Roc Rinaldi Posted February 28, 2007 Share Posted February 28, 2007 I have an A/V Controller on order. In the specs. http://www.mcintoshlabs.com/data/brochures/MX1202.28.07.pdf I noticed under "SUBWOOFER" the statement "Low pass filtered with an 80Hz corner frequency......." What is meant by the term "corner frequency"? Quote Link to comment Share on other sites More sharing options...
michael hurd Posted February 28, 2007 Share Posted February 28, 2007 This is the frequency where the filter begins to roll off. In other words, above 80 hz the roll off starts at whatever slope is implemented. ( IE; 12 or 24 db /octave, possiblt higher ) All frequencies below 80 hz are passed to the subwoofer unaltered. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted February 28, 2007 Share Posted February 28, 2007 That's a crossover frequency. Was the term "corner" a typo or did you mean crossover? Do they possibly allow for corner loading a sub and have some sort of a filter that would not be used if the sub were to be on a wall? An additional "boundary" filter? Quote Link to comment Share on other sites More sharing options...
Roc Rinaldi Posted February 28, 2007 Author Share Posted February 28, 2007 Here is the web site http://www.mcintoshlabs.com/data/brochures/MX1202.28.07.pdf It definitely said "corner". Quote Link to comment Share on other sites More sharing options...
efzauner Posted February 28, 2007 Share Posted February 28, 2007 its how often your wife sends you to the corner of the room because you spent another day in the garage building another speaker and did not even have lunch with the family and kids.../ Quote Link to comment Share on other sites More sharing options...
Roc Rinaldi Posted March 1, 2007 Author Share Posted March 1, 2007 That's good. I like that definition. Quote Link to comment Share on other sites More sharing options...
mas Posted March 1, 2007 Share Posted March 1, 2007 That's a crossover frequency. Was the term "corner" a typo or did you mean crossover? Do they possibly allow for corner loading a sub and have some sort of a filter that would not be used if the sub were to be on a wall? An additional "boundary" filter? A corner frequency is used in reference to the frequency response, most often in crossovers, as you are dealing with the decay of a particular response - in other words, how a particular response 'rolls off'. And this is normally specified in terms of a 'corner frequency' and the rate or slope of decay referenced to that point. It has nothing to do with spatial loading )placement near boundaries, be it the wall, floor or corner. That is actually defined by a ratio known as Q. Here is a diagram to help with the concept of spatial loading. And you can get used to the use of the unit called steradians.[] Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 1, 2007 Share Posted March 1, 2007 I have an A/V Controller on order. In the specs. http://www.mcintoshlabs.com/data/brochures/MX1202.28.07.pdf I noticed under "SUBWOOFER" the statement "Low pass filtered with an 80Hz corner frequency......." What is meant by the term "corner frequency"? The "corner" frequency is defined as the -3dB point of the filter. When people refer to the "crossover frequency" they are just being lazy and simply referring to the "crossover corner frequency". If we wanted to, we could define the corner frequency to anything we wanted...like maybe the -6dB points or the -1dB points. The reason behind the classical -3dB is because this is where the acoustical output will sum to a flat response (provided the phases and all that are correct). So in an ideal world, the frequency where the high-pass filter is -3dB and the frequency where the low-pass filter is -3dB is going to be the same frequency. If we defined it differently (like the -6dB point), then the korner for the high-pass will be a lower frequency than the korner for the low-pass. I spelled it with a 'k' to avoid confusion with the real definition of a corner frequency. I hope I'm not confusing the issue...it makes way more sense if you've got pictures (which I might do in the near future if someone doesn't beat me to it). Anyways, to answer your question "Low pass filtered with an 80Hz corner frequency" is the same thing as saying "an 80Hz low pass filter" or "an 80Hz crossover point". They are all different ways of saying the same thing. Quote Link to comment Share on other sites More sharing options...
mas Posted March 1, 2007 Share Posted March 1, 2007 What both Mikes have said! This is NOT the best diagram, and there are not 'sharp' changes in frequency response as illustrated, but this illustration is the first I ran into that might help illustrate what Doc is saying. The corner frequencies for both curves (the low pass and the high pass) are the same. In this case they are both 5000 Hz. And each curve's rate of decay (the 'rolloff') is 6 dB per octave (which means that the slope will be 6 dB lower for every halving or doubling of the frequency respectively for the high pass and low pass components). Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted March 1, 2007 Share Posted March 1, 2007 Makes sense now. Quote Link to comment Share on other sites More sharing options...
Roc Rinaldi Posted March 2, 2007 Author Share Posted March 2, 2007 It does? Than you are smarter than me. I'm sure that slowly it will sink in but not now.....I have a headache. Quote Link to comment Share on other sites More sharing options...
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