the right 86db. I shut down the receiver, disconnected the cables from the speakers themselves and left the cables there. I then physically moved the speaker that was on the right to the left side and moved the speaker that was originally on the left to the right. Before I did this I marked where the speakers were sitting so that they would sit the same as during the first measurement. I reconnected the speakers, turned on the equipment, and re-tested. Now the Left speaker was reading 86 dB and the right 85 dB. To me that indicates that it's not the channel but the speaker. Besides, I confirmed that it was the speaker by bringing in my Kg-3's and measuring. Both Kg-3's measured 85 dB. ------------------ Primary System: Main KG-4 Center KV-3 Rear RS-3 Yamaha HTR-5250 Sony DVP-S560D Panasonic PV-9664 Sony DBS system Studio: Main KG-3 Sony STR-AV920 Pioneer PD-4351 Quote Link to comment Share on other sites More sharing options...
Marvel Posted August 31, 2001 Share Posted August 31, 2001 uh, Ray, Thanks for the refresher. I went back to my notebooks and of couse, you are correct. That's what I get for sending this from my office when I should be working. My memory only brought part of that back correctly. I have been trying to explain to my kids (aaghhh!!! They're young adults now), that almost everything in math has to do with ratios. I apologize for my error. Marvel Quote Link to comment Share on other sites More sharing options...
Craig6519 Posted August 31, 2001 Share Posted August 31, 2001 Sorry erdric, My confusion I just picked up a pair of KG4's today for $150, they need to be refinished to look great but they really sound good. I see you have the KV3 center Is that the best match for the KG4's? Good luck In getting the speakers sorted out. i have another ? I saw earlier where someone said if the front drivers are white they are 4 ohm speaks and If there black there 6 ohm. Mine have white surrounds and the just under the binding posts they say 6ohms Is this correct? Also can you tell me the year these were made these are the numbers on the back of each speaker KG4 WO RV KG4 WO RV 8941572 8911255 Not matching serial numbers "OH WELL" I'm guessing that the 89 Is 1989 Right? Thanks Craig ------------------ Klipsch KLF30 Mains Klipsch KLF-C7 Center Klipsch KSP-S6 Surrounds Klipsch KSB 1.1 Front Effects Dual SVS 20-39CS Sub's Samaon S700 Sub Amp Yamaha DSP-A1 Yamaha MDX-793 Mini disc Yamaha TX-492 Tuner Sony CDP-C701ES 5 disc Player Panasonic A110 DVD Hitachi MX6080EM Muli-system HI-FI VCR Hitachi 29" T.V. Denon DP-37F Turntable Quote Link to comment Share on other sites More sharing options...
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