Altec 414z enclosure guidance

That makes sense Xtinc...there is so much potential it can be hard to know where to start.

Bowtie - I haven't gotten to the Skywaverider thread yet. When the next train comes through town, I'll load up on hard tack and salt pork.

Until then - I've been messing around in the speakers a bit, and was dismayed to find one of the 414s has a decent sized chunck torn out of the accordion surround (at the top). I'm guessing someone turned the driver at some point and it was stuck to the goo and got torn.

Is the surround something I should send the driver off to Great Plains Audio to get fixed, or can I take a shot at home? If I have to send it off, I might as well go ahead and send them all off to be reconed and de/regaussed, so they're in the same neighborhood specs wise. Speaker sounds fine - no audible indication of the tear that I can hear, but I imagine it will need to be addressed, and I know the other drivers need to be turned and have excess goo removed as well.

I've noticed I need to fully attenuate the horns in order to keep the highs under control - is this something a recap could help address, or should I look straight to building a new network? This is with the boxes horn-side up and raised about 7" off the floor.

There's definitely enough magic here to want to keep these components together in some form or another. What they do well, they do shockingly well - enough to justify the drawbacks.

The 9844 really does sound great...maybe I'll be able to persuade my wife they can look reasonably presentable with a little work....

Need to get that surround tear addressed though!
 
Bowtie will be better able to address your issues than I, but I'm curious about the spot in your surround. You refer to it once as a "chunk torn out," and then as a "tear." Quite a difference. Nonetheless, I've followed at least a couple of threads (can't find them now, though) wherein both issues were repaired. And I've quite nicely repaired a couple on my on. Of course, the tear is a very simple fix. An actual hole in the surround is a little more challenging, but still doable. In the latter case it's a matter of finding similar-weight cloth to form a patch with the same pleating pattern as the original surround, then doping it in. Depends on how handy you are at this kind of thing.
 
gdmoore28 said:
Bowtie will be better able to address your issues than I, but I'm curious about the spot in your surround. You refer to it once as a "chunk torn out," and then as a "tear." Quite a difference. Nonetheless, I've followed at least a couple of threads (can't find them now, though) wherein both issues were repaired. And I've quite nicely repaired a couple on my on. Of course, the tear is a very simple fix. An actual hole in the surround is a little more challenging, but still doable. In the latter case it's a matter of finding similar-weight cloth to form a patch with the same pleating pattern as the original surround, then doping it in. Depends on how handy you are at this kind of thing.
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Thanks very much for this - sorry for my imprecise description. It's sadly a chunk... About 1.5 fingers' width.

There does seem to be a good amount of the Altec 'goop' still on the surrounds, and I've read of folks harvesting enough of it to do a patch, but I'm not certain which type of fabric is best to use, nite what kind of adhesive would be best to augment the goop.
 
You can buy new cloth accordion surrounds. How close they are to the originals is unknown. Probably better than one with a giant hole in it. Lol

I wonder if something like the Vintage AR surround sealer would be similar to the Altec goop. Or close enough
 
elitopus said:
You can buy new cloth accordion surrounds. How close they are to the originals is unknown. Probably better than one with a giant hole in it. Lol

I wonder if something like the Vintage AR surround sealer would be similar to the Altec goop. Or close enough
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I don't know, but willing to find out for the good of the order. Does GPA sell the accordion surrounds, or does one get them elsewhere?
 
jaaronb said:
I don't know, but willing to find out for the good of the order. Does GPA sell the accordion surrounds, or does one get them elsewhere?
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Not sure if they would sell just the surround. I would call Bill and ask him what your options are.

Or someone like GordonW could replace just the surround for you. If you wanted someone else to do it that is.
 
Hey jaaronb, have you considered flipping the cabs on their sides and making a new baffle for the two 414z woofers or use the existing ones, sealing the horn openings and placing horns on top? Maybe get some nice walnut veener and pretty them up and build some nice grills.
Able to post a pic of your speakers as they sit now?
 
Xtinc said:
Hey jaaronb, have you considered flipping the cabs on their sides and making a new baffle for the two 414z woofers or use the existing ones, sealing the horn openings and placing horns on top? Maybe get some nice walnut veener and pretty them up and build some nice grills.
Able to post a pic of your speakers as they sit now?
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I was actually thinking about doing something like that last night. There is a thread on the Hostforum Altec users board on the 9844 - Bowtie posted a few times in it - about maximizing the potential of the 9844. I've considered doing something along the lines of what's discussed there (cabinet bracing, etc), as well as what you suggest. I'll post pics asap - new flooring is about to go in the room where the speakers are, so it's a bit of a mess right now.

I measured the little stools I have the speakers on currently, and they're more like 8.5" off the floor...still a bit below ear level.

If I can easily get the paint off the current boxes (multiple coats, and it's chipping off anyway), I may not even bother with veneer...just strip, sand, stain and finish.

Also going to call GPA today about the 414 with a hole in the surround. I'll probably send that one off to him - the question is whether the rest need to go as well.
 
Dang it - thanks for the reminder Bowtie! I'd forgotten reading where some folks had veneers under that gray lacquer. I scraped and sanded today and sure enough...veneer.

Finding the veneer under there settles it for me. I started this out looking for the simplest way of getting decent-looking enclosures for these speakers, so thanks to you folks I think I've nailed down what I'm going to do:

Keep the boxes. Turn on long end. Strip, sand, stain and finish the veneers. Make a new front baffle for the two 414z drivers. Vent at bottom. Find some vintage grill cloth. Remove horn. Calculate internal volume added by removal of horn and (if necessary) removal of original baffle setback board for drivers. Replace lost internal volume with strong bracing throughout. Stick horns on top. If feeling ambitious, add little corner outrigger legs ala Shindo Latour. Recap crossovers eventually.

What do you all think about that? Replacing the front baffle (i.e., removing the current one) seems like the hardest step here. Anyone attempted it?

I spoke with Bill today at GPA. They can fix the accordion surround hole with a recone. He said it wasn't necessary to send the other drivers in.

The little Shindo feet would be helpful as outriggers and give the boxes the additional 3-4" of height they'd need to get the horns at ear level.

Am I missing anything here?

Don't laugh at my stands...all I have on hand to get the horns up where they need to be. Ok...maybe even a little higher than that.

IMG_20170214_142130.jpg IMG_20170214_151212.jpg Shindo 2.jpg
 
I like them, although I can see the WAF issue with these. Think you have a good plan moving forward. Baffle is going to be challenge. I would cut out a frame in the existing baffle and add additional framing to the setback part of the baffle to level. Install a new baffle on top with beveled edges for a nice contoured look.
 
Xtinc said:
I like them, although I can see the WAF issue with these. Think you have a good plan moving forward. Baffle is going to be challenge. I would cut out a frame in the existing baffle and add additional framing to the setback part of the baffle to level. Install a new baffle on top with beveled edges for a nice contoured look.
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I think I understand what you're suggesting here... Going this route, the drivers would be rear mounted to the new baffle, which would be fitted to the frame and flush mounted on top?

I knocked together a rough scale model of what it would look like... Just to see if the proportions looked OK. I like this... the legs here add 4" to the rise, bringing the center of the horn to ~39".

Screenshot_20170214-233136.png Screenshot_20170214-233553.png
 
The 9844's stepped back motorboard, and rear mounting of the woofers was done to optimize phase coherence. In the stock configuration the acoustic centers of the HF and LF elements are aligned in the vertical plane. I would try to retain that dimensional relationship. Easily done by moving the horn forward or back as required. But, to maintain pleasing WAF, extending the top, bottom, and sides a couple inches out in front of the baffle/motorboard might go a long way.

Most women seem to take offense at the mechanical protruberence of a properly located Altec horn.:)
 
bowtie427ss said:
Most women seem to take offense at the mechanical protruberence of a properly located Altec horn.:)
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HA. Thanks for the tip Bowtie.

I've got all the drivers out of the boxes and about to ship those with torn surrounds to GPA for a recone. Hopefully will be able to have the boxes done by the time the drivers return. Stay tuned - I'm sure I'll need some guidance in getting the baffles replaced. Easiest route right now seems to be to use the original location of the set-back baffle board, which seems to be doable by relocating/replacing the original framing that the horn baffle is mounted to. I'll report back once I've gotten in there. Not looking forward to packing these 414s up for shipping.

Assuming I can get the original baffle out entirely, any thoughts as to whether I should use .75" or 1" ply for the baffles? I'm thinking about skipping grill cloth and making grills later. I'd use a nice furniture-grade void free veneered ply.

EDIT: Turns out three of the drivers had torn surrounds, so I just shipped all four off to GPA. Given their condition, I'd imagine LF performance was somewhat impacted, so looking forward to hearing how they sound upon return.
 
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OK - all drivers are now removed from the cabinets and paint stripping is underway. Crossovers came out easily.

Here's something I wasn't expecting... the motorboard for the woofers was not glued into the enclosure at all... Simply screwed to the baffle frame and to the horn baffle.

So here's my quandry: I do want to retain the original geometry Bowtie referred to with regard to the vertical alignment of the woofer/horn acoustic centers. Retaining the original baffle mounting frame for the woofers, and extending it for a full face baffle (after removing the forward set horn mounting frame rails and noting the vertical location of the horn) seems the easiest way to do this. After unscrewing the woofer motorboard, it slipped right out, leaving the horn baffle, which is glued AND screwed.

What's the best way to get the horn half-baffle and forward set horn baffle frame rails out of the box? Any suggestions? I've attached a pic that shows the empty woofer side and set back woofer baffle frame rails, and the still-intact horn baffle and rails.

I'd greatly appreciate any ideas!

IMG_20170216_203734.jpg
 
bowtie427ss said:
Somewhere in the depths of this place is a thread where the late great Zilch assisted another member(skywaverider) with a modded X-over for his 9844's whereby one woofer played up to meet the horn, but the 2nd woofer was filtered above ~150hz and functioned mainly as a "helper" woofer to augment the lowest octaves. Perhaps that system of components and network in cabinet of Malibu proportions would be a consideration for you.
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This is a very viable idea. I had also started the genesis of such a system (a "2.5 way" with dual 414s and a horn), and had done some modeling- the 414, in about 2 cubic feet (IIRC) each (four cubic feet total, for the two 414s together), tuned to about 35 Hz, and with the lower 414 crossed over at about 80Hz and down (a simple 15mH coil on the second woofer), had good output down to the high-30s. Maybe even mid- to low-30s in-room...

Regards,
Gordon.
 
It's been a while...thought I'd check in with a quick SITREP.

I moved forward with the idea of keeping the original 9844 boxes and orienting them vertically with a new baffle for the dual 414z arrangement with the vents at bottom.

Since my last post I stripped/sanded the boxes down to the raw oak veneers. Given they had about 5 layers of paint on top of the gray lacquer, this part sucked.

I got all four 414z drivers back from GPA where they got the full recone/recharge treatment.

I was able to use a hair dryer to get the original baffle out. I've braced the cabs and am using .75" Baltic Birch for new baffles and rear panels. I'm rear mounting two 414zs per cab using threaded inserts.

After way too much reading, I decided to build new N-800F crossovers with all new caps (Solens and Clarity Caps) and 16 ohn L-pads but utilizing the original iron core inductors. Only modification to the N-800f crossovers I've made is to add a 6uf cap and 8ohm resistor (paralleled) in series with the HF circuit, adding an additional 3db of compensation to the original design - an idea of Zilch's from the epic 9844 thread.

I'm using ~15" long, 1.25" diameter solid oak dowels for legs which will be attached at the four corners ala Shindo Latours. With vibration-controlling leveling inserts, the legs will add 4" of height to the vertically-oriented boxes, which I've braced.

I'll eventually make some small enclosures for the 811b horns (or have them CNC routed), but for now, they'll go on top of the boxes naked. Horns will get a few coats of 3M rubberized undercoating.

I'm hoping to have them fully completed in the next 10 days or so... Most of the hard stuff is done, just assembling/staining/finishing everything at this point. After a coat of varathane stain, I'm finishing the boxes with Waterlox.

I'll post pics soon... Planning to make a lot of progress this weekend.

Thanks to everyone who contributed ideas and encouragement early on...I had no idea how extensive a project this would become, but hoping the effort will be with it and I'll be pleased with the results.
 
Wow! you've been busy. Sounds like excellent progress, and i'm anxious to see the pics.

Solens are great caps. But, if you are running them in a series position on an Altec horn, i will be surprised if you don't eventually find a bit of a sibilant edge in the sound that you can eventually narrow down to those caps. I used to think they just needed break-in time, but eventually resigned to the fact i was just getting trained to them after i'd spend some quality time with another system for reference.
 
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