Yes that is clear Still it remains the more important panel because the direct emission is so much more powerful than lateral top and rear emission
Imhe even just a thick metal bar bolted to the front baffle in its middle can provide huge benefits to the sound It will add mass and stiffness to the baffle
Ok but when the frame is so stiff that panels cannot move It is the case of magico
This is after all the rationale behind cabinet bracing Another great and more human case here
The internal bracing prevents the front baffle to move
In the case of Magico the side panels could be thin sheets of plywood kept in place just with some magnets Removable Ok with some rubber to seal the panels to the cabinet
I am sure they will work perfectly
I think that a good approach is to start design the internal frame and then move to the external panels Like B&W did with the Matrix series
The reason for making the front panel stiff is so that the drivers hammering on the cabinet transfer less energy into the cabinet which will then need to be removed. The (rate of) work done on the cabinet by the drivers is the product of force and velocity. The force is the reaction of the driver to the acceleration of the air, cone and coil which cannot be altered except by mounting the driver differently (e.g. force cancelling pair of woofers or soft grommets). The velocity of the cabinet/baffle will be reduced though by making it stiffer.
The force from the internal air pressure is negligible compared to that from the drivers at typical cabinet resonant frequencies. A separate cabinet for a low frequency driver may benefit from high stiffness to raise the resonances well above the passband of the driver in order to avoid them being driven. This is not the case if the cabinet contains a midrange driver which will contain resonances in typical designs.
If there is a midrange driver attached to the (hopefully stiff) baffle then the primary function of the remaining sides is to dissipate the energy/vibration that has entered via the baffle. This can be done by radiating it away as sound (undesirable) and by damping the motion of the sides (desirable). Stiffness doesn't matter much although high stiffness will raise the resonances to higher frequencies where they are audibly more discernable and intrusive. The optimum approach is likely to be something like stiff enough to mechanically handle the lowest frequencies while introducing the largest amount of damping that is practical. A frame with well damped panels attached is a reasonable approach. It doesn't require anything out of the ordinary to design a cabinet that is acoustically inert so long as the physics is followed. A common example of not doing this is bracing the hell out of everything while not introducing any effective damping.
Sir Isaac Newton strongly objects! Acceleration=Force/Mass
Higher mass driver with high enough strength of magnetic motor will surpass any low mass driver, anytime.
Further, low mass cones are subjects of resonances and no low-frequency output.
@Sonce Stay constructive, we are not here to read we don't know anything ( and you know better). It is better to stay in exchange and understand why people think differently than you.
Why Manufacturer of speaker drivers use light thin foils of materials to make speaker drivers if mass is no object ?
Note you should read more carefully what I wrote. I agree you can compensate mass by force but you have some tradeoffs.
Why Manufacturer of speaker drivers use light thin foils of materials to make speaker drivers if mass is no object ?
Note you should read more carefully what I wrote. I agree you can compensate mass by force but you have some tradeoffs.
I’ll give it one go (and I’m no expert…). Cone design is about trying to move a ‘piston’ in sinoidal movement at the highest frequencies needed, without breaking up. You need to consider the speed of sound in the cone material as well. Furthermore, if the cone breaks up, it should preferably do so in a benign way, either sufficiently damped or high up outside the pass band.
Next comes the challenge of properly attaching suspension, VCA and surround (picking the right surround matching a cone and it’s intended pass band is a piece of engineering itself).
Now cone mass is actually no big issue in the above. Apart from the thing that you have to drive the cone in the end. But mass in itself is no factor in dynamic cone behavior (not without elasticity/damping and geometry of the cone anyways). So in the end only looking at cone mass is giving you not near a quarter of the information you need to assess the quality of it.
Next comes the challenge of properly attaching suspension, VCA and surround (picking the right surround matching a cone and it’s intended pass band is a piece of engineering itself).
Now cone mass is actually no big issue in the above. Apart from the thing that you have to drive the cone in the end. But mass in itself is no factor in dynamic cone behavior (not without elasticity/damping and geometry of the cone anyways). So in the end only looking at cone mass is giving you not near a quarter of the information you need to assess the quality of it.
Just to point out one item: the energy transferred into the cabinet by firmly mounted drivers is independent from baffle/cabinet - it's always the same, unless you add weight, dampening or a counteracting force to the driver itself.
I also tried to mention (but probably in poor wording):
Low frequency cabinets should be made stiff, so the panel resonances are pushed up, out of the pass band. I should add that keeping the reaction forces low by attaching weight or even better cancelling them with a second driver is best. Adding weight to the panels however lowers their resonances!
Mid cabinets should be made heavy (thus lowering resonances out of pass band) and absorptive. Adding bracing can raise panel resonances into pass band!
Midwoofer cabinet has to be a compromise.
I do understand - some people think differently than me because they don't know the basics of physics. Nothing to be ashamed of, we can't know everything.
Because magnetic gap in ribbon tweeter is wide about 15 mm, so the magnetic field/force in the gap is weak. Ribbon foil must be very light and thin, to be moved by that weak magnetic field.
Conventional moving-coil loudspeakers have much higher diaphragm mass, but the magnetic gap is wide only 2 mm, so the magnetic field/force in the gap is very strong.
Mass is important object! But it can be handled, if you know how:
Acceleration = low Force/ low Mass = high Force/ high mass
Sure, assuming that the object is pure osciallatory / pistonic action over a limited BW, up to, say, the VC point-source frequency. That does start to fall apart though when you move into drivers (a large number) designed to use TL / resonant modes to extend their upper BW, since a higher mass / more highly damped cone is unable to do that. Hence W.E. / Bell / Altec came up with progressive decoupling of portions of the cone back in the '30s, variations of which have been used ever since. It could be argued (and Avalon certainly would, at least in their original incarnation) that only pistonic operation should be used -fair play for a company or individual choice, but since it condems the majority of soft / semi-rigid cone drivers & all soft domes to the scrap-heap, however capable they actually are, it can also be a bit extreme if applied generally.
The acceleration business is really just another way of describing conversion efficiency anyway; probably a more intuitive one in some ways too, with the useful transient response being a function of system Q < the mass corner frequency, & VC inductance, diameter & cone diameter / profile in the mass controlled BW.
More mass :
- Frequency response lower
- Less sensitivity
- Worse transient response
- Harder to control
- Less displacement
- More wear and fatigue of the suspension
Some of these issues are observed by listening, note Physics is based on observations. The apple falls on the head of I. Newton as first observation.
Speaker driver is a bunch of compromises.
Note I prefer that type of exchange 🙂
To stay on the subject a loudspeaker is also a bunch of compromises ?
The force is effectively independent but the (rate of) energy transferred is not because it is the product force and velocity. The stiffer the baffle, the less it deflects, the smaller it's velocity and the smaller the (rate of) kinetic energy transferred into the baffle/cabinet.
More displacement rather than less.
Harder to control: depend of amp own spec.
Wear and fatigue: depend of material used.
Transient response: hmmm. Depend of strategy of amp used (mfb).
Wait. It does depict what is needed for a subwoofer. And don't start me on low end transient response... 🙂
Hence why this kind of drivers are used for such tasks. 😉
the only item listed of relevance: all other items have no relation with Mms.
Or better 0.5 g Vs. 5 g
@ 20 kHz, say, also 10 kHz or 1k
( I guess that form follows function, so shape and material...)
Decoupling the drivers with some thicker isolation does a lot to minimize "Körperschall" i.e. vibration transfer onto the box panels.
My all time favorite https://en.toutlehautparleur.com/speaker-audax-hm170g8-8-ohm-6-54-x-6-54-inch.html
And my next speakers in D-Appolito transmision line https://www.diyaudio.com/community/...eded-really-nice-speakers.380190/post-7698438
And my next speakers in D-Appolito transmision line https://www.diyaudio.com/community/...eded-really-nice-speakers.380190/post-7698438
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It depend from lowest freq involved. Ime, Bouncing is not a concern of my, ymmv. Overall decoupling bring more than the issue generated ime.
For mid/high it works great:
https://www.linkwitzlab.com/Driver Decoupling.doc