Radio Shack 40-1197 TQWP by John Rutter Well, I finally have rev 1 of my RS40-1197 TQWP speakers taped together and playing music. Here is a summary of what they are how I got here. I gleaned lots of good information from this and other sites and want to share the results. Thanks everyone. First off, I had very little money after Christmas, so the main criteria for this design was low cost. I estimate that I've got about $40 actually spent on these so far in their plain MDF state. Another goal was a single driver crossover-less design, although I might try a zobel network later... My hope was to get in-room bass response down to 70 Hz. I spent a lot of time nailing down a starting point for cabinet dimensions. Finally, I decided that I would shoot for a mini design to avoid the problems that a low tuned pipe and a small driver would probably create. I settled on a theoretical 80 Hz pipe with a length of about 43". When folded, this makes for an enclosure just over two feet tall. Well, I had enough 3/4" MDF around for that, so I used it even though the thickness is probably overkill. When I ran through the calculations for mouth area, port size, driver location, etc. I ended up with a miniature version of one of the small driver TQWPs from the Bonavolt site, which was encouraging. The outside dimension are: H= 24.5 inches W= 5.5 inches D= 8.25 inches V= 0.33 cu ft Driver center is 4.125" down from the top. Port is 2.1" tapering slightly down inside at same rate as the pipe and is about 2" deep. I used some surplus Teflon insulated network cable inside - no crossover. My wife thought they were cute (but she wanted to put them on a shelf about 4 feet off the ground!) She WILL let me keep them! I damped each 1197 with about 2 feet of window sealing rope putty around the basket in front of the magnet. I think that this sounded better than without, so I'll keep it. Without stuffing, there was a lot of midrange coming out of the port. When I put my SLM in front of the port, it was louder than in front of the driver! Right now, I have 2 oz. of Acousta Stuff in each enclosure, densest at the throat and extending around the sloped partition about 1/3 of the way down the back. I used some self adhesive felt pads just behind the driver and on the bottom back corner of the enclosure behind the port. I also bought some felt chalk board erasers (remember them?!) to try in the top corners. They sound nice! I will run some frequency response curves later, but for now, I'm trying to get a first impression on the sound. Bass is obviously not there, but I think I'm close to my 70 Hz goal. I'll do a compact bandpass sub (or pair of them) later, so I'm not hung up on the low end. With the stuffing, there is just low frequency sound from the port, a big improvement. They definitely sound best on the floor where the port gets some help. I can see myself sitting in the lotus position about 5 or 6 feet away from them with my homebrew trioded 6BQ5 push-pull amp (small tubes, small speakers, small room) forming the fourth point of a diamond… Slipping into reviewer mode - Imaging is very stable - I can stand up and look down at the musicians, or sit down on the floor with them. Soundstage is beyond the outside edges with the speakers toed in. Tonally, they ARE thin, SURPRISE! I want to get a bit more midrange in the balance. I don't think I'll miss a tweeter though, unless the Damar varnish damps the highs too much. I'll post more info as I have time to change things. Top