Designing portable speakers

When designing portable speakers



-Keep an eye on weight, weight in all your components;

-Do deep research on the components you'll be using ;

-Investigate the components used in the amplifier, pre-amplifier and have their datasheets at hand reach;

-Always use class d amplifiers as opposed to class A, B, A/B, etc.. as class d amplifiers are far more efficient as other class amplifiers;

-Almost all class d amplifiers with high output need high voltage supply, so you are left with two options, boost battery voltage and have a higher capacity or, if available, modify pack for most cells in series as possible and less capacity, as this will provide less current draw from amplifier, less charge time, and as the booster will be another component wasting battery by dissipating, even if it has a high efficiency it will always be a factor you should consider in terms of the speakers run time.

-Choose the best speakers possible while also keeping a budget, and try to match speakers power rating to amplifier's power rating, if not possible, get speakers with a power rating below the amp's power rating, as you can easily limit the amplifier output, where if the speakers had bigger power rating than the amplifier, the amplifier would be forced to drive the speakers above it's normal operating conditions and might not give a good result and might even distort.

-Design the speakers graphically before purchasing components;

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Passive radiators

All concepts i learn about passive radiators



-From Fs and Vas you can calculate Cone mass

-Cone area is just pi * diameter^2 / 4
for diameter use half of the surround width.

-The easiest way to design a PR box is to design a ported box with a port the same diameter as the PR, your program will spit out a port length. Add about 3/4 of a port diameter to this length, then calculate the mass of the air in this port. Subtract from this mass the mass of the PR cone and you have the amount of mass you must add.

-A passive radiator can be achieved through a cheap driver that meets your needs, not connected to anything, and the tuning can be made via adding mass to the cone or via a potenciometer between the two leads of the driver thus making a resistive brake(experiment with potenciometer position for ideal tuning).

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