The Subwoofer DIY Page - Discussion Forum

[ The Subwoofer DIY Page - Discussion Forum ] [ FAQ ]

[Previous Message] [Next Message]

Date: December 12, 2001 at 05:21:46
From: newmz, [perax4-009.dialup.optusnet.com.au]
Subject: Re: how to find sub res. freq.


I'm a little confused about the question (and some of the answers you've had), because maybe there's an assumption everyone knows here, but I don't know which resonant frequency you mean. Do you want to know Fs (the free air resonance of the driver), or the resonance of the driver and any box it's in and/or perhaps the trunk? You can measure the Fs if you're lucky enough to have a signal generator (or a good test cd), a frequency counter/meter and a voltmeter.
This is a straight quote, refering to a setup where the freq. counter and V-meter are paralleled on the signal lines from the signal generator, with a 1kohm resistor in series on the +ive line between them, and those lines continue to the driver. It's from "The Loudspeaker Design Cookbook" (- Vance Dickason, I have the 3rd edition);

Using the test setup, hold the driver in midair and vary the generator frequency between 10Hz and 100Hz until you locate a maximum voltage reading. This frequency is the driver free air resonance.


I assume from reading on that you can probably do the same test with the driver in whatever enclose, etc but that will only ever be the *driver* resonance, speaker encloses (including a car) have their own resonances and the total effect is probably some kind of average of them all. I think that Q is a more useful measurement because it more or less tells you what resonance magnification will happen.


  • View the previous message in this thread
  • Go to the top of this thread
  • View entire thread
    		•

    Posted with TalkShop version 2.71-8 BETA

    [Previous Message] [Next Message]



    Follow Ups:

    [ The Subwoofer DIY Page - Discussion Forum ] [ FAQ ]