- The next Audio Club meeting is on Mon, April 21. The meeting time is 5:30 p.m. and the place is 3043 Coover.
- We will discuss the operating principle behind the Class-D amplifier. And we will try our comparison between the 3122 project amp and the GTDT amp that we built last semester. Hopefully, it works this time!
- We will also briefly discuss the new version of the Temp-Time Arduino project. This will be available to build next week. It will be our final project of the semester.
Feb 24, 2025
Regarding the speaker build
- You've seen the finished speakers, and so you have an idea of how big they are. (As a reminder: the outer dimensions are 9 in x 8 in x 6 in.) You will be getting a lot of material, and so be prepared to carry a lot of stuff home. The wood panels will be in grocery bags, but there will be a lot of other loose parts to lug home. You may want to bring a box — something on the order of 1 ft x 1 ft x 1 ft should be fine — or some extra bags to carry everything.
- One of the things that is very different than previous builds is that we will be making a box out of wood. Assembling the box requires gluing and a bit of patience. And then to finish the box, you will probably need to sand the rough edges and possibly use some wood filler to fill gaps and low spots. If you haven't done these kinds of things before, proceed slowly and ask lots of questions.
- When gluing wood parts together, it is necessary to apply some pressure while the glue dries to ensure that the parts properly adhere to each other. The pressure needs to be applied for 30-60 minutes. The usual woodworker approach is to use clamps. I have a bunch of clamps that I will bring to the build session for anyone to use. However, I don't have anywhere near enough clamps for everyone to glue all of the boxes in one build session. (It takes 4 clamps when gluing the sides to the top and bottom and then reuse the 4 clamps to glue on the front. We are doing 32 speaker boxes this semester. That would be a lot of clamps.) An alternative method for applying pressure is to use something heavy (like a stack of books) and gravity. This can work just as well as clamps. However, the "stack of books" method is probably best done at home, since you probably don't want to lug 20 pounds of books to the lab room — if you even own 20 pounds of books.
- There are a few incidental items not in the BoM that will be provided as well, including the wood glue and some zip ties for securing the big inductors of the Carmody cross-over circuit.
- As always, there is no particular order for doing the work. One option is to start gluing the boxes together this week in the lab and then finish gluing at home, if needed. Then do the soldering at a subsequent build session. Another approach would be to solder the cross-over circuits in the lab this week and take the wood home to work on gluing later. A third approach would be to take everything home and work on it whenever you want. This is Audio Club — there are no expectations or rules, and you can do as you like.
Feb 5, 2025
Additions to the web site: The overhead slides used in last Mondays meeting and the complete BoM for teh speaker build. Links are on the documents page.
Be sure to contact Andrew if you would like to build a set speakers and didn't sign up at the meeting or on Discord.
Feb 4, 2025
Club contacts for Spring semester:
- Gary Tuttle (gtuttle@iastate.edu)
- Andrew Chandler (ajc2026@iastate.edu) is the IEEE contact.
These are also listed on the resources page. Contact Andrew if you would like to join the Discord group.
Feb 2, 2025
Audio and Arduino Clubs are shifting back into gear for Spring semester. The first meetings are on Feb 3 and Feb 10, respectively.