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Altec 414z enclosure guidance

bowtie427ss said:
Networks look good, lightly solder one up and give it a working test being sure to proceed with caution, in other words don't try to twist the volume knob off until you are sure you are connected properly and all is working as it should.

IMO, the U-haul blankets are prohibitively thick and will be too acoustically reflective making the combination of those on top of the fiberglass and effective reduction of cabinet volume at many frequencies.

I assume your goal is to capture/trap any loose glass fibers. If that's the case, get some cheesecloth from the hardware store, dye it black(or any color you like) and staple that over the fiberglass, you can double it up if you feel the weave is too open on a single layer. This will serve to trap most any loose glass fibers and retain most of the wide range acoustic performance of the fiberglass.
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Roger that Bowtie. Thanks for the guidance re: the Uhaul blankets. I'll leave those out and grab some cheesecloth or that black upholstery cloth on the bottom of upholstered furniture instead.

Got one of the networks soldered up last night. I'll report back with results!
 
The cheesecloth is a good idea. I have wondered how much fiberglass gets blown out the port of a vented cab.
All my Altec cabs are vented and all of them have fiberglass insulation.

Maybe the OC 703 board would stay put better? I know some people use that inside cabs instead of batt fiberglass.
 
elitopus said:
Maybe the OC 703 board would stay put better? I know some people use that inside cabs instead of batt fiberglass.
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I was just wondering this as well. I'm considering building cabinets for my 414-z's and was considering 703 since I already have some on hand.

- Woody
 
elitopus said:
Maybe the OC 703 board would stay put better? I know some people use that inside cabs instead of batt fiberglass.
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Out of curiosity, what type is the original fiberglass in the 9844 and other Altec enclosures? I've been planning to use the original sections of fiberglass that were in my 9844s, but they've gotten pretty beat up during this rebuild process.

Any thoughts as to whether I should stick with the original or go with something new?
 
jaaronb said:
Out of curiosity, what type is the original fiberglass in the 9844 and other Altec enclosures? I've been planning to use the original sections of fiberglass that were in my 9844s, but they've gotten pretty beat up during this rebuild process.

Any thoughts as to whether I should stick with the original or go with something new?
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From my experience the newer Altec cabs had yellow fiberglass insulation, and the older cabs had pink. There is probably no rule to what was put in them. A few inch thick layer of whatever they had. Bowtie would know more about what the "norm" was.

I know over on the hostboard they were talking about using 1" or 2" OC 703 on a new build.

If I already had some I would experiement with it in place of batt fiberglass. I know in some older Dynaco speakers they used a stiffer insulation in them. They just lined the walls.

In my new cab builds I insulate by ear. Lining the side and back wall usually sounds good to me. If there is too much insulation it makes the woofer sound dead IMO. Maybe I just like a "live" sounding cab
 
Purely a guess on my part guys, i suspect the fiberglass was much like the paint and plywood. When it was time to source, it came from the nearest and quickest supplier. Since we're talking about staples of the building trade which are manufactured to certain standards, these are not materials Altec would have heavily stocked into overhead. That said, they would be somewhat at the mercy of what their supplier carried at any given time, and i'm sure the specific manufacturer of certain materials varied from load to load, and bid to bid.

A side note, some 14's and 19's had their fiberglass spraypainted black where it was visible thru the port. I have seen other manufacturers cover that region only of the fiberglass with dark grill cloth. This is the only area you really have to worry about stray glass fibers entering your room from.

We're not talking about large volumes of air exchange like a ventilation system. It's a relatively small amount of air that gets displaced momentarily, and it is a reciprocal action meaning that as much air has to go back in the port as came out. Ducted ports with longer tubes likely never empty enough of their own volume into the room for air from the cabinet interior to make it into the room. Our classic Altecs with port depth = baffle thickness, they can probably migrate some glass out of the ports. But, this is only going to happen during large excursions from deep bass and high SPL's.
 
Thanks to you both - all is this makes sense. The fiberglass in mine is indeed the yellow ~2"... as I mentioned, it was pretty beat up from the rebuild (I should have removed it sooner), but I don't believe any of it has deteriorated to the point of losing functionality. I picked up some of that thin black breathable landscaping cloth to cover the glass with and to line the bottom to be less visible.

I swear I'm making progress...I sealed the cabs with silicone caulk today and hoping to get the fiberglass back in there also. That'll leave cutting holes in the rear covers for terminals and the L-Pads, soldering the other crossover, wiring and loading the drivers in the boxes.

It's taken much much longer than I expected...hoping I'll be able to say it was all worth it by the end of this week.
 
What beautiful speakers you've created! I love the stain, the finish, and those legs are lovely. And who doesn't like lovely legs? The whole affair is so basic and essential, yet oozes class and style. I love it!

GeeDeeEmm
 
Yes, nice work with the cabinets!
That 703 fiberglass board is like gold. I tried to source some when building my MLTL cabs and met too many dead ends (and I'm a licensed Contractor). It is usually only distributed to the HVAC guys and is going out of favor, being replaced by other duct insulating materials. It would be a very good material for using in larger enclosures. FWIW, I ended up using spun fiberglass batts. I am going back into the enclosures and removing most of what I put in since the MLTL cabs are too deadened for my liking. At that time, I'll cover what I have left with cheese cloth.
 
gdmoore28 said:
What beautiful speakers you've created! I love the stain, the finish, and those legs are lovely. And who doesn't like lovely legs? The whole affair is so basic and essential, yet oozes class and style. I love it!

GeeDeeEmm
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srm51555 said:
They have a nice classic look. Great job.
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westend said:
Yes, nice work with the cabinets!
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Thanks so much for the kind words you all - I've said it before but it bears repeating: no way I'd have started or made it through this project without the support guidance and encouragement from everyone here.

I'm pretty happy with how they're turning out. I used Varathane "American Colonial" stain on everything... It dried for a few weeks before I got around to finishing the cabinets. I used Waterlox Original sealer, and put the allowable 1:4 ratio of stain:Waterlox in the first coat, just in case the Waterlox made the stain run (it didn't).

I think I stopped at about 4 coats of the Waterlox - I'm sure they could look much better with the 6-8 coats people talk about using, but I just don't have that kind of patience. Maybe down the road. I'm gonna do my best to wrap up today and see how they sound! All that's a left now is soldering the second crossover and loading the second cabinet.

What do you all think about a sled of some sort for the horns? I eventually want to have small enclosures that follow the shape of the horns CNC routed.

I stole this image of a simple horn sled/support from somewhere online a while back... May try something like it as a stopgap.
 

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westend said:
Yes, nice work with the cabinets!
That 703 fiberglass board is like gold. I tried to source some when building my MLTL cabs and met too many dead ends (and I'm a licensed Contractor).
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No kidding! I'm kicking myself....a few years ago I got rid of several really large panels of it, or something similar, that were used as sound panels in a large church sanctuary. Bad move on my part.
 
jaaronb said:
What do you all think about a sled of some sort for the horns?
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Make it triangular or trapezoidal such that you can span the entire width of the horn mounting flange, line it with some felt between the flange and the wood, get all 3 bolts in it and securely snugged. This will lend a good deal of damping to the horn and prevent any cabinet resonances from exciting(ringing) the horn.

If they sound even half as good as they're looking, you should be very happy.
 
jaaronb said:
What do you all think about a sled of some sort for the horns? I eventually want to have small enclosures that follow the shape of the horns CNC routed.

I stole this image of a simple horn sled/support from somewhere online a while back... May try something like it as a stopgap.
Click to expand...

I saw that sled design, too, and really like it. But, like Bowtie suggested, I've been trying to conjure up some kind of sled that will lend some damping to the horn, since I've read repeatedly that Altec horns that are bolted in don't have the ringing possibilities possessed by those that are unbolted. I'm so far from that process right now, though, that it doesn't take up too much of the limited space in my brain.

Interested to hear how your crossovers perform, too. I started on my first one yesterday. As noted, it will be a second order LR followed by the M19-style horn compensation that Zilch designed. This is my first from- scratch crossover build and I'm sweating bullets trying to assure I get it right.

GeeDeeEmm
 
Yes, indeed! We need your thoughts on the sound quality. How about posting a uTube video of the speakers playing something substantial? You have a right to be quite proud of what you've done. Congratulations.

GeeDeeEmm
 
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