dB616tl Speaker Project Build Diary



Introduction
Day 1
Day 2
Day 3
Day 4
Day 5
Measurements
Day 6
Day 7
Day 8
Day 9
Day10


Links

dB616tl plans

dB61tl construction/review

Parts Express Forum

Parts Express

Transmission Lines



And of course, take a look at builddiary.net my page for all things excessive-hobby related.







I've had this strange fascination with complex DIY projects for years. It started when I used to read homebuilt airplane magazines when I was a kid. When I rediscovered DIY stuff a few years ago, I fell in love with the idea of making guitars, boats, planes (again), cars, organs, amplifiers... I love any large project that seems almost impossible until you see it broken down into steps. Many people who are similarly fascinated tend to want to build the ultimate, coolest, most expensive, etc. I've always looked at the projects that seemed actually affordable (i.e. "How to build a Sports Car for £250, and RACE it...")
The only hitch with my rediscovered hobby was that I was...
  • A poor college student
  • Lived in a small apartment
  • Didn't own many tools
  • Haven't spent too much time in a shop
Now that I have graduated from college, all the other problems still apply, and I don't feel comfortable building a car in the apartment (something tells me the wife would not approve, no matter how understanding she is, and she's about as understanding as they get.)
I've been thinking about replacing my stereo speakers ever since a day in 1995 when I went speaker shopping with a friend who bought a nice pair of mid-fi Paradigm floorstanders. I know how much a decent pair of speakers cost, and I know that in my present financial conditions, I still can't afford them. So after looking at speakers, and realizing I couldn't buy something I really wanted and still retain a conscience, for some blurry reason lost in the mists of time, I started looking at DIY speakers.
I searched around for a while, finding yet another community of people, much like the communities surrounding other DIY projects. And it dawned on me that I could do this, even within my limited means and space. Besides, I had a good friend only about an hour's drive away who had access to a nice shop and lots of power tools. And this good friend was in as much of a need of something to do as I was.
So next, I had to settle on a design. There are tons of designs available, almost all available for free. I looked at electrostatics (fun, but I'm more of a rock/jazz guy than a jazz/classical guy, plus my amp probably couldn't handle it.). Then looking at one of the electrostatic pages, one design used a subwoofer in something called a transmission line cabinet. So I looked into transmission lines, which seemed like the best way to get the most/best/flattest sound out of a given set of speakers, as long as you don't mind making a complex cabinet to put them in.
This still only narrows the field down to 20 or so designs, but my eye kept coming back to a design by Dave Brown that had everything I was looking for -- a proven design (at least 3-4 pairs built, with people that seemed satisfied with them), relatively inexpensive (no driver costs more than about $16, simple crossovers), not terribly hard to build, and a really detailed website with plenty of construction details.
So I ordered the parts, and called the old friend who seemed happy enough to help, and got started...