but I am not sure if those big wire coils and huge capacitors are needed, as shown in their monitor models. It would be good to have a circuit to take care of frequencies like theirs...
...but something simpler.
And what about design... What would it be the best possible box/case design. Is MDF-wood good enough to make those?
... and if I should seal the case or make it "opened".
Hey guys,Time to upgrade my little PC audio outputs.I am planning to build up, DIY way, a pair of small loudspeaker monitors. Currently, I have:- A pair of these 4 inch mid-bass, 50W RMS 4 Ohms:- And a pair of these 4 inch, 40W RMS 4 Ohms... that looks just like this one (with a little tweeter built-in):These are very good quality speakers in the market here and I was also planning to acquire a separate tweeter for the monitor.What I wanted is advice on design and circuitry for the setup.
I have lurked on a website called http://www.humblehomemadehifi.com/ and there are some pretty good projects there but I am not sure if those big wire coils and huge capacitors are needed, as shown in their monitor models. It would be good to have a circuit to take care of frequencies like theirs but something simpler. Any suggestions?
First of all loudspeaker drivers don't have ruler flat frequency and impedance curves. The load that a driver presents to an amplifier consists of a complex electrical impedance, a combination of resistance and both capacitive and inductive reactance. A loudspeaker driver does not have a constant resistance across its frequency range. Instead, the voice coil is inductive, the driver has mechanical resonances, the enclosure changes the driver's electrical and mechanical characteristics, etc. (source: http://en.wikipedia.org/wiki/Loudspeaker). For example a nominal 8 ohm midwoofer can have an impedance curve with peaks of over 50 ohms and a dip down to 6 ohms. So that makes all static charts, tables and online calculators completely useless.So the only way to design a loudspeaker crossover correctly is to take very accurate measurements of each of the driver's frequency and impedance curves with their corresponding acoustic and electrical phase response, in their final enclosures and after they are fully burnt-in. Also waterfall plots must be made to see if there are any parts of the frequency spectrum that take a little too long to decay. And add in a few off-axis frequency measurements to check baffle edge diffraction problems and some distortion measurements for spotting any other nasties. And don't forget to measure the output from the port either - especially with a two-way system, there can be quite some midrange energy radiating from the bass reflex port!
What I am looking for is basically the best circuit to go with those speakers I presented and if I should seal the case or make it "opened".