Coming up with your own speaker box design is not easy. I’ll give you that. Most people don’t have the understanding of how the loud speaker works to begin a design in the first place. It has nothing to do with a persons level of intelligence. I think most people just don’t care or don’t think that it can be done easily.
To a certain extent this is true; speaker design is not easy. But it is not impossible for the average home theater guy/gal to do either; certainly not impossible.
The basic parts of any cone type speaker are the same, and there are not very many parts either. You have the box, the speaker drivers -or cones, some acoustic stuffing, internal cables, binding posts, paint or veneer, speaker crossover components, and maybe some cones to sit them on. That’s about it.
But the art is in how these items are put together, and how they are balanced that makes or breaks a design.
Arguably the most difficult part of the speaker design is the crossover. Why? It handles the voltage that enters the speaker through the cable and it splits the signal so that the correct information only enters each individual speaker driver. If you send the wrong signal to a driver you can blow speaker drivers in a millisecond. And most high quality speaker drivers are not cheap.
But in the last few years some different types of crossover have begun to gain popularity. They are active and digital crossovers. Digital crossovers differ because they take a signal from your CD, PC, or DVD player and split the signal all while in the digital domain. The advantages of making the crossover in this way are too many to list here. I’ll devote another article to that later. But these digital filters make it possible for even a novice hobbyist to experiment with different slopes and speaker drivers.
The best part of this; is that this digital technology is already available and working now. These digital programs can be installed into a computer or HTPC and used in the home theater system.
And these filters make speaker box design a project that many more enthusiasts can take on with success. Time and phase coherence can also be achieved with digital delays from within the crossover software program. Driver correction and room correction are also functions easily achieved within some of these programs.
Keep in mind you will need a channel of amplification, pre-amplification, and an output channel from the sound-card for each driver used (using a digital or active crossover).
The Speaker Box:
The other elements of speaker design are important too. Drivers should be placed as near to one another as possible. (the mid-range and tweeters) Bass driver positioning is not quite as important as bass waves below 100Hz are mostly omnidirectional.
Cabinet quality is extremely important to the amount of energy the cabinet will release back into the room.
In a perfect situation the cabinet would be completely inert. Meaning; the speaker cabinet would not resonate or make any sympathetic vibration from the back-wave of the speaker cones. The only sound would be the energy from the speaker driver itself.
In the real world achieving this level of resistance to resonance is very difficult. The amount of materials and internal bracing would be considered extreme by most retail speaker builders. But this is the beauty of DIY speaker box design. You can make the cabinet as heavy and inert as your budget allows.
When you build your own speakers you will save a ton of money over retail high end speaker systems. It’s simple really, the amount of labor and markup involved in building speakers is extremely high. And when you do it yourself it’s extremely rewarding.
I wouldn’t have it any other way!