Speaker Cab for Altec Lansing

Ashley D\'Silva · From: Perth , Australia

I am desperately seeking a design, with dimensions, for a Cab to house 2 Altec Lansing 417-8H II Series Speakers. These I will use with my Twin and GFI PSG.

I propose to build it with MDF/PLY Laminate to 3/4 inch thick and then cover with tolex or similar.

Any help/advice with design or dimensions would be much appreciated. I am a reasonably competent carpenter.

Regards
Ashley

Bobby Burns · From: Tennessee, USA

I'd suggest you make the box out of pine instead of plywood, and especially not MDF. The older Fenders were pine. It will sound a lot better, and be a lot lighter weight. Those altecs are going to be heavy enough on their own without all the extra weight of the MDF of ply.

Ashley D\'Silva · From: Perth , Australia

Thanks for that Bobby, I will certainly take that advice on board.

Now for the design, dimensions etc.

Regards

Brett Lanier · From: Hermitage, TN

Rick Johnson talks about design a little on his website www.rickjohnsoncabs.com ,, and he even has a book on it.

Marrs cabs are cool too, and it's a very different design.

Danny Hall · From: Nevada, USA

Hey Ashley:
I'm with Bob 100% on pine cabinets. I use it or spruce if I can find it for all my commercial guitar cabs.

Altec 417-8H are deadly accurate transducers when not pushed to breakup. Carlos Santana, among others used them exclusively for years. That's Mesa breakup, not Altec breakup.

Do you want open or closed back cabinets?

There is a share ware program for designing ported or closed back cabinets called Boxplot. If he's no longer got it on line I can probably figure a way to get you a copy, provided I can locate the writer. It was shareware but he had a pay for it version which I have. You will need the Theile/Small parameters in order to design closed or ported cabs.

On the other hand, Leo Fender designed all of his combos with absolutely no science whatsoever. He just screwed the speakers to the baffle board and designed the chassis to fit in the subsiquent box. You will notice that most of them are about 9" to 10" in depth though. I have tried deeper boxes and I don't like them as much. Take a look at the two 12" open back cabinet offered by Hermida Audio Technology. These are exceptionally nice for a ply cab. The back port is roughly based on the size arrived at empirically by a famous (perhaps most famous) custom amp builder.

Also, Avatar builds a nice cabinet. Check them out for ideas. They won't share the port size with you, so you can do a visual scale from that open back port and be close enough. The object is to feel the back wave with your hand right in front of the opening.

Closed back cabs are generally more focused and intense directly in front of the cab with a narrower beam to the crowd.

Open back cabs are generally more open and "Big" sounding. Beware though, if you place an open back cabinet in front of and the wrong distance from a reflective wall they can sound muddy to the audience. Get yer sound guy to check it out during setup.

Leo used 5/16" ply baffles in his early pine cabs. A good quality 3/8" is good enough and I use pine stiffners on the back side. Especially with heavy speakers like the 417-8H.

I'm going to be building an all spruce 1 15" cabinet for myself this summer. I intend to make the baffle by ripping 6" rough stock into 3/4" strips then jointing for straight and planing to 1/2" then edge joining them with Tite Bond II to make a sheet for the speaker baffle. This is aircraft grade spruce that I paid $500 almost 15 years ago. All 1/4 sawn. It will get nitro and steel corners. Should be a fun project. A JBL-D130 or clone will go in it.
_________________
The Last of the World's Great Human Beings. Ok, well maybe one of the last. Oh alright then, a perfectly ordinary slacker.

Adam Sorber · From: Pennsylvania, USA

I agree with everyone else- Any speaker cabinet I've ever tested that was made out of MDF severely lacked resonance and was "muddy" sounding overall. I personally prefer 13ply baltic birch over any other wood for speaker enclosures.
_________________
Adam Sorber
Sho Bud PROII custom D-10
Sho Bud PROII custom SD-10
Fender Super Twin Reverb
Fender Ultra-linear Twin Reverb

Ashley D\'Silva · From: Perth , Australia

Danny,

Thanks a bunch for the very informative, instructive, constructive & highly enthusiastic response.
You have now got me real fired up and ready to build.
I work away from home 3 weeks at a time and so can only build one week in four and next week is one.

From your comments, I have a lot of research to do before I start.

Once again, Thanks my friend.

Ashley

Paul Honeycutt · From: Colorado, USA

I run one of those Altecs in my Boogie, too. If I were building a cab for two, I'd clone a 60's style small Bassman cab. I have two like that built by a local carpenter, one with JBL K-120's and another with Fender/Cerwin-Vega PS 12's. They're the smallest cab I know of that can deliver the goods.

Forum Index > Electronics		Next oldest topic :: Next newest topic

All times are GMT - 8 Hours	Jump to: