I had considered lightly sanding plastic horn back with rough grit, then gluing some flat lead wheel weights (the type used for inner part of wheel, not the lip) with urethane windshield adhesive. The eurethane is messy, but it's easy to get at any autoparts store, along with wheel weights 
I don't care about extra weight... It's not like I am going to cover the whole thing completely. You can cover as much of the horn as you want with the urethane, and is as many layers as you want I suppose.
I don't care about extra weight... It's not like I am going to cover the whole thing completely. You can cover as much of the horn as you want with the urethane, and is as many layers as you want I suppose.
Plastic horns?
They are "instant molds"... do I need to draw a diagram??
My unscientific advice says that gluing lead weights to a plastic horn is a waste of effort. You are better off rough sanding and covering the back with modeling clay. Or making a conic rear covering and filling with sand (for example).
RTV and lead shot? Very confusing, and smelly... not likely to really bond well... maybe if you were able to seriously rough up the surface for a mechanical hold. Lead shot? Nah... you want something much more able to be in suspension in the RTV and not sag out... sand? Glass beads? Then you want a two part RTV so you can actually mix it up... not the stuff in the tube...
I'd rough it up with like 20 grit, and try the latex mold stuff they sell in the crafts stores, and paint on a few layers, like do it for a week... build it up, with maybe sand or glass beads mixed in/and/or sprinkled on. Yeah, it won't have a 20 year life, but so what? Doesn't smell bad either.
The conic rear (or boxed, or triangular, etc depends on the shape of the horn) filled with sand (seal that with silicone rubber!) is guaranteed to be most effective of all.
_-_-bear
They are "instant molds"... do I need to draw a diagram??
My unscientific advice says that gluing lead weights to a plastic horn is a waste of effort. You are better off rough sanding and covering the back with modeling clay. Or making a conic rear covering and filling with sand (for example).
RTV and lead shot? Very confusing, and smelly... not likely to really bond well... maybe if you were able to seriously rough up the surface for a mechanical hold. Lead shot? Nah... you want something much more able to be in suspension in the RTV and not sag out... sand? Glass beads? Then you want a two part RTV so you can actually mix it up... not the stuff in the tube...
I'd rough it up with like 20 grit, and try the latex mold stuff they sell in the crafts stores, and paint on a few layers, like do it for a week... build it up, with maybe sand or glass beads mixed in/and/or sprinkled on. Yeah, it won't have a 20 year life, but so what? Doesn't smell bad either.
The conic rear (or boxed, or triangular, etc depends on the shape of the horn) filled with sand (seal that with silicone rubber!) is guaranteed to be most effective of all.
_-_-bear
My take is to use bitumen torch down material they sell to cover flat roofs. You just buy one roll of tick bitumen for $70 which is 3'x33' and hand torch from home depot ($10 or so) cut the appropriate pieces melt the sticking side and apply to the surface . You need to be very careful not to burn yourself. It is equally good to damp speakers enclosures. I've got the idea when I looked inside Proac cab and spoted bitumen pads. You can apply few layers one over another. Quite effective .
Joe , regarding 32B horn you meant 90 degree bent small hF horn like the one used in Altec Model 15?
Joe , regarding 32B horn you meant 90 degree bent small hF horn like the one used in Altec Model 15?
I say it's the electric guitar lovers who dig these horns . I haven't heard better . My Edgar tractrixes sounded like poopoo after 511.
I'm going trough my set of Sound Practices again reading Herb casual reactions and looking at adverts ;Tango , Tamura transformers and other exotica for few hundreds .Quick check on Ebay and I have trouble counting zeros
Geezz, I never saw any of those amps from SP on the market .Unfortunately SE movement never really took off and seem to be diminishing lately. And SE speaker market is as bad as it always was.
Yep. The modern version of the WE 32A.
I think I like the plastic ones a bit better than the more desirable metal ones, but I am not sure yet.
I'm not planning to damp these, by the way...
I hoped to find a pair of Model 15s to mess with but I have all of the parts in 16 ohm versions so might put a pair together myself until I find real ones.
I tried and tried to love 511s but failed. Only thing I would use these for is as a funnel to put motor oil in my car.
Lots of people like those dreadful aluminum gongs, so they do have their fans.
Fortunately, they are still easy to get and cheap.
As far as I can see, SE technology is hanging in there. Audio shows are packed with commercial SE amps. I think many builders built enough SE amps and are listening to what they have and trying other things.
It is starting to look as though horns are the main revolution SP spearheaded. When I first start pushing horns for the home, I got hate mail and hate calls!! People really reacted very negatively to what they saw as setting audio back 20 years.
Actually, I was trying to set it back at least 50 YEARS!
Today, there seem to be a lot of good drivers around from the Italians, Spanish, etc., lots of inexpensive waveguides and whatnot to play with, and lots of experimenters working with them. Cool stuff.
Back in the 80s, the good vintage stuff was B&C priced...now, as you noticed, even the horrible junk--low-end EV and Jensen tweeters, for example-- from the 50s-60s is wildly overpriced for the most part.
Well-chosen ALTEC still offers quality per dollar, even if the dollar figure is much higher! Inflation!
Horns are where the main, if not only, excitement in the speaker world is now-- or I suppose I should qualify that--the main thing that gets me excited. I still think the field belongs to DIY but there are some half-decent commercial product horns for the cash-equipped buyer.
One note: I gave up trashing nice vintage gear for experiments long ago. Before you pack 511s in a concrete overcoat, think about selling them to somebody who appreciates them for what they are. They aren't making any more of a lot of these old classics. Just a thought!
"Only thing I would use these for is as a funnel to put motor oil in my car.
Lots of people like those dreadful aluminum gongs, so they do have their fans."
C'mon!! Flaming 511-811's is getting WAY overdone! Yes they ring.OK so dampen them! If your only objection to them is that YOU don't like the sound, ok. To say that they are only fit for the rubbish without clearly backing up such a statement with objective data is to imply that anyone who enjoys them is just to stupid to know better. This sort of trolling has no more place here than on any other forum. Learn to be more respectful of others and their choices. In my own case I enjoy my 511's, not the best but living on social security, it's all I can afford. OK?
Lots of people like those dreadful aluminum gongs, so they do have their fans."
C'mon!! Flaming 511-811's is getting WAY overdone! Yes they ring.OK so dampen them! If your only objection to them is that YOU don't like the sound, ok. To say that they are only fit for the rubbish without clearly backing up such a statement with objective data is to imply that anyone who enjoys them is just to stupid to know better. This sort of trolling has no more place here than on any other forum. Learn to be more respectful of others and their choices. In my own case I enjoy my 511's, not the best but living on social security, it's all I can afford. OK?
May very well be...but I was doing it before it was cool!
Since 1985 or so, to be precise. That's when I gave up on those aluminum sectorals. I tried once more in the 90s.
My objective data is in the measurable tension in my jaw when I listen to these things. I never heard them sound good.
I may joke but I don't troll.
There are horns that I think are far better and which cost less than 511s.
Emilar bowties, Altec 32Cs...better and cheaper. try em out. Thank me later.
I recently sold several pairs of Renkus Heinz horns for $100 pr. They were much better than 511s. A few weeks ago, I saw sixteen 500hz Renkus 1" exponential horns sell on ebay for a buy it now of $19 each!
Check out the old Emilar horns. They are very inexpensive too. Nobody knows what they and R-H are.
I left plenty of room for disagreement and dissenting views , but in my honest, non-troll opinion, damping WILL NOT SAVE THE 511. To my ear, they have a weird, unsettling edgy bite even when damped to the skies.
I wish I did like them. Really tried numerous times. They are a good size and easy to procure.
Same goes for 31As...which are going for huge loot these days. Another gong with a weird sonic undertone.
I heard them again a few months ago with WE 594As and GIP's enhanced 594. They were nasty. Actually these were WE 31As...same difference. $50,000 worth of field coil drivers didn't make them listenable.
I couldn't even get 311-90s to sound good. I could always hear the metal.
No, I must say that I am no fan of Altec cast aluminum horns. Try a few other horns and perhaps you will come to agree that these were not Altec's strong suit.
Otherwise, I am a huge Altec maniac.
I can think of a number of cast aluminum horns that I do appreciate and some that I really like.
But I put in my time with these particular horns, tried clay, sand in latex paint, cutting the vanes with a cut off wheel and inserting rubber like the old ones, sandwiching them between phone books with weights on top...measures that should have fixed any metal bell mode problem and I still wouldn't pick a 511 up off the street.
As mentioned above, I think the problem is in the geometry. Maybe the cross-sectional shape transitions in the throat area? The rough crude casting in that critical zone?
But all that matters is if you, the 511 listener, is happy. I really don't care what anybody else likes...its like sex, as long as I don't have to watch...go at it. Some people are into feet, some people like 511s. Whatever.
Similarly, you should not give a hoot what I think because you are listening to them not me.
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It was never "cool" . You made a decision of personal taste long ago, ok. The length of time passed since you made that choice in no way helps to transform it into universal truth.
Personally, I don't like the sound of JBL horns. I've felt that way since the mid 70's. Does that make any sort of excessively broad statements I might make condemning JBL horns any more valid?? Nope.
My point here was and is not about attacking you. It isn't even about "defending" Altec aluminum horns or their users. It was and is about the sort of wording I see in so many forums that amounts to little more than schoolyard name calling. I don't think expecting polite, respectful civil discourse among those sharing a common hobby is unreasonable, or conversely that mudslinging, regardless of the terms in which it is framed, contributes anything useful to the hobby or the discussion of it.
Personally, I don't like the sound of JBL horns. I've felt that way since the mid 70's. Does that make any sort of excessively broad statements I might make condemning JBL horns any more valid?? Nope.
My point here was and is not about attacking you. It isn't even about "defending" Altec aluminum horns or their users. It was and is about the sort of wording I see in so many forums that amounts to little more than schoolyard name calling. I don't think expecting polite, respectful civil discourse among those sharing a common hobby is unreasonable, or conversely that mudslinging, regardless of the terms in which it is framed, contributes anything useful to the hobby or the discussion of it.
Yes , I agree keep it civil and YOU Joe Roberts keep your mouth shut cuz I just pimped out my street found pair of 511B ;painted them nicely and am going to advertise on swap meet or Ebay in no time OK? Don't have much luck trying to sell my restored altec 15 (maybe I ask too much so YOU're OK praising it's universal beauty
so YOU're OK praising it's universal beautyAttachments
I like this idea, but I am wondering about any solvents that might be in the tar. Has anyone noticed any deleterious effects from using this? Any smell or dripping over time?
OR is it quite stable and permanent?
They are awful. Part of the problem is the aluminim. Part of the problem is the diffraction design of the throat...
You can afford better. But you have to make an effort, this is a DIY forum!
There are a number of techniques that can be used, including paper mache...
Also there are now some obique spheroid "waveguides" in plastic that can be bought commercially that are undoubtedly better for hi-fi than the old 511-811 stuff...
_-_-bear
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