Altec Lansing 511 , 811 Horns

[Dr.db]

Hey,


has anyone tried these horns on JBL-drivers yet...??
Do they fit anyway ? I`m not shure, but I think 811-horns have 1" throat and 511-horns 1,4" throats...!?

So 811 could work with 2420 for example, but is there any way to match a 511 horn to a 2440 2"-driver ?



Regards,
Olaf

[Mike F]

Throat diameters aside, what about bolt patterns?

[cosmos]

has anyone tried these horns on JBL-drivers yet...??

Yes, many have over the years. I did with 2425 drivers with 511 horns and they sounded good..

Do they fit anyway ? I`m not shure, but I think 811-horns have 1" throat and 511-horns 1,4" throats...!?

Not easily.. You will need to redrill the flanges of the horns or create a transition piece.

Now the biggest question.. is it worth it? I would further suggest you buy a $20 plastic PT horn such as used in Zilch's L200 thread... It will sound better and have better dispersion.

[4343]

...

Now the biggest question.. is it worth it? ...

This pic is why I moved away from the 811/511. At least the 2345, crude casting that it was, had some decent damping material applied at the factory. The 1.5-2.5K ring is famous, or famously annoying. I was surprised to see 5K and 8K too.

[fpitas]

I'll defend the 511B to the extent of saying that if properly damped it's a good-sounding horn. It's useful down to 800Hz or lower, well below what most inexpensive waveguides will happily do. Without damping my 511s did sound awful at any output over a whisper, and getting them damped took a bit of effort. Supposedly bolting the flange to a mounting surface helps, but mine are free-standing on top of mid-bass cabinets.

Being in possession of 511Bs and also being somewhat masochistic, I spent the time to figure out what it takes to damp them thoroughly: http://www.diyaudio.com/forums/multi...ml#post3060342

For drivers I'm using Radian 475PBs, which work pretty well down to 800Hz with a 4th-order LR crossover.

[4343]

I'll defend the 511B to the extent of saying that if properly damped it's a good-sounding horn. It's useful down to 800Hz or lower, well below what most inexpensive waveguides will happily do. Without damping my 511s did sound awful at any output over a whisper, and getting them damped took a bit of effort. Supposedly bolting the flange to a mounting surface helps, but mine are free-standing on top of mid-bass cabinets.

Being in possession of 511Bs and also being somewhat masochistic, I spent the time to figure out what it takes to damp them thoroughly: http://www.diyaudio.com/forums/multi...ml#post3060342

For drivers I'm using Radian 475PBs, which work pretty well down to 800Hz with a 4th-order LR crossover.

Possession is 9/10's. As in I had the 811 in a cabinet with a K-140 and someone offered to buy it... It wasn't till I saw the 2345 with all the damping material on it that the idea of metal ringing even crossed my mind. Nice to hear that it can be tamed with the 511.

Interestingly, later I was working in a music store selling the Yamaha speakers with the aluminum radial horns. They also had a reputation for ringing. While thumbing through the catalog, I noticed that the horn and driver were available separately, with lots of damping material applied. It never made sense to me for Yamaha to put the horn minus the damping into cabinets with their name on the front, yet sell the same thing to people to put in their own cabinets with the damping added.

[fpitas]

Possession is 9/10's. As in I had the 811 in a cabinet with a K-140 and someone offered to buy it... It wasn't till I saw the 2345 with all the damping material on it that the idea of metal ringing even crossed my mind. Nice to hear that it can be tamed with the 511.

Interestingly, later I was working in a music store selling the Yamaha speakers with the aluminum radial horns. They also had a reputation for ringing. While thumbing through the catalog, I noticed that the horn and driver were available separately, with lots of damping material applied. It never made sense to me for Yamaha to put the horn minus the damping into cabinets with their name on the front, yet sell the same thing to people to put in their own cabinets with the damping added.

Perhaps they were afraid people wouldn't get it bolted in firmly, with an absorbent gasket, or would use it free-standing.

The whole damping experience made me really appreciate the advantages of wood and sonoglass as horn materials.

[RKLee]

Does mounting the entire horn into an enclosure lessen the ringing?

[fpitas]

Does mounting the entire horn into an enclosure lessen the ringing?

Some people have had good results placing them in a box filled with sand. A friend has his mounted by the flange, it does help quite a bit, although not as much as I'd like.

[Dr.db]

I am aware of different bolt patterns, but I think drilling new one´s should do the job....

But what about the thoat diameter ?
Will a JBL 2"-driver fit the 511-Altec horns ?


What material would be best for damping the horns ? Bitumen....!?

[fpitas]

I am aware of different bolt patterns, but I think drilling new one´s should do the job....

But what about the thoat diameter ?
Will a JBL 2"-driver fit the 511-Altec horns ?


What material would be best for damping the horns ? Bitumen....!?

The 511A and 511B are 1" throat, the 511E is 1.4" throat. See my link for my method of damping. Some people have used car undercoating or roof tar etc., but I wasn't entirely happy with having those materials inside my house.

[Dr.db]

Allrighty, thanks a lot...!!

[RKLee]

Some people have had good results placing them in a box filled with sand. A friend has his mounted by the flange, it does help quite a bit, although not as much as I'd like.

That is how my current 811/806 is mounted. If I am going to add more sound dampening compound to the 811 horn, I will have to build a little shelf to support the 806 driver in the rear. Right now, the whole assembly is light enough to just mount on the flange.