Need help on speaker project

[geespot]

Need some help on a speaker project. I have been given the drivers + crossovers from a pair of Cerwin Vega D-3's. Where is a good place to start on building or buying enclosures for these? The original enclosures are damaged beyond repair, but I have access to them if I need anything else from them. Any bit of information is helpful.

Thanks

g

[Thatch_Ear]

The interior space of the old cabinets and port size and depth if they are ported should be your starting point. Those should be right on the mark for the speaks. The next thing is to find out what kind of tools you have, how well you know them, etc. A table saw and a router are must haves unless you are real good with a Skill saw. If you are lucky and can get someone at the lumber yard to presision cut the pieces for the cabinet that will work too. I like MDF for speaker cabinets but I hate working on the stuff. Another thing to check on when you get the interior measurements is stuffing and wall insulation. Leave the stuff attached to the walls alone but get any stuffing out of one so you know how much is in there. Then we can start.

[geespot]

I have the tools but not very good at the woodworking end. Maybe I can my brother-in-law to build them. I'll grab everything I can out of them (stuffing, port, etc) and have him build some nice cabinets.

How thick of MDF should I use or should I use a solid wood like oak, pine, maple? Should I re-wire the the crossover to a higher quality wire or leave them alone?

g

[steamshooter]

geespot, I'm no speaker builder, but I have read enough to know I don't know enough. Woodworking I can do. Have you thought of just copying the cabs they were in? Maybe some extra bracing here or there. Is enough left of them (cabs) to do that? If anything larger than a small bookshelf I would use 3/4".
Brad

[ProAc_Fan]

I would go with the MDF. Real wood is pretty expensive and the value of drivers and xover from CV D-3's wouldn't really justify the cost. As for the tools required, they do make hole saws in sizes up to 15" because I used to build sub boxes at a local install shop. We had every size from 3/4" up to the big 15" hole saw. BTW 3/4" MDF should be plenty.


Mike

[geespot]

thanks guys for all the input.

One cabinet is still pretty much intact, I'll give it to him and have him build them to the exact specs. If the speaker baffle is still useable maybe he can use that instead of cutting a new one.

thanks again

G

pics will be posted when done

[bully]

Be aware that MDF does a poor job holding screws. I use 1-by to use as cleats/stiffeners. Cheap enough, and also provides for a good seal when glued, then screwed. Solid.
A 15-inch hole saw? Wow, that has got to cost a small fortune.

[steamshooter]

Thanks for saying MDF ProAc_Fan, I knew that, I just forgot. Really. 15" hole saw you say?:eek: How many people have to help hold the drill? Even with a press, I'd be hesitant to use that monster! Don't forget to use caulk in those joints after gluing and screwing. Brad

[gonefishin]

DAng...I've seen a couple 12" hole saws...and they were monsters! they were also quite expensive...I would say get a cheap compass which opens to the desired length...draw out your cirlce...then cut with a jigsaw...you can actually cut out a nice hole this way...just go nice and slow.

Anyone ever use Quiet-Kote in their speakers? I'm thinking of using this in the bass enclosures...which a 6cuft sealed enclosures made and braced with 70lb (instead of the normal 30lb) 3/4" mdf. The speaker that will go into it is a 15" TAD (pioneer) 1601a. All joints are screwed and glued...bracing included.
So far...just the darn box and bracing...no drivers...and without the midrange and tweet on top...just the bass enclosure weighs 74lbs each...then add another 24lbs for the woofer...yikes. Of course that's not including an extra 30lbs for the compression driver and horn...and another 2 lbs or so for the tweeters.

thanks!

a link to the soundKote stuff
http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=7163965&St=1343&St2=-62798478&St3=52828361&DS_ID=3&Product_ID=7107&DID=7

[Thatch_Ear]

GS,
About your xovers, if you know the values of the chokes and they are not big open air coils of copper wire then a complete rebuild might be in order. If the chokes are nice quality then think about replacing the caps, putting in 5 way binding posts if they are not already there and if there is an adjustable pot for the highs you might think about dialing that in to where you like it best, measuring and then replacing it with a single quality resister. Using the same type of wire that you use for cables to hook up the drivers inside the cabinets is a good idea. Again not knowing the way these are constructed a lot of speakers had the xovers built on a thin piece of masonite that was glued and stapled to the inside of the cabinet. Not a real good thing. If it ends up that you do rebuild the cross then replacing that weak point would be a good idea.
The thing to remember is that like most things made in the last 25 years or so if you could save a dollar on the cabinet by using cheap particle board, 2 dollars in xover parts, something on internal wiring and were going to make hundreds of thousands of speakers........well. Bean counters must justify their salaries and we get screwed. This was and is common throughout the audio industry. I have seen cross overs that have come out of big buck speakers that use low quality parts. Carbon cored chokes and cheap NP electrolitic caps mounted on plastic. The great thing about DIY is that in cases like xovers it will cost almost as much to use cheap parts as it will to use good ones. Not the best but much better. For lots of us the reason we DIY is that what we can build would usually cost us at least 10 times as much to buy already built. Or you can't buy it at all.