Hi,
don´t know the KEF construction and didn´t read the linked threads, but here are my thoughts.
If the Basket and magnet of the driver are mounted as stiff as possible and in a truely fixed position, the energy transfer to the moving membrane is maximal.
If the driver is fixed onto a box front panel the vibrating force vector acts in parallel on the panel´s smallest dimension, its thickness.
Hence energy transfer into the front panel is maximal too.
Energy transfer would be minimal, if the driver has no contact to the front panel and be fixed to a cabinet wall(s) where the force vector is in parallel to the largest dimension -or perpendicular to the smallest dimension.
This would be the case with a fixation of the driver onto a brace that connects with the side walls and a soft air-tight seal between the driver´s basket and front panel.
This could probably only be topped by a inertia-cancelling push-push configuration utilizing a second driver.
jauu
Calvin
don´t know the KEF construction and didn´t read the linked threads, but here are my thoughts.
If the Basket and magnet of the driver are mounted as stiff as possible and in a truely fixed position, the energy transfer to the moving membrane is maximal.
If the driver is fixed onto a box front panel the vibrating force vector acts in parallel on the panel´s smallest dimension, its thickness.
Hence energy transfer into the front panel is maximal too.
Energy transfer would be minimal, if the driver has no contact to the front panel and be fixed to a cabinet wall(s) where the force vector is in parallel to the largest dimension -or perpendicular to the smallest dimension.
This would be the case with a fixation of the driver onto a brace that connects with the side walls and a soft air-tight seal between the driver´s basket and front panel.
This could probably only be topped by a inertia-cancelling push-push configuration utilizing a second driver.
jauu
Calvin
Well the rubber surround for the cone does a pretty good job and so sticking a slightly larger one between the cabinet and metal frame would be a cheap and simple thing to do. Possibly in combination with a larger cone suspension for the magnet to control the movement? I think the real problem is more that it does not bring overall benefits for woofers and so is not worth doing either well or badly.
This is only an option if the cabinets are separate and passively isolated from each other. If there is only one cabinet then it is going to resonate in the passband of one or more drivers and some form of damping and/or isolation will be needed for good performance.
Rate of energy (power) = force * velocity in the direction of the force.
The force is given by mass * acceleration of the cone (plus air) and is essentially constant in magnitude. For a stiffer connection to the cabinet, the cabinet will deflect less which will reduce the magnitude of the velocity and indeed looks as if it should reduce the work put into the cabinet.
However, the force and velocity are not going to be aligned in time and so energy will be transferred in both directions between the driver and the cabinet. For example, if the cabinet were a pure spring and the driver moving with simple harmonic motion there would be zero overall energy transfer between the cabinet and driver.
Hi,
hmm sloppy use of the term energy. Should have used the terms excursion or bending instead.
jauu
Calvin
hmm sloppy use of the term energy. Should have used the terms excursion or bending instead.
jauu
Calvin
I don't think this is correct. If you assume that the speaker basket is rigidly connected to the cabinet, then the transfer of vibration from the basket is maximized, not minimized. If there is no connection to the cabinet, then no vibration is transmitted.
I rather like the idea of attaching the driver to the cabinet sides instead of the face.
What is "vibration"? Force, energy, momentum, work, pressure, acceleration, velocity, deflection,...?
If there is no force then indeed there is no work transmitted but also if there is no velocity then there is no work transmitted either. But I did make a mistake in stating the magnitude of the force would be constant which will not be the case. A stiff strut strongly resisting the movement of the driver will feel more force than a soft strut largely following the motion of the driver. So both the velocity and the force will vary and we will need more information to do the sums to say where the maximum energy transfer lies between zero for no force at one end and zero for no movement/velocity at the other.
Um,no.
There is a stimulating force, a reaction to cone movement. No matter the attachment that doesn't change. All that changes is how that stimulus couples to the cabinet. A stiff connection maximizes the amount of energy transmitted to the cabinet. No connection would mean no transmission to the cabinet. You can't change the amount of reaction to the cone movement, only where it goes.
There is a stimulating force, a reaction to cone movement. No matter the attachment that doesn't change. All that changes is how that stimulus couples to the cabinet. A stiff connection maximizes the amount of energy transmitted to the cabinet. No connection would mean no transmission to the cabinet. You can't change the amount of reaction to the cone movement, only where it goes.
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