Your motor bike wheel goes up or down against a step, or hits a pothole.
How the wheel returns to equilibrium is the subject of spring damper relation, decided by the makers who used that combination in the shock absorber.
One is a step input, the other almost sinusoidal.
Different results can be obtained by changing spring and damper rates, and their combinations.
That is at work here, you have three damper rates, and they are all for different frequencies.
Sometimes I talk in shorthand...have difficulty in explaining.
Maybe R-C networks, and capacitor discharge curves could be used as an analogy for spring damper returns to equilibrium. But I am a Mechanical, not Electrical Engineer...
Maybe a power rail, with three different capacitors in parallel, will it not filter three sets of frequencies?
Something like that is what I am trying to explain.
How the wheel returns to equilibrium is the subject of spring damper relation, decided by the makers who used that combination in the shock absorber.
One is a step input, the other almost sinusoidal.
Different results can be obtained by changing spring and damper rates, and their combinations.
That is at work here, you have three damper rates, and they are all for different frequencies.
Sometimes I talk in shorthand...have difficulty in explaining.
Maybe R-C networks, and capacitor discharge curves could be used as an analogy for spring damper returns to equilibrium. But I am a Mechanical, not Electrical Engineer...
Maybe a power rail, with three different capacitors in parallel, will it not filter three sets of frequencies?
Something like that is what I am trying to explain.
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In short, the object is to keep the cab from 'breathing', so tie all six sides together and support/brace the driver to this framework like Dave P10 shows on his various cab drawings, then if the speaker isn't heavy enough to sit inert, either use isolation feet or preferably mass load it with (removable) heavy enough weight(s) perched on top with a general rule-of-thumb' (ROT) of starting with however much the speaker weighs.
FYI, not a good plan to assume that if it's big, heavy as built that it's enough as one DIYer proved here, though note that this is an extreme case since this ancient factory built cab is more about how cheap/light they could build/ship/install it, i.e. a flimsy, resonant piece of junk by today's standards unless of course you want a cab that 'sings' along, which FWIW was apparently also a requirement till the early '80s when they dramatically increased its mass/rigidity (828 cab) due to increasing power handling, sturdier construction for suspended arrays.
mass loaded Altec 825 horn cab
with mid/HF horn added
Well it is definitely one ‘school’ of thought in loudspeaker design for sure.
many however still enjoy the BBC approach and why those speaker designs still sell a ton these days.
pretty fascinating if you ask me.
i wonder what the consensus and science on loudspeaker design will be in the decades following.
will be interesting for sure.
many however still enjoy the BBC approach and why those speaker designs still sell a ton these days.
pretty fascinating if you ask me.
i wonder what the consensus and science on loudspeaker design will be in the decades following.
will be interesting for sure.
you know. I actually understood most of that.
lol
spoken like a true mechanical engineer without paper to draw diagrams.
ha
I’m messing man. That was a pretty nice write up.
too bad I don’t have your knowledge.
SMPS...sometimes a small ceramic / film cap is added in parallel to the main caps to reduce HF noise...
Or in other applications also, say 4700uF / 100uF / 100 pF in parallel across a power supply rail, each will have its own resonant frequency (2*pi*R*C), so you can design it to absorb or amplify the chosen frequencies.
That speaker has the physical equivalent of the circuit above.
Or in other applications also, say 4700uF / 100uF / 100 pF in parallel across a power supply rail, each will have its own resonant frequency (2*pi*R*C), so you can design it to absorb or amplify the chosen frequencies.
That speaker has the physical equivalent of the circuit above.
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In this case, the sound waves pass in series through different layers, and that is where the expert analysis and experience come in, as there may be reflections as well.
Difficult, doable, but ultimately not much improvement will be achieved.
Difficult, doable, but ultimately not much improvement will be achieved.
(I have not read all 8 pages of this thread)
This is not inside the box, it's outside. RoomTune Speaker Clamp
https://db.audioasylum.com/mhtml/m....cgi/search.mpl?forum=vinyl&searchtext=Hana+ML
This is not inside the box, it's outside. RoomTune Speaker Clamp
https://db.audioasylum.com/mhtml/m....cgi/search.mpl?forum=vinyl&searchtext=Hana+ML
A motorcycle spring and damper are in series.
As Dave says, the panel damping and air damping are on different jobs, they've taken their own paths.
All ProAc models use hd mdf or whatever it’s called not standard mdf
25mm front and back with 18mm sides, top and bottom
And the bigger ones are
25mm front back and sides with 18mm top and bottom
All have thicker bitumen the higher up the range you go
All lined with baf wadding in the big models and open cell foam on smaller models such as the DT8
25mm front and back with 18mm sides, top and bottom
And the bigger ones are
25mm front back and sides with 18mm top and bottom
All have thicker bitumen the higher up the range you go
All lined with baf wadding in the big models and open cell foam on smaller models such as the DT8
I wager they will suggest you do not add internal bracing to your ProAc DT8s! 😉