Groovie Posted March 19, 2004 Share Posted March 19, 2004 I thought this issue might have been clipping, but after doing some research it doesn't sound like it was. From what I read clipping is high notes clipped and comes from the tweeters, my problem was with the woofers. The problem resulted from turning my speakers to large and playing the opening scene from Attack of the Clones at a high volume. The RF-15's sounded terrible, I thought it was clipping, but they caved under the bass. I never had a problem with them switched to small with the rw-12 handling the bass, even at higher volumes. My question is what caused the terrible sound my speakers made when they received heavy bass set to large. If you have seen Attack of the Clones, when the spaceship flies in, in the opening sequence it has some serious rumbling bass. Your thoughts are appreciated. Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted March 19, 2004 Share Posted March 19, 2004 Groovie, There is some very low bass in the opening of The Attack of the Clones. The RF-15s cannot physically produce the very low bass notes required. Secondly, many receivers cannot produce the needed power to reproduce the very low bass explosions. Thirdly, the main speakers work againt each other on bass notes. It is far, far better to let the subwoofer handle everthing below 80 or 100 Hz. The mid-range ia cleaner. The receiver is less challenged for power and the bass is cleaner. I have RF-7s run by a 140 watt B&K separate amplifier and I run them as small. The subwoofer handles from 80 Hz on down. The RF-7s do not distort, but the bass is cleaner and tighter when the subwoofer handles bass frequencies below 80 Hz. Bill Quote Link to comment Share on other sites More sharing options...
JohnA Posted March 20, 2004 Share Posted March 20, 2004 Any frequency can be driven into clipping and you will hear the sound out of ALL of the drivers, not the tweeters. The LF content in the movie you used is extremely loud and DEEP (it is painful on my system when set to normal volume). Your woofers were over driven. You asked them to move a greater distance than they physically could, and they clipped the waveform off themselves due to lack of travel. More of that and you'll get to buy some more woofers. Quote Link to comment Share on other sites More sharing options...
ob1clodi Posted March 21, 2004 Share Posted March 21, 2004 Did it make a clacking sound? I did that with AOTC once, I repeat once. Was not pretty at all. What does clipping sound like from the tweeters? I am still new to this and I hope I have never had my reciever into clipping. Quote Link to comment Share on other sites More sharing options...
hoggy Posted March 21, 2004 Share Posted March 21, 2004 I don't think you can actually hear a tweeter clip unless it's when it actually blows. Besides it's the amp that's clipping not the driver. At lweast I think that's how it works. The Tandberg amp I used to own had clipping light indicators. When they'd just barely light I never heard anything sound funny. Of course this was a indication to turn the darn amp down. hoggy Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 22, 2004 Share Posted March 22, 2004 Here is my short version of clipping: Clipping does not just effect the high frequencies, it will be plainly heard on all of the drivers in question. A clipped signal has a large flattened (truncated)extended peak which looks virtually like a plateau, with steep shoulders therefore the power available is higher than expected (its at maximum or beyong its rating) at all frequencies. Whereas it still alternates in current, the flattening peaks are like applying short bursts of DC for the length of the cycle in question. As crossovers cannot deal with DC they tend to pass it on to the drivers. The tweeters tend to go first in that high frequency power is respectively small compared to the current required for low frequencies, and they are not made to take very much wattage in comparison to woofers, etc. This is what fries out speaker voice coils, they are not made to be extended and held there by steady current. This is a simplified explanation, but it should get the point across. It should also be remembered that an amp pushed to the point of clipping is literally tapping out the power supply and giving it to the speaker; it is being pushed beyond its safe operational parameters. Distortion is extreme (forming most of the signal) and the generation of resultant harmonics and such are also fed directly to the speaker. All in all bad things can happen with high powered amps driven in to clipping. I have heard of some amps frying, and while they do it they take out the speakers. All in a single POP. Then it will probably smell bad and cost lots of money. It is a good idea to not overdrive the amp whether the speakers "can take it" or not. Short bursts of clipping can occur without permanent damage, but if you find yourself routinely clipping, then you need a more powerful amp. DM Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 23, 2004 Share Posted March 23, 2004 for the more visually inclined, i drew up a picture to help demonstrate what happens... the red lines represent the maximum output capable by the device. the device really can be anything in the signal chain that recieves an input and puts out a larger output. The most obvious is an amplifier (so we'll use that as the analogy). the black lines represent what the input signal "is supposed to output" and the grey shaded areas represent the actual output based on the maximum output capable by the device. the blue lines, represent where clipping is occuring. in a waveform, the distance from the middle to the crest (or trough) is the amplitude. related back to sound, the amplitude would represent the volume of the signal. as long as the amplitude stays within the means of the device (aka, the black lines are inside the red lines on the diagram), then the signal is clean...aka, no clipping (a form of distortion) is happening. if however, the amplitude exceeds the capability of the device (black lines outside of the red lines on the diagram), then the output starts to get clipped. when clipping occurs, the amplitude of the waveform (the height of the waveform) maxes out and it can't get any louder, but at the same time the input is telling the device to go louder. what ends up happening is the top of the waveform gets cut off and becomes a straight line at the max output of the device until the waveform comes back down into the workable range of the device. This straight line is essentially DC (direct current) which is very effective at burning out drivers. ok, so i explained the whole process referring to the "device" and i mentioned earlier that an amplifier is the most obvious device that comes to mind. however, a speaker too can also be considered a device...when a speaker is no longer capable of playing the amplitude of the signal being pumped into it, then the same thing happens where the amplitude gets cut off. clipping can happen in the reciever, in the cd player, anything in the signal chain. i've even heard clipping coming through the cable box when watching tv! Quote Link to comment Share on other sites More sharing options...
Klipschfoot Posted March 23, 2004 Share Posted March 23, 2004 Did someone say distortion? I like distortion. Quote Link to comment Share on other sites More sharing options...
JohnA Posted March 24, 2004 Share Posted March 24, 2004 Excellent, Doc! Quote Link to comment Share on other sites More sharing options...
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