- As the semester winds down, there are two final build sessions — Monday, Apr. 28 and Mon, May 5. Both sessions will be 2011 Coover and will start at 6:00 p.m. (to avoid any conflicts with scheduled labs). During these sessions, you can:
- Build the revised version of the Temp-Time project. There are a few kits available. Recall that the original version had a problem with temp sensor being two close to the voltage regulator. The new version fixes this problem and adds an optional 9-V battery holder.
- Build the Class-D amp. Several people built amps a couple of weeks ago, and there are still a few kits available.
- Build a box that can be used for the Class-D amp or the small desktop amp (or both). There are ample supplies of parts for building boxes.
- I will bring tools (a drill, bits, wire strippers, pliers, etc.) to facilitate building the projects.
- Contact Andrew on the Discord or send me an email if you would like to build any of these final projects.
- Finally, I had discussed building a sub-woofer as an "un-official summer project". To build this, you would need to buy the driver, port tube, and connectors from Parts-Express, and I will supply wood panels. If you would like to do this project, let me know ASAP (gtuttle). I will cut up the panels and have them available for you at the session on May 5.
To get an idea of how the sub would look, you can see this kit from Parts-Express. The drivers, connectors, and port should cost around $75.
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.