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<blockquote data-quote="Ivan Beaver" data-source="post: 58924" data-attributes="member: 30">Re: Subwoofer comparison SRX728 vs Vertec 4883The question is &quot;exactly what does the -3dB freq ACTUALLY mean?&quot;&nbsp; On the Danley spec sheets, it is 3dB down from the rated sensitivity-that is not always the case with all manufacturers.If you look at a lot of MEASURED RESPONSES (from various manufacturers)- you will see that the &quot;quoted -3dB) is NOT 3 db down from the rated sensitivity (it is for some but not for all-don&#039;t make ANY assumptions-and they vary within different products from the same manufacturer)-they HAVE to be tied together-or else both are meaningless.&nbsp; I have seen cases where the quoted -3dB freq is ACTUALLY 9-10 dB from rated sensitivity.If they are tied together-then a manufacturer has to &quot;choose&quot; whether the numbers should say a lower freq extension AND a lower sensitivity or have a higher sensitivity AND a higher low freq number.&nbsp; It is NOT a matter of choosing the &quot;best of both worlds&quot; but lots of manufacturers do-incorrectly.Of course without a measured graph-you only have the numbers to go on-and then that raises a lot of other questions-where did the actual sensitivity number come from?&nbsp; What is the REAL -3/-10dB point-is it in half or full space and so forth.You ALSO have to look at whether or not there is any DSP &quot;boost&quot; applied down low to get that number.&nbsp; If there is (very common these days), the you HAVE to SUBTRACT that amount of boost (often as much as 6dB or more) from the maximum output rating-at least at the freq at which the boost was applied.So these cabinets may &quot;appear&quot; to go lower at low power levels-but when you ramp it up to loud levels-the low freq cannot keep up.Just things you HAVE to keep in mind when looking at the &quot;simple spec numbers&quot;.&nbsp; They are not always as they appear.</blockquote>

[QUOTE="Ivan Beaver, post: 58924, member: 30"] Re: Subwoofer comparison SRX728 vs Vertec 4883 The question is "exactly what does the -3dB freq ACTUALLY mean?" On the Danley spec sheets, it is 3dB down from the rated sensitivity-that is not always the case with all manufacturers. If you look at a lot of MEASURED RESPONSES (from various manufacturers)- you will see that the "quoted -3dB) is NOT 3 db down from the rated sensitivity (it is for some but not for all-don't make ANY assumptions-and they vary within different products from the same manufacturer)-they HAVE to be tied together-or else both are meaningless. I have seen cases where the quoted -3dB freq is ACTUALLY 9-10 dB from rated sensitivity. If they are tied together-then a manufacturer has to "choose" whether the numbers should say a lower freq extension AND a lower sensitivity or have a higher sensitivity AND a higher low freq number. It is NOT a matter of choosing the "best of both worlds" but lots of manufacturers do-incorrectly. Of course without a measured graph-you only have the numbers to go on-and then that raises a lot of other questions-where did the actual sensitivity number come from? What is the REAL -3/-10dB point-is it in half or full space and so forth. You ALSO have to look at whether or not there is any DSP "boost" applied down low to get that number. If there is (very common these days), the you HAVE to SUBTRACT that amount of boost (often as much as 6dB or more) from the maximum output rating-at least at the freq at which the boost was applied. So these cabinets may "appear" to go lower at low power levels-but when you ramp it up to loud levels-the low freq cannot keep up. Just things you HAVE to keep in mind when looking at the "simple spec numbers". They are not always as they appear. [/QUOTE]

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