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<blockquote data-quote="Ivan Beaver" data-source="post: 49453" data-attributes="member: 30">Re: Need subs that will do 20hz-40hzThe one thing I would really be careful of (when talking about subs specifically that go down to around 20Hz) is to SEE A MEASURED RESPONSE curve.&nbsp; There are a lot of claims out there on the &quot;-3dB&quot; point, but when you look at the ACTUAL response, you will see that a number of them (even the famous names) the stated -3dB point is more like -9dB.&nbsp; That is a lot of ground to make up.I would not trust &quot;simple numbers&quot;-when you are looking for specific responses.&nbsp; But that is just me.I would also be VERY cautious of any sub that suggests an EQ boost in order to get the low freq number they claim.&nbsp; That is all fine-until you get towards the max output area of the sub.&nbsp; If you have already added-say a 6dB bump-then you are going to HAVE to subtract that 6dB from the max available output-at the freq where the bump is.&nbsp; And since that is the main area of interest-the stated max SPL is going to be lower than what you would expect.&nbsp; At higher freq-you should be able to get the stated output-but putting a boost-starts to screw up the numbers.Or stated another way-lets say the spec is 100dB 1w/1m with 1000 watts continuous.&nbsp; I choose those numbers for &quot;easy math&quot;.&nbsp; That would put the max output at 130dB.&nbsp; But if you put a 6dB boost down at say 25Hz, then you are no longer applying 1 watt to the system-but rather 4 watts.&nbsp; So if you refigure the max output, the gain is now 24dB, NOT 30dB.&nbsp; So down low (at 25Hz) the max output is 124dB (assuming the response graph is flat at that point and not starting to roll off already).&nbsp; Now I am assuming that the 6dB boost is used to make the response &quot;flat&quot;-and not to add a &quot;bump&quot; in the low end-most are not used to add a bump-only to make it appear that the cabinet goes lower than it does-with a &quot;nominal&quot; input.You CANNOT use one set of numbers (say the 1 watt/1M) and then &quot;just add&quot; an extra boost and refigure-assuming nothing else has changed.Just be careful how the specific graphs are presented-there are all kinds of &quot;games&quot; out there.Buyer beware is my suggestion.</blockquote>

[QUOTE="Ivan Beaver, post: 49453, member: 30"] Re: Need subs that will do 20hz-40hz The one thing I would really be careful of (when talking about subs specifically that go down to around 20Hz) is to SEE A MEASURED RESPONSE curve. There are a lot of claims out there on the "-3dB" point, but when you look at the ACTUAL response, you will see that a number of them (even the famous names) the stated -3dB point is more like -9dB. That is a lot of ground to make up. I would not trust "simple numbers"-when you are looking for specific responses. But that is just me. I would also be VERY cautious of any sub that suggests an EQ boost in order to get the low freq number they claim. That is all fine-until you get towards the max output area of the sub. If you have already added-say a 6dB bump-then you are going to HAVE to subtract that 6dB from the max available output-at the freq where the bump is. And since that is the main area of interest-the stated max SPL is going to be lower than what you would expect. At higher freq-you should be able to get the stated output-but putting a boost-starts to screw up the numbers. Or stated another way-lets say the spec is 100dB 1w/1m with 1000 watts continuous. I choose those numbers for "easy math". That would put the max output at 130dB. But if you put a 6dB boost down at say 25Hz, then you are no longer applying 1 watt to the system-but rather 4 watts. So if you refigure the max output, the gain is now 24dB, NOT 30dB. So down low (at 25Hz) the max output is 124dB (assuming the response graph is flat at that point and not starting to roll off already). Now I am assuming that the 6dB boost is used to make the response "flat"-and not to add a "bump" in the low end-most are not used to add a bump-only to make it appear that the cabinet goes lower than it does-with a "nominal" input. You CANNOT use one set of numbers (say the 1 watt/1M) and then "just add" an extra boost and refigure-assuming nothing else has changed. Just be careful how the specific graphs are presented-there are all kinds of "games" out there. Buyer beware is my suggestion. [/QUOTE]

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