the crate
I had a problem. I was moving to California for work, and I could only take the belongings that could fit inside my car. Unfortunately, my beloved 2.1 system I owned in college was just too large for my car, let alone a car filled with all my other belongings. Do I simply sell my previous system and buy another when I get there? Sure, I could do that. But I could also make this my own thing and learn something. I tend to learn a lot more when I do something myself.
I'll build it.
Next time you're in front of a good pair of speakers and a well mastered song, listen intently. You might notice you can hear the location and orientation of each of the instruments in the recording studio - this is called sound imaging. Many artists replicate their arrangement in the studio with their arrangement on the stage for this reason. Further, you might feel a wash of sound surrounding you, as if you're being wrapped in blanket of sound - this is called soundstage. If you've ever been to a concert, you've felt this sensation. Many people argue a soundstage can be brute forced with volume alone, but that's an argument for another time. Desriptive imaging and a verbose soundstage coexist with one another, much like how a particular rhetoric helps drive a narrative.
I decided I would build something more portable and with better stereo imaging. There are my requirements. Go from there.
I wanted to make something I would really enjoy and could place anywhere without fear of spoiling a nice looking room. I won't bore you with the details, but I made the following hardware selections. For drivers, I used two Morel MDT12 tweeters and 2 HiVi M5a Woofers - both of which can be found in ultra high end speakers in their own right. I used Dayton Audio 2nd order crossovers rather than design my own as I was a little bit strapped for time. Cabinets and tuning - the crux of speaker design - I initially tuned the box to 55 Hz using this MATLAB script I wrote, but later changed this tune slightly after fine-tuning the port length while listening to it being driven by a live amp. Ports are 1.375" diameter, one of them is 3.68" in length while the other is completely flush, I found making one flush provided a better bass response for an otherwise weak subwoofer performance (as was expectd). 1 inch thick sonic foam was placed on the top and sides of the inside cabinet to dampen the box resonance.
For an amp, I used the Lepai 2020a+ as it was cheap and it would fit... and that was a mistake. The Lepai simply does not have enough clean power to drive the woofers at high volumes. The sound clips and the music degrades substantially at those power levels, which is also bad for the drivers themselves. I've been telling myself to replace this amp since I built it, but i never made time.
Last week, nearly three years after the initial build, I got around to replacing the Lepai amp with a much higher quality SMSL. I've decided to revisit this subject and post this build simply to document the process.
To the right is a video I took during install. I was doing a test to make sure I had all the components hooked up correctly.
Song: American Eyes by Promises Ltd.
Good test song with big soundstage and healthy dynamic range.
Below is the original build album. Click through and follow along with the captions to get a taste of what is going on throughout the build process.
