Rebuild for fun (and hopefully quality!) Picture-Heavy

[Phoenix70]

So today I picked up a pair of Pinncale AC 850's at Goodwill for a grand total of $30. I've been meaning to get into a DIY project, so I thought a good starting point would be to get a set of decent speakers, and replace the internals. Hopefully I'll learn a lot about the process, and with any luck, they'll sound a lot better than they do already (which on my fairly crappy amp, is much better than my current set of Infinity Surrounds). I'm in the process of acquiring/building a tube amp with about 8W RMS output per channel, so the drivers will have to be fairly efficient. Anyway, picture time!

Here they are, fresh from the store

You can probably see a lot of scratches in the veneer, if this all goes well I'll replace that next


Without the covers on


The larger is 8in, the smaller is 4in

The back side:


A peek inside...


You might not be able to tell from here, but the screw holes are totally shot on this. I'll have to rotate it 45 degrees and drill out new pilot holes


The electronics and insulation



The tweeter removed and close up:



Through the top...


This tube leads to the vent out of the back, it was simply hotglued in to provide a seal, that was almost completely gone when I got to it so I pulled it out shortly afterwards.

The electronics close up:


And the back side:


All opened up:


I haven't got to dissasembling the second unit yet, though I imagine it's much the same as the first, if not a little worse for wear (a bit of the wood bordering is falling off, nothing a little glue or a nail won't fix).

So, where would I start for refitting this out? I'm going to hazard a guess and say I'll need new insulation as well, and I may upgrade the posts too. The capacitors aren't that one (I'm guessing 10 years?), but I may as well replace them, at least to gain the experience. So, what would you all reccomend for drivers on these? I usually listen to classic rock, (Beatles, Floyd, Zeppelin, etc), but I also listen to some other stuff as well (Lloyd Weber music, some chello music, old 50's stuff). As I mentioned earlier, I plan to run these with a tube amp at about 8 Watts RMS, so I'll need efficient drivers. Budget is somewhat of a concern, but for now I'm open to anything until I figure out exactly how much I've got to throw around. Thanks for your time!

[mcmahon48]

double bass reflex resonance port tuning is tricky
the cross over is a very simple one it is a second order 12db slope 1 coil and cap for bass roll off and tweeter is a first order 1 cap

tweeter will be easy low price suggested tweeters should you wish to improve top end
here is what is in in now http://www.madisound.com/catalog/pro...oducts_id=1076

http://www.parts-express.com/pe/show...number=264-865
http://www.parts-express.com/pe/show...number=264-578
http://www.parts-express.com/pe/show...number=264-870

replace the coil to a air core coils and switch the capacitors out
with metalized polypropylene that is all that can be done to do easy improvements and keeping it the same in the area of the woofer

if you can figure out the routing of the crossover you could rebuild it but do it point to point wiring which is better

woofer would be expensive

[Phoenix70]

Well I went and made a Solidworks mockup of it today, it should be fairly accurate, most dimensions should be within a 1/16" of true value. It's giving me a volume of 589 cubic inches, but I'm fairly sure that's not accurate (just a quick L*W*H estimate gives me ~2600, minus the volume the wood is taking up). Anyway, here's the technical drawings. If anyone wants a copy of the solidworks file or it converted into AutoCAD or whatever, just let me know. Any other suggestions for what to get? I really don't mind redoing all of the electronics and the woofer, I'd actually prefer it just to learn how.

Sorry for the .pdf format, I can't seem to get Solidworks to output a high res JPEG that you'd actually be able to see everything on.

[Phoenix70]

Also, the tweeter you suggested is actually the exact same one that's in there right now (although somewhat damaged, obviously)

[454Casull]

How are you calculating the volume?

When I export images I usually printscreen and go into an image editing program. That way I don't have to suffer from mandatory quality loss.

[Phoenix70]

I just simulated the area as a box, obviously there's stuff taking up space inside so that's not accurate but Solidworks volume seems far too low to me (maybe I'm wrong?)

[Andersonix]

SW is probably giving you the volume of the cabinet material. As far as I can tell, one needs to create a 'dummy volume' inside the box to query.

[Phoenix70]

Yeah that makes sense, I thought of that earlier and hadn't gotten around to checking it yet. I think I'll just make an exact (solid) replica of the outside of the cabinent, and then subtract the two to find the interior volume. I'll let you all know when I've got that finished. Any more suggestions for new woofers/tweeters?