SoundMods wrote:
tomp wrote:
Shashi:
Looking at the numbers I got for your driver, you would need a box volume of approximately 16 cu ft to get an fB of 30 Hz. Typically with an optimally stuffed box you can expect an increase in the "apparent" volume of the box of about 25%. Therefore, your box under ideal conditions would look like 10 cu ft. That would give an fB of just under 35 Hz. I don't think any amount or type of stuffing will get you to 30 Hz. When stuffed, your current box would give you a Q around .5 which would result in good transient response.
Tom
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Then there is the enclosure. The stiffer the better. You can brace it like Tom has demonstrated or use constrained-layer damping on the outside to save interior volume.
There is no quick fix. Fitting the box with anechoic wedges will not change the resonant behavior of the box other than pushing the box resonance up rather than down and causing unforeseen problems with the overall playback quality.[/color]
Yesterday, I can feel a slight vibration in the backwall when the bass notes are played. That definitely needs stiffening. I will talk to you about it.
That wedges I am considering are not really anechoic in nature, they are just deflection devices. Most of the reflections that reach the cone are from the parallel backwall. By installing the small wedges on the back wall which will alter the angle of the surface there by altering the angle of reflection away from the cone and towards the four side walls (right, left, top and bottom). Since all the walls including the back wall have the acoustic absorption material, each point of incidence will cause loss of energy in the sound waves which eventually die down. Some of them still might reach the cone at significantly lower energy levels. The wedges I a considering are not in place of the stuffing but in addition to and only on the back wall.