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Junior Varsity
Listening Get Together
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<blockquote data-quote="Ivan Beaver" data-source="post: 81922" data-attributes="member: 30"><p>Re: Listening Get Together</p><p></p><p>And while on the subject of measurements in general-let's not forget WHY they are important and WHAT they are used for. And this is measurements in general.</p><p></p><p>1: Sensitivity-power capacity-freq response. These two are used together to get an idea of how much SPL a box can produce at a particular freq at a given distance.</p><p></p><p>1M is the "standard" but in most cases the boxes are not actually measured at 1M. They are measured further away (and back calculated)-so that the physical size of the cabinet does not "get in the way" of the next important part. When you actually measure the box at 1M-it will give a higher SPL than the rating-due to the physical size of the box and the boundary that it represents. But of course if you want to "cheat" then by all means measure up close and get higher numbers-but those numbers are not useful in the real world-but they ARE correct-at least for the measurement condition-which is invalid.</p><p></p><p>Why is that important to know? Because the whole purpose of determining the max SPL is to use normal inverse square calculations to be able for a designer to figure out how loud a box will be at a particular distance. So you can use this figure to see if the box is loud enough for a particular need/application.</p><p></p><p>It is also very important to have the actual freq response in the calculation-or else you do not know if the max SPL is across the intended freq range of the cabinet-or a single peak that can get very loud (but the rest of the cabinet cannot keep up). This is used pretty commonly-even by some major players to get higher numbers-no matter how useless they really are.</p><p></p><p>2: COVERAGE PATTERN This is very important to know how much area a particular loudspeaker can "cover" in both the horizontal and vertical planes. It is NOT a single number-as most manufacturers would like for you to believe. It varies with freq. The more consistent the pattern is in respect to freq-the more even the coverage is going to be across the listening area. If the pattern is 90 at one freq and 30 at another-there is no way the sound is going to be the same across the listening area. Some loudspeaker vary WILDLY with the coverage patterns making it next to impossible to predict anything useful.</p><p></p><p>It is also important when using more than one box-to figure out how to aim them.</p><p></p><p>3: Freq response (in particular high and low extension. For some people this is a big deal-for others-not so much. If you are doing material that has extension on either end of the spectrum-then you HAVE to know how loud a particular box will be at those freq-WITHOUT any processing. Then you can use the other numbers to figure out how loud it can get.</p><p></p><p>For example there is one manufacturer who claims very low freq extension. yes they cabinets can produce those tones (but so can a dome tweeter-just put a 1hz into a dome tweeter and watch it move in and out-it IS producing that freq-just not loud enough to be useful--------------------) but if you look at the sensitivity at those freq and the max power capacity-you will quickly realize that those tone cannot get loud enough for any practical usage-but they still make the claim.</p><p></p><p>You always have to look a bit deeper in order to get the real answer. Simple numbers DON'T EVEN begin to describe the performance of a loudspeaker.</p><p></p><p>I have rambled enough for now-time to get ready for a really hard load in LOTS of walking to get to the listening area 1000+ away from the speakers-and up and down LOTS of steps.</p><p></p><p>And of course there are lots of other parameters-but to me-those are the "biggies". If you don't have adequate information about those-then you simply have no idea what the loudspeaker can actually do. And sadly-this data is missing from MANY loudspeakers-even the largest companies. Maybe for a reason--------------------------</p></blockquote><p></p>
[QUOTE="Ivan Beaver, post: 81922, member: 30"] Re: Listening Get Together And while on the subject of measurements in general-let's not forget WHY they are important and WHAT they are used for. And this is measurements in general. 1: Sensitivity-power capacity-freq response. These two are used together to get an idea of how much SPL a box can produce at a particular freq at a given distance. 1M is the "standard" but in most cases the boxes are not actually measured at 1M. They are measured further away (and back calculated)-so that the physical size of the cabinet does not "get in the way" of the next important part. When you actually measure the box at 1M-it will give a higher SPL than the rating-due to the physical size of the box and the boundary that it represents. But of course if you want to "cheat" then by all means measure up close and get higher numbers-but those numbers are not useful in the real world-but they ARE correct-at least for the measurement condition-which is invalid. Why is that important to know? Because the whole purpose of determining the max SPL is to use normal inverse square calculations to be able for a designer to figure out how loud a box will be at a particular distance. So you can use this figure to see if the box is loud enough for a particular need/application. It is also very important to have the actual freq response in the calculation-or else you do not know if the max SPL is across the intended freq range of the cabinet-or a single peak that can get very loud (but the rest of the cabinet cannot keep up). This is used pretty commonly-even by some major players to get higher numbers-no matter how useless they really are. 2: COVERAGE PATTERN This is very important to know how much area a particular loudspeaker can "cover" in both the horizontal and vertical planes. It is NOT a single number-as most manufacturers would like for you to believe. It varies with freq. The more consistent the pattern is in respect to freq-the more even the coverage is going to be across the listening area. If the pattern is 90 at one freq and 30 at another-there is no way the sound is going to be the same across the listening area. Some loudspeaker vary WILDLY with the coverage patterns making it next to impossible to predict anything useful. It is also important when using more than one box-to figure out how to aim them. 3: Freq response (in particular high and low extension. For some people this is a big deal-for others-not so much. If you are doing material that has extension on either end of the spectrum-then you HAVE to know how loud a particular box will be at those freq-WITHOUT any processing. Then you can use the other numbers to figure out how loud it can get. For example there is one manufacturer who claims very low freq extension. yes they cabinets can produce those tones (but so can a dome tweeter-just put a 1hz into a dome tweeter and watch it move in and out-it IS producing that freq-just not loud enough to be useful--------------------) but if you look at the sensitivity at those freq and the max power capacity-you will quickly realize that those tone cannot get loud enough for any practical usage-but they still make the claim. You always have to look a bit deeper in order to get the real answer. Simple numbers DON'T EVEN begin to describe the performance of a loudspeaker. I have rambled enough for now-time to get ready for a really hard load in LOTS of walking to get to the listening area 1000+ away from the speakers-and up and down LOTS of steps. And of course there are lots of other parameters-but to me-those are the "biggies". If you don't have adequate information about those-then you simply have no idea what the loudspeaker can actually do. And sadly-this data is missing from MANY loudspeakers-even the largest companies. Maybe for a reason-------------------------- [/QUOTE]
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