Novice Loudspeaker Rebuild

[krolholio]

Newbie here. So, I built a set of speakers 30 years ago when I was a senior in high school. Between several moves during college, they took a fair amount of use and abuse, and ultimately took up residency at my parents for at least a decade and a half. The cabinets (3/4" A or B grade plywood) are in great shape - the components, not so much. The existing components are all Radio Shack/Realistic, some of which no longer function. My winter project is to rebuild with new components, and possibly make some slight mods that might help them. I'm sure just about whatever componentry I use will likely be better than the Radio Shack stuff I cobbled together back then. Please remember that we didn't really put much design into these, and are what amounted to a high schooler thought was cool in 1991.
Cabinets measure 21.5"W x 33"H x 13" deep and are completely open inside. We did put a 1.5" (inside diameter) port on the front face, which is about 3.5" in length. Woofer was 15" diameter (13-7/8" rough opening), midrange was 4-1/2" (3-3/4" rough opening), and tweeter was 4-1/4" (3-5/8" rough opening). I don't know what to say about the crossover or the connectors at the back, but I'd anticipate replacing those as well. Attaching some photos for reference.
Any thoughts on possible cabinet modifications (not necessarily looking at extensive, since I don't think I can take them apart easily), as well as components to consider would be welcome.

Thanks in advance.

 

[lovinthehd]

The drivers are all functional? Can you obtain the T/S parameters for those various drivers you used so you can at least put some design into it?

 

[krolholio]

lovinthehd - essentially most of the drivers are not functioning. The last time I hooked them up I think I had one tweeter that had something, and one woofer, albeit with a surround that has deteriorated. That being said, I searched for the Dayton Audio Test System, which I think would help me obtain the T/S parameters, but if I am not able to test the drivers, is that worth ordering?

 

[lovinthehd]

The DATS system is a good thing to have if you're going to dive into diy speakers, especially for determining those for drivers you can't find manufacturer spec for (as well as a measurement mic and analysis software in general....doesn't particularly need to be the DATS/Omnimic bundle Dayton has, tho). Not particularly necessary if you follow someone else's design....just depends how deep a dive. There are books like Vance Dickason's Loudspeaker Design Cookbook.....

Personally I'd start over, even with the box, kinda hard to make an existing box fit the driver/crossovers needed. I'd suggest finding a good pre-defined kit of drivers, box parameters (or even a knocked down cnc'd box, aka flatpack), and crossover design to match. Dayton/Parts-Express is one source, Madisound and Meniscus are good sources, too. Some ideas here in our own DIY subforum, or the one at avsforum.com, or diyaudio.com, etc.

 

[Verdinut]

It is really awkward to start building a new speaker based on the enclosure. Normally, you get your speaker drivers first and then you build the enclosure based on the Thiele-Small parameters of the woofer, or at least the recommendation of the speaker manufacturer. Moreover, the 1.5 inch port pipe is way too small for a 15" driver.

I suggest that you start from scratch and get a speaker kit with all components from a place like Parts-Express, Madisound or Solen.ca, if you want to obtain a successful design. Preferably, the cabinets should be made with MDF board with adequate bracing. Those three firms have complete kits with the appropriate cabinets as well.

 

[CajunLB]

You may luck out and find a diy kit that uses a similar cabinet volume and purchase the drivers and crossovers without the cabinet and use the box that you already have. This would save you some money.
That being said think you might be better off with a complete kit that is proven .

 

[zieglj01]

Build you a pair of decent/nice sounding speakers

TriTrix MTM pair

Home

TriTrix MTM Speaker Kit Pair with Knock-Down CabinetsThe TriTrix MTM vented speaker kit is a compact design that delivers high performance full range audio without breaking the bank. With an F3 in the low 50's and an F10 of 40 Hz, you can expect solid low end from the modest sized enclosures...

www.parts-express.com

 

[TLS Guy]

Build you a pair of decent/nice sounding speakers

TriTrix MTM pair

Home

TriTrix MTM Speaker Kit Pair with Knock-Down CabinetsThe TriTrix MTM vented speaker kit is a compact design that delivers high performance full range audio without breaking the bank. With an F3 in the low 50's and an F10 of 40 Hz, you can expect solid low end from the modest sized enclosures...

www.parts-express.com

Not sure they are decent sounding. A builder who did not like them, got this FR trace.

If he did those measurements correctly I'm not surprised he did not like them.

 

[zieglj01]

Not sure they are decent sounding. A builder who did not like them, got this FR trace.

If he did those measurements correctly I'm not surprised he did not like them.

who knows if he measured them correctly, but it does not seem right, who knows maybe a driver control problem with the tweeters, all in all, there are other options around