Edit 12/5/2014: Went over this DIY thread, fixed all the pics and links I think. Let me know if you spot anything off. Figured I may as well bump it too. Keep in mind I was a total n00b to this in 2005. Enjoy, it came out great and I still have uses for it despite some technical shortcomings. Edit 2/11/2009: NOTE: This is an old build thread that had the pictures lost during multiple forum software upgrades. I have been able to reconstruct the thread which chronicles the driver selection process and the rebuild process. It has excellent technical input from some well known speaker designers and aficionados and I recommend it for beginners to WinISD, cabinet building and design as an example of the issues involved in a successful project outcome. All driver selections are made and the cab is finished, so input on that level is no longer needed. Enjoy! I am working on a rebuild or upgrade of the Radio Shack Building Speaker Enclosures project from a book published by David Weems in 1980 for Radio Shack. I built this cab from scratch in 1982. Subsequent advances in design technology lead me to believe this can be upgraded with significant boosts in performance at reasonable cost. I will post some pics below of the project, but essentially, it is now a 2x12 sealed box with 3 piezo horns, presented at 4 ohms. All speakers are wired in parallel, and the piezo line has a 10-ohm resistor in series. I am going to leave that part alone and only focus on the woofers. The author provided specs on some drivers cited in his long out of print book, though none are available on this driver, Radio Shack Cat No. 40-1314. The driver has a silver dust-cap, I am told from a source at Bose Corp that this was typical of Altec-Lansing. Confirmation, denial or discussion of that would help me evaluate if they are suitable for this project. I have searched the web extensively looking for specs on these drivers to no avail, if anyone knows where I could find them please let me know. With the specs in hand, I was considering porting the bass cabinet. I would prefer to do this without a shelf if at all possible because of the cab construction, it has a removable panel at the rear. It would be quite easy to port the front once the parameters are available. I did acquire a recent copy of Vance Dickason's Loudspeaker Design Cookbook to broaden my understanding of ported box design. The internal dimension's - ID - of the cab are roughly 11.5" x 16.5" x 34.5" = 6546 cu. in and deducting the volume removed by the piezo tweeter shelf I come up with an estimate of 6486 cu, in, or 3.75 cu. ft. for the internal box volume. Plan A would be to port and dampen the cab. ( see below) EDIT: This was not an option Plan B would be to replace the drivers with other drivers suitable for my needs. Just to define my needs more clearly, I would like to use this as a bass cabinet, and reproduce down to Low E 41 hertz without farting, I do not play with a low B 30hz, so rolloff in that area is not an issue for me. I don't need a lot of real high end performance, based on my playing style and tonal taste. I use an Eden WT-300 hybrid SS amplifier, with an internal 12AX7 tube pre-amp. It will deliver 300 watts @ 4 ohms and 220 watts at 8 ohms. So it should have plenty of power to punch those little bad boys. I have a bigger rig as well, an Acoustic 140 head with a 106 bottom, with 2 x 15 drivers. My back is aching looking at it, and it no longer fits in my car, so this upgrade is beginning to look real interesting to me. ======= part II. I fired up the cab after rewiring and punched it pretty hard with the Eden. Though I dont have the Thiele/Small parameters, it is obvious to me that the RS drivers do not have enough low end to handle the bass signal delivered by my passive/active P/J 81 Ibanez Roadster and the Eden wt300. TB'er and friend secretdonkey has an Accugroove Whappo jr., and mentioned to me that they have one 12 that functions as a woofer, and another 12 configured as a mid-range driver. This suggests a low cost solution of finding a suitable 12 woofer replacement and designing a crossover circuit to limit the low end of the RS driver. Does anyone have a suggestion for a suitable woofer? Anything for under a $100? ( EDIT: The driver selection has been made...) Bottom line is that I can get an Eden or Aggie 2x12 for not a lot more than 400 bucks, so throwing more than 200 into this cab probably doesn't make sense. This thread is intended to demonstrate how an old cab can be revived and modernized with a limited expenditure. Footnote: In order to link all the pictures some had to be attached to different posts. All build pictures imaged (not attached) are in the correct sequence. Some attachments are not because of the 2 attachment per post limit.