Questions on sub-woofer amps [message #14925] |
Wed, 06 April 2005 19:06 |
gumby1
Messages: 63 Registered: May 2009
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Viscount |
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Some sub-woofer amps have "Bass boost". What is the purpose of this feature? I have a couple of 240 watt plate amps without "Bass boost" and I'm considering building two 10" sub-woofers, but the designs I'm looking at use plate amps with "Bass boost" (around 5 or 6dB@25Hz). I don't know if the plate amps I have could be used in the designs I'm looking at. If they can't be used, does anyone know of some good 10" sub-woofer designs that would not require "Bass boost"? These subs will be used only for two-channel stereo, not home theater.
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Re: Questions on sub-woofer amps [message #14947 is a reply to message #14926] |
Wed, 27 April 2005 21:30 |
Adrian Mack
Messages: 568 Registered: May 2009
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Illuminati (1st Degree) |
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Its there to artificially boost the low end response. Especially for sealed box subwoofers. If its the typical PE/Apex/Stryke style plate amp, it uses an EC SK 2nd order HP filter. Essentially its a high-Q 2nd order highpass filter. When Q>1.0 it forms a filter peak which is what forms the "bass boost", or EQ. Modifying it is a matter of replacing two resistors on the preamp board, and using simple textbook formula's to choose any Q and Fc you want. It is possible to design a subwoofer which EQ is an integral part of the design to form flat response, but EQ used disappropriately always makes a bad result.
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