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ALTEC Model 15 Project - Now with JBL and Fostex parts!.
- Thread starter hjames
- Start date
Goggle1824
Well-Known Member
So I've since gotten some Heath Altec AS-101 speakers, I decided I didn't need 2 ALTEC projects. So I changed direction on the Model 15s, planned to sell off all the parts I just bought, give away the cabinets, etc. I found a buyer for the 32 horns, horn drivers and crossovers (1 buyer - nice and neat!). So that leaves me with the JBL 2214H drivers I had before. They made a nice sound with the Model 15 parts, actually.
And I tried to give away the Model 15 cabinets (the same way I got them from Joe - freebies!). No takers.
And they occupy a bit of space in my living room. Too much space!
A few more weeks have now passed, and since then, I scored a set of Fostex teak horns and compression drivers for Mids and the matching tweeters off ebay. Not sure what I am going to do with them, then it occured to me! I could stack them on the ALTEC Model 15 cabs, use them as Bass boxes with the JBL 2214H woofers, and build a 3-way crossover to drive them all.
To that end, one of the Fostex folks crafted a crossover design for me with that combo last week - I'll need to order caps and chokes, and see how this all plays out ... together.
I'll need to mount some planks across the horn slots from INSIDE the cabinets - and mount a plate across the hole where the ALTEC crossover panel was before, to put the cabinet into ported woofer territory. I can put controls for the (fostex) mids and tweeters on that crossover plate. Should play very nicely!
And I tried to give away the Model 15 cabinets (the same way I got them from Joe - freebies!). No takers.
And they occupy a bit of space in my living room. Too much space!
A few more weeks have now passed, and since then, I scored a set of Fostex teak horns and compression drivers for Mids and the matching tweeters off ebay. Not sure what I am going to do with them, then it occured to me! I could stack them on the ALTEC Model 15 cabs, use them as Bass boxes with the JBL 2214H woofers, and build a 3-way crossover to drive them all.
To that end, one of the Fostex folks crafted a crossover design for me with that combo last week - I'll need to order caps and chokes, and see how this all plays out ... together.
I'll need to mount some planks across the horn slots from INSIDE the cabinets - and mount a plate across the hole where the ALTEC crossover panel was before, to put the cabinet into ported woofer territory. I can put controls for the (fostex) mids and tweeters on that crossover plate. Should play very nicely!
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The existing front panel is not removable that I can see, and I'm better with electronics than with woodworking.
And since the large hole is a good fit for the Woofer, all I really need to do is get rid of the horn "slot" up top.
And make some kind of grill to cover all that!
The existing front panel is not removable that I can see, and I'm better with electronics than with woodworking.
And since the large hole is a good fit for the Woofer, all I really need to do is get rid of the horn "slot" up top.
And make some kind of grill to cover all that!
Got it. Like I said I didn't know if that baffle on those could come out without damaging the rest of the cabinet. I have some different utility style cabinets here that I was just pulling some Altec drivers out of that look like the baffle front could be removed and replaced with a little work. And something to keep in mind, I just read somewhere that you can often find a local car stereo shop that has CNC capabilities since they build so many boxes. Give them your baffle dimensions and cut-out requirements etc and they can produce it. I understand it is also very cost effective.
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Honest, those boxes will be fine - the JBL 2214H woofers played really well in there with the Altec parts during December -
that's why I figured it was a great plan to just repurpose these boxes for the hybrid systems.
If I decide I "need" prettier boxes, I can commission them later, but they will do fine just to see how these franken-speakers work together.
The Model 15 Cabinets have a 15 x 4.25 opening where the original 32 horn mounted. So if I cut 2 pieces of plywood or similar to 18 x 6,
it should allow plenty of overlap against the inside of the horn hole. I can l slide them into the cabinet via the woofer hole, run a bead of silicon caulk on the face of these "patches",
then pull them tight against the inside of the baffleboard, and secure with 6 or so wood screws through the baffleboard, that should seal that hole effectively.
I have the Woofer hole to reach through as I do this work. It should not be a hard process. It will be more complex making a grill to cover the baffleboard,
and since it still has the Altec Velcro dots that shouldn't be difficult either.
And if I cut the "patches" and during dry-fit checks decide I don't like the look of them mounted internally with the horn hole revealed, I can always mount them OVER the horn-hole instead.
Actually, the most complex thing will probably be building the new crossover - and once I have a schematic - that's not that hard either.
that's why I figured it was a great plan to just repurpose these boxes for the hybrid systems.
If I decide I "need" prettier boxes, I can commission them later, but they will do fine just to see how these franken-speakers work together.
The Model 15 Cabinets have a 15 x 4.25 opening where the original 32 horn mounted. So if I cut 2 pieces of plywood or similar to 18 x 6,
it should allow plenty of overlap against the inside of the horn hole. I can l slide them into the cabinet via the woofer hole, run a bead of silicon caulk on the face of these "patches",
then pull them tight against the inside of the baffleboard, and secure with 6 or so wood screws through the baffleboard, that should seal that hole effectively.
I have the Woofer hole to reach through as I do this work. It should not be a hard process. It will be more complex making a grill to cover the baffleboard,
and since it still has the Altec Velcro dots that shouldn't be difficult either.
And if I cut the "patches" and during dry-fit checks decide I don't like the look of them mounted internally with the horn hole revealed, I can always mount them OVER the horn-hole instead.
Actually, the most complex thing will probably be building the new crossover - and once I have a schematic - that's not that hard either.
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Dropped by Home Despot after work to see what they had in the way of small piece of plywood to cover the horn-hole.
I saw all kinds of pieces of 2' x 4' plywood from $8 or so for chipboard to well over $20 for pieces with nicely veneer on 1 side.
But I only need 2 pieces of 18" x 8" or so - so their stock was overkill - till I saw a decent piece of ply in a 2' x 2' size - 15/32 ply.
It had sticker with a bar code, but no idea what it sold for. Decided to buy it anyway. Got up front and the cashier rang it in - $0.01 - thats it!
Perfect for my project and what a great price!
Now I just need to haul my table saw out of the shed, set it up on the shopmate, and make a couple cuts!
I saw all kinds of pieces of 2' x 4' plywood from $8 or so for chipboard to well over $20 for pieces with nicely veneer on 1 side.
But I only need 2 pieces of 18" x 8" or so - so their stock was overkill - till I saw a decent piece of ply in a 2' x 2' size - 15/32 ply.
It had sticker with a bar code, but no idea what it sold for. Decided to buy it anyway. Got up front and the cashier rang it in - $0.01 - thats it!
Perfect for my project and what a great price!
Now I just need to haul my table saw out of the shed, set it up on the shopmate, and make a couple cuts!
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Goodwill_HiFi
Super Member
Wow, did the cashier have any explanation?
She wasn't very good with english - maybe eastern european? Anyway, she said it did not sell for $0.01,
but I thanked her very much and rang up the other items (4 rolls of clear package tape and some sheetrock screws)
and when it totalled $20 with tax, she told me to have a good night.
My guess is someone had it cut and the buyer left it so they were closing it out - Like I said, their other stock was 2' x 4' ...
I think she simply did not know what to do next after the bar code came up for a penny,
and I wanted to get home before rush hour ...
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Looks like you got lucky. Looks like someone had a panel cut in half and you got the other half.
https://www.homedepot.com/p/Birch-P...76-in-x-23-75-in-x-47-75-in-1503004/202088758
https://www.homedepot.com/p/Birch-P...76-in-x-23-75-in-x-47-75-in-1503004/202088758
Ok, got home early enough to mark up the panel, set up my Shopmate and table saw, cut out my 2 planks, and put the tools back in the shed. I grabbed an Amazon box and sprayed the ugly side of the plywood with Krylon rattlecan black paint. Not sure yet, but I may decide to use a minwax stain on the nice grain side instead - I have options
Anyway, once the planks dried, I dry fitted one to get an idea of what it would look like. I do plan to use a sanding block to clean up the baffleboard around the horn-hole before I install the plank on the inside. That will help me decide if the horn hole plank will be black or wood grained.
Since the cabinet is a a tuned port I do need to close/seal the other openings. I plan to use RTV or a similar sealer to seal the plank to the cabinet for the final assembly (probably Saturday). And, I need to install the JBL woofer, build the crossover, etc. I'll build a panel with 2 attenuators to go where the Altec crossover was, and cover that hole. And probably build a grille to cover the front. But this gives you an idea of the overall build.
Anyway, planks cut from the 15/32" plywood, painted black and drying
Plank on top of the cabinet so you can see size compared to "horn-hole" it needs to seal.
Plank positioned against inside of Baffleboard - dry fit - without screws or RTV sealer - right picture just a visual with Fostex stack
Anyway, once the planks dried, I dry fitted one to get an idea of what it would look like. I do plan to use a sanding block to clean up the baffleboard around the horn-hole before I install the plank on the inside. That will help me decide if the horn hole plank will be black or wood grained.
Since the cabinet is a a tuned port I do need to close/seal the other openings. I plan to use RTV or a similar sealer to seal the plank to the cabinet for the final assembly (probably Saturday). And, I need to install the JBL woofer, build the crossover, etc. I'll build a panel with 2 attenuators to go where the Altec crossover was, and cover that hole. And probably build a grille to cover the front. But this gives you an idea of the overall build.
Anyway, planks cut from the 15/32" plywood, painted black and drying
Plank on top of the cabinet so you can see size compared to "horn-hole" it needs to seal.
Plank positioned against inside of Baffleboard - dry fit - without screws or RTV sealer - right picture just a visual with Fostex stack
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I didn't really like the look with the black panel - so when we went out for our monthly Dim Sum this morning,
I dropped by Home Despot on the way home and got some Minwax stains for the nice side of the panels -
thought maybe I'd touch up some of the places on the cabinets (that got pale after sanding) with it as well.
Just finished a single coat - tried Oak, Cherry and finally settled on Golden Pecan as the closest to the aged Altec Oak color.
Spread a bead of Wood adhesive around the edge of the planks, slipped them into place and locked down with
sheetrock screws through the 4 original horn mounting holes.
That will hold it in place until the glue dries, hopefully the nice bead will seal it to the cabinet.
I'd love to mount the woofers today, but think I'll wait until the glue has dried.
I may want to try another coat of stain on the panels once the glue dries overnight ...
but since I expect to build a grill for the front panel, thats not too critical.
Its a grey drizzly day, so between the poor light and a cellphone picture, they don't look as nice as they do in real life, but the panels ARE a color match to each other - I'd just like them to better match the cabinets!
I dropped by Home Despot on the way home and got some Minwax stains for the nice side of the panels -
thought maybe I'd touch up some of the places on the cabinets (that got pale after sanding) with it as well.
Just finished a single coat - tried Oak, Cherry and finally settled on Golden Pecan as the closest to the aged Altec Oak color.
Spread a bead of Wood adhesive around the edge of the planks, slipped them into place and locked down with
sheetrock screws through the 4 original horn mounting holes.
That will hold it in place until the glue dries, hopefully the nice bead will seal it to the cabinet.
I'd love to mount the woofers today, but think I'll wait until the glue has dried.
I may want to try another coat of stain on the panels once the glue dries overnight ...
but since I expect to build a grill for the front panel, thats not too critical.
Its a grey drizzly day, so between the poor light and a cellphone picture, they don't look as nice as they do in real life, but the panels ARE a color match to each other - I'd just like them to better match the cabinets!
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After church today, I brought up one of the 2214H woofers from my workbench.
I'd had it in these cabinets with the ALTEC horn and crossovers before,
so I know its a good fit. I reinstalled it to eye up the results ...
looks like a good overall "build".
I'd had it in these cabinets with the ALTEC horn and crossovers before,
so I know its a good fit. I reinstalled it to eye up the results ...
looks like a good overall "build".
Dunno - maybe later. I should get the basic config working and then I can try changes to fine tune the sound.
But I decided that before I ordered crossover parts, I should at least put a little signal to them and test the drivers for basic function.
Kinda pointless to build a crossover if something doesn't work.
So I wired each stack in parallel and fed them a bit of the Hejira album ...
The duck lips/horns sound great - the slots are mostly a bit of sizzle on top. Even paralleled the JBL 2214Hs briefly - the combo is not bad - tho it'll be nicer with a crossover!
So knowing that the driver DO work, I can go to Madisound and order some attenuators, caps, chokes and power resisters (and some perf board) and plan to start building crossovers.
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I'm sort of mystified why at this point you haven't AB'd just the Fostex Duck-Lips to your stock Heathkit/Altecs .
Just need some longish wire lengths to make it happen using the builtin Heahkit crossover ( & maybe a toggle switch if you want to make quicker comparisons ).
The Fostex 252/420 combo should be way more extended sounding ( though maybe you don't want to discover this ? ) .
Just need some longish wire lengths to make it happen using the builtin Heahkit crossover ( & maybe a toggle switch if you want to make quicker comparisons ).
The Fostex 252/420 combo should be way more extended sounding ( though maybe you don't want to discover this ? ) .