gdmoore28
Super Member
This is going to be as close as one can get to a "budget" Altec build considering the skyrocketing prices of classic Altec components. Like a lot of you guys and gals, I have little to no money to throw at these pieces, and the process of assembling them has taken three years of swapping and watching for good buys. I'll summarize for those that are interested.
The cabinets will be based on the Altec 606 corner cabinet: http://lansingheritage.org/images/altec/plans/1960's-lf-design/page15.jpg
This cabinet was chosen for a simple reason: I don't have space for anything larger.
Finding the Components (Skip this part if you like. It's just background info.)
I've been entranced by the look of the Altec 811/511 horns since I was a kid in the late fifties. So, yeah, this build is based a lot on nostalgia as much as anything else. But how to afford the components? I was fortunate to be good friends with an aging WWII vet and electronics technician in town and made sure that he knew where to sell his old vintage gear when he was ready. Shortly before his passing, he made the move. I ended up with a University S6 cabinet, two University C15W woofers, two University HF206 super tweeters, two University N3 crossovers, one Altec N500 crossover, one green and one black Altec 511, one Altec 802D, and one Altec 808, along with assorted Altec mounting hardware. Most of this gear was still new in the original boxes.
In short, selling almost all of the above gear allowed me to finance the A-7 components. I found a matching 802D and 511 horn in green to match the one I had, and located a very nice pair of 416-8Z woofers. The woofers are the ones that have the 16" cast frame, along with the "A" model alnico magnets. I believe these were the standard woofers in the 846Bs.
The Cabinets
Having finally located a local source for 3/4" Baltic Birch plywood at prices that earthlings can afford, I was ready to start cutting lumber when I stumbled across a pair of (don't laugh, yet!) new kitchen corner cabinets at the Restore store in town. Whipping out my tape measure I found that the cabinets were within one inch of the measurements of the 606s. For $40 I couldn't see passing these up as a great foundation for what I was about to build. Yes, a few mods and much re-enforcement will follow.
It was first necessary to cut back the front of the cabinets so that the fronts would give me the necessary minimum 24" for the 511 horn width. Plans are to re-extend the front of the cabinets 5.5" in order to recoup the lost volume. Plus, this will be a much more interesting look.
(The joints in these cabinets were simply stapled together, so I knocked them all loose enough to fill the joints with Titebond wood glue. They were then clamped back together as the glue dried.)
These cabinets came with four 1/2" shelves, which I bonded to the top and bottom panels. This, of course, yielded 1" thick panels. The side panels will be bonded to 3/4" Baltic Birch (for 1" side panels) which will extend 1" beyond the cabinet backs. Then, the same 3/4" BB plywood will be used to fabricate the back panels which will fit inside the recess. One of the back panels will be removable for service. More on this as I make progress.
I plan to make 5" risers under the enclosures, and these will be "kick-toed" back about an inch. Depending on how the calculations for volume work out, I may seal these risers and open them up for additional cabinet size. We'll see if it's needed.
I have a decent quantity of nice mahogany veneer that will eventually cover these, along with possible additional cabinet adornments courtesy of a local lumber reclaiming business. They frequently have a good volume of reclaimed cabinet trimmings from old homes that have been demolished. I love the look of fancy old cabinets, so maybe I can do that style here.
The Crossovers
This is the area that has given me the most headache so far. Even though I've been building speakers for over fifty years, I've always followed somebody else's designs. So, outside of installing a standard Altec crossover, it was necessary to design something. I am not trained in electronics, so the last two years I've been immersing myself in learning about crossover design, speaker measurement, yadda, yadda.
In the end, I've decided to start simply and modify as I have access to diagnostic equipment. So, for now, I'm going to use a simple second-order Linkwitz-Riley crossed at 800Hz, followed by the sixteen-ohm version of the Altec 30923 eq/attenuation circuit. As typical, my first intention was to use air-core inductors. Then, I ran across a fellow on ebay who builds really nice iron core versions from 14 guage windings and DCR readings on par with typical air cores. So, that's what I went with. The capacitors are motor start caps. Why? Because I've read good reports about them and (I'm ashamed to say) I dig the way they look. Sort of a Klipsch look. Here's what I came up with:
More later. I'm old and my back is hurting.
Comments are quite welcome.
GeeDeeEmm
The cabinets will be based on the Altec 606 corner cabinet: http://lansingheritage.org/images/altec/plans/1960's-lf-design/page15.jpg
This cabinet was chosen for a simple reason: I don't have space for anything larger.
Finding the Components (Skip this part if you like. It's just background info.)
I've been entranced by the look of the Altec 811/511 horns since I was a kid in the late fifties. So, yeah, this build is based a lot on nostalgia as much as anything else. But how to afford the components? I was fortunate to be good friends with an aging WWII vet and electronics technician in town and made sure that he knew where to sell his old vintage gear when he was ready. Shortly before his passing, he made the move. I ended up with a University S6 cabinet, two University C15W woofers, two University HF206 super tweeters, two University N3 crossovers, one Altec N500 crossover, one green and one black Altec 511, one Altec 802D, and one Altec 808, along with assorted Altec mounting hardware. Most of this gear was still new in the original boxes.
In short, selling almost all of the above gear allowed me to finance the A-7 components. I found a matching 802D and 511 horn in green to match the one I had, and located a very nice pair of 416-8Z woofers. The woofers are the ones that have the 16" cast frame, along with the "A" model alnico magnets. I believe these were the standard woofers in the 846Bs.
The Cabinets
Having finally located a local source for 3/4" Baltic Birch plywood at prices that earthlings can afford, I was ready to start cutting lumber when I stumbled across a pair of (don't laugh, yet!) new kitchen corner cabinets at the Restore store in town. Whipping out my tape measure I found that the cabinets were within one inch of the measurements of the 606s. For $40 I couldn't see passing these up as a great foundation for what I was about to build. Yes, a few mods and much re-enforcement will follow.
It was first necessary to cut back the front of the cabinets so that the fronts would give me the necessary minimum 24" for the 511 horn width. Plans are to re-extend the front of the cabinets 5.5" in order to recoup the lost volume. Plus, this will be a much more interesting look.
(The joints in these cabinets were simply stapled together, so I knocked them all loose enough to fill the joints with Titebond wood glue. They were then clamped back together as the glue dried.)
These cabinets came with four 1/2" shelves, which I bonded to the top and bottom panels. This, of course, yielded 1" thick panels. The side panels will be bonded to 3/4" Baltic Birch (for 1" side panels) which will extend 1" beyond the cabinet backs. Then, the same 3/4" BB plywood will be used to fabricate the back panels which will fit inside the recess. One of the back panels will be removable for service. More on this as I make progress.
I plan to make 5" risers under the enclosures, and these will be "kick-toed" back about an inch. Depending on how the calculations for volume work out, I may seal these risers and open them up for additional cabinet size. We'll see if it's needed.
I have a decent quantity of nice mahogany veneer that will eventually cover these, along with possible additional cabinet adornments courtesy of a local lumber reclaiming business. They frequently have a good volume of reclaimed cabinet trimmings from old homes that have been demolished. I love the look of fancy old cabinets, so maybe I can do that style here.
The Crossovers
This is the area that has given me the most headache so far. Even though I've been building speakers for over fifty years, I've always followed somebody else's designs. So, outside of installing a standard Altec crossover, it was necessary to design something. I am not trained in electronics, so the last two years I've been immersing myself in learning about crossover design, speaker measurement, yadda, yadda.
In the end, I've decided to start simply and modify as I have access to diagnostic equipment. So, for now, I'm going to use a simple second-order Linkwitz-Riley crossed at 800Hz, followed by the sixteen-ohm version of the Altec 30923 eq/attenuation circuit. As typical, my first intention was to use air-core inductors. Then, I ran across a fellow on ebay who builds really nice iron core versions from 14 guage windings and DCR readings on par with typical air cores. So, that's what I went with. The capacitors are motor start caps. Why? Because I've read good reports about them and (I'm ashamed to say) I dig the way they look. Sort of a Klipsch look. Here's what I came up with:
More later. I'm old and my back is hurting.
Comments are quite welcome.
GeeDeeEmm
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