DIY subwoofer: what does it need?

[WmAx]

So would it be true to say that if one has no idea of the mechanical capabilities of one's speaker's woofers (and/or electrical capabilities of one's amp presumably), one should use EQ only to lower peaks, not to raise nulls so as to prevent the potential overstress of either?

Regards

I do not generally recommend boosting nulls, but if the particular system has the available headroom, then it can be done in some cases. IMO, if one has no idea of the capabilities, then one should not boost anything in the low frequencies more than a couple of dB if they typically use their system at realistic SPL levels. Note that some nulls can not be corrected by any significant amount depending on the specific circumstances/conditions of a particular situation. Boosting by 3dB requires twice the power from the amplifier within that boosted band. Ample amounts of amplification are needed to prevent amplifier clipping when using this method.

-Chris

 

[kingdaddy]

According to my most recent experience, the Q of the filter is most important to the SQ. Even with a cut in frequency you can add a severe amount of nasty ringing If the filter Q is wrong. The room plays a major role and every combination is different, so proper measurement is necessary to get the filter settings right on a parametric equalizer. It is of my opinion that a PEQ can cause more problems then it will fix if you don’t carefully set up the filters to match your room modes and other speakers. FR in a sub is not nearly as audible as many think, a few peaks and valleys are not as audible as ringing at cretin frequencies. Until you have actually heard the effect of ringing you will not understand what I mean by this.